<?php
/**
+ * External storage in SQL database.
*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
*
- * DB accessable external objects
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
*
- */
-
-
-
-/**
- * External database storage will use one (or more) separate connection pools
- * from what the main wiki uses. If we load many revisions, such as when doing
- * bulk backups or maintenance, we want to keep them around over the lifetime
- * of the script.
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
*
- * Associative array of LoadBalancer objects, indexed by cluster name.
+ * @file
*/
-global $wgExternalLoadBalancers;
-$wgExternalLoadBalancers = array();
/**
- * One-step cache variable to hold base blobs; operations that
- * pull multiple revisions may often pull multiple times from
- * the same blob. By keeping the last-used one open, we avoid
- * redundant unserialization and decompression overhead.
+ * DB accessable external objects
+ * @ingroup ExternalStorage
*/
-global $wgExternalBlobCache;
-$wgExternalBlobCache = array();
-
class ExternalStoreDB {
- /** @todo Document.*/
+ /**
+ * @param $params array
+ */
+ function __construct( $params = array() ) {
+ $this->mParams = $params;
+ }
+
+ /**
+ * Get a LoadBalancer for the specified cluster
+ *
+ * @param $cluster String: cluster name
+ * @return LoadBalancer object
+ */
function &getLoadBalancer( $cluster ) {
- return wfGetLBFactory()->getExternalLB( $cluster );
+ $wiki = isset($this->mParams['wiki']) ? $this->mParams['wiki'] : false;
+
+ return wfGetLBFactory()->getExternalLB( $cluster, $wiki );
}
- /** @todo Document.*/
+ /**
+ * Get a slave database connection for the specified cluster
+ *
+ * @param $cluster String: cluster name
+ * @return DatabaseBase object
+ */
function &getSlave( $cluster ) {
+ global $wgDefaultExternalStore;
+
+ $wiki = isset($this->mParams['wiki']) ? $this->mParams['wiki'] : false;
$lb =& $this->getLoadBalancer( $cluster );
- return $lb->getConnection( DB_SLAVE );
+
+ if ( !in_array( "DB://" . $cluster, (array)$wgDefaultExternalStore ) ) {
+ wfDebug( "read only external store" );
+ $lb->allowLagged(true);
+ } else {
+ wfDebug( "writable external store" );
+ }
+
+ return $lb->getConnection( DB_SLAVE, array(), $wiki );
}
- /** @todo Document.*/
+ /**
+ * Get a master database connection for the specified cluster
+ *
+ * @param $cluster String: cluster name
+ * @return DatabaseBase object
+ */
function &getMaster( $cluster ) {
+ $wiki = isset($this->mParams['wiki']) ? $this->mParams['wiki'] : false;
$lb =& $this->getLoadBalancer( $cluster );
- return $lb->getConnection( DB_MASTER );
+ return $lb->getConnection( DB_MASTER, array(), $wiki );
}
- /** @todo Document.*/
+ /**
+ * Get the 'blobs' table name for this database
+ *
+ * @param $db DatabaseBase
+ * @return String: table name ('blobs' by default)
+ */
function getTable( &$db ) {
$table = $db->getLBInfo( 'blobs table' );
if ( is_null( $table ) ) {
/**
* Fetch data from given URL
- * @param string $url An url of the form DB://cluster/id or DB://cluster/id/itemid for concatened storage.
+ * @param $url String: an url of the form DB://cluster/id or DB://cluster/id/itemid for concatened storage.
+ * @return mixed
*/
- function fetchFromURL($url) {
+ function fetchFromURL( $url ) {
$path = explode( '/', $url );
- $cluster = $path[2];
- $id = $path[3];
+ $cluster = $path[2];
+ $id = $path[3];
if ( isset( $path[4] ) ) {
$itemID = $path[4];
} else {
* @private
*/
function &fetchBlob( $cluster, $id, $itemID ) {
- global $wgExternalBlobCache;
+ /**
+ * One-step cache variable to hold base blobs; operations that
+ * pull multiple revisions may often pull multiple times from
+ * the same blob. By keeping the last-used one open, we avoid
+ * redundant unserialization and decompression overhead.
+ */
+ static $externalBlobCache = array();
+
$cacheID = ( $itemID === false ) ? "$cluster/$id" : "$cluster/$id/";
- if( isset( $wgExternalBlobCache[$cacheID] ) ) {
+ if( isset( $externalBlobCache[$cacheID] ) ) {
wfDebug( "ExternalStoreDB::fetchBlob cache hit on $cacheID\n" );
- return $wgExternalBlobCache[$cacheID];
+ return $externalBlobCache[$cacheID];
}
wfDebug( "ExternalStoreDB::fetchBlob cache miss on $cacheID\n" );
$dbr =& $this->getSlave( $cluster );
- $ret = $dbr->selectField( $this->getTable( $dbr ), 'blob_text', array( 'blob_id' => $id ) );
+ $ret = $dbr->selectField( $this->getTable( $dbr ), 'blob_text', array( 'blob_id' => $id ), __METHOD__ );
if ( $ret === false ) {
wfDebugLog( 'ExternalStoreDB', "ExternalStoreDB::fetchBlob master fallback on $cacheID\n" );
// Try the master
$dbw =& $this->getMaster( $cluster );
- $ret = $dbw->selectField( $this->getTable( $dbw ), 'blob_text', array( 'blob_id' => $id ) );
+ $ret = $dbw->selectField( $this->getTable( $dbw ), 'blob_text', array( 'blob_id' => $id ), __METHOD__ );
if( $ret === false) {
wfDebugLog( 'ExternalStoreDB', "ExternalStoreDB::fetchBlob master failed to find $cacheID\n" );
}
$ret = unserialize( $ret );
}
- $wgExternalBlobCache = array( $cacheID => &$ret );
+ $externalBlobCache = array( $cacheID => &$ret );
return $ret;
}
*
* @param $cluster String: the cluster name
* @param $data String: the data item
+ * @throws MWException
* @return string URL
*/
function store( $cluster, $data ) {
- $fname = 'ExternalStoreDB::store';
-
- $dbw =& $this->getMaster( $cluster );
-
+ $dbw = $this->getMaster( $cluster );
$id = $dbw->nextSequenceValue( 'blob_blob_id_seq' );
- $dbw->insert( $this->getTable( $dbw ), array( 'blob_id' => $id, 'blob_text' => $data ), $fname );
+ $dbw->insert( $this->getTable( $dbw ),
+ array( 'blob_id' => $id, 'blob_text' => $data ),
+ __METHOD__ );
$id = $dbw->insertId();
+ if ( !$id ) {
+ throw new MWException( __METHOD__.': no insert ID' );
+ }
if ( $dbw->getFlag( DBO_TRX ) ) {
- $dbw->immediateCommit();
+ $dbw->commit( __METHOD__ );
}
return "DB://$cluster/$id";
}
dépôts / lhc / web / wiklou.git / blobdiff