subversion/libsvn_fs_base/bdb/strings-table.h

   1 /* strings-table.h : internal interface to `strings' table
   2  *
   3  * ====================================================================
   4  * Copyright (c) 2000-2004 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_STRINGS_TABLE_H
  19 #define SVN_LIBSVN_FS_STRINGS_TABLE_H
  20
  21 #define APU_WANT_DB
  22 #include <apu_want.h>
  23
  24 #include "svn_io.h"
  25 #include "svn_fs.h"
  26 #include "../trail.h"
  27
  28 #ifdef __cplusplus
  29 extern "C" {
  30 #endif /* __cplusplus */
  31
  32 \f
  33 /* This interface provides raw access to the `strings' table.  It does
  34    not deal with deltification, undeltification, or skels.  It just
  35    reads and writes strings of bytes. */
  36
  37
  38 /* Open a `strings' table in ENV.  If CREATE is non-zero, create
  39  * one if it doesn't exist.  Set *STRINGS_P to the new table.
  40  * Return a Berkeley DB error code.
  41  */
  42 int svn_fs_bdb__open_strings_table(DB **strings_p,
  43                                    DB_ENV *env,
  44                                    svn_boolean_t create);
  45
  46
  47 /* Read *LEN bytes into BUF from OFFSET in string KEY in FS, as part
  48  * of TRAIL.
  49  *
  50  * On return, *LEN is set to the number of bytes read.  If this value
  51  * is less than the number requested, the end of the string has been
  52  * reached (no error is returned on end-of-string).
  53  *
  54  * If OFFSET is past the end of the string, then *LEN will be set to
  55  * zero. Callers which are advancing OFFSET as they read portions of
  56  * the string can terminate their loop when *LEN is returned as zero
  57  * (which will occur when OFFSET == length(the string)).
  58  *
  59  * If string KEY does not exist, the error SVN_ERR_FS_NO_SUCH_STRING
  60  * is returned.
  61  */
  62 svn_error_t *svn_fs_bdb__string_read(svn_fs_t *fs,
  63                                      const char *key,
  64                                      char *buf,
  65                                      svn_filesize_t offset,
  66                                      apr_size_t *len,
  67                                      trail_t *trail,
  68                                      apr_pool_t *pool);
  69
  70
  71 /* Set *SIZE to the size in bytes of string KEY in FS, as part of
  72  * TRAIL.
  73  *
  74  * If string KEY does not exist, return SVN_ERR_FS_NO_SUCH_STRING.
  75  */
  76 svn_error_t *svn_fs_bdb__string_size(svn_filesize_t *size,
  77                                      svn_fs_t *fs,
  78                                      const char *key,
  79                                      trail_t *trail,
  80                                      apr_pool_t *pool);
  81
  82
  83 /* Append LEN bytes from BUF to string *KEY in FS, as part of TRAIL.
  84  *
  85  * If *KEY is null, then create a new string and store the new key in
  86  * *KEY (allocating it in POOL), and write LEN bytes from BUF
  87  * as the initial contents of the string.
  88  *
  89  * If *KEY is not null but there is no string named *KEY, return
  90  * SVN_ERR_FS_NO_SUCH_STRING.
  91  *
  92  * Note: to overwrite the old contents of a string, call
  93  * svn_fs_bdb__string_clear() and then svn_fs_bdb__string_append().  */
  94 svn_error_t *svn_fs_bdb__string_append(svn_fs_t *fs,
  95                                        const char **key,
  96                                        apr_size_t len,
  97                                        const char *buf,
  98                                        trail_t *trail,
  99                                        apr_pool_t *pool);
 100
 101
 102 /* Make string KEY in FS zero length, as part of TRAIL.
 103  * If the string does not exist, return SVN_ERR_FS_NO_SUCH_STRING.
 104  */
 105 svn_error_t *svn_fs_bdb__string_clear(svn_fs_t *fs,
 106                                       const char *key,
 107                                       trail_t *trail,
 108                                       apr_pool_t *pool);
 109
 110
 111 /* Delete string KEY from FS, as part of TRAIL.
 112  *
 113  * If string KEY does not exist, return SVN_ERR_FS_NO_SUCH_STRING.
 114  *
 115  * WARNING: Deleting a string renders unusable any representations
 116  * that refer to it.  Be careful.
 117  */
 118 svn_error_t *svn_fs_bdb__string_delete(svn_fs_t *fs,
 119                                        const char *key,
 120                                        trail_t *trail,
 121                                        apr_pool_t *pool);
 122
 123
 124 /* Copy the contents of the string referred to by KEY in FS into a new
 125  * record, returning the new record's key in *NEW_KEY.  All
 126  * allocations (including *NEW_KEY) occur in POOL.  */
 127 svn_error_t *svn_fs_bdb__string_copy(svn_fs_t *fs,
 128                                      const char **new_key,
 129                                      const char *key,
 130                                      trail_t *trail,
 131                                      apr_pool_t *pool);
 132
 133
 134 #ifdef __cplusplus
 135 }
 136 #endif /* __cplusplus */
 137
 138 #endif /* SVN_LIBSVN_FS_STRINGS_TABLE_H */