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diff --git a/www/wiki/includes/libs/stats/SamplingStatsdClient.php b/www/wiki/includes/libs/stats/SamplingStatsdClient.php
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+++ b/www/wiki/includes/libs/stats/SamplingStatsdClient.php
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+<?php
+/**
+ * Copyright 2015
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * 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
+ *
+ * @file
+ */
+
+use Liuggio\StatsdClient\StatsdClient;
+use Liuggio\StatsdClient\Entity\StatsdData;
+use Liuggio\StatsdClient\Entity\StatsdDataInterface;
+
+/**
+ * A statsd client that applies the sampling rate to the data items before sending them.
+ *
+ * @since 1.26
+ */
+class SamplingStatsdClient extends StatsdClient {
+	protected $samplingRates = [];
+
+	/**
+	 * Sampling rates as an associative array of patterns and rates.
+	 * Patterns are Unix shell patterns (e.g. 'MediaWiki.api.*').
+	 * Rates are sampling probabilities (e.g. 0.1 means 1 in 10 events are sampled).
+	 * @param array $samplingRates
+	 * @since 1.28
+	 */
+	public function setSamplingRates( array $samplingRates ) {
+		$this->samplingRates = $samplingRates;
+	}
+
+	/**
+	 * Sets sampling rate for all items in $data.
+	 * The sample rate specified in a StatsdData entity overrides the sample rate specified here.
+	 *
+	 * @inheritDoc
+	 */
+	public function appendSampleRate( $data, $sampleRate = 1 ) {
+		$samplingRates = $this->samplingRates;
+		if ( !$samplingRates && $sampleRate !== 1 ) {
+			$samplingRates = [ '*' => $sampleRate ];
+		}
+		if ( $samplingRates ) {
+			array_walk( $data, function ( $item ) use ( $samplingRates ) {
+				/** @var StatsdData $item */
+				foreach ( $samplingRates as $pattern => $rate ) {
+					if ( fnmatch( $pattern, $item->getKey(), FNM_NOESCAPE ) ) {
+						$item->setSampleRate( $item->getSampleRate() * $rate );
+						break;
+					}
+				}
+			} );
+		}
+
+		return $data;
+	}
+
+	/**
+	 * Send the metrics over UDP
+	 * Sample the metrics according to their sample rate and send the remaining ones.
+	 *
+	 * @param StatsdDataInterface|StatsdDataInterface[] $data message(s) to sent
+	 *        strings are not allowed here as sampleData requires a StatsdDataInterface
+	 * @param int $sampleRate
+	 *
+	 * @return int the data sent in bytes
+	 */
+	public function send( $data, $sampleRate = 1 ) {
+		if ( !is_array( $data ) ) {
+			$data = [ $data ];
+		}
+		if ( !$data ) {
+			return;
+		}
+		foreach ( $data as $item ) {
+			if ( !( $item instanceof StatsdDataInterface ) ) {
+				throw new InvalidArgumentException(
+					'SamplingStatsdClient does not accept stringified messages' );
+			}
+		}
+
+		// add sampling
+		$data = $this->appendSampleRate( $data, $sampleRate );
+		$data = $this->sampleData( $data );
+
+		$data = array_map( 'strval', $data );
+
+		// reduce number of packets
+		if ( $this->getReducePacket() ) {
+			$data = $this->reduceCount( $data );
+		}
+
+		// failures in any of this should be silently ignored if ..
+		$written = 0;
+		try {
+			$fp = $this->getSender()->open();
+			if ( !$fp ) {
+				return;
+			}
+			foreach ( $data as $message ) {
+				$written += $this->getSender()->write( $fp, $message );
+			}
+			$this->getSender()->close( $fp );
+		} catch ( Exception $e ) {
+			$this->throwException( $e );
+		}
+
+		return $written;
+	}
+
+	/**
+	 * Throw away some of the data according to the sample rate.
+	 * @param StatsdDataInterface[] $data
+	 * @return StatsdDataInterface[]
+	 * @throws LogicException
+	 */
+	protected function sampleData( $data ) {
+		$newData = [];
+		$mt_rand_max = mt_getrandmax();
+		foreach ( $data as $item ) {
+			$samplingRate = $item->getSampleRate();
+			if ( $samplingRate <= 0.0 || $samplingRate > 1.0 ) {
+				throw new LogicException( 'Sampling rate shall be within ]0, 1]' );
+			}
+			if (
+				$samplingRate === 1 ||
+				( mt_rand() / $mt_rand_max <= $samplingRate )
+			) {
+				$newData[] = $item;
+			}
+		}
+		return $newData;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	protected function throwException( Exception $exception ) {
+		if ( !$this->getFailSilently() ) {
+			throw $exception;
+		}
+	}
+}