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Edit File: journal.h
/* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, you can obtain one at https://mozilla.org/MPL/2.0/. * * See the COPYRIGHT file distributed with this work for additional * information regarding copyright ownership. */ #ifndef DNS_JOURNAL_H #define DNS_JOURNAL_H 1 /***** ***** Module Info *****/ /*! \file dns/journal.h * \brief * Database journaling. */ /*** *** Imports ***/ #include <inttypes.h> #include <stdbool.h> #include <isc/lang.h> #include <isc/magic.h> #include <dns/diff.h> #include <dns/name.h> #include <dns/rdata.h> #include <dns/types.h> /*** *** Defines. ***/ #define DNS_JOURNALOPT_RESIGN 0x00000001 #define DNS_JOURNAL_READ 0x00000000 /* false */ #define DNS_JOURNAL_CREATE 0x00000001 /* true */ #define DNS_JOURNAL_WRITE 0x00000002 #define DNS_JOURNAL_SIZE_MAX INT32_MAX #define DNS_JOURNAL_SIZE_MIN 4096 /*% Print transaction header data */ #define DNS_JOURNAL_PRINTXHDR 0x0001 /*% Rewrite whole journal file instead of compacting */ #define DNS_JOURNAL_COMPACTALL 0x0001 #define DNS_JOURNAL_VERSION1 0x0002 /*** *** 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, unsigned int mode, dns_journal_t **journalp); /*%< * Open the journal file 'filename' and create a dns_journal_t object for it. * * DNS_JOURNAL_CREATE open the journal for reading and writing and create * the journal if it does not exist. * DNS_JOURNAL_WRITE open the journal for reading and writing. * DNS_JOURNAL_READ open the journal for reading only. */ 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. */ bool dns_journal_empty(dns_journal_t *j); /*< * Find out if a journal is empty. */ bool dns_journal_recovered(dns_journal_t *j); /*< * Find out if the journal could be opened using old journal format */ uint32_t dns_journal_first_serial(dns_journal_t *j); 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, uint32_t begin_serial, uint32_t end_serial, size_t *xfrsizep); /*%< * Prepare to iterate over the transactions that will bring the database * from SOA serial number 'begin_serial' to 'end_serial'. * * If 'xfrsizep' is not NULL, then on success it will be set to the * total size of all records in the iteration (excluding headers). This * is meant to be a rough approximation of the size of an incremental * zone transfer, though it does not account for DNS message overhead * or name compression.) * * 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 addressable * 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, 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(dns_journal_t *j, dns_db_t *db, unsigned int options); /*%< * 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 'journal' is a valid journal *\li 'db' is a valid database which does not have a version * open for writing. * * Returns: *\li ISC_R_NOTFOUND when current serial in not in journal. *\li ISC_R_RANGE when current serial in not in journals range. *\li DNS_R_UPTODATE when the database was already up to date. *\li ISC_R_SUCCESS journal has been applied successfully to the * database without any issues. * * others */ isc_result_t dns_journal_print(isc_mem_t *mctx, uint32_t flags, 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); isc_result_t dns_db_diffx(dns_diff_t *diff, 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 diff/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' if * non-NULL. */ isc_result_t dns_journal_compact(isc_mem_t *mctx, char *filename, uint32_t serial, uint32_t flags, uint32_t target_size); /*%< * Attempt to compact the journal if it is greater that 'target_size'. * Changes from 'serial' onwards will be preserved. Changes prior than * that may be dropped in order to get the journal below `target_size`. * * If 'flags' includes DNS_JOURNAL_COMPACTALL, the entire journal is copied. * In this case, `serial` is ignored. This flag is used when upgrading or * downgrading the format version of the journal. If 'flags' also includes * DNS_JOURNAL_VERSION1, then the journal is copied out in the original * format used prior to BIND 9.16.12; otherwise it is copied in the * current format. * * If _COMPACTALL is not in use, and the journal file exists and is * non-empty, then 'serial' must exist in the journal. * * Returns: *\li ISC_R_SUCCESS *\li ISC_R_RANGE serial is outside the range existing in the journal * * Other errors may be returned from file operations. */ bool dns_journal_get_sourceserial(dns_journal_t *j, uint32_t *sourceserial); void dns_journal_set_sourceserial(dns_journal_t *j, uint32_t sourceserial); /*%< * Get and set source serial. * * Returns: * true if sourceserial has previously been set. */ ISC_LANG_ENDDECLS #endif /* DNS_JOURNAL_H */