subversion/libsvn_fs_base/bdb/env.h

   1 /* env.h : managing the BDB environment
   2  *
   3  * ====================================================================
   4  * Copyright (c) 2000-2005 CollabNet.  All rights reserved.
   5  *
   6  * This software is licensed as described in the file COPYING, which
   7  * you should have received as part of this distribution.  The terms
   8  * are also available at http://subversion.tigris.org/license-1.html.
   9  * If newer versions of this license are posted there, you may use a
  10  * newer version instead, at your option.
  11  *
  12  * This software consists of voluntary contributions made by many
  13  * individuals.  For exact contribution history, see the revision
  14  * history and logs, available at http://subversion.tigris.org/.
  15  * ====================================================================
  16  */
  17
  18 #ifndef SVN_LIBSVN_FS_BDB_ENV_H
  19 #define SVN_LIBSVN_FS_BDB_ENV_H
  20
  21 #define APU_WANT_DB
  22 #include <apu_want.h>
  23
  24 #include <apr_pools.h>
  25 #include <apr_file_io.h>
  26
  27 #include "bdb_compat.h"
  28
  29 #ifdef __cplusplus
  30 extern "C" {
  31 #endif /* __cplusplus */
  32
  33 \f
  34 /* The name of the Berkeley DB config file.  */
  35 #define BDB_CONFIG_FILE "DB_CONFIG"
  36
  37 /* Prefix string for BDB errors. */
  38 #define BDB_ERRPFX_STRING "svn (bdb): "
  39
  40
  41 /* Opaque descriptor of an open BDB environment. */
  42 typedef struct bdb_env_t bdb_env_t;
  43
  44
  45 /* Thread-specific error info related to the bdb_env_t. */
  46 typedef struct
  47 {
  48   /* We hold the extended info here until the Berkeley DB function returns.
  49      It usually returns an error code, triggering the collection and
  50      wrapping of the additional errors stored here.
  51
  52      Note: In some circumstances BDB will call the error function and not
  53      go on to return an error code, so the caller must always check whether
  54      pending_errors is non-NULL to avoid leaking errors.  This behaviour
  55      has been seen when running recovery on a repository upgraded to 4.3
  56      that still has old 4.2 log files present, a typical error string is
  57      "Skipping log file db/log.0000000002: historic log version 8" */
  58   svn_error_t *pending_errors;
  59
  60   /* We permitted clients of our library to install a Berkeley BDB errcall.
  61      Since we now use the errcall ourselves, we must store and invoke a user
  62      errcall, to maintain our API guarantees. */
  63   void (*user_callback)(const char *errpfx, char *msg);
  64
  65   /* The reference count.  It counts the number of bdb_env_baton_t
  66      instances that refer to this object. */
  67   unsigned refcount;
  68
  69 } bdb_error_info_t;
  70
  71
  72 /* The Berkeley DB environment baton. */
  73 typedef struct
  74 {
  75   /* The Berkeley DB environment. This pointer must be identical to
  76      the one in the bdb_env_t. */
  77   DB_ENV *env;
  78
  79   /* The (opaque) cached environment descriptor. */
  80   bdb_env_t *bdb;
  81
  82   /* The error info related to this baton. */
  83   bdb_error_info_t *error_info;
  84 } bdb_env_baton_t;
  85
  86
  87 \f
  88 /* Flag combination for opening a shared BDB environment. */
  89 #define SVN_BDB_STANDARD_ENV_FLAGS (DB_CREATE       \
  90                                     | DB_INIT_LOCK  \
  91                                     | DB_INIT_LOG   \
  92                                     | DB_INIT_MPOOL \
  93                                     | DB_INIT_TXN   \
  94                                     | SVN_BDB_AUTO_RECOVER)
  95
  96 /* Flag combination for opening a private BDB environment. */
  97 #define SVN_BDB_PRIVATE_ENV_FLAGS (DB_CREATE       \
  98                                    | DB_INIT_LOG   \
  99                                    | DB_INIT_MPOOL \
 100                                    | DB_INIT_TXN   \
 101                                    | DB_PRIVATE)
 102
 103
 104 /* Iniitalize the BDB back-end's private stuff. */
 105 svn_error_t *svn_fs_bdb__init(apr_pool_t* pool);
 106
 107
 108 /* Allocate the Berkeley DB descriptor BDB and open the environment.
 109  *
 110  * Allocate *BDBP from POOL and open (*BDBP)->env in PATH, using FLAGS
 111  * and MODE.  If applicable, set the BDB_AUTO_COMMIT flag for this
 112  * environment.
 113  *
 114  * Use POOL for temporary allocation.
 115  *
 116  * Note: This function may return a bdb_env_baton_t object that refers
 117  *       to a previously opened environment.  If FLAGS contains
 118  *       DB_PRIVATE and the environment is already open, the function
 119  *       will fail (this isn't a problem in practice, because a caller
 120  *       should obtain an exclusive lock on the repository before
 121  *       opening the environment).
 122  */
 123
 124 svn_error_t *svn_fs_bdb__open(bdb_env_baton_t **bdb_batonp,
 125                               const char *path,
 126                               u_int32_t flags, int mode,
 127                               apr_pool_t *pool);
 128
 129 /* Close the Berkeley DB descriptor BDB.
 130  *
 131  * Note: This function might not actually close the environment if it
 132  *       has been opened more than once.
 133  */
 134 svn_error_t *svn_fs_bdb__close(bdb_env_baton_t *bdb_baton);
 135
 136
 137 /* Get the panic state of the open BDB environment. */
 138 svn_boolean_t svn_fs_bdb__get_panic(bdb_env_baton_t *bdb_baton);
 139
 140 /* Set the panic flag on the open BDB environment. */
 141 void svn_fs_bdb__set_panic(bdb_env_baton_t *bdb_baton);
 142
 143
 144 /* Remove the Berkeley DB environment at PATH.
 145  *
 146  * Use POOL for temporary allocation.
 147  */
 148 svn_error_t *svn_fs_bdb__remove(const char *path, apr_pool_t *pool);
 149
 150 #ifdef __cplusplus
 151 }
 152 #endif /* __cplusplus */
 153
 154 #endif /* SVN_LIBSVN_FS_BDB_ENV_H */