subversion/libsvn_fs_base/bdb/changes-table.c

   1 /* changes-table.c : operations on the `changes' table
   2  *
   3  * ====================================================================
   4  * Copyright (c) 2000-2007 CollabNet.  All rights reserved.
   5  *
   6  * This software is licensed as described in the file COPYING, which
   7  * you should have received as part of this distribution.  The terms
   8  * are also available at http://subversion.tigris.org/license-1.html.
   9  * If newer versions of this license are posted there, you may use a
  10  * newer version instead, at your option.
  11  *
  12  * This software consists of voluntary contributions made by many
  13  * individuals.  For exact contribution history, see the revision
  14  * history and logs, available at http://subversion.tigris.org/.
  15  * ====================================================================
  16  */
  17
  18 #include "bdb_compat.h"
  19
  20 #include <apr_hash.h>
  21 #include <apr_tables.h>
  22
  23 #include "svn_fs.h"
  24 #include "svn_pools.h"
  25 #include "svn_path.h"
  26 #include "../fs.h"
  27 #include "../err.h"
  28 #include "../trail.h"
  29 #include "../id.h"
  30 #include "../util/fs_skels.h"
  31 #include "../../libsvn_fs/fs-loader.h"
  32 #include "bdb-err.h"
  33 #include "dbt.h"
  34 #include "changes-table.h"
  35
  36
  37 #include "svn_private_config.h"
  38
  39 \f
  40 /*** Creating and opening the changes table. ***/
  41
  42 int
  43 svn_fs_bdb__open_changes_table(DB **changes_p,
  44                                DB_ENV *env,
  45                                svn_boolean_t create)
  46 {
  47   const u_int32_t open_flags = (create ? (DB_CREATE | DB_EXCL) : 0);
  48   DB *changes;
  49
  50   BDB_ERR(svn_fs_bdb__check_version());
  51   BDB_ERR(db_create(&changes, env, 0));
  52
  53   /* Enable duplicate keys. This allows us to store the changes
  54      one-per-row.  Note: this must occur before ->open().  */
  55   BDB_ERR(changes->set_flags(changes, DB_DUP));
  56
  57   BDB_ERR((changes->open)(SVN_BDB_OPEN_PARAMS(changes, NULL),
  58                           "changes", 0, DB_BTREE,
  59                           open_flags, 0666));
  60
  61   *changes_p = changes;
  62   return 0;
  63 }
  64
  65
  66 \f
  67 /*** Storing and retrieving changes.  ***/
  68
  69 svn_error_t *
  70 svn_fs_bdb__changes_add(svn_fs_t *fs,
  71                         const char *key,
  72                         change_t *change,
  73                         trail_t *trail,
  74                         apr_pool_t *pool)
  75 {
  76   base_fs_data_t *bfd = fs->fsap_data;
  77   DBT query, value;
  78   skel_t *skel;
  79
  80   /* Convert native type to skel. */
  81   SVN_ERR(svn_fs_base__unparse_change_skel(&skel, change, pool));
  82
  83   /* Store a new record into the database. */
  84   svn_fs_base__str_to_dbt(&query, key);
  85   svn_fs_base__skel_to_dbt(&value, skel, pool);
  86   svn_fs_base__trail_debug(trail, "changes", "put");
  87   SVN_ERR(BDB_WRAP(fs, _("creating change"),
  88                    bfd->changes->put(bfd->changes, trail->db_txn,
  89                                      &query, &value, 0)));
  90
  91   return SVN_NO_ERROR;
  92 }
  93
  94
  95 svn_error_t *
  96 svn_fs_bdb__changes_delete(svn_fs_t *fs,
  97                            const char *key,
  98                            trail_t *trail,
  99                            apr_pool_t *pool)
 100 {
 101   int db_err;
 102   DBT query;
 103   base_fs_data_t *bfd = fs->fsap_data;
 104
 105   svn_fs_base__trail_debug(trail, "changes", "del");
 106   db_err = bfd->changes->del(bfd->changes, trail->db_txn,
 107                              svn_fs_base__str_to_dbt(&query, key), 0);
 108
 109   /* If there're no changes for KEY, that is acceptable.  Any other
 110      error should be propogated to the caller, though.  */
 111   if ((db_err) && (db_err != DB_NOTFOUND))
 112     {
 113       SVN_ERR(BDB_WRAP(fs, _("deleting changes"), db_err));
 114     }
 115
 116   return SVN_NO_ERROR;
 117 }
 118
 119
 120 /* Merge the internal-use-only CHANGE into a hash of public-FS
 121    svn_fs_path_change_t CHANGES, collapsing multiple changes into a
 122    single succinct change per path. */
 123 static svn_error_t *
 124 fold_change(apr_hash_t *changes,
 125             const change_t *change)
 126 {
 127   apr_pool_t *pool = apr_hash_pool_get(changes);
 128   svn_fs_path_change_t *old_change, *new_change;
 129   const char *path;
 130
 131   if ((old_change = apr_hash_get(changes, change->path, APR_HASH_KEY_STRING)))
 132     {
 133       /* This path already exists in the hash, so we have to merge
 134          this change into the already existing one. */
 135
 136       /* Since the path already exists in the hash, we don't have to
 137          dup the allocation for the path itself. */
 138       path = change->path;
 139
 140       /* Sanity check:  only allow NULL node revision ID in the
 141          `reset' case. */
 142       if ((! change->noderev_id) && (change->kind != svn_fs_path_change_reset))
 143         return svn_error_create
 144           (SVN_ERR_FS_CORRUPT, NULL,
 145            _("Missing required node revision ID"));
 146
 147       /* Sanity check:  we should be talking about the same node
 148          revision ID as our last change except where the last change
 149          was a deletion. */
 150       if (change->noderev_id
 151           && (! svn_fs_base__id_eq(old_change->node_rev_id,
 152                                    change->noderev_id))
 153           && (old_change->change_kind != svn_fs_path_change_delete))
 154         return svn_error_create
 155           (SVN_ERR_FS_CORRUPT, NULL,
 156            _("Invalid change ordering: new node revision ID without delete"));
 157
 158       /* Sanity check: an add, replacement, or reset must be the first
 159          thing to follow a deletion. */
 160       if ((old_change->change_kind == svn_fs_path_change_delete)
 161           && (! ((change->kind == svn_fs_path_change_replace)
 162                  || (change->kind == svn_fs_path_change_reset)
 163                  || (change->kind == svn_fs_path_change_add))))
 164         return svn_error_create
 165           (SVN_ERR_FS_CORRUPT, NULL,
 166            _("Invalid change ordering: non-add change on deleted path"));
 167
 168       /* Now, merge that change in. */
 169       switch (change->kind)
 170         {
 171         case svn_fs_path_change_reset:
 172           /* A reset here will simply remove the path change from the
 173              hash. */
 174           old_change = NULL;
 175           break;
 176
 177         case svn_fs_path_change_delete:
 178           if (old_change->change_kind == svn_fs_path_change_add)
 179             {
 180               /* If the path was introduced in this transaction via an
 181                  add, and we are deleting it, just remove the path
 182                  altogether. */
 183               old_change = NULL;
 184             }
 185           else
 186             {
 187               /* A deletion overrules all previous changes. */
 188               old_change->change_kind = svn_fs_path_change_delete;
 189               old_change->text_mod = change->text_mod;
 190               old_change->prop_mod = change->prop_mod;
 191             }
 192           break;
 193
 194         case svn_fs_path_change_add:
 195         case svn_fs_path_change_replace:
 196           /* An add at this point must be following a previous delete,
 197              so treat it just like a replace. */
 198           old_change->change_kind = svn_fs_path_change_replace;
 199           old_change->node_rev_id = svn_fs_base__id_copy(change->noderev_id,
 200                                                          pool);
 201           old_change->text_mod = change->text_mod;
 202           old_change->prop_mod = change->prop_mod;
 203           break;
 204
 205         case svn_fs_path_change_modify:
 206         default:
 207           if (change->text_mod)
 208             old_change->text_mod = TRUE;
 209           if (change->prop_mod)
 210             old_change->prop_mod = TRUE;
 211           break;
 212         }
 213
 214       /* Point our new_change to our (possibly modified) old_change. */
 215       new_change = old_change;
 216     }
 217   else
 218     {
 219       /* This change is new to the hash, so make a new public change
 220          structure from the internal one (in the hash's pool), and dup
 221          the path into the hash's pool, too. */
 222       new_change = apr_pcalloc(pool, sizeof(*new_change));
 223       new_change->node_rev_id = svn_fs_base__id_copy(change->noderev_id,
 224                                                      pool);
 225       new_change->change_kind = change->kind;
 226       new_change->text_mod = change->text_mod;
 227       new_change->prop_mod = change->prop_mod;
 228       path = apr_pstrdup(pool, change->path);
 229     }
 230
 231   /* Add (or update) this path. */
 232   apr_hash_set(changes, path, APR_HASH_KEY_STRING, new_change);
 233
 234   return SVN_NO_ERROR;
 235 }
 236
 237
 238 svn_error_t *
 239 svn_fs_bdb__changes_fetch(apr_hash_t **changes_p,
 240                           svn_fs_t *fs,
 241                           const char *key,
 242                           trail_t *trail,
 243                           apr_pool_t *pool)
 244 {
 245   base_fs_data_t *bfd = fs->fsap_data;
 246   DBC *cursor;
 247   DBT query, result;
 248   int db_err = 0, db_c_err = 0;
 249   svn_error_t *err = SVN_NO_ERROR;
 250   apr_hash_t *changes = apr_hash_make(pool);
 251   apr_pool_t *subpool = svn_pool_create(pool);
 252
 253   /* Get a cursor on the first record matching KEY, and then loop over
 254      the records, adding them to the return array. */
 255   svn_fs_base__trail_debug(trail, "changes", "cursor");
 256   SVN_ERR(BDB_WRAP(fs, _("creating cursor for reading changes"),
 257                    bfd->changes->cursor(bfd->changes, trail->db_txn,
 258                                         &cursor, 0)));
 259
 260   /* Advance the cursor to the key that we're looking for. */
 261   svn_fs_base__str_to_dbt(&query, key);
 262   svn_fs_base__result_dbt(&result);
 263   db_err = svn_bdb_dbc_get(cursor, &query, &result, DB_SET);
 264   if (! db_err)
 265     svn_fs_base__track_dbt(&result, pool);
 266
 267   while (! db_err)
 268     {
 269       change_t *change;
 270       skel_t *result_skel;
 271
 272       /* Clear the per-iteration subpool. */
 273       svn_pool_clear(subpool);
 274
 275       /* RESULT now contains a change record associated with KEY.  We
 276          need to parse that skel into an change_t structure ...  */
 277       result_skel = svn_fs_base__parse_skel(result.data, result.size,
 278                                             subpool);
 279       if (! result_skel)
 280         {
 281           err = svn_error_createf(SVN_ERR_FS_CORRUPT, NULL,
 282                                   _("Error reading changes for key '%s'"),
 283                                   key);
 284           goto cleanup;
 285         }
 286       err = svn_fs_base__parse_change_skel(&change, result_skel, subpool);
 287       if (err)
 288         goto cleanup;
 289
 290       /* ... and merge it with our return hash.  */
 291       err = fold_change(changes, change);
 292       if (err)
 293         goto cleanup;
 294
 295       /* Now, if our change was a deletion or replacement, we have to
 296          blow away any changes thus far on paths that are (or, were)
 297          children of this path.
 298          ### i won't bother with another iteration pool here -- at
 299              most we talking about a few extra dups of paths into what
 300              is already a temporary subpool.
 301       */
 302       if ((change->kind == svn_fs_path_change_delete)
 303           || (change->kind == svn_fs_path_change_replace))
 304         {
 305           apr_hash_index_t *hi;
 306
 307           for (hi = apr_hash_first(subpool, changes);
 308                hi;
 309                hi = apr_hash_next(hi))
 310             {
 311               /* KEY is the path. */
 312               const void *hashkey;
 313               apr_ssize_t klen;
 314               apr_hash_this(hi, &hashkey, &klen, NULL);
 315
 316               /* If we come across our own path, ignore it. */
 317               if (strcmp(change->path, hashkey) == 0)
 318                 continue;
 319
 320               /* If we come across a child of our path, remove it. */
 321               if (svn_path_is_child(change->path, hashkey, subpool))
 322                 apr_hash_set(changes, hashkey, klen, NULL);
 323             }
 324         }
 325
 326       /* Advance the cursor to the next record with this same KEY, and
 327          fetch that record. */
 328       svn_fs_base__result_dbt(&result);
 329       db_err = svn_bdb_dbc_get(cursor, &query, &result, DB_NEXT_DUP);
 330       if (! db_err)
 331         svn_fs_base__track_dbt(&result, pool);
 332     }
 333
 334   /* Destroy the per-iteration subpool. */
 335   svn_pool_destroy(subpool);
 336
 337   /* If there are no (more) change records for this KEY, we're
 338      finished.  Just return the (possibly empty) array.  Any other
 339      error, however, needs to get handled appropriately.  */
 340   if (db_err && (db_err != DB_NOTFOUND))
 341     err = BDB_WRAP(fs, _("fetching changes"), db_err);
 342
 343  cleanup:
 344   /* Close the cursor. */
 345   db_c_err = svn_bdb_dbc_close(cursor);
 346
 347   /* If we had an error prior to closing the cursor, return the error. */
 348   if (err)
 349     return err;
 350
 351   /* If our only error thus far was when we closed the cursor, return
 352      that error. */
 353   if (db_c_err)
 354     SVN_ERR(BDB_WRAP(fs, _("closing changes cursor"), db_c_err));
 355
 356   /* Finally, set our return variable and get outta here. */
 357   *changes_p = changes;
 358   return SVN_NO_ERROR;
 359 }
 360
 361
 362 svn_error_t *
 363 svn_fs_bdb__changes_fetch_raw(apr_array_header_t **changes_p,
 364                               svn_fs_t *fs,
 365                               const char *key,
 366                               trail_t *trail,
 367                               apr_pool_t *pool)
 368 {
 369   base_fs_data_t *bfd = fs->fsap_data;
 370   DBC *cursor;
 371   DBT query, result;
 372   int db_err = 0, db_c_err = 0;
 373   svn_error_t *err = SVN_NO_ERROR;
 374   change_t *change;
 375   apr_array_header_t *changes = apr_array_make(pool, 4, sizeof(change));
 376
 377   /* Get a cursor on the first record matching KEY, and then loop over
 378      the records, adding them to the return array. */
 379   svn_fs_base__trail_debug(trail, "changes", "cursor");
 380   SVN_ERR(BDB_WRAP(fs, _("creating cursor for reading changes"),
 381                    bfd->changes->cursor(bfd->changes, trail->db_txn,
 382                                         &cursor, 0)));
 383
 384   /* Advance the cursor to the key that we're looking for. */
 385   svn_fs_base__str_to_dbt(&query, key);
 386   svn_fs_base__result_dbt(&result);
 387   db_err = svn_bdb_dbc_get(cursor, &query, &result, DB_SET);
 388   if (! db_err)
 389     svn_fs_base__track_dbt(&result, pool);
 390
 391   while (! db_err)
 392     {
 393       skel_t *result_skel;
 394
 395       /* RESULT now contains a change record associated with KEY.  We
 396          need to parse that skel into an change_t structure ...  */
 397       result_skel = svn_fs_base__parse_skel(result.data, result.size, pool);
 398       if (! result_skel)
 399         {
 400           err = svn_error_createf(SVN_ERR_FS_CORRUPT, NULL,
 401                                   _("Error reading changes for key '%s'"),
 402                                   key);
 403           goto cleanup;
 404         }
 405       err = svn_fs_base__parse_change_skel(&change, result_skel, pool);
 406       if (err)
 407         goto cleanup;
 408
 409       /* ... and add it to our return array.  */
 410       APR_ARRAY_PUSH(changes, change_t *) = change;
 411
 412       /* Advance the cursor to the next record with this same KEY, and
 413          fetch that record. */
 414       svn_fs_base__result_dbt(&result);
 415       db_err = svn_bdb_dbc_get(cursor, &query, &result, DB_NEXT_DUP);
 416       if (! db_err)
 417         svn_fs_base__track_dbt(&result, pool);
 418     }
 419
 420   /* If there are no (more) change records for this KEY, we're
 421      finished.  Just return the (possibly empty) array.  Any other
 422      error, however, needs to get handled appropriately.  */
 423   if (db_err && (db_err != DB_NOTFOUND))
 424     err = BDB_WRAP(fs, _("fetching changes"), db_err);
 425
 426  cleanup:
 427   /* Close the cursor. */
 428   db_c_err = svn_bdb_dbc_close(cursor);
 429
 430   /* If we had an error prior to closing the cursor, return the error. */
 431   if (err)
 432     return err;
 433
 434   /* If our only error thus far was when we closed the cursor, return
 435      that error. */
 436   if (db_c_err)
 437     SVN_ERR(BDB_WRAP(fs, _("closing changes cursor"), db_c_err));
 438
 439   /* Finally, set our return variable and get outta here. */
 440   *changes_p = changes;
 441   return SVN_NO_ERROR;
 442 }