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Diffstat (limited to 'lib/dns/include/dns/journal.h')
| -rw-r--r-- | lib/dns/include/dns/journal.h | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/lib/dns/include/dns/journal.h b/lib/dns/include/dns/journal.h new file mode 100644 index 0000000..72468f2 --- /dev/null +++ b/lib/dns/include/dns/journal.h @@ -0,0 +1,282 @@ +/* + * Copyright (C) 2004-2008 Internet Systems Consortium, Inc. ("ISC") + * Copyright (C) 1999-2001 Internet Software Consortium. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +/* $Id: journal.h,v 1.33 2008/04/01 23:47:10 tbox Exp $ */ + +#ifndef DNS_JOURNAL_H +#define DNS_JOURNAL_H 1 + +/***** + ***** Module Info + *****/ + +/*! \file dns/journal.h + * \brief + * Database journalling. + */ + +/*** + *** Imports + ***/ + +#include <isc/lang.h> +#include <isc/magic.h> + +#include <dns/name.h> +#include <dns/diff.h> +#include <dns/rdata.h> +#include <dns/types.h> + +/*** + *** Defines. + ***/ +#define DNS_JOURNALOPT_RESIGN 0x00000001 + +/*** + *** Types + ***/ + +/*% + * A dns_journal_t represents an open journal file. This is an opaque type. + * + * A particular dns_journal_t object may be opened for writing, in which case + * it can be used for writing transactions to a journal file, or it can be + * opened for reading, in which case it can be used for reading transactions + * from (iterating over) a journal file. A single dns_journal_t object may + * not be used for both purposes. + */ +typedef struct dns_journal dns_journal_t; + + +/*** + *** Functions + ***/ + +ISC_LANG_BEGINDECLS + +/**************************************************************************/ + +isc_result_t +dns_db_createsoatuple(dns_db_t *db, dns_dbversion_t *ver, isc_mem_t *mctx, + dns_diffop_t op, dns_difftuple_t **tp); +/*!< brief + * Create a diff tuple for the current database SOA. + * XXX this probably belongs somewhere else. + */ + + +/*@{*/ +#define DNS_SERIAL_GT(a, b) ((int)(((a) - (b)) & 0xFFFFFFFF) > 0) +#define DNS_SERIAL_GE(a, b) ((int)(((a) - (b)) & 0xFFFFFFFF) >= 0) +/*!< brief + * Compare SOA serial numbers. DNS_SERIAL_GT(a, b) returns true iff + * a is "greater than" b where "greater than" is as defined in RFC1982. + * DNS_SERIAL_GE(a, b) returns true iff a is "greater than or equal to" b. + */ +/*@}*/ + +/**************************************************************************/ +/* + * Journal object creation and destruction. + */ + +isc_result_t +dns_journal_open(isc_mem_t *mctx, const char *filename, isc_boolean_t write, + dns_journal_t **journalp); +/*%< + * Open the journal file 'filename' and create a dns_journal_t object for it. + * + * If 'write' is ISC_TRUE, the journal is open for writing. If it does + * not exist, it is created. + * + * If 'write' is ISC_FALSE, the journal is open for reading. If it does + * not exist, ISC_R_NOTFOUND is returned. + */ + +void +dns_journal_destroy(dns_journal_t **journalp); +/*%< + * Destroy a dns_journal_t, closing any open files and freeing its memory. + */ + +/**************************************************************************/ +/* + * Writing transactions to journals. + */ + +isc_result_t +dns_journal_begin_transaction(dns_journal_t *j); +/*%< + * Prepare to write a new transaction to the open journal file 'j'. + * + * Requires: + * \li 'j' is open for writing. + */ + +isc_result_t +dns_journal_writediff(dns_journal_t *j, dns_diff_t *diff); +/*%< + * Write 'diff' to the current transaction of journal file 'j'. + * + * Requires: + * \li 'j' is open for writing and dns_journal_begin_transaction() + * has been called. + * + *\li 'diff' is a full or partial, correctly ordered IXFR + * difference sequence. + */ + +isc_result_t +dns_journal_commit(dns_journal_t *j); +/*%< + * Commit the current transaction of journal file 'j'. + * + * Requires: + * \li 'j' is open for writing and dns_journal_begin_transaction() + * has been called. + * + * \li dns_journal_writediff() has been called one or more times + * to form a complete, correctly ordered IXFR difference + * sequence. + */ + +isc_result_t +dns_journal_write_transaction(dns_journal_t *j, dns_diff_t *diff); +/*% + * Write a complete transaction at once to a journal file, + * sorting it if necessary, and commit it. Equivalent to calling + * dns_diff_sort(), dns_journal_begin_transaction(), + * dns_journal_writediff(), and dns_journal_commit(). + * + * Requires: + *\li 'j' is open for writing. + * + * \li 'diff' contains exactly one SOA deletion, one SOA addition + * with a greater serial number, and possibly other changes, + * in arbitrary order. + */ + +/**************************************************************************/ +/* + * Reading transactions from journals. + */ + +isc_uint32_t +dns_journal_first_serial(dns_journal_t *j); +isc_uint32_t +dns_journal_last_serial(dns_journal_t *j); +/*%< + * Get the first and last addressable serial number in the journal. + */ + +isc_result_t +dns_journal_iter_init(dns_journal_t *j, + isc_uint32_t begin_serial, isc_uint32_t end_serial); +/*%< + * Prepare to iterate over the transactions that will bring the database + * from SOA serial number 'begin_serial' to 'end_serial'. + * + * Returns: + *\li ISC_R_SUCCESS + *\li ISC_R_RANGE begin_serial is outside the addressable range. + *\li ISC_R_NOTFOUND begin_serial is within the range of adressable + * serial numbers covered by the journal, but + * this particular serial number does not exist. + */ + +/*@{*/ +isc_result_t +dns_journal_first_rr(dns_journal_t *j); +isc_result_t +dns_journal_next_rr(dns_journal_t *j); +/*%< + * Position the iterator at the first/next RR in a journal + * transaction sequence established using dns_journal_iter_init(). + * + * Requires: + * \li dns_journal_iter_init() has been called. + * + */ +/*@}*/ + +void +dns_journal_current_rr(dns_journal_t *j, dns_name_t **name, isc_uint32_t *ttl, + dns_rdata_t **rdata); +/*%< + * Get the name, ttl, and rdata of the current journal RR. + * + * Requires: + * \li The last call to dns_journal_first_rr() or dns_journal_next_rr() + * returned ISC_R_SUCCESS. + */ + +/**************************************************************************/ +/* + * Database roll-forward. + */ + +isc_result_t +dns_journal_rollforward(isc_mem_t *mctx, dns_db_t *db, unsigned int options, + const char *filename); +/*%< + * Roll forward (play back) the journal file "filename" into the + * database "db". This should be called when the server starts + * after a shutdown or crash. + * + * Requires: + *\li 'mctx' is a valid memory context. + *\li 'db' is a valid database which does not have a version + * open for writing. + *\li 'filename' is the name of the journal file belonging to 'db'. + * + * Returns: + *\li DNS_R_NOJOURNAL when journal does not exist. + *\li ISC_R_NOTFOUND when current serial in not in journal. + *\li ISC_R_RANGE when current serial in not in journals range. + *\li ISC_R_SUCCESS journal has been applied successfully to database. + * others + */ + +isc_result_t +dns_journal_print(isc_mem_t *mctx, const char *filename, FILE *file); +/* For debugging not general use */ + +isc_result_t +dns_db_diff(isc_mem_t *mctx, + dns_db_t *dba, dns_dbversion_t *dbvera, + dns_db_t *dbb, dns_dbversion_t *dbverb, + const char *journal_filename); +/*%< + * Compare the databases 'dba' and 'dbb' and generate a journal + * entry containing the changes to make 'dba' from 'dbb' (note + * the order). This journal entry will consist of a single, + * possibly very large transaction. Append the journal + * entry to the journal file specified by 'journal_filename'. + */ + +isc_result_t +dns_journal_compact(isc_mem_t *mctx, char *filename, isc_uint32_t serial, + isc_uint32_t target_size); +/*%< + * Attempt to compact the journal if it is greater that 'target_size'. + * Changes from 'serial' onwards will be preserved. If the journal + * exists and is non-empty 'serial' must exist in the journal. + */ + +ISC_LANG_ENDDECLS + +#endif /* DNS_JOURNAL_H */ |