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/* 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;
}
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