svn_hash.h revision 299742
1/** 2 * @copyright 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 * @endcopyright 22 * 23 * @file svn_hash.h 24 * @brief Dumping and reading hash tables to/from files. 25 */ 26 27 28#ifndef SVN_HASH_H 29#define SVN_HASH_H 30 31#include <apr.h> 32#include <apr_pools.h> 33#include <apr_hash.h> 34#include <apr_tables.h> 35#include <apr_file_io.h> /* for apr_file_t */ 36 37#include "svn_types.h" 38#include "svn_io.h" /* for svn_stream_t */ 39 40#ifdef __cplusplus 41extern "C" { 42#endif /* __cplusplus */ 43 44 45/** The longest the "K <number>" line can be in one of our hashdump files. */ 46#define SVN_KEYLINE_MAXLEN 100 47 48/** 49 * @defgroup svn_hash_support Hash table serialization support 50 * @{ 51 */ 52 53/*----------------------------------------------------*/ 54 55/** Reading/writing hashtables to disk 56 * 57 * @defgroup svn_hash_read_write Reading and writing hashtables to disk 58 * @{ 59 */ 60 61/** 62 * The conventional terminator for hash dumps. 63 * 64 * @since New in 1.1. 65 */ 66#define SVN_HASH_TERMINATOR "END" 67 68/** 69 * Read a hash table from @a stream, storing the resultants names and 70 * values in @a hash. Use a @a pool for all allocations. @a hash will 71 * have <tt>const char *</tt> keys and <tt>svn_string_t *</tt> values. 72 * If @a terminator is NULL, expect the hash to be terminated by the 73 * end of the stream; otherwise, expect the hash to be terminated by a 74 * line containing @a terminator. Pass @c SVN_HASH_TERMINATOR to use 75 * the conventional terminator "END". 76 * 77 * @since New in 1.1. 78 */ 79svn_error_t * 80svn_hash_read2(apr_hash_t *hash, 81 svn_stream_t *stream, 82 const char *terminator, 83 apr_pool_t *pool); 84 85/** 86 * Dump @a hash to @a stream. Use @a pool for all allocations. @a 87 * hash has <tt>const char *</tt> keys and <tt>svn_string_t *</tt> 88 * values. If @a terminator is not NULL, terminate the hash with a 89 * line containing @a terminator. 90 * 91 * @since New in 1.1. 92 */ 93svn_error_t * 94svn_hash_write2(apr_hash_t *hash, 95 svn_stream_t *stream, 96 const char *terminator, 97 apr_pool_t *pool); 98 99/** 100 * Similar to svn_hash_read2(), but allows @a stream to contain 101 * deletion lines which remove entries from @a hash as well as adding 102 * to it. 103 * 104 * @since New in 1.1. 105 */ 106svn_error_t * 107svn_hash_read_incremental(apr_hash_t *hash, 108 svn_stream_t *stream, 109 const char *terminator, 110 apr_pool_t *pool); 111 112/** 113 * Similar to svn_hash_write2(), but only writes out entries for 114 * keys which differ between @a hash and @a oldhash, and also writes 115 * out deletion lines for keys which are present in @a oldhash but not 116 * in @a hash. 117 * 118 * @since New in 1.1. 119 */ 120svn_error_t * 121svn_hash_write_incremental(apr_hash_t *hash, 122 apr_hash_t *oldhash, 123 svn_stream_t *stream, 124 const char *terminator, 125 apr_pool_t *pool); 126 127/** 128 * This function behaves like svn_hash_read2(), but it only works 129 * on an apr_file_t input, empty files are accepted, and the hash is 130 * expected to be terminated with a line containing "END" or 131 * "PROPS-END". 132 * 133 * @deprecated Provided for backward compatibility with the 1.0 API. 134 */ 135SVN_DEPRECATED 136svn_error_t * 137svn_hash_read(apr_hash_t *hash, 138 apr_file_t *srcfile, 139 apr_pool_t *pool); 140 141/** 142 * This function behaves like svn_hash_write2(), but it only works 143 * on an apr_file_t output, and the terminator is always "END". 144 * 145 * @deprecated Provided for backward compatibility with the 1.0 API. 146 */ 147SVN_DEPRECATED 148svn_error_t * 149svn_hash_write(apr_hash_t *hash, 150 apr_file_t *destfile, 151 apr_pool_t *pool); 152 153/** @} */ 154 155 156/** Taking the "diff" of two hash tables. 157 * 158 * @defgroup svn_hash_diff Taking the diff of two hash tables. 159 * @{ 160 */ 161 162/** Hash key status indicator for svn_hash_diff_func_t. */ 163enum svn_hash_diff_key_status 164 { 165 /* Key is present in both hashes. */ 166 svn_hash_diff_key_both, 167 168 /* Key is present in first hash only. */ 169 svn_hash_diff_key_a, 170 171 /* Key is present in second hash only. */ 172 svn_hash_diff_key_b 173 }; 174 175 176/** Function type for expressing a key's status between two hash tables. */ 177typedef svn_error_t *(*svn_hash_diff_func_t) 178 (const void *key, apr_ssize_t klen, 179 enum svn_hash_diff_key_status status, 180 void *baton); 181 182 183/** Take the diff of two hashtables. 184 * 185 * For each key in the union of @a hash_a's and @a hash_b's keys, invoke 186 * @a diff_func exactly once, passing the key, the key's length, an enum 187 * @c svn_hash_diff_key_status indicating which table(s) the key appears 188 * in, and @a diff_func_baton. 189 * 190 * Process all keys of @a hash_a first, then all remaining keys of @a hash_b. 191 * 192 * If @a diff_func returns error, return that error immediately, without 193 * applying @a diff_func to anything else. 194 * 195 * @a hash_a or @a hash_b or both may be NULL; treat a null table as though 196 * empty. 197 * 198 * Use @a pool for temporary allocation. 199 */ 200svn_error_t * 201svn_hash_diff(apr_hash_t *hash_a, 202 apr_hash_t *hash_b, 203 svn_hash_diff_func_t diff_func, 204 void *diff_func_baton, 205 apr_pool_t *pool); 206 207/** @} */ 208 209 210/** 211 * @defgroup svn_hash_misc Miscellaneous hash APIs 212 * @{ 213 */ 214 215/** 216 * Return the keys to @a hash in @a *array. The keys are assumed to be 217 * (const char *). The keys are in no particular order. 218 * 219 * @a *array itself is allocated in @a pool; however, the keys are not 220 * copied from the hash. 221 * 222 * @since New in 1.5. 223 */ 224svn_error_t * 225svn_hash_keys(apr_array_header_t **array, 226 apr_hash_t *hash, 227 apr_pool_t *pool); 228 229/** 230 * Set @a *hash to a new hash whose keys come from the items in @a keys 231 * (an array of <tt>const char *</tt> items), and whose values are 232 * match their corresponding key. Use @a pool for all allocations 233 * (including @a *hash, its keys, and its values). 234 * 235 * @since New in 1.5. 236 */ 237svn_error_t * 238svn_hash_from_cstring_keys(apr_hash_t **hash, 239 const apr_array_header_t *keys, 240 apr_pool_t *pool); 241 242/** Shortcut for apr_hash_get() with a const char * key. 243 * 244 * @since New in 1.8. 245 */ 246#define svn_hash_gets(ht, key) \ 247 apr_hash_get(ht, key, APR_HASH_KEY_STRING) 248 249/** Shortcut for apr_hash_set() with a const char * key. 250 * 251 * @since New in 1.8. 252 */ 253#define svn_hash_sets(ht, key, val) \ 254 apr_hash_set(ht, key, APR_HASH_KEY_STRING, val) 255 256/** @} */ 257 258/** @} */ 259 260#ifdef __cplusplus 261} 262#endif /* __cplusplus */ 263 264#endif /* SVN_HASH_H */ 265