1 files changed, 87 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/HttpResponseErrorMapper.php b/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/HttpResponseErrorMapper.php
new file mode 100644
index 00000000..080cef7a
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/HttpResponseErrorMapper.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace SMW\SPARQLStore;
+
+use Exception;
+use Onoi\HttpRequest\HttpRequest;
+use SMW\SPARQLStore\Exception\BadHttpEndpointResponseException;
+use SMW\SPARQLStore\Exception\HttpEndpointConnectionException;
+
+/**
+ * Post-processing for a bad inbound responses
+ *
+ * @ingroup Sparql
+ *
+ * @license GNU GPL v2+
+ * @since 2.0
+ *
+ * @author Markus Krötzsch
+ * @author mwjames
+ */
+class HttpResponseErrorMapper {
+
+	private $httpRequest = null;
+
+	/**
+	 * @since  2.0
+	 *
+	 * @param HttpRequest $httpRequest
+	 */
+	public function __construct( HttpRequest $httpRequest ) {
+		$this->httpRequest = $httpRequest;
+	}
+
+	/**
+	 * Either throw a suitable exception or fall through if the error should be
+	 * handled gracefully. It is attempted to throw exceptions for all errors that
+	 * can generally be prevented by proper coding or configuration (e.g. query
+	 * syntax errors), and to be silent on all errors that might be caused by
+	 * network issues or temporary overloading of the server. In this case, calling
+	 * methods rather return something that helps to make the best out of the situation.
+	 *
+	 * @since 2.0
+	 *
+	 * @param $endpoint string URL of endpoint that was used
+	 * @param $sparql string query that caused the problem
+	 *
+	 * @throws Exception
+	 * @throws SparqlDatabaseException
+	 */
+	public function mapErrorResponse( $endpoint, $sparql ) {
+		$error = $this->httpRequest->getLastErrorCode();
+
+		switch ( $error ) {
+			case 22: //	equals CURLE_HTTP_RETURNED_ERROR but this constant is not defined in PHP
+				$this->createResponseToHttpError( $this->httpRequest->getLastTransferInfo( CURLINFO_HTTP_CODE ), $endpoint, $sparql );
+				break;
+			case 52:
+			case CURLE_GOT_NOTHING:
+				break; // happens when 4Store crashes, do not bother the wiki
+			case CURLE_COULDNT_CONNECT:
+				break; // fail gracefully if backend is down
+			default:
+				throw new HttpEndpointConnectionException(
+					$endpoint,
+					$error,
+					$this->httpRequest->getLastError()
+				);
+		}
+	}
+
+	private function createResponseToHttpError( $httpCode, $endpoint, $sparql ) {
+
+		/// TODO We are guessing the meaning of HTTP codes here -- the SPARQL 1.1 spec does not yet provide this information for updates (April 15 2011)
+
+		if ( $httpCode == 400 ) { // malformed query
+			throw new BadHttpEndpointResponseException( BadHttpEndpointResponseException::ERROR_MALFORMED, $sparql, $endpoint, $httpCode );
+		} elseif ( $httpCode == 500 ) { // query refused; maybe fail gracefully here (depending on how stores use this)
+			throw new BadHttpEndpointResponseException( BadHttpEndpointResponseException::ERROR_REFUSED, $sparql, $endpoint, $httpCode );
+		} elseif ( $httpCode == 404 ) {
+			return; // endpoint not found, maybe down; fail gracefully
+		}
+
+		throw new BadHttpEndpointResponseException( BadHttpEndpointResponseException::ERROR_OTHER, $sparql, $endpoint, $httpCode );
+	}
+
+}
+