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 /* Check that REP refers to a revision that exists in FS. */
  54 static svn_error_t *
  55 rep_has_been_born(representation_t *rep,
  56                   svn_fs_t *fs,
  57                   apr_pool_t *pool)
  58 {
  59   SVN_ERR_ASSERT(rep);
  60
  61   SVN_ERR(svn_fs_fs__revision_exists(rep->revision, fs, pool));
  62
  63   return SVN_NO_ERROR;
  64 }
  65
  66
  67 \f
  68 /** Library-private API's. **/
  69
  70 /* Body of svn_fs_fs__open_rep_cache().
  71    Implements svn_atomic__init_once().init_func.
  72  */
  73 static svn_error_t *
  74 open_rep_cache(void *baton,
  75                apr_pool_t *pool)
  76 {
  77   svn_fs_t *fs = baton;
  78   fs_fs_data_t *ffd = fs->fsap_data;
  79   svn_sqlite__db_t *sdb;
  80   const char *db_path;
  81   int version;
  82
  83   /* Open (or create) the sqlite database.  It will be automatically
  84      closed when fs->pool is destoyed. */
  85   db_path = path_rep_cache_db(fs->path, pool);
  86   SVN_ERR(svn_sqlite__open(&sdb, db_path,
  87                            svn_sqlite__mode_rwcreate, statements,
  88                            0, NULL,
  89                            fs->pool, pool));
  90
  91   SVN_ERR(svn_sqlite__read_schema_version(&version, sdb, pool));
  92   if (version < REP_CACHE_SCHEMA_FORMAT)
  93     {
  94       /* Must be 0 -- an uninitialized (no schema) database. Create
  95          the schema. Results in schema version of 1.  */
  96       SVN_ERR(svn_sqlite__exec_statements(sdb, STMT_CREATE_SCHEMA));
  97     }
  98
  99   /* This is used as a flag that the database is available so don't
 100      set it earlier. */
 101   ffd->rep_cache_db = sdb;
 102
 103   return SVN_NO_ERROR;
 104 }
 105
 106 svn_error_t *
 107 svn_fs_fs__open_rep_cache(svn_fs_t *fs,
 108                           apr_pool_t *pool)
 109 {
 110   fs_fs_data_t *ffd = fs->fsap_data;
 111   svn_error_t *err = svn_atomic__init_once(&ffd->rep_cache_db_opened,
 112                                            open_rep_cache, fs, pool);
 113   return svn_error_quick_wrap(err, _("Couldn't open rep-cache database"));
 114 }
 115
 116 svn_error_t *
 117 svn_fs_fs__exists_rep_cache(svn_boolean_t *exists,
 118                             svn_fs_t *fs, apr_pool_t *pool)
 119 {
 120   svn_node_kind_t kind;
 121
 122   SVN_ERR(svn_io_check_path(path_rep_cache_db(fs->path, pool),
 123                             &kind, pool));
 124
 125   *exists = (kind != svn_node_none);
 126   return SVN_NO_ERROR;
 127 }
 128
 129 svn_error_t *
 130 svn_fs_fs__walk_rep_reference(svn_fs_t *fs,
 131                               svn_revnum_t start,
 132                               svn_revnum_t end,
 133                               svn_error_t *(*walker)(representation_t *,
 134                                                      void *,
 135                                                      svn_fs_t *,
 136                                                      apr_pool_t *),
 137                               void *walker_baton,
 138                               svn_cancel_func_t cancel_func,
 139                               void *cancel_baton,
 140                               apr_pool_t *pool)
 141 {
 142   fs_fs_data_t *ffd = fs->fsap_data;
 143   svn_sqlite__stmt_t *stmt;
 144   svn_boolean_t have_row;
 145   int iterations = 0;
 146
 147   apr_pool_t *iterpool = svn_pool_create(pool);
 148
 149   /* Don't check ffd->rep_sharing_allowed. */
 150   SVN_ERR_ASSERT(ffd->format >= SVN_FS_FS__MIN_REP_SHARING_FORMAT);
 151
 152   if (! ffd->rep_cache_db)
 153     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 154
 155   /* Check global invariants. */
 156   if (start == 0)
 157     {
 158       svn_revnum_t max;
 159
 160       SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db,
 161                                         STMT_GET_MAX_REV));
 162       SVN_ERR(svn_sqlite__step(&have_row, stmt));
 163       max = svn_sqlite__column_revnum(stmt, 0);
 164       SVN_ERR(svn_sqlite__reset(stmt));
 165       if (SVN_IS_VALID_REVNUM(max))  /* The rep-cache could be empty. */
 166         SVN_ERR(svn_fs_fs__revision_exists(max, fs, iterpool));
 167     }
 168
 169   SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db,
 170                                     STMT_GET_REPS_FOR_RANGE));
 171   SVN_ERR(svn_sqlite__bindf(stmt, "rr",
 172                             start, end));
 173
 174   /* Walk the cache entries. */
 175   SVN_ERR(svn_sqlite__step(&have_row, stmt));
 176   while (have_row)
 177     {
 178       representation_t *rep;
 179       const char *sha1_digest;
 180       svn_error_t *err;
 181
 182       /* Clear ITERPOOL occasionally. */
 183       if (iterations++ % 16 == 0)
 184         svn_pool_clear(iterpool);
 185
 186       /* Check for cancellation. */
 187       if (cancel_func)
 188         {
 189           err = cancel_func(cancel_baton);
 190           if (err)
 191             return svn_error_compose_create(err, svn_sqlite__reset(stmt));
 192         }
 193
 194       /* Construct a representation_t. */
 195       rep = apr_pcalloc(iterpool, sizeof(*rep));
 196       sha1_digest = svn_sqlite__column_text(stmt, 0, iterpool);
 197       err = svn_checksum_parse_hex(&rep->sha1_checksum,
 198                                    svn_checksum_sha1, sha1_digest,
 199                                    iterpool);
 200       if (err)
 201         return svn_error_compose_create(err, svn_sqlite__reset(stmt));
 202       rep->revision = svn_sqlite__column_revnum(stmt, 1);
 203       rep->offset = svn_sqlite__column_int64(stmt, 2);
 204       rep->size = svn_sqlite__column_int64(stmt, 3);
 205       rep->expanded_size = svn_sqlite__column_int64(stmt, 4);
 206
 207       /* Walk. */
 208       err = walker(rep, walker_baton, fs, iterpool);
 209       if (err)
 210         return svn_error_compose_create(err, svn_sqlite__reset(stmt));
 211
 212       SVN_ERR(svn_sqlite__step(&have_row, stmt));
 213     }
 214
 215   SVN_ERR(svn_sqlite__reset(stmt));
 216   svn_pool_destroy(iterpool);
 217
 218   return SVN_NO_ERROR;
 219 }
 220
 221
 222 /* This function's caller ignores most errors it returns.
 223    If you extend this function, check the callsite to see if you have
 224    to make it not-ignore additional error codes.  */
 225 svn_error_t *
 226 svn_fs_fs__get_rep_reference(representation_t **rep,
 227                              svn_fs_t *fs,
 228                              svn_checksum_t *checksum,
 229                              apr_pool_t *pool)
 230 {
 231   fs_fs_data_t *ffd = fs->fsap_data;
 232   svn_sqlite__stmt_t *stmt;
 233   svn_boolean_t have_row;
 234
 235   SVN_ERR_ASSERT(ffd->rep_sharing_allowed);
 236   if (! ffd->rep_cache_db)
 237     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 238
 239   /* We only allow SHA1 checksums in this table. */
 240   if (checksum->kind != svn_checksum_sha1)
 241     return svn_error_create(SVN_ERR_BAD_CHECKSUM_KIND, NULL,
 242                             _("Only SHA1 checksums can be used as keys in the "
 243                               "rep_cache table.\n"));
 244
 245   SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db, STMT_GET_REP));
 246   SVN_ERR(svn_sqlite__bindf(stmt, "s",
 247                             svn_checksum_to_cstring(checksum, pool)));
 248
 249   SVN_ERR(svn_sqlite__step(&have_row, stmt));
 250   if (have_row)
 251     {
 252       *rep = apr_pcalloc(pool, sizeof(**rep));
 253       (*rep)->sha1_checksum = svn_checksum_dup(checksum, pool);
 254       (*rep)->revision = svn_sqlite__column_revnum(stmt, 0);
 255       (*rep)->offset = svn_sqlite__column_int64(stmt, 1);
 256       (*rep)->size = svn_sqlite__column_int64(stmt, 2);
 257       (*rep)->expanded_size = svn_sqlite__column_int64(stmt, 3);
 258     }
 259   else
 260     *rep = NULL;
 261
 262   SVN_ERR(svn_sqlite__reset(stmt));
 263
 264   if (*rep)
 265     SVN_ERR(rep_has_been_born(*rep, fs, pool));
 266
 267   return SVN_NO_ERROR;
 268 }
 269
 270 svn_error_t *
 271 svn_fs_fs__set_rep_reference(svn_fs_t *fs,
 272                              representation_t *rep,
 273                              svn_boolean_t reject_dup,
 274                              apr_pool_t *pool)
 275 {
 276   fs_fs_data_t *ffd = fs->fsap_data;
 277   svn_sqlite__stmt_t *stmt;
 278   svn_error_t *err;
 279
 280   SVN_ERR_ASSERT(ffd->rep_sharing_allowed);
 281   if (! ffd->rep_cache_db)
 282     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 283
 284   /* We only allow SHA1 checksums in this table. */
 285   if (rep->sha1_checksum == NULL)
 286     return svn_error_create(SVN_ERR_BAD_CHECKSUM_KIND, NULL,
 287                             _("Only SHA1 checksums can be used as keys in the "
 288                               "rep_cache table.\n"));
 289
 290   SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db, STMT_SET_REP));
 291   SVN_ERR(svn_sqlite__bindf(stmt, "siiii",
 292                             svn_checksum_to_cstring(rep->sha1_checksum, pool),
 293                             (apr_int64_t) rep->revision,
 294                             (apr_int64_t) rep->offset,
 295                             (apr_int64_t) rep->size,
 296                             (apr_int64_t) rep->expanded_size));
 297
 298   err = svn_sqlite__insert(NULL, stmt);
 299   if (err)
 300     {
 301       representation_t *old_rep;
 302
 303       if (err->apr_err != SVN_ERR_SQLITE_CONSTRAINT)
 304         return svn_error_trace(err);
 305
 306       svn_error_clear(err);
 307
 308       /* Constraint failed so the mapping for SHA1_CHECKSUM->REP
 309          should exist.  If so, and the value is the same one we were
 310          about to write, that's cool -- just do nothing.  If, however,
 311          the value is *different*, that's a red flag!  */
 312       SVN_ERR(svn_fs_fs__get_rep_reference(&old_rep, fs, rep->sha1_checksum,
 313                                            pool));
 314
 315       if (old_rep)
 316         {
 317           if (reject_dup && ((old_rep->revision != rep->revision)
 318                              || (old_rep->offset != rep->offset)
 319                              || (old_rep->size != rep->size)
 320                              || (old_rep->expanded_size != rep->expanded_size)))
 321             return svn_error_createf(SVN_ERR_FS_CORRUPT, NULL,
 322                                      apr_psprintf(pool,
 323                               _("Representation key for checksum '%%s' exists "
 324                                 "in filesystem '%%s' with a different value "
 325                                 "(%%ld,%%%s,%%%s,%%%s) than what we were about "
 326                                 "to store (%%ld,%%%s,%%%s,%%%s)"),
 327                               APR_OFF_T_FMT, SVN_FILESIZE_T_FMT,
 328                               SVN_FILESIZE_T_FMT, APR_OFF_T_FMT,
 329                               SVN_FILESIZE_T_FMT, SVN_FILESIZE_T_FMT),
 330                  svn_checksum_to_cstring_display(rep->sha1_checksum, pool),
 331                  fs->path, old_rep->revision, old_rep->offset, old_rep->size,
 332                  old_rep->expanded_size, rep->revision, rep->offset, rep->size,
 333                  rep->expanded_size);
 334           else
 335             return SVN_NO_ERROR;
 336         }
 337       else
 338         {
 339           /* Something really odd at this point, we failed to insert the
 340              checksum AND failed to read an existing checksum.  Do we need
 341              to flag this? */
 342         }
 343     }
 344
 345   return SVN_NO_ERROR;
 346 }
 347
 348
 349 svn_error_t *
 350 svn_fs_fs__del_rep_reference(svn_fs_t *fs,
 351                              svn_revnum_t youngest,
 352                              apr_pool_t *pool)
 353 {
 354   fs_fs_data_t *ffd = fs->fsap_data;
 355   svn_sqlite__stmt_t *stmt;
 356
 357   SVN_ERR_ASSERT(ffd->format >= SVN_FS_FS__MIN_REP_SHARING_FORMAT);
 358   if (! ffd->rep_cache_db)
 359     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 360
 361   SVN_ERR(svn_sqlite__get_statement(&stmt, ffd->rep_cache_db,
 362                                     STMT_DEL_REPS_YOUNGER_THAN_REV));
 363   SVN_ERR(svn_sqlite__bindf(stmt, "r", youngest));
 364   SVN_ERR(svn_sqlite__step_done(stmt));
 365
 366   return SVN_NO_ERROR;
 367 }
 368
 369 svn_error_t *
 370 svn_fs_fs__lock_rep_cache(svn_fs_t *fs,
 371                           apr_pool_t *pool)
 372 {
 373   fs_fs_data_t *ffd = fs->fsap_data;
 374
 375   if (! ffd->rep_cache_db)
 376     SVN_ERR(svn_fs_fs__open_rep_cache(fs, pool));
 377
 378   SVN_ERR(svn_sqlite__exec_statements(ffd->rep_cache_db, STMT_LOCK_REP));
 379
 380   return SVN_NO_ERROR;
 381 }