rev_file.h revision 299742 
1/* rev_file.h --- revision file and index access data structure
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__REV_FILE_H
24#define SVN_LIBSVN_FS__REV_FILE_H
25
26#include "svn_fs.h"
27#include "id.h"
28
29/* In format 7, index files must be read in sync with the respective
30 * revision / pack file.  I.e. we must use packed index files for packed
31 * rev files and unpacked ones for non-packed rev files.  So, the whole
32 * point is to open them with matching "is packed" setting in case some
33 * background pack process was run.
34 */
35
36/* Opaque index stream type.
37 */
38typedef struct svn_fs_fs__packed_number_stream_t
39  svn_fs_fs__packed_number_stream_t;
40
41/* Data file, including indexes data, and associated properties for
42 * START_REVISION.  As the FILE is kept open, background pack operations
43 * will not cause access to this file to fail.
44 */
45typedef struct svn_fs_fs__revision_file_t
46{
47  /* first (potentially only) revision in the rev / pack file.
48   * SVN_INVALID_REVNUM for txn proto-rev files. */
49  svn_revnum_t start_revision;
50
51  /* the revision was packed when the first file / stream got opened */
52  svn_boolean_t is_packed;
53
54  /* rev / pack file */
55  apr_file_t *file;
56
57  /* stream based on FILE and not NULL exactly when FILE is not NULL */
58  svn_stream_t *stream;
59
60  /* the opened P2L index stream or NULL.  Always NULL for txns. */
61  svn_fs_fs__packed_number_stream_t *p2l_stream;
62
63  /* the opened L2P index stream or NULL.  Always NULL for txns. */
64  svn_fs_fs__packed_number_stream_t *l2p_stream;
65
66  /* Copied from FS->FFD->BLOCK_SIZE upon creation.  It allows us to
67   * use aligned seek() without having the FS handy. */
68  apr_off_t block_size;
69
70  /* Offset within FILE at which the rev data ends and the L2P index
71   * data starts. Less than P2L_OFFSET. -1 if svn_fs_fs__auto_read_footer
72   * has not been called, yet. */
73  apr_off_t l2p_offset;
74
75  /* MD5 checksum on the whole on-disk representation of the L2P index.
76   * NULL if svn_fs_fs__auto_read_footer has not been called, yet. */
77  svn_checksum_t *l2p_checksum;
78
79  /* Offset within FILE at which the L2P index ends and the P2L index
80   * data starts. Greater than L2P_OFFSET. -1 if svn_fs_fs__auto_read_footer
81   * has not been called, yet. */
82  apr_off_t p2l_offset;
83
84  /* MD5 checksum on the whole on-disk representation of the P2L index.
85   * NULL if svn_fs_fs__auto_read_footer has not been called, yet. */
86  svn_checksum_t *p2l_checksum;
87
88  /* Offset within FILE at which the P2L index ends and the footer starts.
89   * Greater than P2L_OFFSET. -1 if svn_fs_fs__auto_read_footer has not
90   * been called, yet. */
91  apr_off_t footer_offset;
92
93  /* pool containing this object */
94  apr_pool_t *pool;
95} svn_fs_fs__revision_file_t;
96
97/* Open the correct revision file for REV.  If the filesystem FS has
98 * been packed, *FILE will be set to the packed file; otherwise, set *FILE
99 * to the revision file for REV.  Return SVN_ERR_FS_NO_SUCH_REVISION if the
100 * file doesn't exist.  Allocate *FILE in RESULT_POOL and use SCRATCH_POOL
101 * for temporaries. */
102svn_error_t *
103svn_fs_fs__open_pack_or_rev_file(svn_fs_fs__revision_file_t **file,
104                                 svn_fs_t *fs,
105                                 svn_revnum_t rev,
106                                 apr_pool_t *result_pool,
107                                 apr_pool_t *scratch_pool);
108
109/* Open the correct revision file for REV with read and write access.
110 * If necessary, temporarily reset the file's read-only state.  If the
111 * filesystem FS has been packed, *FILE will be set to the packed file;
112 * otherwise, set *FILE to the revision file for REV.
113 *
114 * Return SVN_ERR_FS_NO_SUCH_REVISION if the file doesn't exist.
115 * Allocate *FILE in RESULT_POOL and use SCRATCH_POOLfor temporaries. */
116svn_error_t *
117svn_fs_fs__open_pack_or_rev_file_writable(svn_fs_fs__revision_file_t **file,
118                                          svn_fs_t *fs,
119                                          svn_revnum_t rev,
120                                          apr_pool_t *result_pool,
121                                          apr_pool_t *scratch_pool);
122
123/* If the footer data in FILE has not been read, yet, do so now.
124 * Index locations will only be read upon request as we assume they get
125 * cached and the FILE is usually used for REP data access only.
126 * Hence, the separate step.
127 */
128svn_error_t *
129svn_fs_fs__auto_read_footer(svn_fs_fs__revision_file_t *file);
130
131/* Open the proto-rev file of transaction TXN_ID in FS and return it in *FILE.
132 * Allocate *FILE in RESULT_POOL use and SCRATCH_POOL for temporaries.. */
133svn_error_t *
134svn_fs_fs__open_proto_rev_file(svn_fs_fs__revision_file_t **file,
135                               svn_fs_t *fs,
136                               const svn_fs_fs__id_part_t *txn_id,
137                               apr_pool_t* result_pool,
138                               apr_pool_t *scratch_pool);
139
140/* Close all files and streams in FILE.
141 */
142svn_error_t *
143svn_fs_fs__close_revision_file(svn_fs_fs__revision_file_t *file);
144
145#endif
146