/* dbt.h --- interface to DBT-frobbing functions * * ==================================================================== * Copyright (c) 2000-2004, 2009 CollabNet. All rights reserved. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at http://subversion.tigris.org/license-1.html. * If newer versions of this license are posted there, you may use a * newer version instead, at your option. * * This software consists of voluntary contributions made by many * individuals. For exact contribution history, see the revision * history and logs, available at http://subversion.tigris.org/. * ==================================================================== */ #ifndef SVN_LIBSVN_FS_DBT_H #define SVN_LIBSVN_FS_DBT_H #include <apr_pools.h> #define SVN_WANT_BDB #include "svn_private_config.h" #include "svn_fs.h" #include "private/svn_skel.h" #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ /* Set all fields of DBT to zero. Return DBT. */ DBT *svn_fs_base__clear_dbt(DBT *dbt); /* Set DBT to retrieve no data. This is useful when you're just probing the table to see if an entry exists, or to find a key, but don't care what the value is. Return DBT. */ DBT *svn_fs_base__nodata_dbt(DBT *dbt); /* Set DBT to refer to the SIZE bytes at DATA. Return DBT. */ DBT *svn_fs_base__set_dbt(DBT *dbt, const void *data, u_int32_t size); /* Prepare DBT to hold data returned from Berkeley DB. Return DBT. Clear all its fields to zero, but set the DB_DBT_MALLOC flag, requesting that Berkeley DB place the returned data in a freshly malloc'd block. If the database operation succeeds, the caller then owns the data block, and is responsible for making sure it gets freed. You can use this with svn_fs_base__track_dbt: svn_fs_base__result_dbt (&foo); ... some Berkeley DB operation that puts data in foo ... svn_fs_base__track_dbt (&foo, pool); This arrangement is: - thread-safe --- the returned data is allocated via malloc, and won't be overwritten if some other thread performs an operation on the same table. See the explanation of ``Retrieved key/data permanence'' in the section of the Berkeley DB manual on the DBT type. - pool-friendly --- the data returned by Berkeley DB is now guaranteed to be freed when POOL is cleared. */ DBT *svn_fs_base__result_dbt(DBT *dbt); /* Arrange for POOL to `track' DBT's data: when POOL is cleared, DBT->data will be freed, using `free'. If DBT->data is zero, do nothing. This is meant for use with svn_fs_base__result_dbt; see the explanation there. */ DBT *svn_fs_base__track_dbt(DBT *dbt, apr_pool_t *pool); /* Prepare DBT for use as a key into a RECNO table. This call makes DBT refer to the db_recno_t pointed to by RECNO as its buffer; the record number you assign to *RECNO will be the table key. */ DBT *svn_fs_base__recno_dbt(DBT *dbt, db_recno_t *recno); /* Compare two DBT values in byte-by-byte lexicographic order. */ int svn_fs_base__compare_dbt(const DBT *a, const DBT *b); /* Set DBT to the unparsed form of ID; allocate memory from POOL. Return DBT. */ DBT *svn_fs_base__id_to_dbt(DBT *dbt, const svn_fs_id_t *id, apr_pool_t *pool); /* Set DBT to the unparsed form of SKEL; allocate memory from POOL. Return DBT. */ DBT *svn_fs_base__skel_to_dbt(DBT *dbt, svn_skel_t *skel, apr_pool_t *pool); /* Set DBT to the text of the null-terminated string STR. DBT will refer to STR's storage. Return DBT. */ DBT *svn_fs_base__str_to_dbt(DBT *dbt, const char *str); /* Set DBT to the bytes contained by CHECKSUM. DBT will refer to CHECKSUM's storage. Return DBT.*/ DBT *svn_fs_base__checksum_to_dbt(DBT* dbt, svn_checksum_t *checksum); #ifdef __cplusplus } #endif /* __cplusplus */ #endif /* SVN_LIBSVN_FS_DBT_H */