/** @package MediaWiki */
+
class ExternalStoreDB {
+ var $loadBalancers = array();
+
/**
* Fetch data from given URL
* @param string $url An url
*/
+
+ function &getLoadBalancer( $cluster ) {
+ global $wgExternalServers;
+ if ( !array_key_exists( $cluster, $this->loadBalancers ) ) {
+ $this->loadBalancers[$cluster] = LoadBalancer::newFromParams( $wgExternalServers[$cluster] );
+ }
+ return $this->loadBalancers[$cluster];
+ }
+
+ function &getSlave( $cluster ) {
+ $lb =& $this->getLoadBalancer( $cluster );
+ return $lb->getConnection( DB_SLAVE );
+ }
+
+ function &getMaster( $cluster ) {
+ $lb =& $this->getLoadBalancer( $cluster );
+ return $lb->getConnection( DB_MASTER );
+ }
+
+ function ExternalStoreDB() {
+ $this->mLoadBalancer = LoadBalancer::NewFromParams( $wgExternalServers[$cluster] );
+ }
+
function fetchFromURL($url) {
global $wgExternalServers;
#
- # URLs have the form DB://cluster/id, e.g.
- # DB://cluster1/3298247
+ # URLs have the form DB://cluster/id or DB://cluster/id/itemid for concatenated storage
#
$path = explode( '/', $url );
$cluster = $path[2];
$id = $path[3];
+ if ( isset( $path[4] ) ) {
+ $itemID = $path[4];
+ } else {
+ $itemID = false;
+ }
- $lb = LoadBalancer::NewFromParams( $wgExternalServers[$cluster] );
- $db = $lb->getConnection( DB_SLAVE );
+ $dbr =& $this->getSlave( $cluster );
+ $ret = $dbr->selectField( 'blobs', 'blob_text', array( 'blob_id' => $id ) );
- $ret = $db->selectField( 'blobs', 'blob_text', array( 'blob_id' => $id ) );
+ if ( $itemID !== false ) {
+ # Unserialise object and get item
+ $obj = unserialize( $ret );
+ $ret = $obj->getItem( $itemID );
+ }
return $ret;
}
- /* @fixme XXX: may require other methods, for store, delete,
- * whatever, for initial ext storage
+ /**
+ * Insert a data item into a given cluster
+ *
+ * @param string $cluster The cluster name
+ * @param string $data The data item
+ * @return string URL
*/
+ function store( $cluster, $data ) {
+ global $wgExternalServers;
+ $fname = 'ExternalStoreDB::store';
+
+ $dbw =& $this->getMaster( $cluster );
+
+ $id = $dbw->nextSequenceValue( 'blob_blob_id_seq' );
+ $dbw->insert( 'blobs', array( 'blob_id' => $id, 'blob_text' => $data ), $fname );
+ return "DB://$cluster/" . $dbw->insertId();
+ }
}
?>
}
$flags = explode( ',', $row->old_flags );
if( in_array( 'external', $flags ) ) {
- $url=$row->old_text;
- @list($proto,$path)=explode('://',$url,2);
- if ($path=="") {
- wfProfileOut( $fname );
- return false;
- }
- require_once('ExternalStore.php');
- $row->old_text=ExternalStore::fetchFromUrl($url);
+ $url=$row->old_text;
+ @list($proto,$path)=explode('://',$url,2);
+ if ($path=="") {
+ wfProfileOut( $fname );
+ return false;
+ }
+ require_once('ExternalStore.php');
+ $row->old_text=ExternalStore::fetchFromUrl($url);
}
if( !in_array( 'object', $flags ) ) {