contrib/subversion/subversion/libsvn_fs_fs/rep-cache.c

   1 /* rep-sharing.c --- the rep-sharing cache for fsfs
   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 #include "svn_pools.h"
  24
  25 #include "svn_private_config.h"
  26
  27 #include "fs_fs.h"
  28 #include "fs.h"
  29 #include "rep-cache.h"
  30 #include "../libsvn_fs/fs-loader.h"
  31
  32 #include "svn_path.h"
  33
  34 #include "private/svn_sqlite.h"
  35
  36 #include "rep-cache-db.h"
  37
  38 /* A few magic values */
  39 #define REP_CACHE_SCHEMA_FORMAT   1
  40
  41 REP_CACHE_DB_SQL_DECLARE_STATEMENTS(statements);
  42
  43
  44 \f
  45 /** Helper functions. **/
  46 static APR_INLINE const char *
  47 path_rep_cache_db(const char *fs_path,
  48                   apr_pool_t *result_pool)
  49 {
  50   return svn_dirent_join(fs_path, REP_CACHE_DB_NAME, result_pool);
  51 }
  52
  53 #define SVN_ERR_CLOSE(x, db) do                                       \
  54 {                                                                     \
  55   svn_error_t *svn__err = (x);                                        \
  56   if (svn__err)                                                       \
  57     return svn_error_compose_create(svn__err, svn_sqlite__close(db)); \
  58 } while (0)
  59
  60 \f
  61 /** Library-private API's. **/
  62
  63 /* Body of svn_fs_fs__open_rep_cache().
  64    Implements svn_atomic__init_once().init_func.
  65  */
  66 static svn_error_t *
  67 open_rep_cache(void *baton,
  68                apr_pool_t *pool)
  69 {
  70   svn_fs_t *fs = baton;
  71   fs_fs_data_t *ffd = fs->fsap_data;
  72   svn_sqlite__db_t *sdb;
  73   const char *db_path;
  74   int version;
  75
  76   /* Open (or create) the sqlite database.  It will be automatically
  77      closed when fs->pool is destroyed. */
  78   db_path = path_rep_cache_db(fs->path, pool);
  79 #ifndef WIN32
  80   {
  81     /* We want to extend the permissions that apply to the repository
  82        as a whole when creating a new rep cache and not simply default
  83        to umask. */
  84     svn_boolean_t exists;
  85
  86     SVN_ERR(svn_fs_fs__exists_rep_cache(&exists, fs, pool));
  87     if (!exists)
  88       {
  89         const char *current = svn_fs_fs__path_current(fs, pool);
  90         svn_error_t *err = svn_io_file_create_empty(db_path, pool);
  91
  92         if (err && !APR_STATUS_IS_EEXIST(err->apr_err))
  93           /* A real error. */
  94           return svn_error_trace(err);
  95         else if (err)
  96           /* Some other thread/process created the file. */
  97           svn_error_clear(err);
  98         else
  99           /* We created the file. */
 100           SVN_ERR(svn_io_copy_perms(current, db_path, pool));
 101       }
 102   }
 103 #endif
 104   SVN_ERR(svn_sqlite__open(&sdb, db_path,
 105                            svn_sqlite__mode_rwcreate, statements,
 106                            0, NULL, 0,
 107                            fs->pool, pool));
 108
 109   SVN_ERR_CLOSE(svn_sqlite__read_schema_version(&version, sdb, pool), sdb);
 110   if (version < REP_CACHE_SCHEMA_FORMAT)
 111     {
 112       /* Must be 0 -- an uninitialized (no schema) database. Create
 113          the schema. Results in schema version of 1.  */
 114       SVN_ERR_CLOSE(svn_sqlite__exec_statements(sdb, STMT_CREATE_SCHEMA), sdb);
 115     }
 116
 117   /* This is used as a flag that the database is available so don't
 118      set it earlier. */
 119   ffd->rep_cache_db = sdb;
 120
 121   return SVN_NO_ERROR;
 122 }
 123
 124 svn_error_t *
 125 svn_fs_fs__open_rep_cache(svn_fs_t *fs,
 126                           apr_pool_t *pool)
 127 {
 128   fs_fs_data_t *ffd = fs->fsap_data;
 129   svn_error_t *err = svn_atomic__init_once(&ffd->rep_cache_db_opened,
 130                                            open_rep_cache, fs, pool);
 131   return svn_error_quick_wrap(err, _("Couldn't open rep-cache database"));
 132 }
 133
 134 svn_error_t *
 135 svn_fs_fs__close_rep_cache(svn_fs_t *fs)
 136 {
 137   fs_fs_data_t *ffd = fs->fsap_data;
 138
 139   if (ffd->rep_cache_db)
 140     {
 141       SVN_ERR(svn_sqlite__close(ffd->rep_cache_db));
 142       ffd->rep_cache_db = NULL;
 143       ffd->rep_cache_db_opened = 0;
 144     }
 145
 146   return SVN_NO_ERROR;
 147 }
 148
 149 svn_error_t *
 150 svn_fs_fs__exists_rep_cache(svn_boolean_t *exists,
 151                             svn_fs_t *fs, apr_pool_t *pool)
 152 {
 153   svn_node_kind_t kind;
 154
 155   SVN_ERR(svn_io_check_path(path_rep_cache_db(fs->path, pool),
 156                             &kind, pool));
 157
 158   *exists = (kind != svn_node_none);
 159   return SVN_NO_ERROR;
 160 }
 161
 162 svn_error_t *
 163 svn_fs_fs__walk_rep_reference(svn_fs_t *fs,
 164                               svn_revnum_t start,
 165                               svn_revnum_t end,
 166                               svn_error_t *(*walker)(representation_t *,
 167                                                      void *,
 168                                                      svn_fs_t *,
 169                                                      apr_pool_t *),
 170                               void *walker_baton,
 171                               svn_cancel_func_t cancel_func,
 172                               void *cancel_baton,
 173                               apr_pool_t *pool)
 174 {
 175   fs_fs_data_t *ffd = fs->fsap_data;
 176   svn_sqlite__stmt_t *stmt;
 177   svn_boolean_t have_row;
 178   int iterations = 0;
 179
 180   apr_pool_t *iterpool = svn_pool_create(pool);
 181
 182   /* Don't check ffd->rep_sharing_allowed. */
 183   SVN_ERR_ASSERT(ffd->format >= SVN_FS_FS__MIN_REP_SHARING_FORMAT);
 184
 185   if (! ffd->rep_cache_db)
 186     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 187
 188   /* Check global invariants. */
 189   if (start == 0)
 190     {
 191       svn_revnum_t max;
 192
 193       SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db,
 194                                         STMT_GET_MAX_REV));
 195       SVN_ERR(svn_sqlite__step(&have_row, stmt));
 196       max = svn_sqlite__column_revnum(stmt, 0);
 197       SVN_ERR(svn_sqlite__reset(stmt));
 198       if (SVN_IS_VALID_REVNUM(max))  /* The rep-cache could be empty. */
 199         SVN_ERR(svn_fs_fs__ensure_revision_exists(max, fs, iterpool));
 200     }
 201
 202   SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db,
 203                                     STMT_GET_REPS_FOR_RANGE));
 204   SVN_ERR(svn_sqlite__bindf(stmt, "rr",
 205                             start, end));
 206
 207   /* Walk the cache entries. */
 208   SVN_ERR(svn_sqlite__step(&have_row, stmt));
 209   while (have_row)
 210     {
 211       representation_t *rep;
 212       const char *sha1_digest;
 213       svn_error_t *err;
 214       svn_checksum_t *checksum;
 215
 216       /* Clear ITERPOOL occasionally. */
 217       if (iterations++ % 16 == 0)
 218         svn_pool_clear(iterpool);
 219
 220       /* Check for cancellation. */
 221       if (cancel_func)
 222         {
 223           err = cancel_func(cancel_baton);
 224           if (err)
 225             return svn_error_compose_create(err, svn_sqlite__reset(stmt));
 226         }
 227
 228       /* Construct a representation_t. */
 229       rep = apr_pcalloc(iterpool, sizeof(*rep));
 230       svn_fs_fs__id_txn_reset(&rep->txn_id);
 231       sha1_digest = svn_sqlite__column_text(stmt, 0, iterpool);
 232       err = svn_checksum_parse_hex(&checksum, svn_checksum_sha1,
 233                                    sha1_digest, iterpool);
 234       if (err)
 235         return svn_error_compose_create(err, svn_sqlite__reset(stmt));
 236
 237       rep->has_sha1 = TRUE;
 238       memcpy(rep->sha1_digest, checksum->digest, sizeof(rep->sha1_digest));
 239       rep->revision = svn_sqlite__column_revnum(stmt, 1);
 240       rep->item_index = svn_sqlite__column_int64(stmt, 2);
 241       rep->size = svn_sqlite__column_int64(stmt, 3);
 242       rep->expanded_size = svn_sqlite__column_int64(stmt, 4);
 243
 244       /* Walk. */
 245       err = walker(rep, walker_baton, fs, iterpool);
 246       if (err)
 247         return svn_error_compose_create(err, svn_sqlite__reset(stmt));
 248
 249       SVN_ERR(svn_sqlite__step(&have_row, stmt));
 250     }
 251
 252   SVN_ERR(svn_sqlite__reset(stmt));
 253   svn_pool_destroy(iterpool);
 254
 255   return SVN_NO_ERROR;
 256 }
 257
 258
 259 /* This function's caller ignores most errors it returns.
 260    If you extend this function, check the callsite to see if you have
 261    to make it not-ignore additional error codes.  */
 262 svn_error_t *
 263 svn_fs_fs__get_rep_reference(representation_t **rep,
 264                              svn_fs_t *fs,
 265                              svn_checksum_t *checksum,
 266                              apr_pool_t *pool)
 267 {
 268   fs_fs_data_t *ffd = fs->fsap_data;
 269   svn_sqlite__stmt_t *stmt;
 270   svn_boolean_t have_row;
 271
 272   SVN_ERR_ASSERT(ffd->rep_sharing_allowed);
 273   if (! ffd->rep_cache_db)
 274     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 275
 276   /* We only allow SHA1 checksums in this table. */
 277   if (checksum->kind != svn_checksum_sha1)
 278     return svn_error_create(SVN_ERR_BAD_CHECKSUM_KIND, NULL,
 279                             _("Only SHA1 checksums can be used as keys in the "
 280                               "rep_cache table.\n"));
 281
 282   SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db, STMT_GET_REP));
 283   SVN_ERR(svn_sqlite__bindf(stmt, "s",
 284                             svn_checksum_to_cstring(checksum, pool)));
 285
 286   SVN_ERR(svn_sqlite__step(&have_row, stmt));
 287   if (have_row)
 288     {
 289       *rep = apr_pcalloc(pool, sizeof(**rep));
 290       svn_fs_fs__id_txn_reset(&(*rep)->txn_id);
 291       memcpy((*rep)->sha1_digest, checksum->digest,
 292              sizeof((*rep)->sha1_digest));
 293       (*rep)->has_sha1 = TRUE;
 294       (*rep)->revision = svn_sqlite__column_revnum(stmt, 0);
 295       (*rep)->item_index = svn_sqlite__column_int64(stmt, 1);
 296       (*rep)->size = svn_sqlite__column_int64(stmt, 2);
 297       (*rep)->expanded_size = svn_sqlite__column_int64(stmt, 3);
 298     }
 299   else
 300     *rep = NULL;
 301
 302   SVN_ERR(svn_sqlite__reset(stmt));
 303
 304   if (*rep)
 305     {
 306       /* Check that REP refers to a revision that exists in FS. */
 307       svn_error_t *err = svn_fs_fs__ensure_revision_exists((*rep)->revision,
 308                                                            fs, pool);
 309       if (err)
 310         return svn_error_createf(SVN_ERR_FS_CORRUPT, err,
 311                                  "Checksum '%s' in rep-cache is beyond HEAD",
 312                                  svn_checksum_to_cstring_display(checksum,
 313                                                                  pool));
 314     }
 315
 316   return SVN_NO_ERROR;
 317 }
 318
 319 svn_error_t *
 320 svn_fs_fs__set_rep_reference(svn_fs_t *fs,
 321                              representation_t *rep,
 322                              apr_pool_t *pool)
 323 {
 324   fs_fs_data_t *ffd = fs->fsap_data;
 325   svn_sqlite__stmt_t *stmt;
 326   svn_error_t *err;
 327   svn_checksum_t checksum;
 328   checksum.kind = svn_checksum_sha1;
 329   checksum.digest = rep->sha1_digest;
 330
 331   SVN_ERR_ASSERT(ffd->rep_sharing_allowed);
 332   if (! ffd->rep_cache_db)
 333     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 334
 335   /* We only allow SHA1 checksums in this table. */
 336   if (! rep->has_sha1)
 337     return svn_error_create(SVN_ERR_BAD_CHECKSUM_KIND, NULL,
 338                             _("Only SHA1 checksums can be used as keys in the "
 339                               "rep_cache table.\n"));
 340
 341   SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db, STMT_SET_REP));
 342   SVN_ERR(svn_sqlite__bindf(stmt, "siiii",
 343                             svn_checksum_to_cstring(&checksum, pool),
 344                             (apr_int64_t) rep->revision,
 345                             (apr_int64_t) rep->item_index,
 346                             (apr_int64_t) rep->size,
 347                             (apr_int64_t) rep->expanded_size));
 348
 349   err = svn_sqlite__insert(NULL, stmt);
 350   if (err)
 351     {
 352       representation_t *old_rep;
 353
 354       if (err->apr_err != SVN_ERR_SQLITE_CONSTRAINT)
 355         return svn_error_trace(err);
 356
 357       svn_error_clear(err);
 358
 359       /* Constraint failed so the mapping for SHA1_CHECKSUM->REP
 360          should exist.  If so that's cool -- just do nothing.  If not,
 361          that's a red flag!  */
 362       SVN_ERR(svn_fs_fs__get_rep_reference(&old_rep, fs, &checksum, pool));
 363
 364       if (!old_rep)
 365         {
 366           /* Something really odd at this point, we failed to insert the
 367              checksum AND failed to read an existing checksum.  Do we need
 368              to flag this? */
 369         }
 370     }
 371
 372   return SVN_NO_ERROR;
 373 }
 374
 375
 376 svn_error_t *
 377 svn_fs_fs__del_rep_reference(svn_fs_t *fs,
 378                              svn_revnum_t youngest,
 379                              apr_pool_t *pool)
 380 {
 381   fs_fs_data_t *ffd = fs->fsap_data;
 382   svn_sqlite__stmt_t *stmt;
 383
 384   SVN_ERR_ASSERT(ffd->format >= SVN_FS_FS__MIN_REP_SHARING_FORMAT);
 385   if (! ffd->rep_cache_db)
 386     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 387
 388   SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db,
 389                                     STMT_DEL_REPS_YOUNGER_THAN_REV));
 390   SVN_ERR(svn_sqlite__bindf(stmt, "r", youngest));
 391   SVN_ERR(svn_sqlite__step_done(stmt));
 392
 393   return SVN_NO_ERROR;
 394 }
 395
 396 /* Start a transaction to take an SQLite reserved lock that prevents
 397    other writes.
 398
 399    See unlock_rep_cache(). */
 400 static svn_error_t *
 401 lock_rep_cache(svn_fs_t *fs,
 402                apr_pool_t *pool)
 403 {
 404   fs_fs_data_t *ffd = fs->fsap_data;
 405
 406   if (! ffd->rep_cache_db)
 407     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 408
 409   SVN_ERR(svn_sqlite__exec_statements(ffd->rep_cache_db, STMT_LOCK_REP));
 410
 411   return SVN_NO_ERROR;
 412 }
 413
 414 /* End the transaction started by lock_rep_cache(). */
 415 static svn_error_t *
 416 unlock_rep_cache(svn_fs_t *fs,
 417                  apr_pool_t *pool)
 418 {
 419   fs_fs_data_t *ffd = fs->fsap_data;
 420
 421   SVN_ERR_ASSERT(ffd->rep_cache_db); /* was opened by lock_rep_cache() */
 422
 423   SVN_ERR(svn_sqlite__exec_statements(ffd->rep_cache_db, STMT_UNLOCK_REP));
 424
 425   return SVN_NO_ERROR;
 426 }
 427
 428 svn_error_t *
 429 svn_fs_fs__with_rep_cache_lock(svn_fs_t *fs,
 430                                svn_error_t *(*body)(void *,
 431                                                     apr_pool_t *),
 432                                void *baton,
 433                                apr_pool_t *pool)
 434 {
 435   svn_error_t *err;
 436
 437   SVN_ERR(lock_rep_cache(fs, pool));
 438   err = body(baton, pool);
 439   return svn_error_compose_create(err, unlock_rep_cache(fs, pool));
 440 }