*/
class ExternalStoreDB extends ExternalStoreMedium {
/**
- * The URL returned is of the form of the form DB://cluster/id
+ * The provided URL is in the form of DB://cluster/id
* or DB://cluster/id/itemid for concatened storage.
*
* @see ExternalStoreMedium::fetchFromURL()
*/
public function fetchFromURL( $url ) {
- $path = explode( '/', $url );
- $cluster = $path[2];
- $id = $path[3];
- if ( isset( $path[4] ) ) {
- $itemID = $path[4];
- } else {
- $itemID = false;
- }
-
+ list( $cluster, $id, $itemID ) = $this->parseURL( $url );
$ret =& $this->fetchBlob( $cluster, $id, $itemID );
if ( $itemID !== false && $ret !== false ) {
return $ret;
}
+ /**
+ * Fetch data from given external store URLs.
+ * The provided URLs are in the form of DB://cluster/id
+ * or DB://cluster/id/itemid for concatened storage.
+ *
+ * @param array $urls An array of external store URLs
+ * @return array A map from url to stored content. Failed results
+ * are not represented.
+ */
+ public function batchFetchFromURLs( array $urls ) {
+ $batched = $inverseUrlMap = array();
+ foreach ( $urls as $url ) {
+ list( $cluster, $id, $itemID ) = $this->parseURL( $url );
+ $batched[$cluster][$id][] = $itemID;
+ // false $itemID gets cast to int, but should be ok
+ // since we do === from the $itemID in $batched
+ $inverseUrlMap[$cluster][$id][$itemID] = $url;
+ }
+ $ret = array();
+ foreach ( $batched as $cluster => $batchByCluster ) {
+ $res = $this->batchFetchBlobs( $cluster, $batchByCluster );
+ foreach ( $res as $id => $blob ) {
+ foreach ( $batchByCluster[$id] as $itemID ) {
+ $url = $inverseUrlMap[$cluster][$id][$itemID];
+ if ( $itemID === false ) {
+ $ret[$url] = $blob;
+ } else {
+ $ret[$url] = $blob->getItem( $itemID );
+ }
+ }
+ }
+ }
+ return $ret;
+ }
+
/**
* @see ExternalStoreMedium::store()
*/
__METHOD__ );
$id = $dbw->insertId();
if ( !$id ) {
- throw new MWException( __METHOD__.': no insert ID' );
+ throw new MWException( __METHOD__ . ': no insert ID' );
}
if ( $dbw->getFlag( DBO_TRX ) ) {
$dbw->commit( __METHOD__ );
static $externalBlobCache = array();
$cacheID = ( $itemID === false ) ? "$cluster/$id" : "$cluster/$id/";
- if( isset( $externalBlobCache[$cacheID] ) ) {
+ if ( isset( $externalBlobCache[$cacheID] ) ) {
wfDebugLog( 'ExternalStoreDB-cache', "ExternalStoreDB::fetchBlob cache hit on $cacheID\n" );
return $externalBlobCache[$cacheID];
}
// Try the master
$dbw =& $this->getMaster( $cluster );
$ret = $dbw->selectField( $this->getTable( $dbw ), 'blob_text', array( 'blob_id' => $id ), __METHOD__ );
- if( $ret === false) {
+ if ( $ret === false ) {
wfDebugLog( 'ExternalStoreDB', "ExternalStoreDB::fetchBlob master failed to find $cacheID\n" );
}
}
- if( $itemID !== false && $ret !== false ) {
+ if ( $itemID !== false && $ret !== false ) {
// Unserialise object; caller extracts item
$ret = unserialize( $ret );
}
$externalBlobCache = array( $cacheID => &$ret );
return $ret;
}
+
+ /**
+ * Fetch multiple blob items out of the database
+ *
+ * @param string $cluster A cluster name valid for use with LBFactory
+ * @param array $ids A map from the blob_id's to look for to the requested itemIDs in the blobs
+ * @return array A map from the blob_id's requested to their content. Unlocated ids are not represented
+ */
+ function batchFetchBlobs( $cluster, array $ids ) {
+ $dbr = $this->getSlave( $cluster );
+ $res = $dbr->select( $this->getTable( $dbr ), array( 'blob_id', 'blob_text' ), array( 'blob_id' => array_keys( $ids ) ), __METHOD__ );
+ $ret = array();
+ if ( $res !== false ) {
+ $this->mergeBatchResult( $ret, $ids, $res );
+ }
+ if ( $ids ) {
+ wfDebugLog( __CLASS__, __METHOD__ . " master fallback on '$cluster' for: " . implode( ',', array_keys( $ids ) ) . "\n" );
+ // Try the master
+ $dbw = $this->getMaster( $cluster );
+ $res = $dbw->select( $this->getTable( $dbr ), array( 'blob_id', 'blob_text' ), array( 'blob_id' => array_keys( $ids ) ), __METHOD__ );
+ if ( $res === false ) {
+ wfDebugLog( __CLASS__, __METHOD__ . " master failed on '$cluster'\n" );
+ } else {
+ $this->mergeBatchResult( $ret, $ids, $res );
+ }
+ }
+ if ( $ids ) {
+ wfDebugLog( __CLASS__, __METHOD__ . " master on '$cluster' failed locating items: " . implode( ',', array_keys( $ids ) ) . "\n" );
+ }
+ return $ret;
+ }
+
+ /**
+ * Helper function for self::batchFetchBlobs for merging master/slave results
+ * @param array &$ret Current self::batchFetchBlobs return value
+ * @param array &$ids Map from blob_id to requested itemIDs
+ * @param mixed $res DB result from DatabaseBase::select
+ */
+ private function mergeBatchResult( array &$ret, array &$ids, $res ) {
+ foreach ( $res as $row ) {
+ $id = $row->blob_id;
+ $itemIDs = $ids[$id];
+ unset( $ids[$id] ); // to track if everything is found
+ if ( count( $itemIDs ) === 1 && reset( $itemIDs ) === false ) {
+ // single result stored per blob
+ $ret[$id] = $row->blob_text;
+ } else {
+ // multi result stored per blob
+ $ret[$id] = unserialize( $row->blob_text );
+ }
+ }
+ }
+
+ protected function parseURL( $url ) {
+ $path = explode( '/', $url );
+ return array(
+ $path[2], // cluster
+ $path[3], // id
+ isset( $path[4] ) ? $path[4] : false // itemID
+ );
+ }
}
dépôts / lhc / web / wiklou.git / blobdiff