diff options
Diffstat (limited to 'source/ubiqx')
| -rw-r--r-- | source/ubiqx/.cvsignore | 3 | ||||
| -rw-r--r-- | source/ubiqx/COPYING.LIB | 481 | ||||
| -rw-r--r-- | source/ubiqx/README.UBI | 18 | ||||
| -rw-r--r-- | source/ubiqx/debugparse.c | 308 | ||||
| -rw-r--r-- | source/ubiqx/debugparse.h | 127 | ||||
| -rw-r--r-- | source/ubiqx/sys_include.h | 52 | ||||
| -rw-r--r-- | source/ubiqx/ubi_BinTree.c | 1132 | ||||
| -rw-r--r-- | source/ubiqx/ubi_BinTree.h | 864 | ||||
| -rw-r--r-- | source/ubiqx/ubi_Cache.c | 505 | ||||
| -rw-r--r-- | source/ubiqx/ubi_Cache.h | 412 | ||||
| -rw-r--r-- | source/ubiqx/ubi_SplayTree.c | 512 | ||||
| -rw-r--r-- | source/ubiqx/ubi_SplayTree.h | 377 | ||||
| -rw-r--r-- | source/ubiqx/ubi_dLinkList.c | 171 | ||||
| -rw-r--r-- | source/ubiqx/ubi_dLinkList.h | 242 | ||||
| -rw-r--r-- | source/ubiqx/ubi_sLinkList.c | 187 | ||||
| -rw-r--r-- | source/ubiqx/ubi_sLinkList.h | 254 |
16 files changed, 5645 insertions, 0 deletions
diff --git a/source/ubiqx/.cvsignore b/source/ubiqx/.cvsignore new file mode 100644 index 00000000000..07da2225c72 --- /dev/null +++ b/source/ubiqx/.cvsignore @@ -0,0 +1,3 @@ +*.po +*.po32 + diff --git a/source/ubiqx/COPYING.LIB b/source/ubiqx/COPYING.LIB new file mode 100644 index 00000000000..8c8377da464 --- /dev/null +++ b/source/ubiqx/COPYING.LIB @@ -0,0 +1,481 @@ + GNU LIBRARY GENERAL PUBLIC LICENSE + Version 2, June 1991 + + Copyright (C) 1991 Free Software Foundation, Inc. + 675 Mass Ave, Cambridge, MA 02139, USA + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + +[This is the first released version of the library GPL. It is + numbered 2 because it goes with version 2 of the ordinary GPL.] + + Preamble + + The licenses for most software are designed to take away your +freedom to share and change it. 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See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; if not, write to the Free + Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +Also add information on how to contact you by electronic and paper mail. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a "copyright disclaimer" for the library, if +necessary. Here is a sample; alter the names: + + Yoyodyne, Inc., hereby disclaims all copyright interest in the + library `Frob' (a library for tweaking knobs) written by James Random Hacker. + + <signature of Ty Coon>, 1 April 1990 + Ty Coon, President of Vice + +That's all there is to it! diff --git a/source/ubiqx/README.UBI b/source/ubiqx/README.UBI new file mode 100644 index 00000000000..a2c14ca62c9 --- /dev/null +++ b/source/ubiqx/README.UBI @@ -0,0 +1,18 @@ +Fri Apr 17 10:21:56 CDT 1998 + +The C code files in the samba/source/ubiqx directory are licensed under +the terms of the GNU LIBRARY GENERAL PUBLIC LICENSE (LGPL). A copy of the +LGPL should also be included in this directory under the name COPYING.LIB. +If this file is not present, you can obtain a copy of the LGPL by writing +to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, +USA. + +The versions of the ubiqx modules distributed with Samba may have been +modified for inclusion with Samba. The main distribution, which contains +additional available modules, can be found at: + + http://www.interads.co.uk/~crh/ubiqx/ + +Chris Hertel +Samba Team +ubiqx@ubiqx.mn.org diff --git a/source/ubiqx/debugparse.c b/source/ubiqx/debugparse.c new file mode 100644 index 00000000000..195fc245bc0 --- /dev/null +++ b/source/ubiqx/debugparse.c @@ -0,0 +1,308 @@ +/* ========================================================================== ** + * debugparse.c + * + * Copyright (C) 1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * + * -------------------------------------------------------------------------- ** + * This module is a very simple parser for Samba debug log files. + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * The important function in this module is dbg_char2token(). The rest is + * basically fluff. (Potentially useful fluff, but still fluff.) + * ========================================================================== ** + */ + +#include "debugparse.h" + +/* -------------------------------------------------------------------------- ** + * Constants... + * + * DBG_BSIZE - This internal constant is used only by dbg_test(). It is the + * size of the read buffer. I've tested the function using a + * DBG_BSIZE value of 2. + */ + +#define DBG_BSIZE 128 + +/* -------------------------------------------------------------------------- ** + * Functions... + */ + +const char *dbg_token2string( dbg_Token tok ) + /* ------------------------------------------------------------------------ ** + * Given a token, return a string describing the token. + * + * Input: tok - One of the set of dbg_Tokens defined in debugparse.h. + * + * Output: A string identifying the token. This is useful for debugging, + * etc. + * + * Note: If the token is not known, this function will return the + * string "<unknown>". + * + * ------------------------------------------------------------------------ ** + */ + { + switch( tok ) + { + case dbg_null: + return( "null" ); + case dbg_ignore: + return( "ignore" ); + case dbg_header: + return( "header" ); + case dbg_timestamp: + return( "time stamp" ); + case dbg_level: + return( "level" ); + case dbg_sourcefile: + return( "source file" ); + case dbg_function: + return( "function" ); + case dbg_lineno: + return( "line number" ); + case dbg_message: + return( "message" ); + case dbg_eof: + return( "[EOF]" ); + } + return( "<unknown>" ); + } /* dbg_token2string */ + +dbg_Token dbg_char2token( dbg_Token *state, int c ) + /* ------------------------------------------------------------------------ ** + * Parse input one character at a time. + * + * Input: state - A pointer to a token variable. This is used to + * maintain the parser state between calls. For + * each input stream, you should set up a separate + * state variable and initialize it to dbg_null. + * Pass a pointer to it into this function with each + * character in the input stream. See dbg_test() + * for an example. + * c - The "current" character in the input stream. + * + * Output: A token. + * The token value will change when delimiters are found, + * which indicate a transition between syntactical objects. + * Possible return values are: + * + * dbg_null - The input character was an end-of-line. + * This resets the parser to its initial state + * in preparation for parsing the next line. + * dbg_eof - Same as dbg_null, except that the character + * was an end-of-file. + * dbg_ignore - Returned for whitespace and delimiters. + * These lexical tokens are only of interest + * to the parser. + * dbg_header - Indicates the start of a header line. The + * input character was '[' and was the first on + * the line. + * dbg_timestamp - Indicates that the input character was part + * of a header timestamp. + * dbg_level - Indicates that the input character was part + * of the debug-level value in the header. + * dbg_sourcefile - Indicates that the input character was part + * of the sourcefile name in the header. + * dbg_function - Indicates that the input character was part + * of the function name in the header. + * dbg_lineno - Indicates that the input character was part + * of the DEBUG call line number in the header. + * dbg_message - Indicates that the input character was part + * of the DEBUG message text. + * + * ------------------------------------------------------------------------ ** + */ + { + /* The terminating characters that we see will greatly depend upon + * how they are read. For example, if gets() is used instead of + * fgets(), then we will not see newline characters. A lot also + * depends on the calling function, which may handle terminators + * itself. + * + * '\n', '\0', and EOF are all considered line terminators. The + * dbg_eof token is sent back if an EOF is encountered. + * + * Warning: only allow the '\0' character to be sent if you are + * using gets() to read whole lines (thus replacing '\n' + * with '\0'). Sending '\0' at the wrong time will mess + * up the parsing. + */ + switch( c ) + { + case EOF: + *state = dbg_null; /* Set state to null (initial state) so */ + return( dbg_eof ); /* that we can restart with new input. */ + case '\n': + case '\0': + *state = dbg_null; /* A newline or eoln resets to the null state. */ + return( dbg_null ); + } + + /* When within the body of the message, only a line terminator + * can cause a change of state. We've already checked for line + * terminators, so if the current state is dbg_msgtxt, simply + * return that as our current token. + */ + if( dbg_message == *state ) + return( dbg_message ); + + /* If we are at the start of a new line, and the input character + * is an opening bracket, then the line is a header line, otherwise + * it's a message body line. + */ + if( dbg_null == *state ) + { + if( '[' == c ) + { + *state = dbg_timestamp; + return( dbg_header ); + } + *state = dbg_message; + return( dbg_message ); + } + + /* We've taken care of terminators, text blocks and new lines. + * The remaining possibilities are all within the header line + * itself. + */ + + /* Within the header line, whitespace can be ignored *except* + * within the timestamp. + */ + if( isspace( c ) ) + { + /* Fudge. The timestamp may contain space characters. */ + if( (' ' == c) && (dbg_timestamp == *state) ) + return( dbg_timestamp ); + /* Otherwise, ignore whitespace. */ + return( dbg_ignore ); + } + + /* Okay, at this point we know we're somewhere in the header. + * Valid header *states* are: dbg_timestamp, dbg_level, + * dbg_sourcefile, dbg_function, and dbg_lineno. + */ + switch( c ) + { + case ',': + if( dbg_timestamp == *state ) + { + *state = dbg_level; + return( dbg_ignore ); + } + break; + case ']': + if( dbg_level == *state ) + { + *state = dbg_sourcefile; + return( dbg_ignore ); + } + break; + case ':': + if( dbg_sourcefile == *state ) + { + *state = dbg_function; + return( dbg_ignore ); + } + break; + case '(': + if( dbg_function == *state ) + { + *state = dbg_lineno; + return( dbg_ignore ); + } + break; + case ')': + if( dbg_lineno == *state ) + { + *state = dbg_null; + return( dbg_ignore ); + } + break; + } + + /* If the previous block did not result in a state change, then + * return the current state as the current token. + */ + return( *state ); + } /* dbg_char2token */ + +void dbg_test( void ) + /* ------------------------------------------------------------------------ ** + * Simple test function. + * + * Input: none. + * Output: none. + * Notes: This function was used to test dbg_char2token(). It reads a + * Samba log file from stdin and prints parsing info to stdout. + * It also serves as a simple example. + * + * ------------------------------------------------------------------------ ** + */ + { + char bufr[DBG_BSIZE]; + int i; + int linecount = 1; + dbg_Token old = dbg_null, + new = dbg_null, + state = dbg_null; + + while( fgets( bufr, DBG_BSIZE, stdin ) ) + { + for( i = 0; bufr[i]; i++ ) + { + old = new; + new = dbg_char2token( &state, bufr[i] ); + switch( new ) + { + case dbg_header: + if( linecount > 1 ) + (void)putchar( '\n' ); + break; + case dbg_null: + linecount++; + break; + case dbg_ignore: + break; + default: + if( old != new ) + (void)printf( "\n[%05d]%12s: ", linecount, dbg_token2string(new) ); + (void)putchar( bufr[i] ); + } + } + } + (void)putchar( '\n' ); + } /* dbg_test */ + + +/* -------------------------------------------------------------------------- ** + * This simple main line can be uncommented and used to test the parser. + */ + +/* + * int main( void ) + * { + * dbg_test(); + * return( 0 ); + * } + */ + +/* ========================================================================== */ diff --git a/source/ubiqx/debugparse.h b/source/ubiqx/debugparse.h new file mode 100644 index 00000000000..458eee74558 --- /dev/null +++ b/source/ubiqx/debugparse.h @@ -0,0 +1,127 @@ +#ifndef DEBUGPARSE_H +#define DEBUGPARSE_H +/* ========================================================================== ** + * debugparse.c + * + * Copyright (C) 1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * + * -------------------------------------------------------------------------- ** + * This module is a very simple parser for Samba debug log files. + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * The important function in this module is dbg_char2token(). The rest is + * basically fluff. (Potentially useful fluff, but still fluff.) + * ========================================================================== ** + */ + +#include "sys_include.h" + +/* This module compiles quite nicely outside of the Samba environment. + * You'll need the following headers: +#include <ctype.h> +#include <stdio.h> +#include <string.h> + */ + +/* -------------------------------------------------------------------------- ** + * These are the tokens returned by dbg_char2token(). + */ + +typedef enum + { + dbg_null = 0, + dbg_ignore, + dbg_header, + dbg_timestamp, + dbg_level, + dbg_sourcefile, + dbg_function, + dbg_lineno, + dbg_message, + dbg_eof + } dbg_Token; + +/* -------------------------------------------------------------------------- ** + * Function prototypes... + */ + + const char *dbg_token2string( dbg_Token tok ); + /* ------------------------------------------------------------------------ ** + * Given a token, return a string describing the token. + * + * Input: tok - One of the set of dbg_Tokens defined in debugparse.h. + * + * Output: A string identifying the token. This is useful for debugging, + * etc. + * + * Note: If the token is not known, this function will return the + * string "<unknown>". + * + * ------------------------------------------------------------------------ ** + */ + + dbg_Token dbg_char2token( dbg_Token *state, int c ); + /* ------------------------------------------------------------------------ ** + * Parse input one character at a time. + * + * Input: state - A pointer to a token variable. This is used to + * maintain the parser state between calls. For + * each input stream, you should set up a separate + * state variable and initialize it to dbg_null. + * Pass a pointer to it into this function with each + * character in the input stream. See dbg_test() + * for an example. + * c - The "current" character in the input stream. + * + * Output: A token. + * The token value will change when delimiters are found, + * which indicate a transition between syntactical objects. + * Possible return values are: + * + * dbg_null - The input character was an end-of-line. + * This resets the parser to its initial state + * in preparation for parsing the next line. + * dbg_eof - Same as dbg_null, except that the character + * was an end-of-file. + * dbg_ignore - Returned for whitespace and delimiters. + * These lexical tokens are only of interest + * to the parser. + * dbg_header - Indicates the start of a header line. The + * input character was '[' and was the first on + * the line. + * dbg_timestamp - Indicates that the input character was part + * of a header timestamp. + * dbg_level - Indicates that the input character was part + * of the debug-level value in the header. + * dbg_sourcefile - Indicates that the input character was part + * of the sourcefile name in the header. + * dbg_function - Indicates that the input character was part + * of the function name in the header. + * dbg_lineno - Indicates that the input character was part + * of the DEBUG call line number in the header. + * dbg_message - Indicates that the input character was part + * of the DEBUG message text. + * + * ------------------------------------------------------------------------ ** + */ + + +/* -------------------------------------------------------------------------- */ +#endif /* DEBUGPARSE_H */ diff --git a/source/ubiqx/sys_include.h b/source/ubiqx/sys_include.h new file mode 100644 index 00000000000..8ff270afe85 --- /dev/null +++ b/source/ubiqx/sys_include.h @@ -0,0 +1,52 @@ +#ifndef SYS_INCLUDE_H +#define SYS_INCLUDE_H +/* ========================================================================== ** + * sys_include.h + * + * Copyright (C) 1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * This header provides system declarations and data types used internally + * by the ubiqx modules. + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * Samba version of sys_include.h + * + * ========================================================================== ** + */ + +#ifndef _INCLUDES_H + +/* Block the inclusion of some Samba headers so that ubiqx types won't be + * used before the headers that define them. These headers are not needed + * in the ubiqx modules anyway. + */ +#define _PROTO_H_ +#define _NAMESERV_H_ +#define _HASH_H_ + +/* The main Samba system-adaptive header file. + */ +#include "includes.h" + +#endif /* _INCLUDES_H */ + +/* ================================ The End ================================= */ +#endif /* SYS_INCLUDE_H */ diff --git a/source/ubiqx/ubi_BinTree.c b/source/ubiqx/ubi_BinTree.c new file mode 100644 index 00000000000..8a4d4612800 --- /dev/null +++ b/source/ubiqx/ubi_BinTree.c @@ -0,0 +1,1132 @@ +/* ========================================================================== ** + * ubi_BinTree.c + * + * Copyright (C) 1991-1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * This module implements a simple binary tree. + * + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_BinTree.c,v + * Revision 4.10 2000/06/06 20:38:40 crh + * In the ReplaceNode() function, the old node header was being copied + * to the new node header using a byte-by-byte copy. This was causing + * the 'insure' software testing program to report a memory leak. The + * fix was to do a simple assignement: *newnode = *oldnode; + * This quieted the (errant) memory leak reports and is probably a bit + * faster than the bytewise copy. + * + * Revision 4.9 2000/01/08 23:24:30 crh + * Clarified a variety of if( pointer ) lines, replacing them with + * if( NULL != pointer ). This is more correct, and I have heard + * of at least one (obscure?) system out there that uses a non-zero + * value for NULL. + * Also, speed improvement in Neighbor(). It was comparing pointers + * when it could have compared two gender values. The pointer + * comparison was somewhat indirect (does pointer equal the pointer + * of the parent of the node pointed to by pointer). Urq. + * + * Revision 4.8 1999/09/22 03:40:30 crh + * Modified ubi_btTraverse() and ubi_btKillTree(). They now return an + * unsigned long indicating the number of nodes processed. The change + * is subtle. An empty tree formerly returned False, and now returns + * zero. + * + * Revision 4.7 1998/10/21 06:14:42 crh + * Fixed bugs in FirstOf() and LastOf() reported by Massimo Campostrini. + * See function comments. + * + * Revision 4.6 1998/07/25 17:02:10 crh + * Added the ubi_trNewTree() macro. + * + * Revision 4.5 1998/06/04 21:29:27 crh + * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. + * This is more "standard", and is what people expect. Weird, eh? + * + * Revision 4.4 1998/06/03 17:42:46 crh + * Further fiddling with sys_include.h. It's now in ubi_BinTree.h which is + * included by all of the binary tree files. + * + * Reminder: Some of the ubi_tr* macros in ubi_BinTree.h are redefined in + * ubi_AVLtree.h and ubi_SplayTree.h. This allows easy swapping + * of tree types by simply changing a header. Unfortunately, the + * macro redefinitions in ubi_AVLtree.h and ubi_SplayTree.h will + * conflict if used together. You must either choose a single tree + * type, or use the underlying function calls directly. Compare + * the two header files for more information. + * + * Revision 4.3 1998/06/02 01:28:43 crh + * Changed ubi_null.h to sys_include.h to make it more generic. + * + * Revision 4.2 1998/05/20 04:32:36 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * Also, the balance and gender fields of the node were declared as + * signed char. As I understand it, at least one SunOS or Solaris + * compiler doesn't like "signed char". The declarations were + * wrong anyway, so I changed them to simple "char". + * + * Revision 4.1 1998/03/31 06:11:57 crh + * Thomas Aglassinger sent E'mail pointing out errors in the + * dereferencing of function pointers, and a missing typecast. + * Thanks, Thomas! + * + * Revision 4.0 1998/03/10 03:19:22 crh + * Added the AVL field 'balance' to the ubi_btNode structure. This means + * that all BinTree modules now use the same basic node structure, which + * greatly simplifies the AVL module. + * Decided that this was a big enough change to justify a new major revision + * number. 3.0 was an error, so we're at 4.0. + * + * Revision 2.6 1998/01/24 06:27:46 crh + * Added ubi_trCount() macro. + * + * Revision 2.5 1997/12/23 03:56:29 crh + * In this version, all constants & macros defined in the header file have + * the ubi_tr prefix. Also cleaned up anything that gcc complained about + * when run with '-pedantic -fsyntax-only -Wall'. + * + * Revision 2.4 1997/07/26 04:11:10 crh + * + Just to be annoying I changed ubi_TRUE and ubi_FALSE to ubi_trTRUE + * and ubi_trFALSE. + * + There is now a type ubi_trBool to go with ubi_trTRUE and ubi_trFALSE. + * + There used to be something called "ubi_TypeDefs.h". I got rid of it. + * + Added function ubi_btLeafNode(). + * + * Revision 2.3 1997/06/03 05:16:17 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid conflicts. + * Also changed the interface to function InitTree(). See the comments + * for this function for more information. + * + * Revision 2.2 1995/10/03 22:00:07 CRH + * Ubisized! + * + * Revision 2.1 95/03/09 23:37:10 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/02/27 22:00:17 CRH + * Revision 2.0 of this program includes the following changes: + * + * 1) A fix to a major typo in the RepaceNode() function. + * 2) The addition of the static function Border(). + * 3) The addition of the public functions FirstOf() and LastOf(), which + * use Border(). These functions are used with trees that allow + * duplicate keys. + * 4) A complete rewrite of the Locate() function. Locate() now accepts + * a "comparison" operator. + * 5) Overall enhancements to both code and comments. + * + * I decided to give this a new major rev number because the interface has + * changed. In particular, there are two new functions, and changes to the + * Locate() function. + * + * Revision 1.0 93/10/15 22:44:59 CRH + * With this revision, I have added a set of #define's that provide a single, + * standard API to all existing tree modules. Until now, each of the three + * existing modules had a different function and typedef prefix, as follows: + * + * Module Prefix + * ubi_BinTree ubi_bt + * ubi_AVLtree ubi_avl + * ubi_SplayTree ubi_spt + * + * To further complicate matters, only those portions of the base module + * (ubi_BinTree) that were superceeded in the new module had the new names. + * For example, if you were using ubi_SplayTree, the locate function was + * called "ubi_sptLocate", but the next and previous functions remained + * "ubi_btNext" and "ubi_btPrev". + * + * This was not too terrible if you were familiar with the modules and knew + * exactly which tree model you wanted to use. If you wanted to be able to + * change modules (for speed comparisons, etc), things could get messy very + * quickly. + * + * So, I have added a set of defined names that get redefined in any of the + * descendant modules. To use this standardized interface in your code, + * simply replace all occurances of "ubi_bt", "ubi_avl", and "ubi_spt" with + * "ubi_tr". The "ubi_tr" names will resolve to the correct function or + * datatype names for the module that you are using. Just remember to + * include the header for that module in your program file. Because these + * names are handled by the preprocessor, there is no added run-time + * overhead. + * + * Note that the original names do still exist, and can be used if you wish + * to write code directly to a specific module. This should probably only be + * done if you are planning to implement a new descendant type, such as + * red/black trees. CRH + * + * V0.0 - June, 1991 - Written by Christopher R. Hertel (CRH). + * + * ========================================================================== ** + */ + +#include "ubi_BinTree.h" /* Header for this module. */ + +/* ========================================================================== ** + * Static data. + */ + +static char ModuleID[] = "ubi_BinTree\n\ +\tRevision: 4.10 \n\ +\tDate: 2000/06/06 20:38:40 \n\ +\tAuthor: crh \n"; + +/* ========================================================================== ** + * Internal (private) functions. + */ + +static ubi_btNodePtr qFind( ubi_btCompFunc cmp, + ubi_btItemPtr FindMe, + register ubi_btNodePtr p ) + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for a node + * matching a specific key. It is called "qFind()" because it is + * faster that TreeFind (below). + * + * Input: + * cmp - a pointer to the tree's comparison function. + * FindMe - a pointer to the key value for which to search. + * p - a pointer to the starting point of the search. <p> + * is considered to be the root of a subtree, and only + * the subtree will be searched. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. + * ------------------------------------------------------------------------ ** + */ + { + int tmp; + + while( (NULL != p) + && ((tmp = ubi_trAbNormal( (*cmp)(FindMe, p) )) != ubi_trEQUAL) ) + p = p->Link[tmp]; + + return( p ); + } /* qFind */ + +static ubi_btNodePtr TreeFind( ubi_btItemPtr findme, + ubi_btNodePtr p, + ubi_btNodePtr *parentp, + char *gender, + ubi_btCompFunc CmpFunc ) + /* ------------------------------------------------------------------------ ** + * TreeFind() searches a tree for a given value (findme). It will return a + * pointer to the target node, if found, or NULL if the target node was not + * found. + * + * TreeFind() also returns, via parameters, a pointer to the parent of the + * target node, and a LEFT or RIGHT value indicating which child of the + * parent is the target node. *If the target is not found*, then these + * values indicate the place at which the target *should be found*. This + * is useful when inserting a new node into a tree or searching for nodes + * "near" the target node. + * + * The parameters are: + * + * findme - is a pointer to the key information to be searched for. + * p - points to the root of the tree to be searched. + * parentp - will return a pointer to a pointer to the !parent! of the + * target node, which can be especially usefull if the target + * was not found. + * gender - returns LEFT or RIGHT to indicate which child of *parentp + * was last searched. + * CmpFunc - points to the comparison function. + * + * This function is called by ubi_btLocate() and ubi_btInsert(). + * ------------------------------------------------------------------------ ** + */ + { + register ubi_btNodePtr tmp_p = p; + ubi_btNodePtr tmp_pp = NULL; + char tmp_gender = ubi_trEQUAL; + int tmp_cmp; + + while( (NULL != tmp_p) + && (ubi_trEQUAL != (tmp_cmp = ubi_trAbNormal((*CmpFunc)(findme, tmp_p)))) ) + { + tmp_pp = tmp_p; /* Keep track of previous node. */ + tmp_gender = (char)tmp_cmp; /* Keep track of sex of child. */ + tmp_p = tmp_p->Link[tmp_cmp]; /* Go to child. */ + } + *parentp = tmp_pp; /* Return results. */ + *gender = tmp_gender; + return( tmp_p ); + } /* TreeFind */ + +static void ReplaceNode( ubi_btNodePtr *parent, + ubi_btNodePtr oldnode, + ubi_btNodePtr newnode ) + /* ------------------------------------------------------------------------ ** + * Remove node oldnode from the tree, replacing it with node newnode. + * + * Input: + * parent - A pointer to he parent pointer of the node to be + * replaced. <parent> may point to the Link[] field of + * a parent node, or it may indicate the root pointer at + * the top of the tree. + * oldnode - A pointer to the node that is to be replaced. + * newnode - A pointer to the node that is to be installed in the + * place of <*oldnode>. + * + * Notes: Don't forget to free oldnode. + * Also, this function used to have a really nasty typo + * bug. "oldnode" and "newnode" were swapped in the line + * that now reads: + * ((unsigned char *)newnode)[i] = ((unsigned char *)oldnode)[i]; + * Bleah! + * ------------------------------------------------------------------------ ** + */ + { + *newnode = *oldnode; /* Copy node internals to new node. */ + + (*parent) = newnode; /* Old node's parent points to new child. */ + /* Now tell the children about their new step-parent. */ + if( oldnode->Link[ubi_trLEFT] ) + (oldnode->Link[ubi_trLEFT])->Link[ubi_trPARENT] = newnode; + if( oldnode->Link[ubi_trRIGHT] ) + (oldnode->Link[ubi_trRIGHT])->Link[ubi_trPARENT] = newnode; + } /* ReplaceNode */ + +static void SwapNodes( ubi_btRootPtr RootPtr, + ubi_btNodePtr Node1, + ubi_btNodePtr Node2 ) + /* ------------------------------------------------------------------------ ** + * This function swaps two nodes in the tree. Node1 will take the place of + * Node2, and Node2 will fill in the space left vacant by Node 1. + * + * Input: + * RootPtr - pointer to the tree header structure for this tree. + * Node1 - \ + * > These are the two nodes which are to be swapped. + * Node2 - / + * + * Notes: + * This function does a three step swap, using a dummy node as a place + * holder. This function is used by ubi_btRemove(). + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr *Parent; + ubi_btNode dummy; + ubi_btNodePtr dummy_p = &dummy; + + /* Replace Node 1 with the dummy, thus removing Node1 from the tree. */ + if( NULL != Node1->Link[ubi_trPARENT] ) + Parent = &((Node1->Link[ubi_trPARENT])->Link[(int)(Node1->gender)]); + else + Parent = &(RootPtr->root); + ReplaceNode( Parent, Node1, dummy_p ); + + /* Swap Node 1 with Node 2, placing Node 1 back into the tree. */ + if( NULL != Node2->Link[ubi_trPARENT] ) + Parent = &((Node2->Link[ubi_trPARENT])->Link[(int)(Node2->gender)]); + else + Parent = &(RootPtr->root); + ReplaceNode( Parent, Node2, Node1 ); + + /* Swap Node 2 and the dummy, thus placing Node 2 back into the tree. */ + if( NULL != dummy_p->Link[ubi_trPARENT] ) + Parent = &((dummy_p->Link[ubi_trPARENT])->Link[(int)(dummy_p->gender)]); + else + Parent = &(RootPtr->root); + ReplaceNode( Parent, dummy_p, Node2 ); + } /* SwapNodes */ + +/* -------------------------------------------------------------------------- ** + * These routines allow you to walk through the tree, forwards or backwards. + */ + +static ubi_btNodePtr SubSlide( register ubi_btNodePtr P, + register int whichway ) + /* ------------------------------------------------------------------------ ** + * Slide down the side of a subtree. + * + * Given a starting node, this function returns a pointer to the LEFT-, or + * RIGHT-most descendent, *or* (if whichway is PARENT) to the tree root. + * + * Input: P - a pointer to a starting place. + * whichway - the direction (LEFT, RIGHT, or PARENT) in which to + * travel. + * Output: A pointer to a node that is either the root, or has no + * whichway-th child but is within the subtree of P. Note that + * the return value may be the same as P. The return value *will + * be* NULL if P is NULL. + * ------------------------------------------------------------------------ ** + */ + { + + if( NULL != P ) + while( NULL != P->Link[ whichway ] ) + P = P->Link[ whichway ]; + return( P ); + } /* SubSlide */ + +static ubi_btNodePtr Neighbor( register ubi_btNodePtr P, + register int whichway ) + /* ------------------------------------------------------------------------ ** + * Given starting point p, return the (key order) next or preceeding node + * in the tree. + * + * Input: P - Pointer to our starting place node. + * whichway - the direction in which to travel to find the + * neighbor, i.e., the RIGHT neighbor or the LEFT + * neighbor. + * + * Output: A pointer to the neighboring node, or NULL if P was NULL. + * + * Notes: If whichway is PARENT, the results are unpredictable. + * ------------------------------------------------------------------------ ** + */ + { + if( P ) + { + if( NULL != P->Link[ whichway ] ) + return( SubSlide( P->Link[ whichway ], (char)ubi_trRevWay(whichway) ) ); + else + while( NULL != P->Link[ ubi_trPARENT ] ) + { + if( whichway == P->gender ) + P = P->Link[ ubi_trPARENT ]; + else + return( P->Link[ ubi_trPARENT ] ); + } + } + return( NULL ); + } /* Neighbor */ + +static ubi_btNodePtr Border( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_btNodePtr p, + int whichway ) + /* ------------------------------------------------------------------------ ** + * Given starting point p, which has a key value equal to *FindMe, locate + * the first (index order) node with the same key value. + * + * This function is useful in trees that have can have duplicate keys. + * For example, consider the following tree: + * Tree Traversal + * 2 If <p> points to the root and <whichway> is RIGHT, 3 + * / \ then the return value will be a pointer to the / \ + * 2 2 RIGHT child of the root node. The tree on 2 5 + * / / \ the right shows the order of traversal. / / \ + * 1 2 3 1 4 6 + * + * Input: RootPtr - Pointer to the tree root structure. + * FindMe - Key value for comparisons. + * p - Pointer to the starting-point node. + * whichway - the direction in which to travel to find the + * neighbor, i.e., the RIGHT neighbor or the LEFT + * neighbor. + * + * Output: A pointer to the first (index, or "traversal", order) node with + * a Key value that matches *FindMe. + * + * Notes: If whichway is PARENT, or if the tree does not allow duplicate + * keys, this function will return <p>. + * ------------------------------------------------------------------------ ** + */ + { + register ubi_btNodePtr q; + + /* Exit if there's nothing that can be done. */ + if( !ubi_trDups_OK( RootPtr ) || (ubi_trPARENT == whichway) ) + return( p ); + + /* First, if needed, move up the tree. We need to get to the root of the + * subtree that contains all of the matching nodes. + */ + q = p->Link[ubi_trPARENT]; + while( (NULL != q) + && (ubi_trEQUAL == ubi_trAbNormal( (*(RootPtr->cmp))(FindMe, q) )) ) + { + p = q; + q = p->Link[ubi_trPARENT]; + } + + /* Next, move back down in the "whichway" direction. */ + q = p->Link[whichway]; + while( NULL != q ) + { + q = qFind( RootPtr->cmp, FindMe, q ); + if( q ) + { + p = q; + q = p->Link[whichway]; + } + } + return( p ); + } /* Border */ + + +/* ========================================================================== ** + * Exported utilities. + */ + +long ubi_btSgn( register long x ) + /* ------------------------------------------------------------------------ ** + * Return the sign of x; {negative,zero,positive} ==> {-1, 0, 1}. + * + * Input: x - a signed long integer value. + * + * Output: the "sign" of x, represented as follows: + * -1 == negative + * 0 == zero (no sign) + * 1 == positive + * + * Note: This utility is provided in order to facilitate the conversion + * of C comparison function return values into BinTree direction + * values: {LEFT, PARENT, EQUAL}. It is INCORPORATED into the + * ubi_trAbNormal() conversion macro! + * + * ------------------------------------------------------------------------ ** + */ + { + return( (x)?((x>0)?(1):(-1)):(0) ); + } /* ubi_btSgn */ + +ubi_btNodePtr ubi_btInitNode( ubi_btNodePtr NodePtr ) + /* ------------------------------------------------------------------------ ** + * Initialize a tree node. + * + * Input: a pointer to a ubi_btNode structure to be initialized. + * Output: a pointer to the initialized ubi_btNode structure (ie. the + * same as the input pointer). + * ------------------------------------------------------------------------ ** + */ + { + NodePtr->Link[ ubi_trLEFT ] = NULL; + NodePtr->Link[ ubi_trPARENT ] = NULL; + NodePtr->Link[ ubi_trRIGHT ] = NULL; + NodePtr->gender = ubi_trEQUAL; + NodePtr->balance = ubi_trEQUAL; + return( NodePtr ); + } /* ubi_btInitNode */ + +ubi_btRootPtr ubi_btInitTree( ubi_btRootPtr RootPtr, + ubi_btCompFunc CompFunc, + char Flags ) + /* ------------------------------------------------------------------------ ** + * Initialize the fields of a Tree Root header structure. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure to be + * initialized. + * CompFunc - a pointer to a comparison function that will be used + * whenever nodes in the tree must be compared against + * outside values. + * Flags - One bytes worth of flags. Flags include + * ubi_trOVERWRITE and ubi_trDUPKEY. See the header + * file for more info. + * + * Output: a pointer to the initialized ubi_btRoot structure (ie. the + * same value as RootPtr). + * + * Note: The interface to this function has changed from that of + * previous versions. The <Flags> parameter replaces two + * boolean parameters that had the same basic effect. + * + * ------------------------------------------------------------------------ ** + */ + { + if( RootPtr ) + { + RootPtr->root = NULL; + RootPtr->count = 0L; + RootPtr->cmp = CompFunc; + RootPtr->flags = (Flags & ubi_trDUPKEY) ? ubi_trDUPKEY : Flags; + } /* There are only two supported flags, and they are + * mutually exclusive. ubi_trDUPKEY takes precedence + * over ubi_trOVERWRITE. + */ + return( RootPtr ); + } /* ubi_btInitTree */ + +ubi_trBool ubi_btInsert( ubi_btRootPtr RootPtr, + ubi_btNodePtr NewNode, + ubi_btItemPtr ItemPtr, + ubi_btNodePtr *OldNode ) + /* ------------------------------------------------------------------------ ** + * This function uses a non-recursive algorithm to add a new element to the + * tree. + * + * Input: RootPtr - a pointer to the ubi_btRoot structure that indicates + * the root of the tree to which NewNode is to be added. + * NewNode - a pointer to an ubi_btNode structure that is NOT + * part of any tree. + * ItemPtr - A pointer to the sort key that is stored within + * *NewNode. ItemPtr MUST point to information stored + * in *NewNode or an EXACT DUPLICATE. The key data + * indicated by ItemPtr is used to place the new node + * into the tree. + * OldNode - a pointer to an ubi_btNodePtr. When searching + * the tree, a duplicate node may be found. If + * duplicates are allowed, then the new node will + * be simply placed into the tree. If duplicates + * are not allowed, however, then one of two things + * may happen. + * 1) if overwritting *is not* allowed, this + * function will return FALSE (indicating that + * the new node could not be inserted), and + * *OldNode will point to the duplicate that is + * still in the tree. + * 2) if overwritting *is* allowed, then this + * function will swap **OldNode for *NewNode. + * In this case, *OldNode will point to the node + * that was removed (thus allowing you to free + * the node). + * ** If you are using overwrite mode, ALWAYS ** + * ** check the return value of this parameter! ** + * Note: You may pass NULL in this parameter, the + * function knows how to cope. If you do this, + * however, there will be no way to return a + * pointer to an old (ie. replaced) node (which is + * a problem if you are using overwrite mode). + * + * Output: a boolean value indicating success or failure. The function + * will return FALSE if the node could not be added to the tree. + * Such failure will only occur if duplicates are not allowed, + * nodes cannot be overwritten, AND a duplicate key was found + * within the tree. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr OtherP, + parent = NULL; + char tmp; + + if( NULL == OldNode ) /* If they didn't give us a pointer, supply our own. */ + OldNode = &OtherP; + + (void)ubi_btInitNode( NewNode ); /* Init the new node's BinTree fields. */ + + /* Find a place for the new node. */ + *OldNode = TreeFind(ItemPtr, (RootPtr->root), &parent, &tmp, (RootPtr->cmp)); + + /* Now add the node to the tree... */ + if( NULL == (*OldNode) ) /* The easy one: we have a space for a new node! */ + { + if( NULL == parent ) + RootPtr->root = NewNode; + else + { + parent->Link[(int)tmp] = NewNode; + NewNode->Link[ubi_trPARENT] = parent; + NewNode->gender = tmp; + } + (RootPtr->count)++; + return( ubi_trTRUE ); + } + + /* If we reach this point, we know that a duplicate node exists. This + * section adds the node to the tree if duplicate keys are allowed. + */ + if( ubi_trDups_OK(RootPtr) ) /* Key exists, add duplicate */ + { + ubi_btNodePtr q; + + tmp = ubi_trRIGHT; + q = (*OldNode); + *OldNode = NULL; + while( NULL != q ) + { + parent = q; + if( tmp == ubi_trEQUAL ) + tmp = ubi_trRIGHT; + q = q->Link[(int)tmp]; + if ( q ) + tmp = ubi_trAbNormal( (*(RootPtr->cmp))(ItemPtr, q) ); + } + parent->Link[(int)tmp] = NewNode; + NewNode->Link[ubi_trPARENT] = parent; + NewNode->gender = tmp; + (RootPtr->count)++; + return( ubi_trTRUE ); + } + + /* If we get to *this* point, we know that we are not allowed to have + * duplicate nodes, but our node keys match, so... may we replace the + * old one? + */ + if( ubi_trOvwt_OK(RootPtr) ) /* Key exists, we replace */ + { + if( NULL == parent ) + ReplaceNode( &(RootPtr->root), *OldNode, NewNode ); + else + ReplaceNode( &(parent->Link[(int)((*OldNode)->gender)]), + *OldNode, NewNode ); + return( ubi_trTRUE ); + } + + return( ubi_trFALSE ); /* Failure: could not replace an existing node. */ + } /* ubi_btInsert */ + +ubi_btNodePtr ubi_btRemove( ubi_btRootPtr RootPtr, + ubi_btNodePtr DeadNode ) + /* ------------------------------------------------------------------------ ** + * This function removes the indicated node from the tree. + * + * Input: RootPtr - A pointer to the header of the tree that contains + * the node to be removed. + * DeadNode - A pointer to the node that will be removed. + * + * Output: This function returns a pointer to the node that was removed + * from the tree (ie. the same as DeadNode). + * + * Note: The node MUST be in the tree indicated by RootPtr. If not, + * strange and evil things will happen to your trees. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p, + *parentp; + int tmp; + + /* if the node has both left and right subtrees, then we have to swap + * it with another node. The other node we choose will be the Prev()ious + * node, which is garunteed to have no RIGHT child. + */ + if( (NULL != DeadNode->Link[ubi_trLEFT]) + && (NULL != DeadNode->Link[ubi_trRIGHT]) ) + SwapNodes( RootPtr, DeadNode, ubi_btPrev( DeadNode ) ); + + /* The parent of the node to be deleted may be another node, or it may be + * the root of the tree. Since we're not sure, it's best just to have + * a pointer to the parent pointer, whatever it is. + */ + if( NULL == DeadNode->Link[ubi_trPARENT] ) + parentp = &( RootPtr->root ); + else + parentp = &((DeadNode->Link[ubi_trPARENT])->Link[(int)(DeadNode->gender)]); + + /* Now link the parent to the only grand-child and patch up the gender. */ + tmp = ((DeadNode->Link[ubi_trLEFT])?ubi_trLEFT:ubi_trRIGHT); + + p = (DeadNode->Link[tmp]); + if( NULL != p ) + { + p->Link[ubi_trPARENT] = DeadNode->Link[ubi_trPARENT]; + p->gender = DeadNode->gender; + } + (*parentp) = p; + + /* Finished, reduce the node count and return. */ + (RootPtr->count)--; + return( DeadNode ); + } /* ubi_btRemove */ + +ubi_btNodePtr ubi_btLocate( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_trCompOps CompOp ) + /* ------------------------------------------------------------------------ ** + * The purpose of ubi_btLocate() is to find a node or set of nodes given + * a target value and a "comparison operator". The Locate() function is + * more flexible and (in the case of trees that may contain dupicate keys) + * more precise than the ubi_btFind() function. The latter is faster, + * but it only searches for exact matches and, if the tree contains + * duplicates, Find() may return a pointer to any one of the duplicate- + * keyed records. + * + * Input: + * RootPtr - A pointer to the header of the tree to be searched. + * FindMe - An ubi_btItemPtr that indicates the key for which to + * search. + * CompOp - One of the following: + * CompOp Return a pointer to the node with + * ------ --------------------------------- + * ubi_trLT - the last key value that is less + * than FindMe. + * ubi_trLE - the first key matching FindMe, or + * the last key that is less than + * FindMe. + * ubi_trEQ - the first key matching FindMe. + * ubi_trGE - the first key matching FindMe, or the + * first key greater than FindMe. + * ubi_trGT - the first key greater than FindMe. + * Output: + * A pointer to the node matching the criteria listed above under + * CompOp, or NULL if no node matched the criteria. + * + * Notes: + * In the case of trees with duplicate keys, Locate() will behave as + * follows: + * + * Find: 3 Find: 3 + * Keys: 1 2 2 2 3 3 3 3 3 4 4 Keys: 1 1 2 2 2 4 4 5 5 5 6 + * ^ ^ ^ ^ ^ + * LT EQ GT LE GE + * + * That is, when returning a pointer to a node with a key that is LESS + * THAN the target key (FindMe), Locate() will return a pointer to the + * LAST matching node. + * When returning a pointer to a node with a key that is GREATER + * THAN the target key (FindMe), Locate() will return a pointer to the + * FIRST matching node. + * + * See Also: ubi_btFind(), ubi_btFirstOf(), ubi_btLastOf(). + * ------------------------------------------------------------------------ ** + */ + { + register ubi_btNodePtr p; + ubi_btNodePtr parent; + char whichkid; + + /* Start by searching for a matching node. */ + p = TreeFind( FindMe, + RootPtr->root, + &parent, + &whichkid, + RootPtr->cmp ); + + if( NULL != p ) /* If we have found a match, we can resolve as follows: */ + { + switch( CompOp ) + { + case ubi_trLT: /* It's just a jump to the left... */ + p = Border( RootPtr, FindMe, p, ubi_trLEFT ); + return( Neighbor( p, ubi_trLEFT ) ); + case ubi_trGT: /* ...and then a jump to the right. */ + p = Border( RootPtr, FindMe, p, ubi_trRIGHT ); + return( Neighbor( p, ubi_trRIGHT ) ); + default: + p = Border( RootPtr, FindMe, p, ubi_trLEFT ); + return( p ); + } + } + + /* Else, no match. */ + if( ubi_trEQ == CompOp ) /* If we were looking for an exact match... */ + return( NULL ); /* ...forget it. */ + + /* We can still return a valid result for GT, GE, LE, and LT. + * <parent> points to a node with a value that is either just before or + * just after the target value. + * Remaining possibilities are LT and GT (including LE & GE). + */ + if( (ubi_trLT == CompOp) || (ubi_trLE == CompOp) ) + return( (ubi_trLEFT == whichkid) ? Neighbor( parent, whichkid ) : parent ); + else + return( (ubi_trRIGHT == whichkid) ? Neighbor( parent, whichkid ) : parent ); + } /* ubi_btLocate */ + +ubi_btNodePtr ubi_btFind( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe ) + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for any node + * matching a specific key. + * + * Input: + * RootPtr - a pointer to the header of the tree to be searched. + * FindMe - a pointer to the key value for which to search. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. In such a tree, it may be more useful to use + * ubi_btLocate(). + * ------------------------------------------------------------------------ ** + */ + { + return( qFind( RootPtr->cmp, FindMe, RootPtr->root ) ); + } /* ubi_btFind */ + +ubi_btNodePtr ubi_btNext( ubi_btNodePtr P ) + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Next node in the + * tree. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "next" node in the tree, or NULL if P pointed + * to the "last" node in the tree or was NULL. + * ------------------------------------------------------------------------ ** + */ + { + return( Neighbor( P, ubi_trRIGHT ) ); + } /* ubi_btNext */ + +ubi_btNodePtr ubi_btPrev( ubi_btNodePtr P ) + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Previous node in + * the tree. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "previous" node in the tree, or NULL if P + * pointed to the "first" node in the tree or was NULL. + * ------------------------------------------------------------------------ ** + */ + { + return( Neighbor( P, ubi_trLEFT ) ); + } /* ubi_btPrev */ + +ubi_btNodePtr ubi_btFirst( ubi_btNodePtr P ) + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) First node in the + * subtree of which *P is the root. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "first" node in a subtree that has *P as its + * root. This function will return NULL only if P is NULL. + * Note: In general, you will be passing in the value of the root field + * of an ubi_btRoot structure. + * ------------------------------------------------------------------------ ** + */ + { + return( SubSlide( P, ubi_trLEFT ) ); + } /* ubi_btFirst */ + +ubi_btNodePtr ubi_btLast( ubi_btNodePtr P ) + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Last node in the + * subtree of which *P is the root. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "last" node in a subtree that has *P as its + * root. This function will return NULL only if P is NULL. + * Note: In general, you will be passing in the value of the root field + * of an ubi_btRoot structure. + * ------------------------------------------------------------------------ ** + */ + { + return( SubSlide( P, ubi_trRIGHT ) ); + } /* ubi_btLast */ + +ubi_btNodePtr ubi_btFirstOf( ubi_btRootPtr RootPtr, + ubi_btItemPtr MatchMe, + ubi_btNodePtr p ) + /* ------------------------------------------------------------------------ ** + * Given a tree that a allows duplicate keys, and a pointer to a node in + * the tree, this function will return a pointer to the first (traversal + * order) node with the same key value. + * + * Input: RootPtr - A pointer to the root of the tree. + * MatchMe - A pointer to the key value. This should probably + * point to the key within node *p. + * p - A pointer to a node in the tree. + * Output: A pointer to the first node in the set of nodes with keys + * matching <FindMe>. + * Notes: Node *p MUST be in the set of nodes with keys matching + * <FindMe>. If not, this function will return NULL. + * + * 4.7: Bug found & fixed by Massimo Campostrini, + * Istituto Nazionale di Fisica Nucleare, Sezione di Pisa. + * + * ------------------------------------------------------------------------ ** + */ + { + /* If our starting point is invalid, return NULL. */ + if( (NULL == p) + || (ubi_trEQUAL != ubi_trAbNormal( (*(RootPtr->cmp))( MatchMe, p ) )) ) + return( NULL ); + return( Border( RootPtr, MatchMe, p, ubi_trLEFT ) ); + } /* ubi_btFirstOf */ + +ubi_btNodePtr ubi_btLastOf( ubi_btRootPtr RootPtr, + ubi_btItemPtr MatchMe, + ubi_btNodePtr p ) + /* ------------------------------------------------------------------------ ** + * Given a tree that a allows duplicate keys, and a pointer to a node in + * the tree, this function will return a pointer to the last (traversal + * order) node with the same key value. + * + * Input: RootPtr - A pointer to the root of the tree. + * MatchMe - A pointer to the key value. This should probably + * point to the key within node *p. + * p - A pointer to a node in the tree. + * Output: A pointer to the last node in the set of nodes with keys + * matching <FindMe>. + * Notes: Node *p MUST be in the set of nodes with keys matching + * <FindMe>. If not, this function will return NULL. + * + * 4.7: Bug found & fixed by Massimo Campostrini, + * Istituto Nazionale di Fisica Nucleare, Sezione di Pisa. + * + * ------------------------------------------------------------------------ ** + */ + { + /* If our starting point is invalid, return NULL. */ + if( (NULL != p) + || (ubi_trEQUAL != ubi_trAbNormal( (*(RootPtr->cmp))( MatchMe, p ) )) ) + return( NULL ); + return( Border( RootPtr, MatchMe, p, ubi_trRIGHT ) ); + } /* ubi_btLastOf */ + +unsigned long ubi_btTraverse( ubi_btRootPtr RootPtr, + ubi_btActionRtn EachNode, + void *UserData ) + /* ------------------------------------------------------------------------ ** + * Traverse a tree in sorted order (non-recursively). At each node, call + * (*EachNode)(), passing a pointer to the current node, and UserData as the + * second parameter. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates + * the tree to be traversed. + * EachNode - a pointer to a function to be called at each node + * as the node is visited. + * UserData - a generic pointer that may point to anything that + * you choose. + * + * Output: A count of the number of nodes visited. This will be zero + * if the tree is empty. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p = ubi_btFirst( RootPtr->root ); + unsigned long count = 0; + + while( NULL != p ) + { + (*EachNode)( p, UserData ); + count++; + p = ubi_btNext( p ); + } + return( count ); + } /* ubi_btTraverse */ + +unsigned long ubi_btKillTree( ubi_btRootPtr RootPtr, + ubi_btKillNodeRtn FreeNode ) + /* ------------------------------------------------------------------------ ** + * Delete an entire tree (non-recursively) and reinitialize the ubi_btRoot + * structure. Return a count of the number of nodes deleted. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates + * the root of the tree to delete. + * FreeNode - a function that will be called for each node in the + * tree to deallocate the memory used by the node. + * + * Output: The number of nodes removed from the tree. + * A value of 0 will be returned if: + * - The tree actually contains 0 entries. + * - the value of <RootPtr> is NULL, in which case the tree is + * assumed to be empty + * - the value of <FreeNode> is NULL, in which case entries + * cannot be removed, so 0 is returned. *Make sure that you + * provide a valid value for <FreeNode>*. + * In all other cases, you should get a positive value equal to + * the value of RootPtr->count upon entry. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p, q; + unsigned long count = 0; + + if( (NULL == RootPtr) || (NULL == FreeNode) ) + return( 0 ); + + p = ubi_btFirst( RootPtr->root ); + while( NULL != p ) + { + q = p; + while( q->Link[ubi_trRIGHT] ) + q = SubSlide( q->Link[ubi_trRIGHT], ubi_trLEFT ); + p = q->Link[ubi_trPARENT]; + if( NULL != p ) + p->Link[ ((p->Link[ubi_trLEFT] == q)?ubi_trLEFT:ubi_trRIGHT) ] = NULL; + (*FreeNode)((void *)q); + count++; + } + + /* overkill... */ + (void)ubi_btInitTree( RootPtr, + RootPtr->cmp, + RootPtr->flags ); + return( count ); + } /* ubi_btKillTree */ + +ubi_btNodePtr ubi_btLeafNode( ubi_btNodePtr leader ) + /* ------------------------------------------------------------------------ ** + * Returns a pointer to a leaf node. + * + * Input: leader - Pointer to a node at which to start the descent. + * + * Output: A pointer to a leaf node selected in a somewhat arbitrary + * manner. + * + * Notes: I wrote this function because I was using splay trees as a + * database cache. The cache had a maximum size on it, and I + * needed a way of choosing a node to sacrifice if the cache + * became full. In a splay tree, less recently accessed nodes + * tend toward the bottom of the tree, meaning that leaf nodes + * are good candidates for removal. (I really can't think of + * any other reason to use this function.) + * + In a simple binary tree or an AVL tree, the most recently + * added nodes tend to be nearer the bottom, making this a *bad* + * way to choose which node to remove from the cache. + * + Randomizing the traversal order is probably a good idea. You + * can improve the randomization of leaf node selection by passing + * in pointers to nodes other than the root node each time. A + * pointer to any node in the tree will do. Of course, if you + * pass a pointer to a leaf node you'll get the same thing back. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr follower = NULL; + int whichway = ubi_trLEFT; + + while( NULL != leader ) + { + follower = leader; + leader = follower->Link[ whichway ]; + if( NULL == leader ) + { + whichway = ubi_trRevWay( whichway ); + leader = follower->Link[ whichway ]; + } + } + + return( follower ); + } /* ubi_btLeafNode */ + +int ubi_btModuleID( int size, char *list[] ) + /* ------------------------------------------------------------------------ ** + * Returns a set of strings that identify the module. + * + * Input: size - The number of elements in the array <list>. + * list - An array of pointers of type (char *). This array + * should, initially, be empty. This function will fill + * in the array with pointers to strings. + * Output: The number of elements of <list> that were used. If this value + * is less than <size>, the values of the remaining elements are + * not guaranteed. + * + * Notes: Please keep in mind that the pointers returned indicate strings + * stored in static memory. Don't free() them, don't write over + * them, etc. Just read them. + * ------------------------------------------------------------------------ ** + */ + { + if( size > 0 ) + { + list[0] = ModuleID; + if( size > 1 ) + list[1] = NULL; + return( 1 ); + } + return( 0 ); + } /* ubi_btModuleID */ + + +/* ========================================================================== */ diff --git a/source/ubiqx/ubi_BinTree.h b/source/ubiqx/ubi_BinTree.h new file mode 100644 index 00000000000..c0c6d593094 --- /dev/null +++ b/source/ubiqx/ubi_BinTree.h @@ -0,0 +1,864 @@ +#ifndef UBI_BINTREE_H +#define UBI_BINTREE_H +/* ========================================================================== ** + * ubi_BinTree.h + * + * Copyright (C) 1991-1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * This module implements a simple binary tree. + * + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_BinTree.h,v + * Revision 4.10 2000/06/06 20:38:40 crh + * In the ReplaceNode() function, the old node header was being copied + * to the new node header using a byte-by-byte copy. This was causing + * the 'insure' software testing program to report a memory leak. The + * fix was to do a simple assignement: *newnode = *oldnode; + * This quieted the (errant) memory leak reports and is probably a bit + * faster than the bytewise copy. + * + * Revision 4.9 2000/01/08 23:24:30 crh + * Clarified a variety of if( pointer ) lines, replacing them with + * if( NULL != pointer ). This is more correct, and I have heard + * of at least one (obscure?) system out there that uses a non-zero + * value for NULL. + * Also, speed improvement in Neighbor(). It was comparing pointers + * when it could have compared two gender values. The pointer + * comparison was somewhat indirect (does pointer equal the pointer + * of the parent of the node pointed to by pointer). Urq. + * + * Revision 4.8 1999/09/22 03:40:30 crh + * Modified ubi_btTraverse() and ubi_btKillTree(). They now return an + * unsigned long indicating the number of nodes processed. The change + * is subtle. An empty tree formerly returned False, and now returns + * zero. + * + * Revision 4.7 1998/10/21 06:15:07 crh + * Fixed bugs in FirstOf() and LastOf() reported by Massimo Campostrini. + * See function comments. + * + * Revision 4.6 1998/07/25 17:02:10 crh + * Added the ubi_trNewTree() macro. + * + * Revision 4.5 1998/06/04 21:29:27 crh + * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. + * This is more "standard", and is what people expect. Weird, eh? + * + * Revision 4.4 1998/06/03 17:42:46 crh + * Further fiddling with sys_include.h. It's now in ubi_BinTree.h which is + * included by all of the binary tree files. + * + * Reminder: Some of the ubi_tr* macros in ubi_BinTree.h are redefined in + * ubi_AVLtree.h and ubi_SplayTree.h. This allows easy swapping + * of tree types by simply changing a header. Unfortunately, the + * macro redefinitions in ubi_AVLtree.h and ubi_SplayTree.h will + * conflict if used together. You must either choose a single tree + * type, or use the underlying function calls directly. Compare + * the two header files for more information. + * + * Revision 4.3 1998/06/02 01:28:43 crh + * Changed ubi_null.h to sys_include.h to make it more generic. + * + * Revision 4.2 1998/05/20 04:32:36 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * Also, the balance and gender fields of the node were declared as + * signed char. As I understand it, at least one SunOS or Solaris + * compiler doesn't like "signed char". The declarations were + * wrong anyway, so I changed them to simple "char". + * + * Revision 4.1 1998/03/31 06:13:47 crh + * Thomas Aglassinger sent E'mail pointing out errors in the + * dereferencing of function pointers, and a missing typecast. + * Thanks, Thomas! + * + * Revision 4.0 1998/03/10 03:16:04 crh + * Added the AVL field 'balance' to the ubi_btNode structure. This means + * that all BinTree modules now use the same basic node structure, which + * greatly simplifies the AVL module. + * Decided that this was a big enough change to justify a new major revision + * number. 3.0 was an error, so we're at 4.0. + * + * Revision 2.6 1998/01/24 06:27:30 crh + * Added ubi_trCount() macro. + * + * Revision 2.5 1997/12/23 03:59:21 crh + * In this version, all constants & macros defined in the header file have + * the ubi_tr prefix. Also cleaned up anything that gcc complained about + * when run with '-pedantic -fsyntax-only -Wall'. + * + * Revision 2.4 1997/07/26 04:11:14 crh + * + Just to be annoying I changed ubi_TRUE and ubi_FALSE to ubi_trTRUE + * and ubi_trFALSE. + * + There is now a type ubi_trBool to go with ubi_trTRUE and ubi_trFALSE. + * + There used to be something called "ubi_TypeDefs.h". I got rid of it. + * + Added function ubi_btLeafNode(). + * + * Revision 2.3 1997/06/03 05:15:27 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid conflicts. + * Also changed the interface to function InitTree(). See the comments + * for this function for more information. + * + * Revision 2.2 1995/10/03 22:00:40 CRH + * Ubisized! + * + * Revision 2.1 95/03/09 23:43:46 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/02/27 22:00:33 CRH + * Revision 2.0 of this program includes the following changes: + * + * 1) A fix to a major typo in the RepaceNode() function. + * 2) The addition of the static function Border(). + * 3) The addition of the public functions FirstOf() and LastOf(), which + * use Border(). These functions are used with trees that allow + * duplicate keys. + * 4) A complete rewrite of the Locate() function. Locate() now accepts + * a "comparison" operator. + * 5) Overall enhancements to both code and comments. + * + * I decided to give this a new major rev number because the interface has + * changed. In particular, there are two new functions, and changes to the + * Locate() function. + * + * Revision 1.0 93/10/15 22:55:04 CRH + * With this revision, I have added a set of #define's that provide a single, + * standard API to all existing tree modules. Until now, each of the three + * existing modules had a different function and typedef prefix, as follows: + * + * Module Prefix + * ubi_BinTree ubi_bt + * ubi_AVLtree ubi_avl + * ubi_SplayTree ubi_spt + * + * To further complicate matters, only those portions of the base module + * (ubi_BinTree) that were superceeded in the new module had the new names. + * For example, if you were using ubi_SplayTree, the locate function was + * called "ubi_sptLocate", but the next and previous functions remained + * "ubi_btNext" and "ubi_btPrev". + * + * This was not too terrible if you were familiar with the modules and knew + * exactly which tree model you wanted to use. If you wanted to be able to + * change modules (for speed comparisons, etc), things could get messy very + * quickly. + * + * So, I have added a set of defined names that get redefined in any of the + * descendant modules. To use this standardized interface in your code, + * simply replace all occurances of "ubi_bt", "ubi_avl", and "ubi_spt" with + * "ubi_tr". The "ubi_tr" names will resolve to the correct function or + * datatype names for the module that you are using. Just remember to + * include the header for that module in your program file. Because these + * names are handled by the preprocessor, there is no added run-time + * overhead. + * + * Note that the original names do still exist, and can be used if you wish + * to write code directly to a specific module. This should probably only be + * done if you are planning to implement a new descendant type, such as + * red/black trees. CRH + * + * V0.0 - June, 1991 - Written by Christopher R. Hertel (CRH). + * + * ========================================================================== ** + */ + +#include "sys_include.h" /* Global include file, used to adapt the ubiqx + * modules to the host environment and the project + * with which the modules will be used. See + * sys_include.h for more info. + */ + +/* -------------------------------------------------------------------------- ** + * Macros and constants. + * + * General purpose: + * ubi_trTRUE - Boolean TRUE. + * ubi_trFALSE - Boolean FALSE. + * + * Flags used in the tree header: + * ubi_trOVERWRITE - This flag indicates that an existing node may be + * overwritten by a new node with a matching key. + * ubi_trDUPKEY - This flag indicates that the tree allows duplicate + * keys. If the tree does allow duplicates, the + * overwrite flag is ignored. + * + * Node link array index constants: (Each node has an array of three + * pointers. One to the left, one to the right, and one back to the + * parent.) + * ubi_trLEFT - Left child pointer. + * ubi_trPARENT - Parent pointer. + * ubi_trRIGHT - Right child pointer. + * ubi_trEQUAL - Synonym for PARENT. + * + * ubi_trCompOps: These values are used in the ubi_trLocate() function. + * ubi_trLT - request the first instance of the greatest key less than + * the search key. + * ubi_trLE - request the first instance of the greatest key that is less + * than or equal to the search key. + * ubi_trEQ - request the first instance of key that is equal to the + * search key. + * ubi_trGE - request the first instance of a key that is greater than + * or equal to the search key. + * ubi_trGT - request the first instance of the first key that is greater + * than the search key. + * -------------------------------------------------------------------------- ** + */ + +#define ubi_trTRUE 0xFF +#define ubi_trFALSE 0x00 + +#define ubi_trOVERWRITE 0x01 /* Turn on allow overwrite */ +#define ubi_trDUPKEY 0x02 /* Turn on allow duplicate keys */ + +/* Pointer array index constants... */ +#define ubi_trLEFT 0x00 +#define ubi_trPARENT 0x01 +#define ubi_trRIGHT 0x02 +#define ubi_trEQUAL ubi_trPARENT + +typedef enum { + ubi_trLT = 1, + ubi_trLE, + ubi_trEQ, + ubi_trGE, + ubi_trGT + } ubi_trCompOps; + +/* -------------------------------------------------------------------------- ** + * These three macros allow simple manipulation of pointer index values (LEFT, + * RIGHT, and PARENT). + * + * Normalize() - converts {LEFT, PARENT, RIGHT} into {-1, 0 ,1}. C + * uses {negative, zero, positive} values to indicate + * {less than, equal to, greater than}. + * AbNormal() - converts {negative, zero, positive} to {LEFT, PARENT, + * RIGHT} (opposite of Normalize()). Note: C comparison + * functions, such as strcmp(), return {negative, zero, + * positive} values, which are not necessarily {-1, 0, + * 1}. This macro uses the the ubi_btSgn() function to + * compensate. + * RevWay() - converts LEFT to RIGHT and RIGHT to LEFT. PARENT (EQUAL) + * is left as is. + * -------------------------------------------------------------------------- ** + */ +#define ubi_trNormalize(W) ((char)( (W) - ubi_trEQUAL )) +#define ubi_trAbNormal(W) ((char)( ((char)ubi_btSgn( (long)(W) )) \ + + ubi_trEQUAL )) +#define ubi_trRevWay(W) ((char)( ubi_trEQUAL - ((W) - ubi_trEQUAL) )) + +/* -------------------------------------------------------------------------- ** + * These macros allow us to quickly read the values of the OVERWRITE and + * DUPlicate KEY bits of the tree root flags field. + * -------------------------------------------------------------------------- ** + */ +#define ubi_trDups_OK(A) \ + ((ubi_trDUPKEY & ((A)->flags))?(ubi_trTRUE):(ubi_trFALSE)) +#define ubi_trOvwt_OK(A) \ + ((ubi_trOVERWRITE & ((A)->flags))?(ubi_trTRUE):(ubi_trFALSE)) + +/* -------------------------------------------------------------------------- ** + * Additional Macros... + * + * ubi_trCount() - Given a pointer to a tree root, this macro returns the + * number of nodes currently in the tree. + * + * ubi_trNewTree() - This macro makes it easy to declare and initialize a + * tree header in one step. The line + * + * static ubi_trNewTree( MyTree, cmpfn, ubi_trDUPKEY ); + * + * is equivalent to + * + * static ubi_trRoot MyTree[1] + * = {{ NULL, cmpfn, 0, ubi_trDUPKEY }}; + * + * -------------------------------------------------------------------------- ** + */ + +#define ubi_trCount( R ) (((ubi_trRootPtr)(R))->count) + +#define ubi_trNewTree( N, C, F ) ubi_trRoot (N)[1] = {{ NULL, (C), 0, (F) }} + +/* -------------------------------------------------------------------------- ** + * Typedefs... + * + * ubi_trBool - Your typcial true or false... + * + * Item Pointer: The ubi_btItemPtr is a generic pointer. It is used to + * indicate a key that is being searched for within the tree. + * Searching occurs whenever the ubi_trFind(), ubi_trLocate(), + * or ubi_trInsert() functions are called. + * -------------------------------------------------------------------------- ** + */ + +typedef unsigned char ubi_trBool; + +typedef void *ubi_btItemPtr; /* A pointer to key data within a node. */ + +/* ------------------------------------------------------------------------- ** + * Binary Tree Node Structure: This structure defines the basic elements of + * the tree nodes. In general you *SHOULD NOT PLAY WITH THESE FIELDS*! + * But, of course, I have to put the structure into this header so that + * you can use it as a building block. + * + * The fields are as follows: + * Link - an array of pointers. These pointers are manipulated by + * the BT routines. The pointers indicate the left and right + * child nodes and the parent node. By keeping track of the + * parent pointer, we avoid the need for recursive routines or + * hand-tooled stacks to keep track of our path back to the + * root. The use of these pointers is subject to change without + * notice. + * gender - a one-byte field indicating whether the node is the RIGHT or + * LEFT child of its parent. If the node is the root of the + * tree, gender will be PARENT. + * balance - only used by the AVL tree module. This field indicates + * the height balance at a given node. See ubi_AVLtree for + * details. + * + * ------------------------------------------------------------------------- ** + */ +typedef struct ubi_btNodeStruct { + struct ubi_btNodeStruct *Link[ 3 ]; + char gender; + char balance; + } ubi_btNode; + +typedef ubi_btNode *ubi_btNodePtr; /* Pointer to an ubi_btNode structure. */ + +/* ------------------------------------------------------------------------- ** + * The next three typedefs define standard function types used by the binary + * tree management routines. In particular: + * + * ubi_btCompFunc is a pointer to a comparison function. Comparison + * functions are passed an ubi_btItemPtr and an + * ubi_btNodePtr. They return a value that is (<0), 0, + * or (>0) to indicate that the Item is (respectively) + * "less than", "equal to", or "greater than" the Item + * contained within the node. (See ubi_btInitTree()). + * ubi_btActionRtn is a pointer to a function that may be called for each + * node visited when performing a tree traversal (see + * ubi_btTraverse()). The function will be passed two + * parameters: the first is a pointer to a node in the + * tree, the second is a generic pointer that may point to + * anything that you like. + * ubi_btKillNodeRtn is a pointer to a function that will deallocate the + * memory used by a node (see ubi_btKillTree()). Since + * memory management is left up to you, deallocation may + * mean anything that you want it to mean. Just remember + * that the tree *will* be destroyed and that none of the + * node pointers will be valid any more. + * ------------------------------------------------------------------------- ** + */ + +typedef int (*ubi_btCompFunc)( ubi_btItemPtr, ubi_btNodePtr ); + +typedef void (*ubi_btActionRtn)( ubi_btNodePtr, void * ); + +typedef void (*ubi_btKillNodeRtn)( ubi_btNodePtr ); + +/* -------------------------------------------------------------------------- ** + * Tree Root Structure: This structure gives us a convenient handle for + * accessing whole binary trees. The fields are: + * root - A pointer to the root node of the tree. + * count - A count of the number of nodes stored in the tree. + * cmp - A pointer to the comparison routine to be used when building or + * searching the tree. + * flags - A set of bit flags. Two flags are currently defined: + * + * ubi_trOVERWRITE - If set, this flag indicates that a new node should + * (bit 0x01) overwrite an old node if the two have identical + * keys (ie., the keys are equal). + * ubi_trDUPKEY - If set, this flag indicates that the tree is + * (bit 0x02) allowed to contain nodes with duplicate keys. + * + * NOTE: ubi_trInsert() tests ubi_trDUPKEY before ubi_trOVERWRITE. + * + * All of these values are set when you initialize the root structure by + * calling ubi_trInitTree(). + * -------------------------------------------------------------------------- ** + */ + +typedef struct { + ubi_btNodePtr root; /* A pointer to the root node of the tree */ + ubi_btCompFunc cmp; /* A pointer to the tree's comparison function */ + unsigned long count; /* A count of the number of nodes in the tree */ + char flags; /* Overwrite Y|N, Duplicate keys Y|N... */ + } ubi_btRoot; + +typedef ubi_btRoot *ubi_btRootPtr; /* Pointer to an ubi_btRoot structure. */ + + +/* -------------------------------------------------------------------------- ** + * Function Prototypes. + */ + +long ubi_btSgn( long x ); + /* ------------------------------------------------------------------------ ** + * Return the sign of x; {negative,zero,positive} ==> {-1, 0, 1}. + * + * Input: x - a signed long integer value. + * + * Output: the "sign" of x, represented as follows: + * -1 == negative + * 0 == zero (no sign) + * 1 == positive + * + * Note: This utility is provided in order to facilitate the conversion + * of C comparison function return values into BinTree direction + * values: {LEFT, PARENT, EQUAL}. It is INCORPORATED into the + * AbNormal() conversion macro! + * + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btInitNode( ubi_btNodePtr NodePtr ); + /* ------------------------------------------------------------------------ ** + * Initialize a tree node. + * + * Input: a pointer to a ubi_btNode structure to be initialized. + * Output: a pointer to the initialized ubi_btNode structure (ie. the + * same as the input pointer). + * ------------------------------------------------------------------------ ** + */ + +ubi_btRootPtr ubi_btInitTree( ubi_btRootPtr RootPtr, + ubi_btCompFunc CompFunc, + char Flags ); + /* ------------------------------------------------------------------------ ** + * Initialize the fields of a Tree Root header structure. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure to be + * initialized. + * CompFunc - a pointer to a comparison function that will be used + * whenever nodes in the tree must be compared against + * outside values. + * Flags - One bytes worth of flags. Flags include + * ubi_trOVERWRITE and ubi_trDUPKEY. See the header + * file for more info. + * + * Output: a pointer to the initialized ubi_btRoot structure (ie. the + * same value as RootPtr). + * + * Note: The interface to this function has changed from that of + * previous versions. The <Flags> parameter replaces two + * boolean parameters that had the same basic effect. + * ------------------------------------------------------------------------ ** + */ + +ubi_trBool ubi_btInsert( ubi_btRootPtr RootPtr, + ubi_btNodePtr NewNode, + ubi_btItemPtr ItemPtr, + ubi_btNodePtr *OldNode ); + /* ------------------------------------------------------------------------ ** + * This function uses a non-recursive algorithm to add a new element to the + * tree. + * + * Input: RootPtr - a pointer to the ubi_btRoot structure that indicates + * the root of the tree to which NewNode is to be added. + * NewNode - a pointer to an ubi_btNode structure that is NOT + * part of any tree. + * ItemPtr - A pointer to the sort key that is stored within + * *NewNode. ItemPtr MUST point to information stored + * in *NewNode or an EXACT DUPLICATE. The key data + * indicated by ItemPtr is used to place the new node + * into the tree. + * OldNode - a pointer to an ubi_btNodePtr. When searching + * the tree, a duplicate node may be found. If + * duplicates are allowed, then the new node will + * be simply placed into the tree. If duplicates + * are not allowed, however, then one of two things + * may happen. + * 1) if overwritting *is not* allowed, this + * function will return FALSE (indicating that + * the new node could not be inserted), and + * *OldNode will point to the duplicate that is + * still in the tree. + * 2) if overwritting *is* allowed, then this + * function will swap **OldNode for *NewNode. + * In this case, *OldNode will point to the node + * that was removed (thus allowing you to free + * the node). + * ** If you are using overwrite mode, ALWAYS ** + * ** check the return value of this parameter! ** + * Note: You may pass NULL in this parameter, the + * function knows how to cope. If you do this, + * however, there will be no way to return a + * pointer to an old (ie. replaced) node (which is + * a problem if you are using overwrite mode). + * + * Output: a boolean value indicating success or failure. The function + * will return FALSE if the node could not be added to the tree. + * Such failure will only occur if duplicates are not allowed, + * nodes cannot be overwritten, AND a duplicate key was found + * within the tree. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btRemove( ubi_btRootPtr RootPtr, + ubi_btNodePtr DeadNode ); + /* ------------------------------------------------------------------------ ** + * This function removes the indicated node from the tree. + * + * Input: RootPtr - A pointer to the header of the tree that contains + * the node to be removed. + * DeadNode - A pointer to the node that will be removed. + * + * Output: This function returns a pointer to the node that was removed + * from the tree (ie. the same as DeadNode). + * + * Note: The node MUST be in the tree indicated by RootPtr. If not, + * strange and evil things will happen to your trees. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btLocate( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_trCompOps CompOp ); + /* ------------------------------------------------------------------------ ** + * The purpose of ubi_btLocate() is to find a node or set of nodes given + * a target value and a "comparison operator". The Locate() function is + * more flexible and (in the case of trees that may contain dupicate keys) + * more precise than the ubi_btFind() function. The latter is faster, + * but it only searches for exact matches and, if the tree contains + * duplicates, Find() may return a pointer to any one of the duplicate- + * keyed records. + * + * Input: + * RootPtr - A pointer to the header of the tree to be searched. + * FindMe - An ubi_btItemPtr that indicates the key for which to + * search. + * CompOp - One of the following: + * CompOp Return a pointer to the node with + * ------ --------------------------------- + * ubi_trLT - the last key value that is less + * than FindMe. + * ubi_trLE - the first key matching FindMe, or + * the last key that is less than + * FindMe. + * ubi_trEQ - the first key matching FindMe. + * ubi_trGE - the first key matching FindMe, or the + * first key greater than FindMe. + * ubi_trGT - the first key greater than FindMe. + * Output: + * A pointer to the node matching the criteria listed above under + * CompOp, or NULL if no node matched the criteria. + * + * Notes: + * In the case of trees with duplicate keys, Locate() will behave as + * follows: + * + * Find: 3 Find: 3 + * Keys: 1 2 2 2 3 3 3 3 3 4 4 Keys: 1 1 2 2 2 4 4 5 5 5 6 + * ^ ^ ^ ^ ^ + * LT EQ GT LE GE + * + * That is, when returning a pointer to a node with a key that is LESS + * THAN the target key (FindMe), Locate() will return a pointer to the + * LAST matching node. + * When returning a pointer to a node with a key that is GREATER + * THAN the target key (FindMe), Locate() will return a pointer to the + * FIRST matching node. + * + * See Also: ubi_btFind(), ubi_btFirstOf(), ubi_btLastOf(). + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btFind( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe ); + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for any node + * matching a specific key. + * + * Input: + * RootPtr - a pointer to the header of the tree to be searched. + * FindMe - a pointer to the key value for which to search. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. In such a tree, it may be more useful to use + * ubi_btLocate(). + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btNext( ubi_btNodePtr P ); + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Next node in the + * tree. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "next" node in the tree, or NULL if P pointed + * to the "last" node in the tree or was NULL. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btPrev( ubi_btNodePtr P ); + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Previous node in + * the tree. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "previous" node in the tree, or NULL if P + * pointed to the "first" node in the tree or was NULL. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btFirst( ubi_btNodePtr P ); + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) First node in the + * subtree of which *P is the root. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "first" node in a subtree that has *P as its + * root. This function will return NULL only if P is NULL. + * Note: In general, you will be passing in the value of the root field + * of an ubi_btRoot structure. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btLast( ubi_btNodePtr P ); + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Last node in the + * subtree of which *P is the root. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "last" node in a subtree that has *P as its + * root. This function will return NULL only if P is NULL. + * Note: In general, you will be passing in the value of the root field + * of an ubi_btRoot structure. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btFirstOf( ubi_btRootPtr RootPtr, + ubi_btItemPtr MatchMe, + ubi_btNodePtr p ); + /* ------------------------------------------------------------------------ ** + * Given a tree that a allows duplicate keys, and a pointer to a node in + * the tree, this function will return a pointer to the first (traversal + * order) node with the same key value. + * + * Input: RootPtr - A pointer to the root of the tree. + * MatchMe - A pointer to the key value. This should probably + * point to the key within node *p. + * p - A pointer to a node in the tree. + * Output: A pointer to the first node in the set of nodes with keys + * matching <FindMe>. + * Notes: Node *p MUST be in the set of nodes with keys matching + * <FindMe>. If not, this function will return NULL. + * + * 4.7: Bug found & fixed by Massimo Campostrini, + * Istituto Nazionale di Fisica Nucleare, Sezione di Pisa. + * + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btLastOf( ubi_btRootPtr RootPtr, + ubi_btItemPtr MatchMe, + ubi_btNodePtr p ); + /* ------------------------------------------------------------------------ ** + * Given a tree that a allows duplicate keys, and a pointer to a node in + * the tree, this function will return a pointer to the last (traversal + * order) node with the same key value. + * + * Input: RootPtr - A pointer to the root of the tree. + * MatchMe - A pointer to the key value. This should probably + * point to the key within node *p. + * p - A pointer to a node in the tree. + * Output: A pointer to the last node in the set of nodes with keys + * matching <FindMe>. + * Notes: Node *p MUST be in the set of nodes with keys matching + * <FindMe>. If not, this function will return NULL. + * + * 4.7: Bug found & fixed by Massimo Campostrini, + * Istituto Nazionale di Fisica Nucleare, Sezione di Pisa. + * + * ------------------------------------------------------------------------ ** + */ + +unsigned long ubi_btTraverse( ubi_btRootPtr RootPtr, + ubi_btActionRtn EachNode, + void *UserData ); + /* ------------------------------------------------------------------------ ** + * Traverse a tree in sorted order (non-recursively). At each node, call + * (*EachNode)(), passing a pointer to the current node, and UserData as the + * second parameter. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates + * the tree to be traversed. + * EachNode - a pointer to a function to be called at each node + * as the node is visited. + * UserData - a generic pointer that may point to anything that + * you choose. + * + * Output: A count of the number of nodes visited. This will be zero + * if the tree is empty. + * + * ------------------------------------------------------------------------ ** + */ + + +unsigned long ubi_btKillTree( ubi_btRootPtr RootPtr, + ubi_btKillNodeRtn FreeNode ); + /* ------------------------------------------------------------------------ ** + * Delete an entire tree (non-recursively) and reinitialize the ubi_btRoot + * structure. Return a count of the number of nodes deleted. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates + * the root of the tree to delete. + * FreeNode - a function that will be called for each node in the + * tree to deallocate the memory used by the node. + * + * Output: The number of nodes removed from the tree. + * A value of 0 will be returned if: + * - The tree actually contains 0 entries. + * - the value of <RootPtr> is NULL, in which case the tree is + * assumed to be empty + * - the value of <FreeNode> is NULL, in which case entries + * cannot be removed, so 0 is returned. *Make sure that you + * provide a valid value for <FreeNode>*. + * In all other cases, you should get a positive value equal to + * the value of RootPtr->count upon entry. + * + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btLeafNode( ubi_btNodePtr leader ); + /* ------------------------------------------------------------------------ ** + * Returns a pointer to a leaf node. + * + * Input: leader - Pointer to a node at which to start the descent. + * + * Output: A pointer to a leaf node selected in a somewhat arbitrary + * manner. + * + * Notes: I wrote this function because I was using splay trees as a + * database cache. The cache had a maximum size on it, and I + * needed a way of choosing a node to sacrifice if the cache + * became full. In a splay tree, less recently accessed nodes + * tend toward the bottom of the tree, meaning that leaf nodes + * are good candidates for removal. (I really can't think of + * any other reason to use this function.) + * + In a simple binary tree or an AVL tree, the most recently + * added nodes tend to be nearer the bottom, making this a *bad* + * way to choose which node to remove from the cache. + * + Randomizing the traversal order is probably a good idea. You + * can improve the randomization of leaf node selection by passing + * in pointers to nodes other than the root node each time. A + * pointer to any node in the tree will do. Of course, if you + * pass a pointer to a leaf node you'll get the same thing back. + * + * ------------------------------------------------------------------------ ** + */ + + +int ubi_btModuleID( int size, char *list[] ); + /* ------------------------------------------------------------------------ ** + * Returns a set of strings that identify the module. + * + * Input: size - The number of elements in the array <list>. + * list - An array of pointers of type (char *). This array + * should, initially, be empty. This function will fill + * in the array with pointers to strings. + * Output: The number of elements of <list> that were used. If this value + * is less than <size>, the values of the remaining elements are + * not guaranteed. + * + * Notes: Please keep in mind that the pointers returned indicate strings + * stored in static memory. Don't free() them, don't write over + * them, etc. Just read them. + * ------------------------------------------------------------------------ ** + */ + +/* -------------------------------------------------------------------------- ** + * Masquarade... + * + * This set of defines allows you to write programs that will use any of the + * implemented binary tree modules (currently BinTree, AVLtree, and SplayTree). + * Instead of using ubi_bt..., use ubi_tr..., and select the tree type by + * including the appropriate module header. + */ + +#define ubi_trItemPtr ubi_btItemPtr + +#define ubi_trNode ubi_btNode +#define ubi_trNodePtr ubi_btNodePtr + +#define ubi_trRoot ubi_btRoot +#define ubi_trRootPtr ubi_btRootPtr + +#define ubi_trCompFunc ubi_btCompFunc +#define ubi_trActionRtn ubi_btActionRtn +#define ubi_trKillNodeRtn ubi_btKillNodeRtn + +#define ubi_trSgn( x ) ubi_btSgn( x ) + +#define ubi_trInitNode( Np ) ubi_btInitNode( (ubi_btNodePtr)(Np) ) + +#define ubi_trInitTree( Rp, Cf, Fl ) \ + ubi_btInitTree( (ubi_btRootPtr)(Rp), (ubi_btCompFunc)(Cf), (Fl) ) + +#define ubi_trInsert( Rp, Nn, Ip, On ) \ + ubi_btInsert( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Nn), \ + (ubi_btItemPtr)(Ip), (ubi_btNodePtr *)(On) ) + +#define ubi_trRemove( Rp, Dn ) \ + ubi_btRemove( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Dn) ) + +#define ubi_trLocate( Rp, Ip, Op ) \ + ubi_btLocate( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_trCompOps)(Op) ) + +#define ubi_trFind( Rp, Ip ) \ + ubi_btFind( (ubi_btRootPtr)(Rp), (ubi_btItemPtr)(Ip) ) + +#define ubi_trNext( P ) ubi_btNext( (ubi_btNodePtr)(P) ) + +#define ubi_trPrev( P ) ubi_btPrev( (ubi_btNodePtr)(P) ) + +#define ubi_trFirst( P ) ubi_btFirst( (ubi_btNodePtr)(P) ) + +#define ubi_trLast( P ) ubi_btLast( (ubi_btNodePtr)(P) ) + +#define ubi_trFirstOf( Rp, Ip, P ) \ + ubi_btFirstOf( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_btNodePtr)(P) ) + +#define ubi_trLastOf( Rp, Ip, P ) \ + ubi_btLastOf( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_btNodePtr)(P) ) + +#define ubi_trTraverse( Rp, En, Ud ) \ + ubi_btTraverse((ubi_btRootPtr)(Rp), (ubi_btActionRtn)(En), (void *)(Ud)) + +#define ubi_trKillTree( Rp, Fn ) \ + ubi_btKillTree( (ubi_btRootPtr)(Rp), (ubi_btKillNodeRtn)(Fn) ) + +#define ubi_trLeafNode( Nd ) \ + ubi_btLeafNode( (ubi_btNodePtr)(Nd) ) + +#define ubi_trModuleID( s, l ) ubi_btModuleID( s, l ) + +/* ========================================================================== */ +#endif /* UBI_BINTREE_H */ diff --git a/source/ubiqx/ubi_Cache.c b/source/ubiqx/ubi_Cache.c new file mode 100644 index 00000000000..f428dcefe97 --- /dev/null +++ b/source/ubiqx/ubi_Cache.c @@ -0,0 +1,505 @@ +/* ========================================================================== ** + * ubi_Cache.c + * + * Copyright (C) 1997 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * This module implements a generic cache. + * + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * This module uses a splay tree to implement a simple cache. The cache + * module adds a thin layer of functionality to the splay tree. In + * particular: + * + * - The tree (cache) may be limited in size by the number of + * entries permitted or the amount of memory used. When either + * limit is exceeded cache entries are removed until the cache + * conforms. + * - Some statistical information is kept so that an approximate + * "hit ratio" can be calculated. + * - There are several functions available that provide access to + * and management of cache size limits, hit ratio, and tree + * trimming. + * + * The splay tree is used because recently accessed items tend toward the + * top of the tree and less recently accessed items tend toward the bottom. + * This makes it easy to purge less recently used items should the cache + * exceed its limits. + * + * To use this module, you will need to supply a comparison function of + * type ubi_trCompFunc and a node-freeing function of type + * ubi_trKillNodeRtn. See ubi_BinTree.h for more information on + * these. (This is all basic ubiqx tree management stuff.) + * + * Notes: + * + * - Cache performance will start to suffer dramatically if the + * cache becomes large enough to force the OS to start swapping + * memory to disk. This is because the nodes of the underlying tree + * will be scattered across memory in an order that is completely + * unrelated to their traversal order. As more and more of the + * cache is placed into swap space, more and more swaps will be + * required for a simple traversal (...and then there's the splay + * operation). + * + * In one simple test under Linux, the load and dump of a cache of + * 400,000 entries took only 1min, 40sec of real time. The same + * test with 450,000 records took 2 *hours* and eight minutes. + * + * - In an effort to save memory, I considered using an unsigned + * short to save the per-entry entry size. I would have tucked this + * value into some unused space in the tree node structure. On + * 32-bit word aligned systems this would have saved an additional + * four bytes per entry. I may revisit this issue, but for now I've + * decided against it. + * + * Using an unsigned short would limit the size of an entry to 64K + * bytes. That's probably more than enough for most applications. + * The key word in that last sentence, however, is "probably". I + * really dislike imposing such limits on things. + * + * - Each entry keeps track of the amount of memory it used and the + * cache header keeps the total. This information is provided via + * the EntrySize parameter in ubi_cachePut(), so it is up to you to + * make sure that the numbers are accurate. (The numbers don't even + * have to represent bytes used.) + * + * As you consider this, note that the strdup() function--as an + * example--will call malloc(). The latter generally allocates a + * multiple of the system word size, which may be more than the + * number of bytes needed to store the string. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_Cache.c,v + * Revision 0.4 1999/09/22 03:42:24 crh + * Fixed a minor typo. + * + * Revision 0.3 1998/06/03 18:00:15 crh + * Further fiddling with sys_include.h, which is no longer explicitly + * included by this module since it is inherited from ubi_BinTree.h. + * + * Revision 0.2 1998/06/02 01:36:18 crh + * Changed include name from ubi_null.h to sys_include.h to make it + * more generic. + * + * Revision 0.1 1998/05/20 04:36:02 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * + * Revision 0.0 1997/12/18 06:24:33 crh + * Initial Revision. + * + * ========================================================================== ** + */ + +#include "ubi_Cache.h" /* Header for *this* module. */ + +/* -------------------------------------------------------------------------- ** + * Static data... + */ + +/* commented out until I make use of it... +static char ModuleID[] = +"ubi_Cache\n\ +\tRevision: 0.4 \n\ +\tDate: 1999/09/22 03:42:24 \n\ +\tAuthor: crh \n"; +*/ + +/* -------------------------------------------------------------------------- ** + * Internal functions... + */ + +static void free_entry( ubi_cacheRootPtr CachePtr, ubi_cacheEntryPtr EntryPtr ) + /* ------------------------------------------------------------------------ ** + * Free a ubi_cacheEntry, and adjust the mem_used counter accordingly. + * + * Input: CachePtr - A pointer to the cache from which the entry has + * been removed. + * EntryPtr - A pointer to the already removed entry. + * + * Output: none. + * + * Notes: The entry must be removed from the cache *before* this function + * is called!!!! + * ------------------------------------------------------------------------ ** + */ + { + CachePtr->mem_used -= EntryPtr->entry_size; + (*CachePtr->free_func)( (void *)EntryPtr ); + } /* free_entry */ + +static void cachetrim( ubi_cacheRootPtr crptr ) + /* ------------------------------------------------------------------------ ** + * Remove entries from the cache until the number of entries and the amount + * of memory used are *both* below or at the maximum. + * + * Input: crptr - pointer to the cache to be trimmed. + * + * Output: None. + * + * ------------------------------------------------------------------------ ** + */ + { + while( ( crptr->max_entries && (crptr->max_entries < crptr->root.count) ) + || ( crptr->max_memory && (crptr->max_memory < crptr->mem_used) ) ) + { + if( !ubi_cacheReduce( crptr, 1 ) ) + return; + } + } /* cachetrim */ + + +/* -------------------------------------------------------------------------- ** + * Exported functions... + */ + +ubi_cacheRootPtr ubi_cacheInit( ubi_cacheRootPtr CachePtr, + ubi_trCompFunc CompFunc, + ubi_trKillNodeRtn FreeFunc, + unsigned long MaxEntries, + unsigned long MaxMemory ) + /* ------------------------------------------------------------------------ ** + * Initialize a cache header structure. + * + * Input: CachePtr - A pointer to a ubi_cacheRoot structure that is + * to be initialized. + * CompFunc - A pointer to the function that will be called + * to compare two cache values. See the module + * comments, above, for more information. + * FreeFunc - A pointer to a function that will be called + * to free a cache entry. If you allocated + * the cache entry using malloc(), then this + * will likely be free(). If you are allocating + * cache entries from a free list, then this will + * likely be a function that returns memory to the + * free list, etc. + * MaxEntries - The maximum number of entries that will be + * allowed to exist in the cache. If this limit + * is exceeded, then existing entries will be + * removed from the cache. A value of zero + * indicates that there is no limit on the number + * of cache entries. See ubi_cachePut(). + * MaxMemory - The maximum amount of memory, in bytes, to be + * allocated to the cache (excluding the cache + * header). If this is exceeded, existing entries + * in the cache will be removed until enough memory + * has been freed to meet the condition. See + * ubi_cachePut(). + * + * Output: A pointer to the initialized cache (i.e., the same as CachePtr). + * + * Notes: Both MaxEntries and MaxMemory may be changed after the cache + * has been created. See + * ubi_cacheSetMaxEntries() + * ubi_cacheSetMaxMemory() + * ubi_cacheGetMaxEntries() + * ubi_cacheGetMaxMemory() (the latter two are macros). + * + * - Memory is allocated in multiples of the word size. The + * return value of the strlen() function does not reflect + * this; it will allways be less than or equal to the amount + * of memory actually allocated. Keep this in mind when + * choosing a value for MaxMemory. + * + * ------------------------------------------------------------------------ ** + */ + { + if( CachePtr ) + { + (void)ubi_trInitTree( CachePtr, CompFunc, ubi_trOVERWRITE ); + CachePtr->free_func = FreeFunc; + CachePtr->max_entries = MaxEntries; + CachePtr->max_memory = MaxMemory; + CachePtr->mem_used = 0; + CachePtr->cache_hits = 0; + CachePtr->cache_trys = 0; + } + return( CachePtr ); + } /* ubi_cacheInit */ + +ubi_cacheRootPtr ubi_cacheClear( ubi_cacheRootPtr CachePtr ) + /* ------------------------------------------------------------------------ ** + * Remove and free all entries in an existing cache. + * + * Input: CachePtr - A pointer to the cache that is to be cleared. + * + * Output: A pointer to the cache header (i.e., the same as CachePtr). + * This function re-initializes the cache header. + * + * ------------------------------------------------------------------------ ** + */ + { + if( CachePtr ) + { + (void)ubi_trKillTree( CachePtr, CachePtr->free_func ); + CachePtr->mem_used = 0; + CachePtr->cache_hits = 0; + CachePtr->cache_trys = 0; + } + return( CachePtr ); + } /* ubi_cacheClear */ + +void ubi_cachePut( ubi_cacheRootPtr CachePtr, + unsigned long EntrySize, + ubi_cacheEntryPtr EntryPtr, + ubi_trItemPtr Key ) + /* ------------------------------------------------------------------------ ** + * Add an entry to the cache. + * + * Input: CachePtr - A pointer to the cache into which the entry + * will be added. + * EntrySize - The size, in bytes, of the memory block indicated + * by EntryPtr. This will be copied into the + * EntryPtr->entry_size field. + * EntryPtr - A pointer to a memory block that begins with a + * ubi_cacheEntry structure. The entry structure + * should be followed immediately by the data to be + * cached (even if that is a pointer to yet more data). + * Key - Pointer used to identify the lookup key within the + * Entry. + * + * Output: None. + * + * Notes: After adding the new node, the cache is "trimmed". This + * removes extra nodes if the tree has exceeded it's memory or + * entry count limits. It is unlikely that the newly added node + * will be purged from the cache (assuming a reasonably large + * cache), since new nodes in a splay tree (which is what this + * module was designed to use) are moved to the top of the tree + * and the cache purge process removes nodes from the bottom of + * the tree. + * - The underlying splay tree is opened in OVERWRITE mode. If + * the input key matches an existing key, the existing entry will + * be politely removed from the tree and freed. + * - Memory is allocated in multiples of the word size. The + * return value of the strlen() function does not reflect + * this; it will allways be less than or equal to the amount + * of memory actually allocated. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_trNodePtr OldNode; + + EntryPtr->entry_size = EntrySize; + CachePtr->mem_used += EntrySize; + (void)ubi_trInsert( CachePtr, EntryPtr, Key, &OldNode ); + if( OldNode ) + free_entry( CachePtr, (ubi_cacheEntryPtr)OldNode ); + + cachetrim( CachePtr ); + } /* ubi_cachePut */ + +ubi_cacheEntryPtr ubi_cacheGet( ubi_cacheRootPtr CachePtr, + ubi_trItemPtr FindMe ) + /* ------------------------------------------------------------------------ ** + * Attempt to retrieve an entry from the cache. + * + * Input: CachePtr - A ponter to the cache that is to be searched. + * FindMe - A ubi_trItemPtr that indicates the key for which + * to search. + * + * Output: A pointer to the cache entry that was found, or NULL if no + * matching entry was found. + * + * Notes: This function also updates the hit ratio counters. + * The counters are unsigned short. If the number of cache tries + * reaches 32768, then both the number of tries and the number of + * hits are divided by two. This prevents the counters from + * overflowing. See the comments in ubi_cacheHitRatio() for + * additional notes. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_trNodePtr FoundPtr; + + FoundPtr = ubi_trFind( CachePtr, FindMe ); + + if( FoundPtr ) + CachePtr->cache_hits++; + CachePtr->cache_trys++; + + if( CachePtr->cache_trys & 0x8000 ) + { + CachePtr->cache_hits = CachePtr->cache_hits / 2; + CachePtr->cache_trys = CachePtr->cache_trys / 2; + } + + return( (ubi_cacheEntryPtr)FoundPtr ); + } /* ubi_cacheGet */ + +ubi_trBool ubi_cacheDelete( ubi_cacheRootPtr CachePtr, ubi_trItemPtr DeleteMe ) + /* ------------------------------------------------------------------------ ** + * Find and delete the specified cache entry. + * + * Input: CachePtr - A pointer to the cache. + * DeleteMe - The key of the entry to be deleted. + * + * Output: TRUE if the entry was found & freed, else FALSE. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_trNodePtr FoundPtr; + + FoundPtr = ubi_trFind( CachePtr, DeleteMe ); + if( FoundPtr ) + { + (void)ubi_trRemove( CachePtr, FoundPtr ); + free_entry( CachePtr, (ubi_cacheEntryPtr)FoundPtr ); + return( ubi_trTRUE ); + } + return( ubi_trFALSE ); + } /* ubi_cacheDelete */ + +ubi_trBool ubi_cacheReduce( ubi_cacheRootPtr CachePtr, unsigned long count ) + /* ------------------------------------------------------------------------ ** + * Remove <count> entries from the bottom of the cache. + * + * Input: CachePtr - A pointer to the cache which is to be reduced in + * size. + * count - The number of entries to remove. + * + * Output: The function will return TRUE if <count> entries were removed, + * else FALSE. A return value of FALSE should indicate that + * there were less than <count> entries in the cache, and that the + * cache is now empty. + * + * Notes: This function forces a reduction in the number of cache entries + * without requiring that the MaxMemory or MaxEntries values be + * changed. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_trNodePtr NodePtr; + + while( count ) + { + NodePtr = ubi_trLeafNode( CachePtr->root.root ); + if( NULL == NodePtr ) + return( ubi_trFALSE ); + else + { + (void)ubi_trRemove( CachePtr, NodePtr ); + free_entry( CachePtr, (ubi_cacheEntryPtr)NodePtr ); + } + count--; + } + return( ubi_trTRUE ); + } /* ubi_cacheReduce */ + +unsigned long ubi_cacheSetMaxEntries( ubi_cacheRootPtr CachePtr, + unsigned long NewSize ) + /* ------------------------------------------------------------------------ ** + * Change the maximum number of entries allowed to exist in the cache. + * + * Input: CachePtr - A pointer to the cache to be modified. + * NewSize - The new maximum number of cache entries. + * + * Output: The maximum number of entries previously allowed to exist in + * the cache. + * + * Notes: If the new size is less than the old size, this function will + * trim the cache (remove excess entries). + * - A value of zero indicates an unlimited number of entries. + * + * ------------------------------------------------------------------------ ** + */ + { + unsigned long oldsize = CachePtr->max_entries; /* Save the old value. */ + + CachePtr->max_entries = NewSize; /* Apply the new value. */ + if( (NewSize < oldsize) || (NewSize && !oldsize) ) /* If size is smaller, */ + cachetrim( CachePtr ); /* remove excess. */ + return( oldsize ); + } /* ubi_cacheSetMaxEntries */ + +unsigned long ubi_cacheSetMaxMemory( ubi_cacheRootPtr CachePtr, + unsigned long NewSize ) + /* ------------------------------------------------------------------------ ** + * Change the maximum amount of memory to be used for storing cache + * entries. + * + * Input: CachePtr - A pointer to the cache to be modified. + * NewSize - The new cache memory size. + * + * Output: The previous maximum memory size. + * + * Notes: If the new size is less than the old size, this function will + * trim the cache (remove excess entries). + * - A value of zero indicates that the cache has no memory limit. + * + * ------------------------------------------------------------------------ ** + */ + { + unsigned long oldsize = CachePtr->max_memory; /* Save the old value. */ + + CachePtr->max_memory = NewSize; /* Apply the new value. */ + if( (NewSize < oldsize) || (NewSize && !oldsize) ) /* If size is smaller, */ + cachetrim( CachePtr ); /* remove excess. */ + return( oldsize ); + } /* ubi_cacheSetMaxMemory */ + +int ubi_cacheHitRatio( ubi_cacheRootPtr CachePtr ) + /* ------------------------------------------------------------------------ ** + * Returns a value that is 10,000 times the slightly weighted average hit + * ratio for the cache. + * + * Input: CachePtr - Pointer to the cache to be queried. + * + * Output: An integer that is 10,000 times the number of successful + * cache hits divided by the number of cache lookups, or: + * (10000 * hits) / trys + * You can easily convert this to a float, or do something + * like this (where i is the return value of this function): + * + * printf( "Hit rate : %d.%02d%%\n", (i/100), (i%100) ); + * + * Notes: I say "slightly-weighted", because the numerator and + * denominator are both accumulated in locations of type + * 'unsigned short'. If the number of cache trys becomes + * large enough, both are divided by two. (See function + * ubi_cacheGet().) + * Dividing both numerator and denominator by two does not + * change the ratio (much...it is an integer divide), but it + * does mean that subsequent increments to either counter will + * have twice as much significance as previous ones. + * + * - The value returned by this function will be in the range + * [0..10000] because ( 0 <= cache_hits <= cache_trys ) will + * always be true. + * + * ------------------------------------------------------------------------ ** + */ + { + int tmp = 0; + + if( CachePtr->cache_trys ) + tmp = (int)( (10000 * (long)(CachePtr->cache_hits) ) + / (long)(CachePtr->cache_trys) ); + return( tmp ); + } /* ubi_cacheHitRatio */ + +/* -------------------------------------------------------------------------- */ diff --git a/source/ubiqx/ubi_Cache.h b/source/ubiqx/ubi_Cache.h new file mode 100644 index 00000000000..0fc3a074f72 --- /dev/null +++ b/source/ubiqx/ubi_Cache.h @@ -0,0 +1,412 @@ +#ifndef UBI_CACHE_H +#define UBI_CACHE_H +/* ========================================================================== ** + * ubi_Cache.h + * + * Copyright (C) 1997 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * This module implements a generic cache. + * + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * This module uses a splay tree to implement a simple cache. The cache + * module adds a thin layer of functionality to the splay tree. In + * particular: + * + * - The tree (cache) may be limited in size by the number of + * entries permitted or the amount of memory used. When either + * limit is exceeded cache entries are removed until the cache + * conforms. + * - Some statistical information is kept so that an approximate + * "hit ratio" can be calculated. + * - There are several functions available that provide access to + * and management of cache size limits, hit ratio, and tree + * trimming. + * + * The splay tree is used because recently accessed items tend toward the + * top of the tree and less recently accessed items tend toward the bottom. + * This makes it easy to purge less recently used items should the cache + * exceed its limits. + * + * To use this module, you will need to supply a comparison function of + * type ubi_trCompFunc and a node-freeing function of type + * ubi_trKillNodeRtn. See ubi_BinTree.h for more information on + * these. (This is all basic ubiqx tree management stuff.) + * + * Notes: + * + * - Cache performance will start to suffer dramatically if the + * cache becomes large enough to force the OS to start swapping + * memory to disk. This is because the nodes of the underlying tree + * will be scattered across memory in an order that is completely + * unrelated to their traversal order. As more and more of the + * cache is placed into swap space, more and more swaps will be + * required for a simple traversal (...and then there's the splay + * operation). + * + * In one simple test under Linux, the load and dump of a cache of + * 400,000 entries took only 1min, 40sec of real time. The same + * test with 450,000 records took 2 *hours* and eight minutes. + * + * - In an effort to save memory, I considered using an unsigned + * short to save the per-entry entry size. I would have tucked this + * value into some unused space in the tree node structure. On + * 32-bit word aligned systems this would have saved an additional + * four bytes per entry. I may revisit this issue, but for now I've + * decided against it. + * + * Using an unsigned short would limit the size of an entry to 64K + * bytes. That's probably more than enough for most applications. + * The key word in that last sentence, however, is "probably". I + * really dislike imposing such limits on things. + * + * - Each entry keeps track of the amount of memory it used and the + * cache header keeps the total. This information is provided via + * the EntrySize parameter in ubi_cachePut(), so it is up to you to + * make sure that the numbers are accurate. (The numbers don't even + * have to represent bytes used.) + * + * As you consider this, note that the strdup() function--as an + * example--will call malloc(). The latter generally allocates a + * multiple of the system word size, which may be more than the + * number of bytes needed to store the string. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_Cache.h,v + * Revision 0.4 1999/09/22 03:42:24 crh + * Fixed a minor typo. + * + * Revision 0.3 1998/06/03 18:00:15 crh + * Further fiddling with sys_include.h, which is no longer explicitly + * included by this module since it is inherited from ubi_BinTree.h. + * + * Revision 0.2 1998/06/02 01:36:18 crh + * Changed include name from ubi_null.h to sys_include.h to make it + * more generic. + * + * Revision 0.1 1998/05/20 04:36:02 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * + * Revision 0.0 1997/12/18 06:25:23 crh + * Initial Revision. + * + * ========================================================================== ** + */ + +#include "ubi_SplayTree.h" + +/* -------------------------------------------------------------------------- ** + * Typedefs... + * + * ubi_cacheRoot - Cache header structure, which consists of a binary + * tree root and other required housekeeping fields, as + * listed below. + * ubi_cacheRootPtr - Pointer to a Cache. + * + * ubi_cacheEntry - A cache Entry, which consists of a tree node + * structure and the size (in bytes) of the entry + * data. The entry size should be supplied via + * the EntrySize parameter of the ubi_cachePut() + * function. + * + * ubi_cacheEntryPtr - Pointer to a ubi_cacheEntry. + * + */ + +typedef struct + { + ubi_trRoot root; /* Splay tree control structure. */ + ubi_trKillNodeRtn free_func; /* Function used to free entries. */ + unsigned long max_entries; /* Max cache entries. 0 == unlimited */ + unsigned long max_memory; /* Max memory to use. 0 == unlimited */ + unsigned long mem_used; /* Memory currently in use (bytes). */ + unsigned short cache_hits; /* Incremented on succesful find. */ + unsigned short cache_trys; /* Incremented on cache lookup. */ + } ubi_cacheRoot; + +typedef ubi_cacheRoot *ubi_cacheRootPtr; + + +typedef struct + { + ubi_trNode node; /* Tree node structure. */ + unsigned long entry_size; /* Entry size. Used when managing + * caches with maximum memory limits. + */ + } ubi_cacheEntry; + +typedef ubi_cacheEntry *ubi_cacheEntryPtr; + + +/* -------------------------------------------------------------------------- ** + * Macros... + * + * ubi_cacheGetMaxEntries() - Report the current maximum number of entries + * allowed in the cache. Zero indicates no + * maximum. + * ubi_cacheGetMaxMemory() - Report the current maximum amount of memory + * that may be used in the cache. Zero + * indicates no maximum. + * ubi_cacheGetEntryCount() - Report the current number of entries in the + * cache. + * ubi_cacheGetMemUsed() - Report the amount of memory currently in use + * by the cache. + */ + +#define ubi_cacheGetMaxEntries( Cptr ) (((ubi_cacheRootPtr)(Cptr))->max_entries) +#define ubi_cacheGetMaxMemory( Cptr ) (((ubi_cacheRootPtr)(Cptr))->max_memory) + +#define ubi_cacheGetEntryCount( Cptr ) (((ubi_cacheRootPtr)(Cptr))->root.count) +#define ubi_cacheGetMemUsed( Cptr ) (((ubi_cacheRootPtr)(Cptr))->mem_used) + +/* -------------------------------------------------------------------------- ** + * Prototypes... + */ + +ubi_cacheRootPtr ubi_cacheInit( ubi_cacheRootPtr CachePtr, + ubi_trCompFunc CompFunc, + ubi_trKillNodeRtn FreeFunc, + unsigned long MaxEntries, + unsigned long MaxMemory ); + /* ------------------------------------------------------------------------ ** + * Initialize a cache header structure. + * + * Input: CachePtr - A pointer to a ubi_cacheRoot structure that is + * to be initialized. + * CompFunc - A pointer to the function that will be called + * to compare two cache values. See the module + * comments, above, for more information. + * FreeFunc - A pointer to a function that will be called + * to free a cache entry. If you allocated + * the cache entry using malloc(), then this + * will likely be free(). If you are allocating + * cache entries from a free list, then this will + * likely be a function that returns memory to the + * free list, etc. + * MaxEntries - The maximum number of entries that will be + * allowed to exist in the cache. If this limit + * is exceeded, then existing entries will be + * removed from the cache. A value of zero + * indicates that there is no limit on the number + * of cache entries. See ubi_cachePut(). + * MaxMemory - The maximum amount of memory, in bytes, to be + * allocated to the cache (excluding the cache + * header). If this is exceeded, existing entries + * in the cache will be removed until enough memory + * has been freed to meet the condition. See + * ubi_cachePut(). + * + * Output: A pointer to the initialized cache (i.e., the same as CachePtr). + * + * Notes: Both MaxEntries and MaxMemory may be changed after the cache + * has been created. See + * ubi_cacheSetMaxEntries() + * ubi_cacheSetMaxMemory() + * ubi_cacheGetMaxEntries() + * ubi_cacheGetMaxMemory() (the latter two are macros). + * + * - Memory is allocated in multiples of the word size. The + * return value of the strlen() function does not reflect + * this; it will allways be less than or equal to the amount + * of memory actually allocated. Keep this in mind when + * choosing a value for MaxMemory. + * + * ------------------------------------------------------------------------ ** + */ + +ubi_cacheRootPtr ubi_cacheClear( ubi_cacheRootPtr CachePtr ); + /* ------------------------------------------------------------------------ ** + * Remove and free all entries in an existing cache. + * + * Input: CachePtr - A pointer to the cache that is to be cleared. + * + * Output: A pointer to the cache header (i.e., the same as CachePtr). + * This function re-initializes the cache header. + * + * ------------------------------------------------------------------------ ** + */ + +void ubi_cachePut( ubi_cacheRootPtr CachePtr, + unsigned long EntrySize, + ubi_cacheEntryPtr EntryPtr, + ubi_trItemPtr Key ); + /* ------------------------------------------------------------------------ ** + * Add an entry to the cache. + * + * Input: CachePtr - A pointer to the cache into which the entry + * will be added. + * EntrySize - The size, in bytes, of the memory block indicated + * by EntryPtr. This will be copied into the + * EntryPtr->entry_size field. + * EntryPtr - A pointer to a memory block that begins with a + * ubi_cacheEntry structure. The entry structure + * should be followed immediately by the data to be + * cached (even if that is a pointer to yet more data). + * Key - Pointer used to identify the lookup key within the + * Entry. + * + * Output: None. + * + * Notes: After adding the new node, the cache is "trimmed". This + * removes extra nodes if the tree has exceeded it's memory or + * entry count limits. It is unlikely that the newly added node + * will be purged from the cache (assuming a reasonably large + * cache), since new nodes in a splay tree (which is what this + * module was designed to use) are moved to the top of the tree + * and the cache purge process removes nodes from the bottom of + * the tree. + * - The underlying splay tree is opened in OVERWRITE mode. If + * the input key matches an existing key, the existing entry will + * be politely removed from the tree and freed. + * - Memory is allocated in multiples of the word size. The + * return value of the strlen() function does not reflect + * this; it will allways be less than or equal to the amount + * of memory actually allocated. + * + * ------------------------------------------------------------------------ ** + */ + +ubi_cacheEntryPtr ubi_cacheGet( ubi_cacheRootPtr CachePtr, + ubi_trItemPtr FindMe ); + /* ------------------------------------------------------------------------ ** + * Attempt to retrieve an entry from the cache. + * + * Input: CachePtr - A ponter to the cache that is to be searched. + * FindMe - A ubi_trItemPtr that indicates the key for which + * to search. + * + * Output: A pointer to the cache entry that was found, or NULL if no + * matching entry was found. + * + * Notes: This function also updates the hit ratio counters. + * The counters are unsigned short. If the number of cache tries + * reaches 32768, then both the number of tries and the number of + * hits are divided by two. This prevents the counters from + * overflowing. See the comments in ubi_cacheHitRatio() for + * additional notes. + * + * ------------------------------------------------------------------------ ** + */ + +ubi_trBool ubi_cacheDelete( ubi_cacheRootPtr CachePtr, ubi_trItemPtr DeleteMe ); + /* ------------------------------------------------------------------------ ** + * Find and delete the specified cache entry. + * + * Input: CachePtr - A pointer to the cache. + * DeleteMe - The key of the entry to be deleted. + * + * Output: TRUE if the entry was found & freed, else FALSE. + * + * ------------------------------------------------------------------------ ** + */ + +ubi_trBool ubi_cacheReduce( ubi_cacheRootPtr CachePtr, unsigned long count ); + /* ------------------------------------------------------------------------ ** + * Remove <count> entries from the bottom of the cache. + * + * Input: CachePtr - A pointer to the cache which is to be reduced in + * size. + * count - The number of entries to remove. + * + * Output: The function will return TRUE if <count> entries were removed, + * else FALSE. A return value of FALSE should indicate that + * there were less than <count> entries in the cache, and that the + * cache is now empty. + * + * Notes: This function forces a reduction in the number of cache entries + * without requiring that the MaxMemory or MaxEntries values be + * changed. + * + * ------------------------------------------------------------------------ ** + */ + +unsigned long ubi_cacheSetMaxEntries( ubi_cacheRootPtr CachePtr, + unsigned long NewSize ); + /* ------------------------------------------------------------------------ ** + * Change the maximum number of entries allowed to exist in the cache. + * + * Input: CachePtr - A pointer to the cache to be modified. + * NewSize - The new maximum number of cache entries. + * + * Output: The maximum number of entries previously allowed to exist in + * the cache. + * + * Notes: If the new size is less than the old size, this function will + * trim the cache (remove excess entries). + * - A value of zero indicates an unlimited number of entries. + * + * ------------------------------------------------------------------------ ** + */ + +unsigned long ubi_cacheSetMaxMemory( ubi_cacheRootPtr CachePtr, + unsigned long NewSize ); + /* ------------------------------------------------------------------------ ** + * Change the maximum amount of memory to be used for storing cache + * entries. + * + * Input: CachePtr - A pointer to the cache to be modified. + * NewSize - The new cache memory size. + * + * Output: The previous maximum memory size. + * + * Notes: If the new size is less than the old size, this function will + * trim the cache (remove excess entries). + * - A value of zero indicates that the cache has no memory limit. + * + * ------------------------------------------------------------------------ ** + */ + +int ubi_cacheHitRatio( ubi_cacheRootPtr CachePtr ); + /* ------------------------------------------------------------------------ ** + * Returns a value that is 10,000 times the slightly weighted average hit + * ratio for the cache. + * + * Input: CachePtr - Pointer to the cache to be queried. + * + * Output: An integer that is 10,000 times the number of successful + * cache hits divided by the number of cache lookups, or: + * (10000 * hits) / trys + * You can easily convert this to a float, or do something + * like this (where i is the return value of this function): + * + * printf( "Hit rate : %d.%02d%%\n", (i/100), (i%100) ); + * + * Notes: I say "slightly-weighted", because the numerator and + * denominator are both accumulated in locations of type + * 'unsigned short'. If the number of cache trys becomes + * large enough, both are divided by two. (See function + * ubi_cacheGet().) + * Dividing both numerator and denominator by two does not + * change the ratio (much...it is an integer divide), but it + * does mean that subsequent increments to either counter will + * have twice as much significance as previous ones. + * + * - The value returned by this function will be in the range + * [0..10000] because ( 0 <= cache_hits <= cache_trys ) will + * always be true. + * + * ------------------------------------------------------------------------ ** + */ + +/* -------------------------------------------------------------------------- */ +#endif /* ubi_CACHE_H */ diff --git a/source/ubiqx/ubi_SplayTree.c b/source/ubiqx/ubi_SplayTree.c new file mode 100644 index 00000000000..222506bd06b --- /dev/null +++ b/source/ubiqx/ubi_SplayTree.c @@ -0,0 +1,512 @@ +/* ========================================================================== ** + * ubi_SplayTree.c + * + * Copyright (C) 1993-1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * This module implements "splay" trees. Splay trees are binary trees + * that are rearranged (splayed) whenever a node is accessed. The + * splaying process *tends* to make the tree bushier (improves balance), + * and the nodes that are accessed most frequently *tend* to be closer to + * the top. + * + * References: "Self-Adjusting Binary Search Trees", by Daniel Sleator and + * Robert Tarjan. Journal of the Association for Computing + * Machinery Vol 32, No. 3, July 1985 pp. 652-686 + * + * See also: http://www.cs.cmu.edu/~sleator/ + * + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_SplayTree.c,v + * Revision 4.5 2000/01/08 23:26:49 crh + * Added ubi_trSplay() macro, which does a type cast for us. + * + * Revision 4.4 1998/06/04 21:29:27 crh + * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. + * This is more "standard", and is what people expect. Weird, eh? + * + * Revision 4.3 1998/06/03 17:45:05 crh + * Further fiddling with sys_include.h. It's now in ubi_BinTree.h which is + * included by all of the binary tree files. + * + * Also fixed some warnings produced by lint on Irix 6.2, which doesn't seem + * to like syntax like this: + * + * if( (a = b) ) + * + * The fix was to change lines like the above to: + * + * if( 0 != (a=b) ) + * + * Which means the same thing. + * + * Reminder: Some of the ubi_tr* macros in ubi_BinTree.h are redefined in + * ubi_AVLtree.h and ubi_SplayTree.h. This allows easy swapping + * of tree types by simply changing a header. Unfortunately, the + * macro redefinitions in ubi_AVLtree.h and ubi_SplayTree.h will + * conflict if used together. You must either choose a single tree + * type, or use the underlying function calls directly. Compare + * the two header files for more information. + * + * Revision 4.2 1998/06/02 01:29:14 crh + * Changed ubi_null.h to sys_include.h to make it more generic. + * + * Revision 4.1 1998/05/20 04:37:54 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * + * Revision 4.0 1998/03/10 03:41:33 crh + * Minor comment changes. The revision number is now 4.0 to match the + * BinTree and AVLtree modules. + * + * Revision 2.7 1998/01/24 06:37:08 crh + * Added a URL for more information. + * + * Revision 2.6 1997/12/23 04:01:12 crh + * In this version, all constants & macros defined in the header file have + * the ubi_tr prefix. Also cleaned up anything that gcc complained about + * when run with '-pedantic -fsyntax-only -Wall'. + * + * Revision 2.5 1997/07/26 04:15:42 crh + * + Cleaned up a few minor syntax annoyances that gcc discovered for me. + * + Changed ubi_TRUE and ubi_FALSE to ubi_trTRUE and ubi_trFALSE. + * + * Revision 2.4 1997/06/03 04:42:21 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid causing + * problems. + * + * Revision 2.3 1995/10/03 22:19:07 CRH + * Ubisized! + * Also, added the function ubi_sptSplay(). + * + * Revision 2.1 95/03/09 23:54:42 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/02/27 22:34:46 CRH + * This module was updated to match the interface changes made to the + * ubi_BinTree module. In particular, the interface to the Locate() function + * has changed. See ubi_BinTree for more information on changes and new + * functions. + * + * The revision number was also upped to match ubi_BinTree. + * + * Revision 1.1 93/10/18 20:35:16 CRH + * I removed the hard-coded logical device names from the include file + * specifications. CRH + * + * Revision 1.0 93/10/15 23:00:15 CRH + * With this revision, I have added a set of #define's that provide a single, + * standard API to all existing tree modules. Until now, each of the three + * existing modules had a different function and typedef prefix, as follows: + * + * Module Prefix + * ubi_BinTree ubi_bt + * ubi_AVLtree ubi_avl + * ubi_SplayTree ubi_spt + * + * To further complicate matters, only those portions of the base module + * (ubi_BinTree) that were superceeded in the new module had the new names. + * For example, if you were using ubi_SplayTree, the locate function was + * called "ubi_sptLocate", but the next and previous functions remained + * "ubi_btNext" and "ubi_btPrev". + * + * This was not too terrible if you were familiar with the modules and knew + * exactly which tree model you wanted to use. If you wanted to be able to + * change modules (for speed comparisons, etc), things could get messy very + * quickly. + * + * So, I have added a set of defined names that get redefined in any of the + * descendant modules. To use this standardized interface in your code, + * simply replace all occurances of "ubi_bt", "ubi_avl", and "ubi_spt" with + * "ubi_tr". The "ubi_tr" names will resolve to the correct function or + * datatype names for the module that you are using. Just remember to + * include the header for that module in your program file. Because these + * names are handled by the preprocessor, there is no added run-time + * overhead. + * + * Note that the original names do still exist, and can be used if you wish + * to write code directly to a specific module. This should probably only be + * done if you are planning to implement a new descendant type, such as + * red/black trees. CRH + * + * Revision 0.1 93/04/25 22:03:32 CRH + * Simply changed the <exec/types.h> #include reference the .c file to + * use <stdlib.h> instead. The latter is portable, the former is not. + * + * Revision 0.0 93/04/21 23:05:52 CRH + * Initial version, written by Christopher R. Hertel. + * This module implements Splay Trees using the ubi_BinTree module as a basis. + * + * ========================================================================== ** + */ + +#include "ubi_SplayTree.h" /* Header for THIS module. */ + +/* ========================================================================== ** + * Static data. + */ + +static char ModuleID[] = "ubi_SplayTree\n\ +\tRevision: 4.5 \n\ +\tDate: 2000/01/08 23:26:49 \n\ +\tAuthor: crh \n"; + + +/* ========================================================================== ** + * Private functions... + */ + +static void Rotate( ubi_btNodePtr p ) + /* ------------------------------------------------------------------------ ** + * This function performs a single rotation, moving node *p up one level + * in the tree. + * + * Input: p - a pointer to an ubi_btNode in a tree. + * + * Output: None. + * + * Notes: This implements a single rotation in either direction (left + * or right). This is the basic building block of all splay + * tree rotations. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr parentp; + ubi_btNodePtr tmp; + char way; + char revway; + + parentp = p->Link[ubi_trPARENT]; /* Find parent. */ + + if( parentp ) /* If no parent, then we're already the root. */ + { + way = p->gender; + revway = ubi_trRevWay(way); + tmp = p->Link[(int)revway]; + + parentp->Link[(int)way] = tmp; + if( tmp ) + { + tmp->Link[ubi_trPARENT] = parentp; + tmp->gender = way; + } + + tmp = parentp->Link[ubi_trPARENT]; + p->Link[ubi_trPARENT] = tmp; + p->gender = parentp->gender; + if( tmp ) + tmp->Link[(int)(p->gender)] = p; + + parentp->Link[ubi_trPARENT] = p; + parentp->gender = revway; + p->Link[(int)revway] = parentp; + } + } /* Rotate */ + +static ubi_btNodePtr Splay( ubi_btNodePtr SplayWithMe ) + /* ------------------------------------------------------------------------ ** + * Move the node indicated by SplayWithMe to the root of the tree by + * splaying the tree. + * + * Input: SplayWithMe - A pointer to an ubi_btNode within a tree. + * + * Output: A pointer to the root of the splay tree (i.e., the same as + * SplayWithMe). + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr parent; + + while( NULL != (parent = SplayWithMe->Link[ubi_trPARENT]) ) + { + if( parent->gender == SplayWithMe->gender ) /* Zig-Zig */ + Rotate( parent ); + else + { + if( ubi_trEQUAL != parent->gender ) /* Zig-Zag */ + Rotate( SplayWithMe ); + } + Rotate( SplayWithMe ); /* Zig */ + } /* while */ + return( SplayWithMe ); + } /* Splay */ + +/* ========================================================================== ** + * Exported utilities. + */ + +ubi_trBool ubi_sptInsert( ubi_btRootPtr RootPtr, + ubi_btNodePtr NewNode, + ubi_btItemPtr ItemPtr, + ubi_btNodePtr *OldNode ) + /* ------------------------------------------------------------------------ ** + * This function uses a non-recursive algorithm to add a new element to the + * splay tree. + * + * Input: RootPtr - a pointer to the ubi_btRoot structure that indicates + * the root of the tree to which NewNode is to be added. + * NewNode - a pointer to an ubi_btNode structure that is NOT + * part of any tree. + * ItemPtr - A pointer to the sort key that is stored within + * *NewNode. ItemPtr MUST point to information stored + * in *NewNode or an EXACT DUPLICATE. The key data + * indicated by ItemPtr is used to place the new node + * into the tree. + * OldNode - a pointer to an ubi_btNodePtr. When searching + * the tree, a duplicate node may be found. If + * duplicates are allowed, then the new node will + * be simply placed into the tree. If duplicates + * are not allowed, however, then one of two things + * may happen. + * 1) if overwritting *is not* allowed, this + * function will return FALSE (indicating that + * the new node could not be inserted), and + * *OldNode will point to the duplicate that is + * still in the tree. + * 2) if overwritting *is* allowed, then this + * function will swap **OldNode for *NewNode. + * In this case, *OldNode will point to the node + * that was removed (thus allowing you to free + * the node). + * ** If you are using overwrite mode, ALWAYS ** + * ** check the return value of this parameter! ** + * Note: You may pass NULL in this parameter, the + * function knows how to cope. If you do this, + * however, there will be no way to return a + * pointer to an old (ie. replaced) node (which is + * a problem if you are using overwrite mode). + * + * Output: a boolean value indicating success or failure. The function + * will return FALSE if the node could not be added to the tree. + * Such failure will only occur if duplicates are not allowed, + * nodes cannot be overwritten, AND a duplicate key was found + * within the tree. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr OtherP; + + if( !(OldNode) ) + OldNode = &OtherP; + + if( ubi_btInsert( RootPtr, NewNode, ItemPtr, OldNode ) ) + { + RootPtr->root = Splay( NewNode ); + return( ubi_trTRUE ); + } + + /* Splay the unreplacable, duplicate keyed, unique, old node. */ + RootPtr->root = Splay( (*OldNode) ); + return( ubi_trFALSE ); + } /* ubi_sptInsert */ + +ubi_btNodePtr ubi_sptRemove( ubi_btRootPtr RootPtr, ubi_btNodePtr DeadNode ) + /* ------------------------------------------------------------------------ ** + * This function removes the indicated node from the tree. + * + * Input: RootPtr - A pointer to the header of the tree that contains + * the node to be removed. + * DeadNode - A pointer to the node that will be removed. + * + * Output: This function returns a pointer to the node that was removed + * from the tree (ie. the same as DeadNode). + * + * Note: The node MUST be in the tree indicated by RootPtr. If not, + * strange and evil things will happen to your trees. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p; + + (void)Splay( DeadNode ); /* Move dead node to root. */ + if( NULL != (p = DeadNode->Link[ubi_trLEFT]) ) + { /* If left subtree exists... */ + ubi_btNodePtr q = DeadNode->Link[ubi_trRIGHT]; + + p->Link[ubi_trPARENT] = NULL; /* Left subtree node becomes root.*/ + p->gender = ubi_trPARENT; + p = ubi_btLast( p ); /* Find rightmost left node... */ + p->Link[ubi_trRIGHT] = q; /* ...attach right tree. */ + if( q ) + q->Link[ubi_trPARENT] = p; + RootPtr->root = Splay( p ); /* Resplay at p. */ + } + else + { + if( NULL != (p = DeadNode->Link[ubi_trRIGHT]) ) + { /* No left, but right subtree exists... */ + p->Link[ubi_trPARENT] = NULL; /* Right subtree root becomes... */ + p->gender = ubi_trPARENT; /* ...overall tree root. */ + RootPtr->root = p; + } + else + RootPtr->root = NULL; /* No subtrees => empty tree. */ + } + + (RootPtr->count)--; /* Decrement node count. */ + return( DeadNode ); /* Return pointer to pruned node. */ + } /* ubi_sptRemove */ + +ubi_btNodePtr ubi_sptLocate( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_trCompOps CompOp ) + /* ------------------------------------------------------------------------ ** + * The purpose of ubi_btLocate() is to find a node or set of nodes given + * a target value and a "comparison operator". The Locate() function is + * more flexible and (in the case of trees that may contain dupicate keys) + * more precise than the ubi_btFind() function. The latter is faster, + * but it only searches for exact matches and, if the tree contains + * duplicates, Find() may return a pointer to any one of the duplicate- + * keyed records. + * + * Input: + * RootPtr - A pointer to the header of the tree to be searched. + * FindMe - An ubi_btItemPtr that indicates the key for which to + * search. + * CompOp - One of the following: + * CompOp Return a pointer to the node with + * ------ --------------------------------- + * ubi_trLT - the last key value that is less + * than FindMe. + * ubi_trLE - the first key matching FindMe, or + * the last key that is less than + * FindMe. + * ubi_trEQ - the first key matching FindMe. + * ubi_trGE - the first key matching FindMe, or the + * first key greater than FindMe. + * ubi_trGT - the first key greater than FindMe. + * Output: + * A pointer to the node matching the criteria listed above under + * CompOp, or NULL if no node matched the criteria. + * + * Notes: + * In the case of trees with duplicate keys, Locate() will behave as + * follows: + * + * Find: 3 Find: 3 + * Keys: 1 2 2 2 3 3 3 3 3 4 4 Keys: 1 1 2 2 2 4 4 5 5 5 6 + * ^ ^ ^ ^ ^ + * LT EQ GT LE GE + * + * That is, when returning a pointer to a node with a key that is LESS + * THAN the target key (FindMe), Locate() will return a pointer to the + * LAST matching node. + * When returning a pointer to a node with a key that is GREATER + * THAN the target key (FindMe), Locate() will return a pointer to the + * FIRST matching node. + * + * See Also: ubi_btFind(), ubi_btFirstOf(), ubi_btLastOf(). + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p; + + p = ubi_btLocate( RootPtr, FindMe, CompOp ); + if( p ) + RootPtr->root = Splay( p ); + return( p ); + } /* ubi_sptLocate */ + +ubi_btNodePtr ubi_sptFind( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe ) + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for any node + * matching a specific key. + * + * Input: + * RootPtr - a pointer to the header of the tree to be searched. + * FindMe - a pointer to the key value for which to search. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. In such a tree, it may be more useful to use + * ubi_sptLocate(). + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p; + + p = ubi_btFind( RootPtr, FindMe ); + if( p ) + RootPtr->root = Splay( p ); + return( p ); + } /* ubi_sptFind */ + +void ubi_sptSplay( ubi_btRootPtr RootPtr, + ubi_btNodePtr SplayMe ) + /* ------------------------------------------------------------------------ ** + * This function allows you to splay the tree at a given node, thus moving + * the node to the top of the tree. + * + * Input: + * RootPtr - a pointer to the header of the tree to be splayed. + * SplayMe - a pointer to a node within the tree. This will become + * the new root node. + * Output: None. + * + * Notes: This is an uncharacteristic function for this group of modules + * in that it provides access to the internal balancing routines, + * which would normally be hidden. + * Splaying the tree will not damage it (assuming that I've done + * *my* job), but there is overhead involved. I don't recommend + * that you use this function unless you understand the underlying + * Splay Tree principles involved. + * ------------------------------------------------------------------------ ** + */ + { + RootPtr->root = Splay( SplayMe ); + } /* ubi_sptSplay */ + +int ubi_sptModuleID( int size, char *list[] ) + /* ------------------------------------------------------------------------ ** + * Returns a set of strings that identify the module. + * + * Input: size - The number of elements in the array <list>. + * list - An array of pointers of type (char *). This array + * should, initially, be empty. This function will fill + * in the array with pointers to strings. + * Output: The number of elements of <list> that were used. If this value + * is less than <size>, the values of the remaining elements are + * not guaranteed. + * + * Notes: Please keep in mind that the pointers returned indicate strings + * stored in static memory. Don't free() them, don't write over + * them, etc. Just read them. + * ------------------------------------------------------------------------ ** + */ + { + if( size > 0 ) + { + list[0] = ModuleID; + if( size > 1 ) + return( 1 + ubi_btModuleID( --size, &(list[1]) ) ); + return( 1 ); + } + return( 0 ); + } /* ubi_sptModuleID */ + +/* ================================ The End ================================= */ + diff --git a/source/ubiqx/ubi_SplayTree.h b/source/ubiqx/ubi_SplayTree.h new file mode 100644 index 00000000000..e4fac796a91 --- /dev/null +++ b/source/ubiqx/ubi_SplayTree.h @@ -0,0 +1,377 @@ +#ifndef UBI_SPLAYTREE_H +#define UBI_SPLAYTREE_H +/* ========================================================================== ** + * ubi_SplayTree.h + * + * Copyright (C) 1993-1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * This module implements "splay" trees. Splay trees are binary trees + * that are rearranged (splayed) whenever a node is accessed. The + * splaying process *tends* to make the tree bushier (improves balance), + * and the nodes that are accessed most frequently *tend* to be closer to + * the top. + * + * References: "Self-Adjusting Binary Search Trees", by Daniel Sleator and + * Robert Tarjan. Journal of the Association for Computing + * Machinery Vol 32, No. 3, July 1985 pp. 652-686 + * + * See also: http://www.cs.cmu.edu/~sleator/ + * + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_SplayTree.h,v + * Revision 4.5 2000/01/08 23:26:49 crh + * Added ubi_trSplay() macro, which does a type cast for us. + * + * Revision 4.4 1998/06/04 21:29:27 crh + * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. + * This is more "standard", and is what people expect. Weird, eh? + * + * Revision 4.3 1998/06/03 17:45:05 crh + * Further fiddling with sys_include.h. It's now in ubi_BinTree.h which is + * included by all of the binary tree files. + * + * Also fixed some warnings produced by lint on Irix 6.2, which doesn't seem + * to like syntax like this: + * + * if( (a = b) ) + * + * The fix was to change lines like the above to: + * + * if( 0 != (a=b) ) + * + * Which means the same thing. + * + * Reminder: Some of the ubi_tr* macros in ubi_BinTree.h are redefined in + * ubi_AVLtree.h and ubi_SplayTree.h. This allows easy swapping + * of tree types by simply changing a header. Unfortunately, the + * macro redefinitions in ubi_AVLtree.h and ubi_SplayTree.h will + * conflict if used together. You must either choose a single tree + * type, or use the underlying function calls directly. Compare + * the two header files for more information. + * + * Revision 4.2 1998/06/02 01:29:14 crh + * Changed ubi_null.h to sys_include.h to make it more generic. + * + * Revision 4.1 1998/05/20 04:37:54 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * + * Revision 4.0 1998/03/10 03:40:57 crh + * Minor comment changes. The revision number is now 4.0 to match the + * BinTree and AVLtree modules. + * + * Revision 2.7 1998/01/24 06:37:57 crh + * Added a URL for more information. + * + * Revision 2.6 1997/12/23 04:02:20 crh + * In this version, all constants & macros defined in the header file have + * the ubi_tr prefix. Also cleaned up anything that gcc complained about + * when run with '-pedantic -fsyntax-only -Wall'. + * + * Revision 2.5 1997/07/26 04:15:46 crh + * + Cleaned up a few minor syntax annoyances that gcc discovered for me. + * + Changed ubi_TRUE and ubi_FALSE to ubi_trTRUE and ubi_trFALSE. + * + * Revision 2.4 1997/06/03 05:22:56 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid causing + * problems. + * + * Revision 2.3 1995/10/03 22:19:37 CRH + * Ubisized! + * Also, added the function ubi_sptSplay(). + * + * Revision 2.1 95/03/09 23:55:04 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/02/27 22:34:55 CRH + * This module was updated to match the interface changes made to the + * ubi_BinTree module. In particular, the interface to the Locate() function + * has changed. See ubi_BinTree for more information on changes and new + * functions. + * + * The revision number was also upped to match ubi_BinTree. + * + * + * Revision 1.0 93/10/15 22:59:36 CRH + * With this revision, I have added a set of #define's that provide a single, + * standard API to all existing tree modules. Until now, each of the three + * existing modules had a different function and typedef prefix, as follows: + * + * Module Prefix + * ubi_BinTree ubi_bt + * ubi_AVLtree ubi_avl + * ubi_SplayTree ubi_spt + * + * To further complicate matters, only those portions of the base module + * (ubi_BinTree) that were superceeded in the new module had the new names. + * For example, if you were using ubi_SplayTree, the locate function was + * called "ubi_sptLocate", but the next and previous functions remained + * "ubi_btNext" and "ubi_btPrev". + * + * This was not too terrible if you were familiar with the modules and knew + * exactly which tree model you wanted to use. If you wanted to be able to + * change modules (for speed comparisons, etc), things could get messy very + * quickly. + * + * So, I have added a set of defined names that get redefined in any of the + * descendant modules. To use this standardized interface in your code, + * simply replace all occurances of "ubi_bt", "ubi_avl", and "ubi_spt" with + * "ubi_tr". The "ubi_tr" names will resolve to the correct function or + * datatype names for the module that you are using. Just remember to + * include the header for that module in your program file. Because these + * names are handled by the preprocessor, there is no added run-time + * overhead. + * + * Note that the original names do still exist, and can be used if you wish + * to write code directly to a specific module. This should probably only be + * done if you are planning to implement a new descendant type, such as + * red/black trees. CRH + * + * Revision 0.0 93/04/21 23:07:13 CRH + * Initial version, written by Christopher R. Hertel. + * This module implements Splay Trees using the ubi_BinTree module as a basis. + * + * ========================================================================== ** + */ + +#include "ubi_BinTree.h" /* Base binary tree functions, types, etc. */ + +/* ========================================================================== ** + * Function prototypes... + */ + +ubi_trBool ubi_sptInsert( ubi_btRootPtr RootPtr, + ubi_btNodePtr NewNode, + ubi_btItemPtr ItemPtr, + ubi_btNodePtr *OldNode ); + /* ------------------------------------------------------------------------ ** + * This function uses a non-recursive algorithm to add a new element to the + * splay tree. + * + * Input: RootPtr - a pointer to the ubi_btRoot structure that indicates + * the root of the tree to which NewNode is to be added. + * NewNode - a pointer to an ubi_btNode structure that is NOT + * part of any tree. + * ItemPtr - A pointer to the sort key that is stored within + * *NewNode. ItemPtr MUST point to information stored + * in *NewNode or an EXACT DUPLICATE. The key data + * indicated by ItemPtr is used to place the new node + * into the tree. + * OldNode - a pointer to an ubi_btNodePtr. When searching + * the tree, a duplicate node may be found. If + * duplicates are allowed, then the new node will + * be simply placed into the tree. If duplicates + * are not allowed, however, then one of two things + * may happen. + * 1) if overwritting *is not* allowed, this + * function will return FALSE (indicating that + * the new node could not be inserted), and + * *OldNode will point to the duplicate that is + * still in the tree. + * 2) if overwritting *is* allowed, then this + * function will swap **OldNode for *NewNode. + * In this case, *OldNode will point to the node + * that was removed (thus allowing you to free + * the node). + * ** If you are using overwrite mode, ALWAYS ** + * ** check the return value of this parameter! ** + * Note: You may pass NULL in this parameter, the + * function knows how to cope. If you do this, + * however, there will be no way to return a + * pointer to an old (ie. replaced) node (which is + * a problem if you are using overwrite mode). + * + * Output: a boolean value indicating success or failure. The function + * will return FALSE if the node could not be added to the tree. + * Such failure will only occur if duplicates are not allowed, + * nodes cannot be overwritten, AND a duplicate key was found + * within the tree. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_sptRemove( ubi_btRootPtr RootPtr, ubi_btNodePtr DeadNode ); + /* ------------------------------------------------------------------------ ** + * This function removes the indicated node from the tree. + * + * Input: RootPtr - A pointer to the header of the tree that contains + * the node to be removed. + * DeadNode - A pointer to the node that will be removed. + * + * Output: This function returns a pointer to the node that was removed + * from the tree (ie. the same as DeadNode). + * + * Note: The node MUST be in the tree indicated by RootPtr. If not, + * strange and evil things will happen to your trees. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_sptLocate( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_trCompOps CompOp ); + /* ------------------------------------------------------------------------ ** + * The purpose of ubi_btLocate() is to find a node or set of nodes given + * a target value and a "comparison operator". The Locate() function is + * more flexible and (in the case of trees that may contain dupicate keys) + * more precise than the ubi_btFind() function. The latter is faster, + * but it only searches for exact matches and, if the tree contains + * duplicates, Find() may return a pointer to any one of the duplicate- + * keyed records. + * + * Input: + * RootPtr - A pointer to the header of the tree to be searched. + * FindMe - An ubi_btItemPtr that indicates the key for which to + * search. + * CompOp - One of the following: + * CompOp Return a pointer to the node with + * ------ --------------------------------- + * ubi_trLT - the last key value that is less + * than FindMe. + * ubi_trLE - the first key matching FindMe, or + * the last key that is less than + * FindMe. + * ubi_trEQ - the first key matching FindMe. + * ubi_trGE - the first key matching FindMe, or the + * first key greater than FindMe. + * ubi_trGT - the first key greater than FindMe. + * Output: + * A pointer to the node matching the criteria listed above under + * CompOp, or NULL if no node matched the criteria. + * + * Notes: + * In the case of trees with duplicate keys, Locate() will behave as + * follows: + * + * Find: 3 Find: 3 + * Keys: 1 2 2 2 3 3 3 3 3 4 4 Keys: 1 1 2 2 2 4 4 5 5 5 6 + * ^ ^ ^ ^ ^ + * LT EQ GT LE GE + * + * That is, when returning a pointer to a node with a key that is LESS + * THAN the target key (FindMe), Locate() will return a pointer to the + * LAST matching node. + * When returning a pointer to a node with a key that is GREATER + * THAN the target key (FindMe), Locate() will return a pointer to the + * FIRST matching node. + * + * See Also: ubi_btFind(), ubi_btFirstOf(), ubi_btLastOf(). + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_sptFind( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe ); + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for any node + * matching a specific key. + * + * Input: + * RootPtr - a pointer to the header of the tree to be searched. + * FindMe - a pointer to the key value for which to search. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. In such a tree, it may be more useful to use + * ubi_sptLocate(). + * ------------------------------------------------------------------------ ** + */ + +void ubi_sptSplay( ubi_btRootPtr RootPtr, + ubi_btNodePtr SplayMe ); + /* ------------------------------------------------------------------------ ** + * This function allows you to splay the tree at a given node, thus moving + * the node to the top of the tree. + * + * Input: + * RootPtr - a pointer to the header of the tree to be splayed. + * SplayMe - a pointer to a node within the tree. This will become + * the new root node. + * Output: None. + * + * Notes: This is an uncharacteristic function for this group of modules + * in that it provides access to the internal balancing routines, + * which would normally be hidden. + * Splaying the tree will not damage it (assuming that I've done + * *my* job), but there is overhead involved. I don't recommend + * that you use this function unless you understand the underlying + * Splay Tree principles involved. + * ------------------------------------------------------------------------ ** + */ + +int ubi_sptModuleID( int size, char *list[] ); + /* ------------------------------------------------------------------------ ** + * Returns a set of strings that identify the module. + * + * Input: size - The number of elements in the array <list>. + * list - An array of pointers of type (char *). This array + * should, initially, be empty. This function will fill + * in the array with pointers to strings. + * Output: The number of elements of <list> that were used. If this value + * is less than <size>, the values of the remaining elements are + * not guaranteed. + * + * Notes: Please keep in mind that the pointers returned indicate strings + * stored in static memory. Don't free() them, don't write over + * them, etc. Just read them. + * ------------------------------------------------------------------------ ** + */ + +/* -------------------------------------------------------------------------- ** + * Masquarade... + * + * This set of defines allows you to write programs that will use any of the + * implemented binary tree modules (currently BinTree, AVLtree, and SplayTree). + * Instead of using ubi_bt..., use ubi_tr..., and select the tree type by + * including the appropriate module header. + */ + +#undef ubi_trInsert +#undef ubi_trRemove +#undef ubi_trLocate +#undef ubi_trFind +#undef ubi_trModuleID + +#define ubi_trInsert( Rp, Nn, Ip, On ) \ + ubi_sptInsert( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Nn), \ + (ubi_btItemPtr)(Ip), (ubi_btNodePtr *)(On) ) + +#define ubi_trRemove( Rp, Dn ) \ + ubi_sptRemove( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Dn) ) + +#define ubi_trLocate( Rp, Ip, Op ) \ + ubi_sptLocate( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_trCompOps)(Op) ) + +#define ubi_trFind( Rp, Ip ) \ + ubi_sptFind( (ubi_btRootPtr)(Rp), (ubi_btItemPtr)(Ip) ) + +#define ubi_trSplay( Rp, Sm ) \ + ubi_sptSplay( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Sm) ) + +#define ubi_trModuleID( s, l ) ubi_sptModuleID( s, l ) + +/* ================================ The End ================================= */ +#endif /* UBI_SPLAYTREE_H */ diff --git a/source/ubiqx/ubi_dLinkList.c b/source/ubiqx/ubi_dLinkList.c new file mode 100644 index 00000000000..eb95033c695 --- /dev/null +++ b/source/ubiqx/ubi_dLinkList.c @@ -0,0 +1,171 @@ +/* ========================================================================== ** + * ubi_dLinkList.c + * + * Copyright (C) 1997, 1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * This module implements simple doubly-linked lists. + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_dLinkList.c,v + * Revision 0.11 1999/06/19 16:58:06 crh + * Renamed the ubi_slRemove() function in ubi_sLinkList to + * ubi_slRemoveNext(). I was bothered by the fact that it didn't + * match the functionality of the ubi_dlRemove() function in + * ubi_dLinkList. The new name is more 'correct'. + * + * Revision 0.10 1998/07/24 07:30:20 crh + * Added the ubi_dlNewList() macro. + * + * Revision 0.9 1998/06/04 21:29:27 crh + * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. + * This is more "standard", and is what people expect. Weird, eh? + * + * Revision 0.8 1998/06/03 18:06:03 crh + * Further fiddling with sys_include.h, which has been moved from the .c file + * to the .h file. + * + * Revision 0.7 1998/06/02 01:38:47 crh + * Changed include file name from ubi_null.h to sys_include.h to make it + * more generic. + * + * Revision 0.6 1998/05/20 04:38:05 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * + * Revision 0.5 1998/03/10 02:55:00 crh + * Simplified the code and added macros for stack & queue manipulations. + * + * Revision 0.4 1998/01/03 01:53:56 crh + * Added ubi_dlCount() macro. + * + * Revision 0.3 1997/10/15 03:05:39 crh + * Added some handy type casting to the macros. Added AddHere and RemThis + * macros. + * + * Revision 0.2 1997/10/08 03:07:21 crh + * Fixed a few forgotten link-ups in Insert(), and fixed the AddHead() + * macro, which was passing the wrong value for <After> to Insert(). + * + * Revision 0.1 1997/10/07 04:34:07 crh + * Initial Revision. + * + * -------------------------------------------------------------------------- ** + * This module is similar to the ubi_sLinkList module, but it is neither a + * descendant type nor an easy drop-in replacement for the latter. One key + * difference is that the ubi_dlRemove() function removes the indicated node, + * while the ubi_slRemoveNext() function (in ubi_sLinkList) removes the node + * *following* the indicated node. + * + * ========================================================================== ** + */ + +#include "ubi_dLinkList.h" /* Header for *this* module. */ + +/* ========================================================================== ** + * Functions... + */ + +ubi_dlListPtr ubi_dlInitList( ubi_dlListPtr ListPtr ) + /* ------------------------------------------------------------------------ ** + * Initialize a doubly-linked list header. + * + * Input: ListPtr - A pointer to the list structure that is to be + * initialized for use. + * + * Output: A pointer to the initialized list header (i.e., same as + * <ListPtr>). + * + * ------------------------------------------------------------------------ ** + */ + { + ListPtr->Head = NULL; + ListPtr->Tail = NULL; + ListPtr->count = 0; + return( ListPtr ); + } /* ubi_dlInitList */ + +ubi_dlNodePtr ubi_dlInsert( ubi_dlListPtr ListPtr, + ubi_dlNodePtr New, + ubi_dlNodePtr After ) + /* ------------------------------------------------------------------------ ** + * Insert a new node into the list. + * + * Input: ListPtr - A pointer to the list into which the node is to + * be inserted. + * New - Pointer to the new node. + * After - NULL, or a pointer to a node that is already in the + * list. + * If NULL, then <New> will be added at the head of the + * list, else it will be added following <After>. + * + * Output: A pointer to the node that was inserted into the list (i.e., + * the same as <New>). + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_dlNodePtr PredNode = After ? After : (ubi_dlNodePtr)ListPtr; + + New->Next = PredNode->Next; + New->Prev = After; + PredNode->Next = New; + if( New->Next ) + New->Next->Prev = New; + else + ListPtr->Tail = New; + + (ListPtr->count)++; + + return( New ); + } /* ubi_dlInsert */ + +ubi_dlNodePtr ubi_dlRemove( ubi_dlListPtr ListPtr, ubi_dlNodePtr Old ) + /* ------------------------------------------------------------------------ ** + * Remove a node from the list. + * + * Input: ListPtr - A pointer to the list from which <Old> is to be + * removed. + * Old - A pointer to the node that is to be removed from the + * list. + * + * Output: A pointer to the node that was removed (i.e., <Old>). + * + * ------------------------------------------------------------------------ ** + */ + { + if( Old ) + { + if( Old->Next ) + Old->Next->Prev = Old->Prev; + else + ListPtr->Tail = Old->Prev; + + if( Old->Prev ) + Old->Prev->Next = Old->Next; + else + ListPtr->Head = Old->Next; + + (ListPtr->count)--; + } + + return( Old ); + } /* ubi_dlRemove */ + +/* ================================ The End ================================= */ diff --git a/source/ubiqx/ubi_dLinkList.h b/source/ubiqx/ubi_dLinkList.h new file mode 100644 index 00000000000..682e566ee67 --- /dev/null +++ b/source/ubiqx/ubi_dLinkList.h @@ -0,0 +1,242 @@ +#ifndef UBI_DLINKLIST_H +#define UBI_DLINKLIST_H +/* ========================================================================== ** + * ubi_dLinkList.h + * + * Copyright (C) 1997, 1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * This module implements simple doubly-linked lists. + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_dLinkList.h,v + * Revision 0.11 1999/06/19 16:58:06 crh + * Renamed the ubi_slRemove() function in ubi_sLinkList to + * ubi_slRemoveNext(). I was bothered by the fact that it didn't + * match the functionality of the ubi_dlRemove() function in + * ubi_dLinkList. The new name is more 'correct'. + * + * Revision 0.10 1998/07/24 07:30:20 crh + * Added the ubi_dlNewList() macro. + * + * Revision 0.9 1998/06/04 21:29:27 crh + * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. + * This is more "standard", and is what people expect. Weird, eh? + * + * Revision 0.8 1998/06/03 18:06:03 crh + * Further fiddling with sys_include.h, which has been moved from the .c file + * to the .h file. + * + * Revision 0.7 1998/06/02 01:38:47 crh + * Changed include file name from ubi_null.h to sys_include.h to make it + * more generic. + * + * Revision 0.6 1998/05/20 04:38:05 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * + * Revision 0.5 1998/03/10 02:54:04 crh + * Simplified the code and added macros for stack & queue manipulations. + * + * Revision 0.4 1998/01/03 01:53:44 crh + * Added ubi_dlCount() macro. + * + * Revision 0.3 1997/10/15 03:04:31 crh + * Added some handy type casting to the macros. Added AddHere and RemThis + * macros. + * + * Revision 0.2 1997/10/08 03:08:16 crh + * Fixed a few forgotten link-ups in Insert(), and fixed the AddHead() + * macro, which was passing the wrong value for <After> to Insert(). + * + * Revision 0.1 1997/10/07 04:34:38 crh + * Initial Revision. + * + * -------------------------------------------------------------------------- ** + * This module is similar to the ubi_sLinkList module, but it is neither a + * descendant type nor an easy drop-in replacement for the latter. One key + * difference is that the ubi_dlRemove() function removes the indicated node, + * while the ubi_slRemoveNext() function (in ubi_sLinkList) removes the node + * *following* the indicated node. + * + * ========================================================================== ** + */ + +#include "sys_include.h" /* System-specific includes. */ + +/* ========================================================================== ** + * Typedefs... + * + * ubi_dlNode - This is the basic node structure. + * ubi_dlNodePtr - Pointer to a node. + * ubi_dlList - This is the list header structure. + * ubi_dlListPtr - Pointer to a List (i.e., a list header structure). + * + */ + +typedef struct ubi_dlListNode + { + struct ubi_dlListNode *Next; + struct ubi_dlListNode *Prev; + } ubi_dlNode; + +typedef ubi_dlNode *ubi_dlNodePtr; + +typedef struct + { + ubi_dlNodePtr Head; + ubi_dlNodePtr Tail; + unsigned long count; + } ubi_dlList; + +typedef ubi_dlList *ubi_dlListPtr; + +/* ========================================================================== ** + * Macros... + * + * ubi_dlNewList - Macro used to declare and initialize a new list in one + * swell foop. It is used when defining a variable of + * type ubi_dlList. The definition + * static ubi_dlNewList( gerbil ); + * is translated to + * static ubi_dlList gerbil[1] = {{ NULL, NULL, 0 }}; + * + * ubi_dlCount - Return the number of entries currently in the list. + * + * ubi_dlAddHead - Add a new node at the head of the list. + * ubi_dlAddNext - Add a node following the given node. + * ubi_dlAddTail - Add a new node at the tail of the list. + * Note: AddTail evaluates the L parameter twice. + * + * ubi_dlRemHead - Remove the node at the head of the list, if any. + * Note: RemHead evaluates the L parameter twice. + * ubi_dlRemThis - Remove the indicated node. + * ubi_dlRemTail - Remove the node at the tail of the list, if any. + * Note: RemTail evaluates the L parameter twice. + * + * ubi_dlFirst - Return a pointer to the first node in the list, if any. + * ubi_dlLast - Return a pointer to the last node in the list, if any. + * ubi_dlNext - Given a node, return a pointer to the next node. + * ubi_dlPrev - Given a node, return a pointer to the previous node. + * + * ubi_dlPush - Add a node at the head of the list (synonym of AddHead). + * ubi_dlPop - Remove a node at the head of the list (synonym of RemHead). + * ubi_dlEnqueue - Add a node at the tail of the list (sysnonym of AddTail). + * ubi_dlDequeue - Remove a node at the head of the list (synonym of RemHead). + * + * Note that all of these provide type casting of the parameters. The + * Add and Rem macros are nothing more than nice front-ends to the + * Insert and Remove operations. + * + * Also note that the First, Next and Last macros do no parameter checking! + * + */ + +#define ubi_dlNewList( L ) ubi_dlList (L)[1] = {{ NULL, NULL, 0 }} + +#define ubi_dlCount( L ) (((ubi_dlListPtr)(L))->count) + +#define ubi_dlAddHead( L, N ) \ + ubi_dlInsert( (ubi_dlListPtr)(L), (ubi_dlNodePtr)(N), NULL ) + +#define ubi_dlAddNext( L, N, A ) \ + ubi_dlInsert( (ubi_dlListPtr)(L), \ + (ubi_dlNodePtr)(N), \ + (ubi_dlNodePtr)(A) ) + +#define ubi_dlAddTail( L, N ) \ + ubi_dlInsert( (ubi_dlListPtr)(L), \ + (ubi_dlNodePtr)(N), \ + (((ubi_dlListPtr)(L))->Tail) ) + +#define ubi_dlRemHead( L ) ubi_dlRemove( (ubi_dlListPtr)(L), \ + (((ubi_dlListPtr)(L))->Head) ) + +#define ubi_dlRemThis( L, N ) ubi_dlRemove( (ubi_dlListPtr)(L), \ + (ubi_dlNodePtr)(N) ) + +#define ubi_dlRemTail( L ) ubi_dlRemove( (ubi_dlListPtr)(L), \ + (((ubi_dlListPtr)(L))->Tail) ) + +#define ubi_dlFirst( L ) (((ubi_dlListPtr)(L))->Head) + +#define ubi_dlLast( L ) (((ubi_dlListPtr)(L))->Tail) + +#define ubi_dlNext( N ) (((ubi_dlNodePtr)(N))->Next) + +#define ubi_dlPrev( N ) (((ubi_dlNodePtr)(N))->Prev) + +#define ubi_dlPush ubi_dlAddHead +#define ubi_dlPop ubi_dlRemHead +#define ubi_dlEnqueue ubi_dlAddTail +#define ubi_dlDequeue ubi_dlRemHead + +/* ========================================================================== ** + * Function prototypes... + */ + +ubi_dlListPtr ubi_dlInitList( ubi_dlListPtr ListPtr ); + /* ------------------------------------------------------------------------ ** + * Initialize a doubly-linked list header. + * + * Input: ListPtr - A pointer to the list structure that is to be + * initialized for use. + * + * Output: A pointer to the initialized list header (i.e., same as + * <ListPtr>). + * + * ------------------------------------------------------------------------ ** + */ + +ubi_dlNodePtr ubi_dlInsert( ubi_dlListPtr ListPtr, + ubi_dlNodePtr New, + ubi_dlNodePtr After ); + /* ------------------------------------------------------------------------ ** + * Insert a new node into the list. + * + * Input: ListPtr - A pointer to the list into which the node is to + * be inserted. + * New - Pointer to the new node. + * After - NULL, or a pointer to a node that is already in the + * list. + * If NULL, then <New> will be added at the head of the + * list, else it will be added following <After>. + * + * Output: A pointer to the node that was inserted into the list (i.e., + * the same as <New>). + * + * ------------------------------------------------------------------------ ** + */ + +ubi_dlNodePtr ubi_dlRemove( ubi_dlListPtr ListPtr, ubi_dlNodePtr Old ); + /* ------------------------------------------------------------------------ ** + * Remove a node from the list. + * + * Input: ListPtr - A pointer to the list from which <Old> is to be + * removed. + * Old - A pointer to the node that is to be removed from the + * list. + * + * Output: A pointer to the node that was removed (i.e., <Old>). + * + * ------------------------------------------------------------------------ ** + */ + +/* ================================ The End ================================= */ +#endif /* UBI_DLINKLIST_H */ diff --git a/source/ubiqx/ubi_sLinkList.c b/source/ubiqx/ubi_sLinkList.c new file mode 100644 index 00000000000..ff75931b470 --- /dev/null +++ b/source/ubiqx/ubi_sLinkList.c @@ -0,0 +1,187 @@ +/* ========================================================================== ** + * ubi_sLinkList.c + * + * Copyright (C) 1997, 1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * This module implements a simple singly-linked list. + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_sLinkList.c,v + * Revision 0.10 1999/06/19 16:58:06 crh + * Renamed the ubi_slRemove() function in ubi_sLinkList to + * ubi_slRemoveNext(). I was bothered by the fact that it didn't + * match the functionality of the ubi_dlRemove() function in + * ubi_dLinkList. The new name is more 'correct'. + * + * Revision 0.9 1998/07/24 07:30:20 crh + * Added the ubi_slNewList() macro. + * + * Revision 0.8 1998/06/04 21:29:27 crh + * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. + * This is more "standard", and is what people expect. Weird, eh? + * + * Revision 0.7 1998/06/03 18:06:03 crh + * Further fiddling with sys_include.h, which has been moved from the .c file + * to the .h file. + * + * Revision 0.6 1998/06/02 01:38:47 crh + * Changed include file name from ubi_null.h to sys_include.h to make it + * more generic. + * + * Revision 0.5 1998/05/20 04:38:05 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * + * Revision 0.4 1998/03/10 02:23:20 crh + * Combined ubi_StackQueue and ubi_sLinkList into one module. Redesigned + * the functions and macros. Not a complete rewrite but close to it. + * + * Revision 0.3 1998/01/03 01:59:52 crh + * Added ubi_slCount() macro. + * + * Revision 0.2 1997/10/21 03:35:18 crh + * Added parameter <After> in function Insert(). Made necessary changes + * to macro AddHead() and added macro AddHere(). + * + * Revision 0.1 1997/10/16 02:53:45 crh + * Initial Revision. + * + * -------------------------------------------------------------------------- ** + * This module implements a singly-linked list which may also be used as a + * queue or a stack. For a queue, entries are added at the tail and removed + * from the head of the list. For a stack, the entries are entered and + * removed from the head of the list. A traversal of the list will always + * start at the head of the list and proceed toward the tail. This is all + * mind-numbingly simple, but I'm surprised by the number of programs out + * there which re-implement this a dozen or so times. + * + * Note: When the list header is initialized, the Tail pointer is set to + * point to the Head pointer. This simplifies things a great deal, + * except that you can't initialize a stack or queue by simply + * zeroing it out. One sure way to initialize the header is to call + * ubi_slInit(). Another option would be something like this: + * + * ubi_slNewList( MyList ); + * + * Which translates to: + * + * ubi_slList MyList[1] = { NULL, (ubi_slNodePtr)MyList, 0 }; + * + * See ubi_slInit(), ubi_slNewList(), and the ubi_slList structure + * for more info. + * + * + Also, note that this module is similar to the ubi_dLinkList + * module. There are three key differences: + * - This is a singly-linked list, the other is a doubly-linked + * list. + * - In this module, if the list is empty, the tail pointer will + * point back to the head of the list as described above. This + * is not done in ubi_dLinkList. + * - The ubi_slRemoveNext() function, by necessity, removes the + * 'next' node. In ubi_dLinkList, the ubi_dlRemove() function + * removes the 'current' node. + * + * ========================================================================== ** + */ + +#include "ubi_sLinkList.h" /* Header for *this* module. */ + +/* ========================================================================== ** + * Functions... + */ + +ubi_slListPtr ubi_slInitList( ubi_slListPtr ListPtr ) + /* ------------------------------------------------------------------------ ** + * Initialize a singly-linked list header. + * + * Input: ListPtr - A pointer to the list structure that is to be + * initialized for use. + * + * Output: A pointer to the initialized list header (i.e., same as + * <ListPtr>). + * + * ------------------------------------------------------------------------ ** + */ + { + ListPtr->Head = NULL; + ListPtr->Tail = (ubi_slNodePtr)ListPtr; + ListPtr->count = 0; + return( ListPtr ); + } /* ubi_slInitList */ + +ubi_slNodePtr ubi_slInsert( ubi_slListPtr ListPtr, + ubi_slNodePtr New, + ubi_slNodePtr After ) + /* ------------------------------------------------------------------------ ** + * Add a node to the list. + * + * Input: ListPtr - A pointer to the list into which the node is to + * be inserted. + * New - Pointer to the node that is to be added to the list. + * After - Pointer to a list in a node after which the new node + * will be inserted. If NULL, then the new node will + * be added at the head of the list. + * + * Output: A pointer to the node that was inserted into the list (i.e., + * the same as <New>). + * + * ------------------------------------------------------------------------ ** + */ + { + After = After ? After : (ubi_slNodePtr)ListPtr; + New->Next = After->Next; + After->Next = New; + if( !(New->Next) ) + ListPtr->Tail = New; + (ListPtr->count)++; + return( New ); + } /* ubi_slInsert */ + +ubi_slNodePtr ubi_slRemoveNext( ubi_slListPtr ListPtr, ubi_slNodePtr AfterMe ) + /* ------------------------------------------------------------------------ ** + * Remove the node followng <AfterMe>. If <AfterMe> is NULL, remove from + * the head of the list. + * + * Input: ListPtr - A pointer to the list from which the node is to be + * removed. + * AfterMe - Pointer to the node preceeding the node to be + * removed. + * + * Output: A pointer to the node that was removed, or NULL if the list is + * empty. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_slNodePtr DelNode; + + AfterMe = AfterMe ? AfterMe : (ubi_slNodePtr)ListPtr; + DelNode = AfterMe->Next; + if( DelNode ) + { + if( !(DelNode->Next) ) + ListPtr->Tail = AfterMe; + AfterMe->Next = DelNode->Next; + (ListPtr->count)--; + } + return( DelNode ); + } /* ubi_slRemoveNext */ + +/* ================================ The End ================================= */ diff --git a/source/ubiqx/ubi_sLinkList.h b/source/ubiqx/ubi_sLinkList.h new file mode 100644 index 00000000000..53bfa400671 --- /dev/null +++ b/source/ubiqx/ubi_sLinkList.h @@ -0,0 +1,254 @@ +#ifndef UBI_SLINKLIST_H +#define UBI_SLINKLIST_H +/* ========================================================================== ** + * ubi_sLinkList.h + * + * Copyright (C) 1997, 1998 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * This module implements a simple singly-linked list. + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * + * Log: ubi_sLinkList.h,v + * Revision 0.10 1999/06/19 16:58:06 crh + * Renamed the ubi_slRemove() function in ubi_sLinkList to + * ubi_slRemoveNext(). I was bothered by the fact that it didn't + * match the functionality of the ubi_dlRemove() function in + * ubi_dLinkList. The new name is more 'correct'. + * + * Revision 0.9 1998/07/24 07:30:20 crh + * Added the ubi_slNewList() macro. + * + * Revision 0.8 1998/06/04 21:29:27 crh + * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. + * This is more "standard", and is what people expect. Weird, eh? + * + * Revision 0.7 1998/06/03 18:06:03 crh + * Further fiddling with sys_include.h, which has been moved from the .c file + * to the .h file. + * + * Revision 0.6 1998/06/02 01:38:47 crh + * Changed include file name from ubi_null.h to sys_include.h to make it + * more generic. + * + * Revision 0.5 1998/05/20 04:38:05 crh + * The C file now includes ubi_null.h. See ubi_null.h for more info. + * + * Revision 0.4 1998/03/10 02:22:39 crh + * Combined ubi_StackQueue and ubi_sLinkList into one module. Redesigned + * the functions and macros. Not a complete rewrite but close to it. + * + * Revision 0.3 1998/01/03 02:00:02 crh + * Added ubi_slCount() macro. + * + * Revision 0.2 1997/10/21 03:36:14 crh + * Added parameter <After> in function Insert(). Made necessary changes + * to macro AddHead() and added macro AddHere(). + * + * Revision 0.1 1997/10/16 02:54:08 crh + * Initial Revision. + * + * -------------------------------------------------------------------------- ** + * This module implements a singly-linked list which may also be used as a + * queue or a stack. For a queue, entries are added at the tail and removed + * from the head of the list. For a stack, the entries are entered and + * removed from the head of the list. A traversal of the list will always + * start at the head of the list and proceed toward the tail. This is all + * mind-numbingly simple, but I'm surprised by the number of programs out + * there which re-implement this a dozen or so times. + * + * Note: When the list header is initialized, the Tail pointer is set to + * point to the Head pointer. This simplifies things a great deal, + * except that you can't initialize a stack or queue by simply + * zeroing it out. One sure way to initialize the header is to call + * ubi_slInit(). Another option would be something like this: + * + * ubi_slNewList( MyList ); + * + * Which translates to: + * + * ubi_slList MyList[1] = { NULL, (ubi_slNodePtr)MyList, 0 }; + * + * See ubi_slInit(), ubi_slNewList(), and the ubi_slList structure + * for more info. + * + * + Also, note that this module is similar to the ubi_dLinkList + * module. There are three key differences: + * - This is a singly-linked list, the other is a doubly-linked + * list. + * - In this module, if the list is empty, the tail pointer will + * point back to the head of the list as described above. This + * is not done in ubi_dLinkList. + * - The ubi_slRemoveNext() function, by necessity, removes the + * 'next' node. In ubi_dLinkList, the ubi_dlRemove() function + * removes the 'current' node. + * + * ========================================================================== ** + */ + +#include "sys_include.h" /* System-specific includes. */ + +/* ========================================================================== ** + * Typedefs... + * + * ubi_slNode - This is the basic node structure. + * ubi_slNodePtr - Pointer to a node. + * ubi_slList - This is the list header structure. + * ubi_slListPtr - Pointer to a List (i.e., a list header structure). + * + */ + +typedef struct ubi_slListNode + { + struct ubi_slListNode *Next; + } ubi_slNode; + +typedef ubi_slNode *ubi_slNodePtr; + +typedef struct + { + ubi_slNodePtr Head; + ubi_slNodePtr Tail; + unsigned long count; + } ubi_slList; + +typedef ubi_slList *ubi_slListPtr; + + +/* ========================================================================== ** + * Macros... + * + * ubi_slNewList - Macro used to declare and initialize a list header in + * one step. + * + * ubi_slCount - Returns the current number of entries in the list. + * + * ubi_slAddHead - Add a new node at the head of the list. + * ubi_slAddNext - Add a new node following the indicated node. + * ubi_slAddTail - Add a new node to the tail of the list. + * Note: AddTail evaluates the L parameter twice. + * + * ubi_slRemHead - Remove the node at the head of the list, if any. + * ubi_slRemNext - Remove the node following the given node. + * + * ubi_slFirst - Return a pointer to the first node in the list, if any. + * ubi_slNext - Given a node, return a pointer to the next node. + * ubi_slLast - Return a pointer to the last node in the list, if any. + * + * ubi_slPush - Add a node at the head of the list (synonym of AddHead). + * ubi_slPop - Remove a node at the head of the list (synonym of RemHead). + * ubi_slEnqueue - Add a node at the tail of the list (sysnonym of AddTail). + * ubi_slDequeue - Remove a node at the head of the list (synonym of RemHead). + * + * Note that all of these provide type casting of the parameters. The + * Add and Rem macros are nothing more than nice front-ends to the + * Insert and Remove functions. + * + * Also note that the First, Next and Last macros do no parameter checking! + * + */ + +#define ubi_slNewList( L ) ubi_slList (L)[1] = {{ NULL, (ubi_slNodePtr)(L), 0 }} + +#define ubi_slCount( L ) (((ubi_slListPtr)(L))->count) + +#define ubi_slAddHead( L, N ) \ + ubi_slInsert( (ubi_slListPtr)(L), (ubi_slNodePtr)(N), NULL ) + +#define ubi_slAddNext( L, N, A ) \ + ubi_slInsert( (ubi_slListPtr)(L), \ + (ubi_slNodePtr)(N), \ + (ubi_slNodePtr)(A) ) + +#define ubi_slAddTail( L, N ) \ + ubi_slInsert( (ubi_slListPtr)(L), \ + (ubi_slNodePtr)(N), \ + ((ubi_slListPtr)(L))->Tail ) + +#define ubi_slRemHead( L ) ubi_slRemoveNext( (ubi_slListPtr)(L), NULL ) + +#define ubi_slRemNext( L, N ) \ + ubi_slRemoveNext( (ubi_slListPtr)(L), (ubi_slNodePtr)(N) ) + +#define ubi_slFirst( L ) (((ubi_slListPtr)(L))->Head) + +#define ubi_slNext( N ) (((ubi_slNodePtr)(N))->Next) + +#define ubi_slLast( L ) (((ubi_slListPtr)(L))->Tail) + +#define ubi_slPush ubi_slAddHead +#define ubi_slPop ubi_slRemHead +#define ubi_slEnqueue ubi_slAddTail +#define ubi_slDequeue ubi_slRemHead + +/* ========================================================================== ** + * Function prototypes... + */ + +ubi_slListPtr ubi_slInitList( ubi_slListPtr ListPtr ); + /* ------------------------------------------------------------------------ ** + * Initialize a singly-linked list header. + * + * Input: ListPtr - A pointer to the list structure that is to be + * initialized for use. + * + * Output: A pointer to the initialized list header (i.e., same as + * <ListPtr>). + * + * ------------------------------------------------------------------------ ** + */ + +ubi_slNodePtr ubi_slInsert( ubi_slListPtr ListPtr, + ubi_slNodePtr New, + ubi_slNodePtr After ); + /* ------------------------------------------------------------------------ ** + * Add a node to the list. + * + * Input: ListPtr - A pointer to the list into which the node is to + * be inserted. + * New - Pointer to the node that is to be added to the list. + * After - Pointer to a list in a node after which the new node + * will be inserted. If NULL, then the new node will + * be added at the head of the list. + * + * Output: A pointer to the node that was inserted into the list (i.e., + * the same as <New>). + * + * ------------------------------------------------------------------------ ** + */ + +ubi_slNodePtr ubi_slRemoveNext( ubi_slListPtr ListPtr, ubi_slNodePtr AfterMe ); + /* ------------------------------------------------------------------------ ** + * Remove the node followng <AfterMe>. If <AfterMe> is NULL, remove from + * the head of the list. + * + * Input: ListPtr - A pointer to the list from which the node is to be + * removed. + * AfterMe - Pointer to the node preceeding the node to be + * removed. + * + * Output: A pointer to the node that was removed, or NULL if the list is + * empty. + * + * ------------------------------------------------------------------------ ** + */ + +/* ================================ The End ================================= */ +#endif /* UBI_SLINKLIST_H */ |