1 files changed, 235 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/Utils/BufferedStatsdCollector.php b/www/wiki/extensions/SemanticMediaWiki/src/Utils/BufferedStatsdCollector.php
new file mode 100644
index 00000000..10d4b508
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/Utils/BufferedStatsdCollector.php
@@ -0,0 +1,235 @@
+<?php
+
+namespace SMW\Utils;
+
+use Onoi\BlobStore\BlobStore;
+use SMW\ApplicationFactory;
+
+/**
+ * Collect statistics in a provisional schema-free storage that depends on the
+ * availability of the cache back-end.
+ *
+ * @license GNU GPL v2+
+ * @since 2.5
+ *
+ * @author mwjames
+ */
+class BufferedStatsdCollector {
+
+	/**
+	 * Update this version number when the serialization format
+	 * changes.
+	 */
+	const VERSION = '0.2';
+
+	/**
+	 * Available operations
+	 */
+	const STATS_INIT = 'init';
+	const STATS_INCR = 'incr';
+	const STATS_SET = 'set';
+	const STATS_MEDIAN = 'median';
+
+	/**
+	 * Namespace occupied by the BlobStore
+	 */
+	const CACHE_NAMESPACE = 'smw:stats:store';
+
+	/**
+	 * @var BlobStore
+	 */
+	private $blobStore;
+
+	/**
+	 * @var string|integer
+	 */
+	private $statsdId;
+
+	/**
+	 * @var boolean
+	 */
+	private $shouldRecord = true;
+
+	/**
+	 * @var array
+	 */
+	private $stats = [];
+
+	/**
+	 * Identifies an update fingerprint to compare invoked deferred updates
+	 * against each other and filter those with the same print to avoid recording
+	 * duplicate stats.
+	 *
+	 * @var string
+	 */
+	private $fingerprint = null;
+
+	/**
+	 * @var array
+	 */
+	private $operations = [];
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param BlobStore $blobStore
+	 * @param string $statsdId
+	 */
+	public function __construct( BlobStore $blobStore, $statsdId ) {
+		$this->blobStore = $blobStore;
+		$this->statsdId = $statsdId;
+		$this->fingerprint = $statsdId . uniqid();
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param boolean $shouldRecord
+	 */
+	public function shouldRecord( $shouldRecord ) {
+		$this->shouldRecord = (bool)$shouldRecord;
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @return array
+	 */
+	public function getStats() {
+
+		$container = $this->blobStore->read(
+			md5( $this->statsdId . self::VERSION )
+		);
+
+		return StatsFormatter::getStatsFromFlatKey( $container->getData(), '.' );
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param string|array $key
+	 */
+	public function incr( $key ) {
+
+		if ( !isset( $this->stats[$key] ) ) {
+			$this->stats[$key] = 0;
+		}
+
+		$this->stats[$key]++;
+		$this->operations[$key] = self::STATS_INCR;
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param string|array $key
+	 * @param string|integer $default
+	 */
+	public function init( $key, $default ) {
+		$this->stats[$key] = $default;
+		$this->operations[$key] = self::STATS_INIT;
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param string|array $key
+	 * @param string|integer $value
+	 */
+	public function set( $key, $value ) {
+		$this->stats[$key] = $value;
+		$this->operations[$key] = self::STATS_SET;
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param string|array $key
+	 * @param integer $value
+	 */
+	public function calcMedian( $key, $value ) {
+
+		if ( !isset( $this->stats[$key] ) ) {
+			$this->stats[$key] = $value;
+		} else {
+			$this->stats[$key] = ( $this->stats[$key] + $value ) / 2;
+		}
+
+		$this->operations[$key] = self::STATS_MEDIAN;
+	}
+
+	/**
+	 * @since 2.5
+	 */
+	public function saveStats() {
+
+		if ( $this->stats === [] ) {
+			return;
+		}
+
+		$container = $this->blobStore->read(
+			md5( $this->statsdId . self::VERSION )
+		);
+
+		foreach ( $this->stats as $key => $value ) {
+
+			$old = $container->has( $key ) ? $container->get( $key ) : 0;
+
+			if ( $this->operations[$key] === self::STATS_INIT && $old != 0 ) {
+				$value = $old;
+			}
+
+			if ( $this->operations[$key] === self::STATS_INCR ) {
+				$value = $old + $value;
+			}
+
+			// Use as-is
+			// $this->operations[$key] === self::STATS_SET
+
+			if ( $this->operations[$key] === self::STATS_MEDIAN ) {
+				$value = $old > 0 ? ( $old + $value ) / 2 : $value;
+			}
+
+			$container->set( $key, $value );
+		}
+
+		$this->blobStore->save(
+			$container
+		);
+
+		$this->stats = [];
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param boolean $asPending
+	 */
+	public function recordStats( $asPending = false ) {
+
+		if ( $this->shouldRecord === false ) {
+			return $this->stats = [];
+		}
+
+		// #2046
+		// __destruct as event trigger has shown to be unreliable in a MediaWiki
+		// environment therefore rely on the deferred update and any caller
+		// that invokes the recordStats method
+
+		$deferredTransactionalUpdate = ApplicationFactory::getInstance()->newDeferredTransactionalCallableUpdate(
+			function() { $this->saveStats();
+			}
+		);
+
+		$deferredTransactionalUpdate->setOrigin( __METHOD__ );
+		$deferredTransactionalUpdate->waitOnTransactionIdle();
+
+		$deferredTransactionalUpdate->setFingerprint(
+			__METHOD__ . $this->fingerprint
+		);
+
+		$deferredTransactionalUpdate->markAsPending( $asPending );
+		$deferredTransactionalUpdate->pushUpdate();
+	}
+
+}