1 /* low_level.c --- low level r/w access to FSX file structures 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_X_LOW_LEVEL_H 24 #define SVN_LIBSVN_FS_X_LOW_LEVEL_H 25 26 #include "svn_fs.h" 27 28 #include "fs_x.h" 29 #include "id.h" 30 31 #ifdef __cplusplus 32 extern "C" { 33 #endif /* __cplusplus */ 34 35 /* Kinds that a node-rev can be. */ 36 #define SVN_FS_X__KIND_FILE "file" 37 #define SVN_FS_X__KIND_DIR "dir" 38 39 /* The functions are grouped as follows: 40 * 41 * - revision footer 42 * - representation (as in "text:" and "props:" lines) 43 * - node revision 44 * - representation header ("DELTA" lines) 45 * - changed path list 46 */ 47 48 /* Given the FSX revision / pack FOOTER, parse it destructively 49 * and return the start offsets of the index data in *L2P_OFFSET and 50 * *P2L_OFFSET, respectively. Also, return the expected checksums in 51 * in *L2P_CHECKSUM and *P2L_CHECKSUM. 52 * 53 * FOOTER_OFFSET is used for validation. 54 * 55 * Note that REV is only used to construct nicer error objects that 56 * mention this revision. Allocate the checksums in RESULT_POOL. 57 */ 58 svn_error_t * 59 svn_fs_x__parse_footer(apr_off_t *l2p_offset, 60 svn_checksum_t **l2p_checksum, 61 apr_off_t *p2l_offset, 62 svn_checksum_t **p2l_checksum, 63 svn_stringbuf_t *footer, 64 svn_revnum_t rev, 65 apr_off_t footer_offset, 66 apr_pool_t *result_pool); 67 68 /* Given the offset of the L2P index data in L2P_OFFSET, the content 69 * checksum in L2P_CHECKSUM and the offset plus checksum of the P2L 70 * index data in P2L_OFFSET and P2L_CHECKSUM. 71 * 72 * Return the corresponding format 7+ revision / pack file footer. 73 * Allocate it in RESULT_POOL and use SCRATCH_POOL for temporary. 74 */ 75 svn_stringbuf_t * 76 svn_fs_x__unparse_footer(apr_off_t l2p_offset, 77 svn_checksum_t *l2p_checksum, 78 apr_off_t p2l_offset, 79 svn_checksum_t *p2l_checksum, 80 apr_pool_t *result_pool, 81 apr_pool_t *scratch_pool); 82 83 /* Parse the description of a representation from TEXT and store it 84 into *REP_P. TEXT will be invalidated by this call. Allocate *REP_P in 85 RESULT_POOL and use SCRATCH_POOL for temporaries. */ 86 svn_error_t * 87 svn_fs_x__parse_representation(svn_fs_x__representation_t **rep_p, 88 svn_stringbuf_t *text, 89 apr_pool_t *result_pool, 90 apr_pool_t *scratch_pool); 91 92 /* Return a formatted string that represents the location of representation 93 * REP. If MUTABLE_REP_TRUNCATED is given, the rep is for props or dir 94 * contents, and only a "-1" revision number will be given for a mutable rep. 95 * If MAY_BE_CORRUPT is true, guard for NULL when constructing the string. 96 * Allocate the result in RESULT_POOL and temporaries in SCRATCH_POOL. */ 97 svn_stringbuf_t * 98 svn_fs_x__unparse_representation(svn_fs_x__representation_t *rep, 99 svn_boolean_t mutable_rep_truncated, 100 apr_pool_t *result_pool, 101 apr_pool_t *scratch_pool); 102 103 /* Read a node-revision from STREAM. Set *NODEREV to the new structure, 104 allocated in RESULT_POOL. */ 105 svn_error_t * 106 svn_fs_x__read_noderev(svn_fs_x__noderev_t **noderev, 107 svn_stream_t *stream, 108 apr_pool_t *result_pool, 109 apr_pool_t *scratch_pool); 110 111 /* Write the node-revision NODEREV into the stream OUTFILE. 112 Temporary allocations are from SCRATCH_POOL. */ 113 svn_error_t * 114 svn_fs_x__write_noderev(svn_stream_t *outfile, 115 svn_fs_x__noderev_t *noderev, 116 apr_pool_t *scratch_pool); 117 118 /* This type enumerates all forms of representations that we support. */ 119 typedef enum svn_fs_x__rep_type_t 120 { 121 /* this is a DELTA representation with no base representation */ 122 svn_fs_x__rep_self_delta, 123 124 /* this is a DELTA representation against some base representation */ 125 svn_fs_x__rep_delta, 126 127 /* this is a representation in a star-delta container */ 128 svn_fs_x__rep_container 129 } svn_fs_x__rep_type_t; 130 131 /* This structure is used to hold the information stored in a representation 132 * header. */ 133 typedef struct svn_fs_x__rep_header_t 134 { 135 /* type of the representation, i.e. whether self-DELTA etc. */ 136 svn_fs_x__rep_type_t type; 137 138 /* if this rep is a delta against some other rep, that base rep can 139 * be found in this revision. Should be 0 if there is no base rep. */ 140 svn_revnum_t base_revision; 141 142 /* if this rep is a delta against some other rep, that base rep can 143 * be found at this item index within the base rep's revision. Should 144 * be 0 if there is no base rep. */ 145 apr_off_t base_item_index; 146 147 /* if this rep is a delta against some other rep, this is the (deltified) 148 * size of that base rep. Should be 0 if there is no base rep. */ 149 svn_filesize_t base_length; 150 151 /* length of the textual representation of the header in the rep or pack 152 * file, including EOL. Only valid after reading it from disk. 153 * Should be 0 otherwise. */ 154 apr_size_t header_size; 155 } svn_fs_x__rep_header_t; 156 157 /* Read the next line from STREAM and parse it as a text 158 representation header. Return the parsed entry in *HEADER, allocated 159 in RESULT_POOL. Perform temporary allocations in SCRATCH_POOL. */ 160 svn_error_t * 161 svn_fs_x__read_rep_header(svn_fs_x__rep_header_t **header, 162 svn_stream_t *stream, 163 apr_pool_t *result_pool, 164 apr_pool_t *scratch_pool); 165 166 /* Write the representation HEADER to STREAM. 167 * Use SCRATCH_POOL for allocations. */ 168 svn_error_t * 169 svn_fs_x__write_rep_header(svn_fs_x__rep_header_t *header, 170 svn_stream_t *stream, 171 apr_pool_t *scratch_pool); 172 173 /* Read up to MAX_COUNT of the changes from STREAM and store them in 174 *CHANGES, allocated in RESULT_POOL. Do temporary allocations in 175 SCRATCH_POOL. */ 176 svn_error_t * 177 svn_fs_x__read_changes(apr_array_header_t **changes, 178 svn_stream_t *stream, 179 int max_count, 180 apr_pool_t *result_pool, 181 apr_pool_t *scratch_pool); 182 183 /* Callback function used by svn_fs_x__read_changes_incrementally(), 184 * asking the receiver to process to process CHANGE using BATON. CHANGE 185 * and SCRATCH_POOL will not be valid beyond the current callback invocation. 186 */ 187 typedef svn_error_t *(*svn_fs_x__change_receiver_t)( 188 void *baton, 189 svn_fs_x__change_t *change, 190 apr_pool_t *scratch_pool); 191 192 /* Read all the changes from STREAM and invoke CHANGE_RECEIVER on each change. 193 Do all allocations in SCRATCH_POOL. */ 194 svn_error_t * 195 svn_fs_x__read_changes_incrementally(svn_stream_t *stream, 196 svn_fs_x__change_receiver_t 197 change_receiver, 198 void *change_receiver_baton, 199 apr_pool_t *scratch_pool); 200 201 /* Write the changed path info from CHANGES in filesystem FS to the 202 output stream STREAM. You may call this function multiple time on 203 the same stream. If you are writing to a (proto-)revision file, 204 the last call must set TERMINATE_LIST to write an extra empty line 205 that marks the end of the changed paths list. 206 Perform temporary allocations in SCRATCH_POOL. 207 */ 208 svn_error_t * 209 svn_fs_x__write_changes(svn_stream_t *stream, 210 svn_fs_t *fs, 211 apr_hash_t *changes, 212 svn_boolean_t terminate_list, 213 apr_pool_t *scratch_pool); 214 215 /* Parse the property list serialized in CONTENT and return it in 216 *PROPERTIES, allocated from RESULT_POOL. CONTENT must remain 217 valid at least until the next cleanup of RESULT_POOL. 218 */ 219 svn_error_t * 220 svn_fs_x__parse_properties(apr_hash_t **properties, 221 const svn_string_t *content, 222 apr_pool_t *result_pool); 223 224 /* Write the property list PROPLIST to STREAM in serialized format. 225 Use SCRATCH_POOL for temporary allocations. 226 */ 227 svn_error_t * 228 svn_fs_x__write_properties(svn_stream_t *stream, 229 apr_hash_t *proplist, 230 apr_pool_t *scratch_pool); 231 232 #ifdef __cplusplus 233 } 234 #endif /* __cplusplus */ 235 236 #endif /* SVN_LIBSVN_FS_X_LOW_LEVEL_H */ 237