1/* strings-table.h : internal interface to `strings' table
2 *
3 * ====================================================================
4 *    Licensed to the Apache Software Foundation (ASF) under one
5 *    or more contributor license agreements.  See the NOTICE file
6 *    distributed with this work for additional information
7 *    regarding copyright ownership.  The ASF licenses this file
8 *    to you under the Apache License, Version 2.0 (the
9 *    "License"); you may not use this file except in compliance
10 *    with the License.  You may obtain a copy of the License at
11 *
12 *      http://www.apache.org/licenses/LICENSE-2.0
13 *
14 *    Unless required by applicable law or agreed to in writing,
15 *    software distributed under the License is distributed on an
16 *    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 *    KIND, either express or implied.  See the License for the
18 *    specific language governing permissions and limitations
19 *    under the License.
20 * ====================================================================
21 */
22
23#ifndef SVN_LIBSVN_FS_STRINGS_TABLE_H
24#define SVN_LIBSVN_FS_STRINGS_TABLE_H
25
26#define SVN_WANT_BDB
27#include "svn_private_config.h"
28
29#include "svn_io.h"
30#include "svn_fs.h"
31#include "../trail.h"
32
33#ifdef __cplusplus
34extern "C" {
35#endif /* __cplusplus */
36
37
38/* This interface provides raw access to the `strings' table.  It does
39   not deal with deltification, undeltification, or skels.  It just
40   reads and writes strings of bytes. */
41
42
43/* Open a `strings' table in ENV.  If CREATE is non-zero, create
44 * one if it doesn't exist.  Set *STRINGS_P to the new table.
45 * Return a Berkeley DB error code.
46 */
47int svn_fs_bdb__open_strings_table(DB **strings_p,
48                                   DB_ENV *env,
49                                   svn_boolean_t create);
50
51
52/* Read *LEN bytes into BUF from OFFSET in string KEY in FS, as part
53 * of TRAIL.
54 *
55 * On return, *LEN is set to the number of bytes read.  If this value
56 * is less than the number requested, the end of the string has been
57 * reached (no error is returned on end-of-string).
58 *
59 * If OFFSET is past the end of the string, then *LEN will be set to
60 * zero. Callers which are advancing OFFSET as they read portions of
61 * the string can terminate their loop when *LEN is returned as zero
62 * (which will occur when OFFSET == length(the string)).
63 *
64 * If string KEY does not exist, the error SVN_ERR_FS_NO_SUCH_STRING
65 * is returned.
66 */
67svn_error_t *svn_fs_bdb__string_read(svn_fs_t *fs,
68                                     const char *key,
69                                     char *buf,
70                                     svn_filesize_t offset,
71                                     apr_size_t *len,
72                                     trail_t *trail,
73                                     apr_pool_t *pool);
74
75
76/* Set *SIZE to the size in bytes of string KEY in FS, as part of
77 * TRAIL.
78 *
79 * If string KEY does not exist, return SVN_ERR_FS_NO_SUCH_STRING.
80 */
81svn_error_t *svn_fs_bdb__string_size(svn_filesize_t *size,
82                                     svn_fs_t *fs,
83                                     const char *key,
84                                     trail_t *trail,
85                                     apr_pool_t *pool);
86
87
88/* Append LEN bytes from BUF to string *KEY in FS, as part of TRAIL.
89 *
90 * If *KEY is null, then create a new string and store the new key in
91 * *KEY (allocating it in POOL), and write LEN bytes from BUF
92 * as the initial contents of the string.
93 *
94 * If *KEY is not null but there is no string named *KEY, return
95 * SVN_ERR_FS_NO_SUCH_STRING.
96 *
97 * Note: to overwrite the old contents of a string, call
98 * svn_fs_bdb__string_clear() and then svn_fs_bdb__string_append().  */
99svn_error_t *svn_fs_bdb__string_append(svn_fs_t *fs,
100                                       const char **key,
101                                       apr_size_t len,
102                                       const char *buf,
103                                       trail_t *trail,
104                                       apr_pool_t *pool);
105
106
107/* Make string KEY in FS zero length, as part of TRAIL.
108 * If the string does not exist, return SVN_ERR_FS_NO_SUCH_STRING.
109 */
110svn_error_t *svn_fs_bdb__string_clear(svn_fs_t *fs,
111                                      const char *key,
112                                      trail_t *trail,
113                                      apr_pool_t *pool);
114
115
116/* Delete string KEY from FS, as part of TRAIL.
117 *
118 * If string KEY does not exist, return SVN_ERR_FS_NO_SUCH_STRING.
119 *
120 * WARNING: Deleting a string renders unusable any representations
121 * that refer to it.  Be careful.
122 */
123svn_error_t *svn_fs_bdb__string_delete(svn_fs_t *fs,
124                                       const char *key,
125                                       trail_t *trail,
126                                       apr_pool_t *pool);
127
128
129/* Copy the contents of the string referred to by KEY in FS into a new
130 * record, returning the new record's key in *NEW_KEY.  All
131 * allocations (including *NEW_KEY) occur in POOL.  */
132svn_error_t *svn_fs_bdb__string_copy(svn_fs_t *fs,
133                                     const char **new_key,
134                                     const char *key,
135                                     trail_t *trail,
136                                     apr_pool_t *pool);
137
138
139#ifdef __cplusplus
140}
141#endif /* __cplusplus */
142
143#endif /* SVN_LIBSVN_FS_STRINGS_TABLE_H */
144