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/* Definition of serial stream class (strm).
*
* A serial stream provides serial data access. In theory, serial streams
* can be implemented via a number of methods (e.g. files or in-memory
* streams). In practice, there currently only exist the file type (aka
* "driver").
*
* In practice, many stream features are bound to files. I have not yet made
* any serious effort, except for the naming of this class, to try to make
* the interfaces very generic. However, I assume that we could work much
* like in the strm class, where some properties are simply ignored when
* the wrong strm mode is selected (which would translate here to the wrong
* stream mode).
*
* Most importantly, this class provides generic input and output functions
* which can directly be used to work with the strms and file output. It
* provides such useful things like a circular file buffer and, hopefully
* at a later stage, a lazy writer. The object is also seriazable and thus
* can easily be persistet. The bottom line is that it makes much sense to
* use this class whereever possible as its features may grow in the future.
*
* An important note on writing gzip format via zlib (kept anonymous
* by request):
*
* --------------------------------------------------------------------------
* We'd like to make sure the output file is in full gzip format
* (compatible with gzip -d/zcat etc). There is a flag in how the output
* is initialized within zlib to properly add the gzip wrappers to the
* output. (gzip is effectively a small metadata wrapper around raw
* zstream output.)
*
* I had written an old bit of code to do this - the documentation on
* deflatInit2() was pretty tricky to nail down on this specific feature:
*
* int deflateInit2 (z_streamp strm, int level, int method, int windowBits,
* int memLevel, int strategy);
*
* I believe "31" would be the value for the "windowBits" field that you'd
* want to try:
*
* deflateInit2(zstrmptr, 6, Z_DEFLATED, 31, 9, Z_DEFAULT_STRATEGY);
* --------------------------------------------------------------------------
*
* Copyright 2008, 2009 Rainer Gerhards and Adiscon GmbH.
*
* This file is part of the rsyslog runtime library.
*
* The rsyslog runtime library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* The rsyslog runtime 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the rsyslog runtime library. If not, see <http://www.gnu.org/licenses/>.
*
* A copy of the GPL can be found in the file "COPYING" in this distribution.
* A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution.
*/
#ifndef STREAM_H_INCLUDED
#define STREAM_H_INCLUDED
#include <pthread.h>
#include "obj-types.h"
#include "glbl.h"
#include "stream.h"
#include "zlibw.h"
#include "apc.h"
/* stream types */
typedef enum {
STREAMTYPE_FILE_SINGLE = 0, /**< read a single file */
STREAMTYPE_FILE_CIRCULAR = 1, /**< circular files */
STREAMTYPE_FILE_MONITOR = 2 /**< monitor a (third-party) file */
} strmType_t;
typedef enum { /* when extending, do NOT change existing modes! */
STREAMMMODE_INVALID = 0,
STREAMMODE_READ = 1,
STREAMMODE_WRITE = 2,
STREAMMODE_WRITE_TRUNC = 3,
STREAMMODE_WRITE_APPEND = 4
} strmMode_t;
#define STREAM_ASYNC_NUMBUFS 2 /* must be a power of 2 -- TODO: make configurable */
/* The strm_t data structure */
typedef struct strm_s {
BEGINobjInstance; /* Data to implement generic object - MUST be the first data element! */
strmType_t sType;
/* descriptive properties */
int iCurrFNum;/* current file number (NOT descriptor, but the number in the file name!) */
uchar *pszFName; /* prefix for generated filenames */
int lenFName;
strmMode_t tOperationsMode;
mode_t tOpenMode;
int64 iMaxFileSize;/* maximum size a file may grow to */
int iMaxFiles; /* maximum number of files if a circular mode is in use */
int iFileNumDigits;/* min number of digits to use in file number (only in circular mode) */
bool bDeleteOnClose; /* set to 1 to auto-delete on close -- be careful with that setting! */
int64 iCurrOffs;/* current offset */
int64 *pUsrWCntr; /* NULL or a user-provided counter that receives the nbr of bytes written since the last CntrSet() */
/* dynamic properties, valid only during file open, not to be persistet */
bool bDisabled; /* should file no longer be written to? (currently set only if omfile file size limit fails) */
bool bSync; /* sync this file after every write? */
size_t sIOBufSize;/* size of IO buffer */
uchar *pszDir; /* Directory */
int lenDir;
int fd; /* the file descriptor, -1 if closed */
int fdDir; /* the directory's descriptor, in case bSync is requested (-1 if closed) */
uchar *pszCurrFName; /* name of current file (if open) */
uchar *pIOBuf; /* the iobuffer currently in use to gather data */
size_t iBufPtrMax; /* current max Ptr in Buffer (if partial read!) */
size_t iBufPtr; /* pointer into current buffer */
int iUngetC; /* char set via UngetChar() call or -1 if none set */
bool bInRecord; /* if 1, indicates that we are currently writing a not-yet complete record */
bool bInClose; /* used to break "deadly close loops", tells us we are already inside a close */
int iZipLevel; /* zip level (0..9). If 0, zip is completely disabled */
Bytef *pZipBuf;
/* support for async flush procesing */
bool bAsyncWrite; /* do asynchronous writes (always if a flush interval is given) */
bool bStopWriter; /* shall writer thread terminate? */
bool bDoTimedWait; /* instruct writer thread to do a times wait to support flush timeouts */
int iFlushInterval; /* flush in which interval - 0, no flushing */
apc_id_t apcID; /* id of current Apc request (used for cancelling) */
pthread_mutex_t mut;/* mutex for flush in async mode */
pthread_cond_t notFull;
pthread_cond_t notEmpty;
pthread_cond_t isEmpty;
unsigned short iEnq; /* this MUST be unsigned as we use module arithmetic (else invalid indexing happens!) */
unsigned short iDeq; /* this MUST be unsigned as we use module arithmetic (else invalid indexing happens!) */
short iCnt; /* current nbr of elements in buffer */
struct {
uchar *pBuf;
size_t lenBuf;
} asyncBuf[STREAM_ASYNC_NUMBUFS];
pthread_t writerThreadID;
int apcRequested; /* is an apc Requested? */
/* support for omfile size-limiting commands, special counters, NOT persisted! */
off_t iSizeLimit; /* file size limit, 0 = no limit */
uchar *pszSizeLimitCmd; /* command to carry out when size limit is reached */
bool bIsTTY; /* is this a tty file? */
} strm_t;
/* interfaces */
BEGINinterface(strm) /* name must also be changed in ENDinterface macro! */
rsRetVal (*Construct)(strm_t **ppThis);
rsRetVal (*ConstructFinalize)(strm_t *pThis);
rsRetVal (*Destruct)(strm_t **ppThis);
rsRetVal (*SetMaxFileSize)(strm_t *pThis, int64 iMaxFileSize);
rsRetVal (*SetFileName)(strm_t *pThis, uchar *pszName, size_t iLenName);
rsRetVal (*ReadChar)(strm_t *pThis, uchar *pC);
rsRetVal (*UnreadChar)(strm_t *pThis, uchar c);
rsRetVal (*ReadLine)(strm_t *pThis, cstr_t **ppCStr);
rsRetVal (*SeekCurrOffs)(strm_t *pThis);
rsRetVal (*Write)(strm_t *pThis, uchar *pBuf, size_t lenBuf);
rsRetVal (*WriteChar)(strm_t *pThis, uchar c);
rsRetVal (*WriteLong)(strm_t *pThis, long i);
rsRetVal (*SetFName)(strm_t *pThis, uchar *pszPrefix, size_t iLenPrefix);
rsRetVal (*SetDir)(strm_t *pThis, uchar *pszDir, size_t iLenDir);
rsRetVal (*Flush)(strm_t *pThis);
rsRetVal (*RecordBegin)(strm_t *pThis);
rsRetVal (*RecordEnd)(strm_t *pThis);
rsRetVal (*Serialize)(strm_t *pThis, strm_t *pStrm);
rsRetVal (*GetCurrOffset)(strm_t *pThis, int64 *pOffs);
rsRetVal (*SetWCntr)(strm_t *pThis, number_t *pWCnt);
rsRetVal (*Dup)(strm_t *pThis, strm_t **ppNew);
INTERFACEpropSetMeth(strm, bDeleteOnClose, int);
INTERFACEpropSetMeth(strm, iMaxFileSize, int);
INTERFACEpropSetMeth(strm, iMaxFiles, int);
INTERFACEpropSetMeth(strm, iFileNumDigits, int);
INTERFACEpropSetMeth(strm, tOperationsMode, int);
INTERFACEpropSetMeth(strm, tOpenMode, mode_t);
INTERFACEpropSetMeth(strm, sType, strmType_t);
INTERFACEpropSetMeth(strm, iZipLevel, int);
INTERFACEpropSetMeth(strm, bSync, int);
INTERFACEpropSetMeth(strm, sIOBufSize, size_t);
INTERFACEpropSetMeth(strm, iSizeLimit, off_t);
INTERFACEpropSetMeth(strm, iFlushInterval, int);
INTERFACEpropSetMeth(strm, pszSizeLimitCmd, uchar*);
ENDinterface(strm)
#define strmCURR_IF_VERSION 5 /* increment whenever you change the interface structure! */
/* prototypes */
PROTOTYPEObjClassInit(strm);
#endif /* #ifndef STREAM_H_INCLUDED */
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