diff options
Diffstat (limited to 'subversion/libsvn_fs_base/bdb/rev-table.c')
| -rw-r--r-- | subversion/libsvn_fs_base/bdb/rev-table.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/subversion/libsvn_fs_base/bdb/rev-table.c b/subversion/libsvn_fs_base/bdb/rev-table.c new file mode 100644 index 0000000..b752249 --- /dev/null +++ b/subversion/libsvn_fs_base/bdb/rev-table.c @@ -0,0 +1,221 @@ + /* rev-table.c : working with the `revisions' table + * + * ==================================================================== + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + * ==================================================================== + */ + +#include "bdb_compat.h" + +#include "svn_fs.h" +#include "private/svn_skel.h" + +#include "../fs.h" +#include "../err.h" +#include "../util/fs_skels.h" +#include "../../libsvn_fs/fs-loader.h" +#include "bdb-err.h" +#include "dbt.h" +#include "rev-table.h" + +#include "svn_private_config.h" +#include "private/svn_fs_util.h" + + +/* Opening/creating the `revisions' table. */ + +int svn_fs_bdb__open_revisions_table(DB **revisions_p, + DB_ENV *env, + svn_boolean_t create) +{ + const u_int32_t open_flags = (create ? (DB_CREATE | DB_EXCL) : 0); + DB *revisions; + + BDB_ERR(svn_fs_bdb__check_version()); + BDB_ERR(db_create(&revisions, env, 0)); + BDB_ERR((revisions->open)(SVN_BDB_OPEN_PARAMS(revisions, NULL), + "revisions", 0, DB_RECNO, + open_flags, 0666)); + + *revisions_p = revisions; + return 0; +} + + + +/* Storing and retrieving filesystem revisions. */ + + +svn_error_t * +svn_fs_bdb__get_rev(revision_t **revision_p, + svn_fs_t *fs, + svn_revnum_t rev, + trail_t *trail, + apr_pool_t *pool) +{ + base_fs_data_t *bfd = fs->fsap_data; + int db_err; + DBT key, value; + svn_skel_t *skel; + revision_t *revision; + + /* Turn the revision number into a Berkeley DB record number. + Revisions are numbered starting with zero; Berkeley DB record + numbers begin with one. */ + db_recno_t recno = (db_recno_t) rev + 1; + + svn_fs_base__trail_debug(trail, "revisions", "get"); + db_err = bfd->revisions->get(bfd->revisions, trail->db_txn, + svn_fs_base__set_dbt(&key, &recno, + sizeof(recno)), + svn_fs_base__result_dbt(&value), + 0); + svn_fs_base__track_dbt(&value, pool); + + /* If there's no such revision, return an appropriately specific error. */ + if (db_err == DB_NOTFOUND) + return svn_fs_base__err_dangling_rev(fs, rev); + + /* Handle any other error conditions. */ + SVN_ERR(BDB_WRAP(fs, N_("reading filesystem revision"), db_err)); + + /* Parse REVISION skel. */ + skel = svn_skel__parse(value.data, value.size, pool); + if (! skel) + return svn_fs_base__err_corrupt_fs_revision(fs, rev); + + /* Convert skel to native type. */ + SVN_ERR(svn_fs_base__parse_revision_skel(&revision, skel, pool)); + + *revision_p = revision; + return SVN_NO_ERROR; +} + + +/* Write REVISION to FS as part of TRAIL. If *REV is a valid revision + number, write this revision as one that corresponds to *REV, else + write a new revision and return its newly created revision number + in *REV. */ +svn_error_t * +svn_fs_bdb__put_rev(svn_revnum_t *rev, + svn_fs_t *fs, + const revision_t *revision, + trail_t *trail, + apr_pool_t *pool) +{ + base_fs_data_t *bfd = fs->fsap_data; + int db_err; + db_recno_t recno = 0; + svn_skel_t *skel; + DBT key, value; + + /* Convert native type to skel. */ + SVN_ERR(svn_fs_base__unparse_revision_skel(&skel, revision, pool)); + + if (SVN_IS_VALID_REVNUM(*rev)) + { + DBT query, result; + + /* Update the filesystem revision with the new skel. */ + recno = (db_recno_t) *rev + 1; + svn_fs_base__trail_debug(trail, "revisions", "put"); + db_err = bfd->revisions->put + (bfd->revisions, trail->db_txn, + svn_fs_base__set_dbt(&query, &recno, sizeof(recno)), + svn_fs_base__skel_to_dbt(&result, skel, pool), 0); + return BDB_WRAP(fs, N_("updating filesystem revision"), db_err); + } + + svn_fs_base__trail_debug(trail, "revisions", "put"); + db_err = bfd->revisions->put(bfd->revisions, trail->db_txn, + svn_fs_base__recno_dbt(&key, &recno), + svn_fs_base__skel_to_dbt(&value, skel, pool), + DB_APPEND); + SVN_ERR(BDB_WRAP(fs, N_("storing filesystem revision"), db_err)); + + /* Turn the record number into a Subversion revision number. + Revisions are numbered starting with zero; Berkeley DB record + numbers begin with one. */ + *rev = recno - 1; + return SVN_NO_ERROR; +} + + + +/* Getting the youngest revision. */ + + +svn_error_t * +svn_fs_bdb__youngest_rev(svn_revnum_t *youngest_p, + svn_fs_t *fs, + trail_t *trail, + apr_pool_t *pool) +{ + base_fs_data_t *bfd = fs->fsap_data; + int db_err; + DBC *cursor = 0; + DBT key, value; + db_recno_t recno; + + SVN_ERR(svn_fs__check_fs(fs, TRUE)); + + /* Create a database cursor. */ + svn_fs_base__trail_debug(trail, "revisions", "cursor"); + SVN_ERR(BDB_WRAP(fs, N_("getting youngest revision (creating cursor)"), + bfd->revisions->cursor(bfd->revisions, trail->db_txn, + &cursor, 0))); + + /* Find the last entry in the `revisions' table. */ + db_err = svn_bdb_dbc_get(cursor, + svn_fs_base__recno_dbt(&key, &recno), + svn_fs_base__nodata_dbt(&value), + DB_LAST); + + if (db_err) + { + /* Free the cursor. Ignore any error value --- the error above + is more interesting. */ + svn_bdb_dbc_close(cursor); + + if (db_err == DB_NOTFOUND) + /* The revision 0 should always be present, at least. */ + return + svn_error_createf + (SVN_ERR_FS_CORRUPT, 0, + "Corrupt DB: revision 0 missing from 'revisions' table, in " + "filesystem '%s'", fs->path); + + SVN_ERR(BDB_WRAP(fs, N_("getting youngest revision (finding last entry)"), + db_err)); + } + + /* You can't commit a transaction with open cursors, because: + 1) key/value pairs don't get deleted until the cursors referring + to them are closed, so closing a cursor can fail for various + reasons, and txn_commit shouldn't fail that way, and + 2) using a cursor after committing its transaction can cause + undetectable database corruption. */ + SVN_ERR(BDB_WRAP(fs, N_("getting youngest revision (closing cursor)"), + svn_bdb_dbc_close(cursor))); + + /* Turn the record number into a Subversion revision number. + Revisions are numbered starting with zero; Berkeley DB record + numbers begin with one. */ + *youngest_p = recno - 1; + return SVN_NO_ERROR; +} |
