/* changes-table.c : operations on the `changes' 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 <apr_hash.h>
#include <apr_tables.h>
#include "svn_hash.h"
#include "svn_fs.h"
#include "svn_pools.h"
#include "svn_path.h"
#include "../fs.h"
#include "../err.h"
#include "../trail.h"
#include "../id.h"
#include "../util/fs_skels.h"
#include "../../libsvn_fs/fs-loader.h"
#include "bdb-err.h"
#include "dbt.h"
#include "changes-table.h"
#include "private/svn_fs_util.h"
#include "private/svn_fspath.h"
#include "svn_private_config.h"
/*** Creating and opening the changes table. ***/
int
svn_fs_bdb__open_changes_table(DB **changes_p,
DB_ENV *env,
svn_boolean_t create)
{
const u_int32_t open_flags = (create ? (DB_CREATE | DB_EXCL) : 0);
DB *changes;
BDB_ERR(svn_fs_bdb__check_version());
BDB_ERR(db_create(&changes, env, 0));
/* Enable duplicate keys. This allows us to store the changes
one-per-row. Note: this must occur before ->open(). */
BDB_ERR(changes->set_flags(changes, DB_DUP));
BDB_ERR((changes->open)(SVN_BDB_OPEN_PARAMS(changes, NULL),
"changes", 0, DB_BTREE,
open_flags, 0666));
*changes_p = changes;
return 0;
}
/*** Storing and retrieving changes. ***/
svn_error_t *
svn_fs_bdb__changes_add(svn_fs_t *fs,
const char *key,
change_t *change,
trail_t *trail,
apr_pool_t *pool)
{
base_fs_data_t *bfd = fs->fsap_data;
DBT query, value;
svn_skel_t *skel;
/* Convert native type to skel. */
SVN_ERR(svn_fs_base__unparse_change_skel(&skel, change, pool));
/* Store a new record into the database. */
svn_fs_base__str_to_dbt(&query, key);
svn_fs_base__skel_to_dbt(&value, skel, pool);
svn_fs_base__trail_debug(trail, "changes", "put");
return BDB_WRAP(fs, N_("creating change"),
bfd->changes->put(bfd->changes, trail->db_txn,
&query, &value, 0));
}
svn_error_t *
svn_fs_bdb__changes_delete(svn_fs_t *fs,
const char *key,
trail_t *trail,
apr_pool_t *pool)
{
int db_err;
DBT query;
base_fs_data_t *bfd = fs->fsap_data;
svn_fs_base__trail_debug(trail, "changes", "del");
db_err = bfd->changes->del(bfd->changes, trail->db_txn,
svn_fs_base__str_to_dbt(&query, key), 0);
/* If there're no changes for KEY, that is acceptable. Any other
error should be propagated to the caller, though. */
if ((db_err) && (db_err != DB_NOTFOUND))
{
SVN_ERR(BDB_WRAP(fs, N_("deleting changes"), db_err));
}
return SVN_NO_ERROR;
}
/* Merge the internal-use-only CHANGE into a hash of public-FS
svn_fs_path_change2_t CHANGES, collapsing multiple changes into a
single succinct change per path. */
static svn_error_t *
fold_change(apr_hash_t *changes,
const change_t *change)
{
apr_pool_t *pool = apr_hash_pool_get(changes);
svn_fs_path_change2_t *old_change, *new_change;
const char *path;
if ((old_change = svn_hash_gets(changes, change->path)))
{
/* This path already exists in the hash, so we have to merge
this change into the already existing one. */
/* Since the path already exists in the hash, we don't have to
dup the allocation for the path itself. */
path = change->path;
/* Sanity check: only allow NULL node revision ID in the
`reset' case. */
if ((! change->noderev_id) && (change->kind != svn_fs_path_change_reset))
return svn_error_create
(SVN_ERR_FS_CORRUPT, NULL,
_("Missing required node revision ID"));
/* Sanity check: we should be talking about the same node
revision ID as our last change except where the last change
was a deletion. */
if (change->noderev_id
&& (! svn_fs_base__id_eq(old_change->node_rev_id,
change->noderev_id))
&& (old_change->change_kind != svn_fs_path_change_delete))
return svn_error_create
(SVN_ERR_FS_CORRUPT, NULL,
_("Invalid change ordering: new node revision ID without delete"));
/* Sanity check: an add, replacement, or reset must be the first
thing to follow a deletion. */
if ((old_change->change_kind == svn_fs_path_change_delete)
&& (! ((change->kind == svn_fs_path_change_replace)
|| (change->kind == svn_fs_path_change_reset)
|| (change->kind == svn_fs_path_change_add))))
return svn_error_create
(SVN_ERR_FS_CORRUPT, NULL,
_("Invalid change ordering: non-add change on deleted path"));
/* Sanity check: an add can't follow anything except
a delete or reset. */
if ((change->kind == svn_fs_path_change_add)
&& (old_change->change_kind != svn_fs_path_change_delete)
&& (old_change->change_kind != svn_fs_path_change_reset))
return svn_error_create
(SVN_ERR_FS_CORRUPT, NULL,
_("Invalid change ordering: add change on preexisting path"));
/* Now, merge that change in. */
switch (change->kind)
{
case svn_fs_path_change_reset:
/* A reset here will simply remove the path change from the
hash. */
old_change = NULL;
break;
case svn_fs_path_change_delete:
if (old_change->change_kind == svn_fs_path_change_add)
{
/* If the path was introduced in this transaction via an
add, and we are deleting it, just remove the path
altogether. */
old_change = NULL;
}
else
{
/* A deletion overrules all previous changes. */
old_change->change_kind = svn_fs_path_change_delete;
old_change->text_mod = change->text_mod;
old_change->prop_mod = change->prop_mod;
}
break;
case svn_fs_path_change_add:
case svn_fs_path_change_replace:
/* An add at this point must be following a previous delete,
so treat it just like a replace. */
old_change->change_kind = svn_fs_path_change_replace;
old_change->node_rev_id = svn_fs_base__id_copy(change->noderev_id,
pool);
old_change->text_mod = change->text_mod;
old_change->prop_mod = change->prop_mod;
break;
case svn_fs_path_change_modify:
default:
if (change->text_mod)
old_change->text_mod = TRUE;
if (change->prop_mod)
old_change->prop_mod = TRUE;
break;
}
/* Point our new_change to our (possibly modified) old_change. */
new_change = old_change;
}
else
{
/* This change is new to the hash, so make a new public change
structure from the internal one (in the hash's pool), and dup
the path into the hash's pool, too. */
new_change = svn_fs__path_change_create_internal(
svn_fs_base__id_copy(change->noderev_id, pool),
change->kind,
pool);
new_change->text_mod = change->text_mod;
new_change->prop_mod = change->prop_mod;
new_change->node_kind = svn_node_unknown;
new_change->copyfrom_known = FALSE;
path = apr_pstrdup(pool, change->path);
}
/* Add (or update) this path. */
svn_hash_sets(changes, path, new_change);
return SVN_NO_ERROR;
}
svn_error_t *
svn_fs_bdb__changes_fetch(apr_hash_t **changes_p,
svn_fs_t *fs,
const char *key,
trail_t *trail,
apr_pool_t *pool)
{
base_fs_data_t *bfd = fs->fsap_data;
DBC *cursor;
DBT query, result;
int db_err = 0, db_c_err = 0;
svn_error_t *err = SVN_NO_ERROR;
apr_hash_t *changes = apr_hash_make(pool);
apr_pool_t *subpool = svn_pool_create(pool);
/* Get a cursor on the first record matching KEY, and then loop over
the records, adding them to the return array. */
svn_fs_base__trail_debug(trail, "changes", "cursor");
SVN_ERR(BDB_WRAP(fs, N_("creating cursor for reading changes"),
bfd->changes->cursor(bfd->changes, trail->db_txn,
&cursor, 0)));
/* Advance the cursor to the key that we're looking for. */
svn_fs_base__str_to_dbt(&query, key);
svn_fs_base__result_dbt(&result);
db_err = svn_bdb_dbc_get(cursor, &query, &result, DB_SET);
if (! db_err)
svn_fs_base__track_dbt(&result, pool);
while (! db_err)
{
change_t *change;
svn_skel_t *result_skel;
/* Clear the per-iteration subpool. */
svn_pool_clear(subpool);
/* RESULT now contains a change record associated with KEY. We
need to parse that skel into an change_t structure ... */
result_skel = svn_skel__parse(result.data, result.size, subpool);
if (! result_skel)
{
err = svn_error_createf(SVN_ERR_FS_CORRUPT, NULL,
_("Error reading changes for key '%s'"),
key);
goto cleanup;
}
err = svn_fs_base__parse_change_skel(&change, result_skel, subpool);
if (err)
goto cleanup;
/* ... and merge it with our return hash. */
err = fold_change(changes, change);
if (err)
goto cleanup;
/* Now, if our change was a deletion or replacement, we have to
blow away any changes thus far on paths that are (or, were)
children of this path.
### i won't bother with another iteration pool here -- at
most we talking about a few extra dups of paths into what
is already a temporary subpool.
*/
if ((change->kind == svn_fs_path_change_delete)
|| (change->kind == svn_fs_path_change_replace))
{
apr_hash_index_t *hi;
for (hi = apr_hash_first(subpool, changes);
hi;
hi = apr_hash_next(hi))
{
/* KEY is the path. */
const void *hashkey;
apr_ssize_t klen;
const char *child_relpath;
apr_hash_this(hi, &hashkey, &klen, NULL);
/* If we come across our own path, ignore it.
If we come across a child of our path, remove it. */
child_relpath = svn_fspath__skip_ancestor(change->path, hashkey);
if (child_relpath && *child_relpath)
apr_hash_set(changes, hashkey, klen, NULL);
}
}
/* Advance the cursor to the next record with this same KEY, and
fetch that record. */
svn_fs_base__result_dbt(&result);
db_err = svn_bdb_dbc_get(cursor, &query, &result, DB_NEXT_DUP);
if (! db_err)
svn_fs_base__track_dbt(&result, pool);
}
/* Destroy the per-iteration subpool. */
svn_pool_destroy(subpool);
/* If there are no (more) change records for this KEY, we're
finished. Just return the (possibly empty) array. Any other
error, however, needs to get handled appropriately. */
if (db_err && (db_err != DB_NOTFOUND))
err = BDB_WRAP(fs, N_("fetching changes"), db_err);
cleanup:
/* Close the cursor. */
db_c_err = svn_bdb_dbc_close(cursor);
/* If we had an error prior to closing the cursor, return the error. */
if (err)
return svn_error_trace(err);
/* If our only error thus far was when we closed the cursor, return
that error. */
if (db_c_err)
SVN_ERR(BDB_WRAP(fs, N_("closing changes cursor"), db_c_err));
/* Finally, set our return variable and get outta here. */
*changes_p = changes;
return SVN_NO_ERROR;
}
svn_error_t *
svn_fs_bdb__changes_fetch_raw(apr_array_header_t **changes_p,
svn_fs_t *fs,
const char *key,
trail_t *trail,
apr_pool_t *pool)
{
base_fs_data_t *bfd = fs->fsap_data;
DBC *cursor;
DBT query, result;
int db_err = 0, db_c_err = 0;
svn_error_t *err = SVN_NO_ERROR;
change_t *change;
apr_array_header_t *changes = apr_array_make(pool, 4, sizeof(change));
/* Get a cursor on the first record matching KEY, and then loop over
the records, adding them to the return array. */
svn_fs_base__trail_debug(trail, "changes", "cursor");
SVN_ERR(BDB_WRAP(fs, N_("creating cursor for reading changes"),
bfd->changes->cursor(bfd->changes, trail->db_txn,
&cursor, 0)));
/* Advance the cursor to the key that we're looking for. */
svn_fs_base__str_to_dbt(&query, key);
svn_fs_base__result_dbt(&result);
db_err = svn_bdb_dbc_get(cursor, &query, &result, DB_SET);
if (! db_err)
svn_fs_base__track_dbt(&result, pool);
while (! db_err)
{
svn_skel_t *result_skel;
/* RESULT now contains a change record associated with KEY. We
need to parse that skel into an change_t structure ... */
result_skel = svn_skel__parse(result.data, result.size, pool);
if (! result_skel)
{
err = svn_error_createf(SVN_ERR_FS_CORRUPT, NULL,
_("Error reading changes for key '%s'"),
key);
goto cleanup;
}
err = svn_fs_base__parse_change_skel(&change, result_skel, pool);
if (err)
goto cleanup;
/* ... and add it to our return array. */
APR_ARRAY_PUSH(changes, change_t *) = change;
/* Advance the cursor to the next record with this same KEY, and
fetch that record. */
svn_fs_base__result_dbt(&result);
db_err = svn_bdb_dbc_get(cursor, &query, &result, DB_NEXT_DUP);
if (! db_err)
svn_fs_base__track_dbt(&result, pool);
}
/* If there are no (more) change records for this KEY, we're
finished. Just return the (possibly empty) array. Any other
error, however, needs to get handled appropriately. */
if (db_err && (db_err != DB_NOTFOUND))
err = BDB_WRAP(fs, N_("fetching changes"), db_err);
cleanup:
/* Close the cursor. */
db_c_err = svn_bdb_dbc_close(cursor);
/* If we had an error prior to closing the cursor, return the error. */
if (err)
return svn_error_trace(err);
/* If our only error thus far was when we closed the cursor, return
that error. */
if (db_c_err)
SVN_ERR(BDB_WRAP(fs, N_("closing changes cursor"), db_c_err));
/* Finally, set our return variable and get outta here. */
*changes_p = changes;
return SVN_NO_ERROR;
}