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diff --git a/www/wiki/includes/sparql/SparqlClient.php b/www/wiki/includes/sparql/SparqlClient.php
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+++ b/www/wiki/includes/sparql/SparqlClient.php
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+<?php
+/**
+ * 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
+ */
+
+namespace MediaWiki\Sparql;
+
+use Http;
+use MediaWiki\Http\HttpRequestFactory;
+
+/**
+ * Simple SPARQL client
+ *
+ * @author Stas Malyshev
+ */
+class SparqlClient {
+
+	/**
+	 * Limit on how long can be the query to be sent by GET.
+	 */
+	const MAX_GET_SIZE = 2048;
+
+	/**
+	 * User agent for HTTP requests.
+	 * @var string
+	 */
+	private $userAgent;
+
+	/**
+	 * Query timeout (seconds)
+	 * @var int
+	 */
+	private $timeout = 30;
+
+	/**
+	 * SPARQL endpoint URL
+	 * @var string
+	 */
+	private $endpoint;
+
+	/**
+	 * Client options
+	 * @var array
+	 */
+	private $options = [];
+
+	/**
+	 * @var HttpRequestFactory
+	 */
+	private $requestFactory;
+
+	/**
+	 * @param string $url SPARQL Endpoint
+	 * @param HttpRequestFactory $requestFactory
+	 */
+	public function __construct( $url, HttpRequestFactory $requestFactory ) {
+		$this->endpoint = $url;
+		$this->requestFactory = $requestFactory;
+		$this->userAgent = Http::userAgent() . " SparqlClient";
+	}
+
+	/**
+	 * Set query timeout (in seconds)
+	 * @param int $timeout
+	 * @return $this
+	 */
+	public function setTimeout( $timeout ) {
+		if ( $timeout >= 0 ) {
+			$this->timeout = $timeout;
+		}
+		return $this;
+	}
+
+	/**
+	 * Set client options
+	 * @param array $options
+	 * @return $this
+	 */
+	public function setClientOptions( $options ) {
+		$this->options = $options;
+		return $this;
+	}
+
+	/**
+	 * Get current user agent.
+	 * @return string
+	 */
+	public function getUserAgent() {
+		return $this->userAgent;
+	}
+
+	/**
+	 * Set user agent string.
+	 *
+	 * Mote it is not recommended to completely override user agent for
+	 * most applications.
+	 * @see appendUserAgent() for recommended way of specifying user agent.
+	 *
+	 * @param string $agent
+	 */
+	public function setUserAgent( $agent ) {
+		$this->userAgent = $agent;
+	}
+
+	/**
+	 * Append specific string to user agent.
+	 *
+	 * This is the recommended way of specifying the user agent
+	 * for specific applications of the SparqlClient inside MediaWiki
+	 * and extension code.
+	 *
+	 * @param string $agent
+	 */
+	public function appendUserAgent( $agent ) {
+		$this->userAgent .= ' ' . $agent;
+	}
+
+	/**
+	 * Query SPARQL endpoint
+	 *
+	 * @param string $sparql query
+	 * @param bool $rawData Whether to return only values or full data objects
+	 *
+	 * @return array List of results, one row per array element
+	 *               Each row will contain fields indexed by variable name.
+	 * @throws SparqlException
+	 */
+	public function query( $sparql, $rawData = false ) {
+		if ( empty( $this->endpoint ) ) {
+			throw new SparqlException( 'Endpoint URL can not be empty' );
+		}
+		$queryData = [ "query" => $sparql, "format" => "json" ];
+		$options = array_merge( [ 'method' => 'GET' ], $this->options );
+
+		if ( empty( $options['userAgent'] ) ) {
+			$options['userAgent'] = $this->userAgent;
+		}
+
+		if ( $this->timeout >= 0 ) {
+			// Blazegraph setting, see https://wiki.blazegraph.com/wiki/index.php/REST_API
+			$queryData['maxQueryTimeMillis'] = $this->timeout * 1000;
+			$options['timeout'] = $this->timeout;
+		}
+
+		if ( strlen( $sparql ) > self::MAX_GET_SIZE ) {
+			// big requests go to POST
+			$options['method'] = 'POST';
+			$options['postData'] = 'query=' . urlencode( $sparql );
+			unset( $queryData['query'] );
+		}
+
+		$url = wfAppendQuery( $this->endpoint, $queryData );
+		$request = $this->requestFactory->create( $url, $options, __METHOD__ );
+
+		$status = $request->execute();
+
+		if ( !$status->isOK() ) {
+			throw new SparqlException( "HTTP error: {$status->getWikiText()}" );
+		}
+		$result = $request->getContent();
+		\Wikimedia\suppressWarnings();
+		$data = json_decode( $result, true );
+		\Wikimedia\restoreWarnings();
+		if ( $data === null || $data === false ) {
+			throw new SparqlException( "HTTP request failed, response:\n" .
+				substr( $result, 1024 ) );
+		}
+
+		return $this->extractData( $data, $rawData );
+	}
+
+	/**
+	 * Extract data from SPARQL response format.
+	 * The response must be in format described in:
+	 * https://www.w3.org/TR/sparql11-results-json/
+	 *
+	 * @param array $data SPARQL result
+	 * @param bool  $rawData Whether to return only values or full data objects
+	 *
+	 * @return array List of results, one row per element.
+	 */
+	private function extractData( $data, $rawData = false ) {
+		$result = [];
+		if ( $data && !empty( $data['results'] ) ) {
+			$vars = $data['head']['vars'];
+			$resrow = [];
+			foreach ( $data['results']['bindings'] as $row ) {
+				foreach ( $vars as $var ) {
+					if ( !isset( $row[$var] ) ) {
+						$resrow[$var] = null;
+						continue;
+					}
+					if ( $rawData ) {
+						$resrow[$var] = $row[$var];
+					} else {
+						$resrow[$var] = $row[$var]['value'];
+					}
+				}
+				$result[] = $resrow;
+			}
+		}
+		return $result;
+	}
+
+}