* @since 1.19
*/
abstract class FileBackendStore extends FileBackend {
+ /** @var BagOStuff */
+ protected $memCache;
+
/** @var Array Map of paths to small (RAM/disk) cache items */
protected $cache = array(); // (storage path => key => value)
protected $maxCacheSize = 100; // integer; max paths with entries
protected $maxFileSize = 4294967296; // integer bytes (4GiB)
+ /**
+ * @see FileBackend::__construct()
+ *
+ * @param $config Array
+ */
+ public function __construct( array $config ) {
+ parent::__construct( $config );
+ $this->memCache = new EmptyBagOStuff(); // disabled by default
+ }
+
/**
* Get the maximum allowable file size given backend
* medium restrictions and basic performance constraints.
if ( $shard !== null ) { // confined to a single container/shard
$status->merge( $this->doCleanInternal( $fullCont, $dir, $params ) );
+ $this->deleteContainerCache( $fullCont ); // purge cache
} else { // directory is on several shards
wfDebug( __METHOD__ . ": iterating over all container shards.\n" );
list( $b, $shortCont, $r ) = self::splitStoragePath( $params['dir'] );
foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
$status->merge( $this->doCleanInternal( "{$fullCont}{$suffix}", $dir, $params ) );
+ $this->deleteContainerCache( "{$fullCont}{$suffix}" ); // purge cache
}
}
}
}
- // Clear any cache entries (after locks acquired)
+ // Clear any file cache entries (after locks acquired)
$this->clearCache();
+ // Load from the persistent container cache
+ $this->primeContainerCache( $performOps );
+
// Actually attempt the operation batch...
$subStatus = FileOp::attemptBatch( $performOps, $opts, $this->fileJournal );
protected function resolveContainerPath( $container, $relStoragePath ) {
return $relStoragePath;
}
+
+ /**
+ * Get the cache key for a container
+ *
+ * @param $container Resolved container name
+ * @return string
+ */
+ private function containerCacheKey( $container ) {
+ return wfMemcKey( 'backend', $this->getName(), 'container', $container );
+ }
+
+ /**
+ * Set the cached info for a container
+ *
+ * @param $container Resolved container name
+ * @param $val mixed Information to cache
+ * @return void
+ */
+ final protected function setContainerCache( $container, $val ) {
+ $this->memCache->set( $this->containerCacheKey( $container ), $val, 7*86400 );
+ }
+
+ /**
+ * Delete the cached info for a container
+ *
+ * @param $container Resolved container name
+ * @return void
+ */
+ final protected function deleteContainerCache( $container ) {
+ $this->memCache->delete( $this->containerCacheKey( $container ) );
+ }
+
+ /**
+ * Do a batch lookup from cache for container stats for all containers
+ * used in a list of container names, storage paths, or FileOp objects.
+ *
+ * @param $items Array List of storage paths or FileOps
+ * @return void
+ */
+ final protected function primeContainerCache( array $items ) {
+ $paths = array(); // list of storage paths
+ $contNames = array(); // (cache key => resolved container name)
+ // Get all the paths/containers from the items...
+ foreach ( $items as $item ) {
+ if ( $item instanceof FileOp ) {
+ $paths = array_merge( $paths, $item->storagePathsRead() );
+ $paths = array_merge( $paths, $item->storagePathsChanged() );
+ } elseif ( self::isStoragePath( $item ) ) {
+ $paths[] = $item;
+ } elseif ( is_string( $item ) ) { // full container name
+ $contNames[$this->containerCacheKey( $item )] = $item;
+ }
+ }
+ // Get all the corresponding cache keys for paths...
+ foreach ( $paths as $path ) {
+ list( $fullCont, $r, $s ) = $this->resolveStoragePath( $path );
+ if ( $fullCont !== null ) { // valid path for this backend
+ $contNames[$this->containerCacheKey( $fullCont )] = $fullCont;
+ }
+ }
+
+ $contInfo = array(); // (resolved container name => cache value)
+ // Get all cache entries for these container cache keys...
+ $values = $this->memCache->getBatch( array_keys( $contNames ) );
+ foreach ( $values as $cacheKey => $val ) {
+ $contInfo[$contNames[$cacheKey]] = $val;
+ }
+
+ // Populate the container process cache for the backend...
+ $this->doPrimeContainerCache( array_filter( $contInfo, 'is_array' ) );
+ }
+
+ /**
+ * Fill the backend-specific process cache given an array of
+ * resolved container names and their corresponding cached info.
+ * Only containers that actually exist should appear in the map.
+ *
+ * @param $containerInfo Array Map of resolved container names to cached info
+ * @return void
+ */
+ protected function doPrimeContainerCache( array $containerInfo ) {}
}
/**
$this->shardViaHashLevels = isset( $config['shardViaHashLevels'] )
? $config['shardViaHashLevels']
: '';
+ // Cache container info to mask latency
+ $this->memCache = wfGetMainCache();
}
/**
* Use $reCache if the file count or byte count is needed.
*
* @param $container string Container name
- * @param $reCache bool Refresh the process cache
+ * @param $bypassCache bool Bypass all caches and load from Swift
* @return CF_Container
+ * @throws InvalidResponseException
*/
- protected function getContainer( $container, $reCache = false ) {
+ protected function getContainer( $container, $bypassCache = false ) {
$conn = $this->getConnection(); // Swift proxy connection
- if ( $reCache ) {
- unset( $this->connContainers[$container] ); // purge cache
+ if ( $bypassCache ) { // purge cache
+ unset( $this->connContainers[$container] );
+ } elseif ( !isset( $this->connContainers[$container] ) ) {
+ $this->primeContainerCache( array( $container ) ); // check persistent cache
}
if ( !isset( $this->connContainers[$container] ) ) {
$contObj = $conn->get_container( $container );
// NoSuchContainerException not thrown: container must exist
if ( count( $this->connContainers ) >= $this->maxContCacheSize ) { // trim cache?
reset( $this->connContainers );
- $key = key( $this->connContainers );
- unset( $this->connContainers[$key] );
+ unset( $this->connContainers[key( $this->connContainers )] );
}
$this->connContainers[$container] = $contObj; // cache it
+ if ( !$bypassCache ) {
+ $this->setContainerCache( $container, // update persistent cache
+ array( 'bytes' => $contObj->bytes_used, 'count' => $contObj->object_count )
+ );
+ }
}
return $this->connContainers[$container];
}
*
* @param $container string Container name
* @return CF_Container
+ * @throws InvalidResponseException
*/
protected function createContainer( $container ) {
$conn = $this->getConnection(); // Swift proxy connection
*
* @param $container string Container name
* @return void
+ * @throws InvalidResponseException
*/
protected function deleteContainer( $container ) {
$conn = $this->getConnection(); // Swift proxy connection
unset( $this->connContainers[$container] ); // purge cache
}
+ /**
+ * @see FileBackendStore::doPrimeContainerCache()
+ * @return void
+ */
+ protected function doPrimeContainerCache( array $containerInfo ) {
+ try {
+ $conn = $this->getConnection(); // Swift proxy connection
+ foreach ( $containerInfo as $container => $info ) {
+ $this->connContainers[$container] = new CF_Container(
+ $conn->cfs_auth,
+ $conn->cfs_http,
+ $container,
+ $info['count'],
+ $info['bytes']
+ );
+ }
+ } catch ( InvalidResponseException $e ) {
+ } catch ( Exception $e ) { // some other exception?
+ $this->logException( $e, __METHOD__, array() );
+ }
+ }
+
/**
* Log an unexpected exception for this backend
*