diff options
Diffstat (limited to 'www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/RepositoryConnectors/FourstoreRepositoryConnector.php')
| -rw-r--r-- | www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/RepositoryConnectors/FourstoreRepositoryConnector.php | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/RepositoryConnectors/FourstoreRepositoryConnector.php b/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/RepositoryConnectors/FourstoreRepositoryConnector.php new file mode 100644 index 00000000..a5a5bfaf --- /dev/null +++ b/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/RepositoryConnectors/FourstoreRepositoryConnector.php @@ -0,0 +1,169 @@ +<?php + +namespace SMW\SPARQLStore\RepositoryConnectors; + +use SMW\SPARQLStore\Exception\BadHttpEndpointResponseException; +use SMW\SPARQLStore\QueryEngine\RepositoryResult; +use SMW\SPARQLStore\QueryEngine\XmlResponseParser; +use SMWTurtleSerializer as TurtleSerializer; + +/** + * Specific modifications of the SPARQL database implementation for 4Store. + * + * @license GNU GPL v2+ + * @since 1.6 + * + * @author Markus Krötzsch + */ +class FourstoreRepositoryConnector extends GenericRepositoryConnector { + + /** + * Execute a SPARQL query and return an RepositoryResult object + * that contains the results. Compared to GenericHttpDatabaseConnector::doQuery(), + * this also supports the parameter "restricted=1" which 4Store provides + * to enforce strict resource bounds on query answering. The method also + * checks if these bounds have been met, and records this in the query + * result. + * + * @note The restricted option in 4Store mainly enforces the given soft + * limit more strictly. To disable/configure it, simply change the soft + * limit settings of your 4Store server. + * + * @param $sparql string with the complete SPARQL query (SELECT or ASK) + * @return RepositoryResult + */ + public function doQuery( $sparql ) { + + if ( $this->repositoryClient->getQueryEndpoint() === '' ) { + throw new BadHttpEndpointResponseException( BadHttpEndpointResponseException::ERROR_NOSERVICE, $sparql, 'not specified' ); + } + + $this->httpRequest->setOption( CURLOPT_URL, $this->repositoryClient->getQueryEndpoint() ); + $this->httpRequest->setOption( CURLOPT_HTTPHEADER, ['Accept: application/sparql-results+xml,application/xml;q=0.8' ]); + $this->httpRequest->setOption( CURLOPT_POST, true ); + + $defaultGraph = $this->repositoryClient->getDefaultGraph(); + + $parameterString = "query=" . urlencode( $sparql ) . "&restricted=1" . + ( ( $defaultGraph !== '' )? '&default-graph-uri=' . urlencode( $defaultGraph ) : '' ); + + $this->httpRequest->setOption( CURLOPT_POSTFIELDS, $parameterString ); + + $httpResponse = $this->httpRequest->execute(); + + if ( $this->httpRequest->getLastErrorCode() == 0 ) { + $xmlResponseParser = new XmlResponseParser(); + $result = $xmlResponseParser->parse( $httpResponse ); + } else { + $this->mapHttpRequestError( $this->repositoryClient->getQueryEndpoint(), $sparql ); + $result = new RepositoryResult(); + $result->setErrorCode( RepositoryResult::ERROR_UNREACHABLE ); + } + + foreach ( $result->getComments() as $comment ) { + if ( strpos( $comment, 'warning: hit complexity limit' ) === 0 || + strpos( $comment, 'some results have been dropped' ) === 0 ) { + $result->setErrorCode( RepositoryResult::ERROR_INCOMPLETE ); + } //else debug_zval_dump($comment); + } + + return $result; + } + + /** + * Complex SPARQL Update delete operations are not supported in 4Store + * as of v1.1.3, hence this implementation uses a less efficient method + * for accomplishing this. + * + * @param $propertyName string Turtle name of marking property + * @param $objectName string Turtle name of marking object/value + * @param $extraNamespaces array (associative) of namespaceId => namespaceUri + * @return boolean stating whether the operations succeeded + */ + public function deleteContentByValue( $propertyName, $objectName, $extraNamespaces = [] ) { + $affectedObjects = $this->select( '*', "?s $propertyName $objectName", [], $extraNamespaces ); + $success = ( $affectedObjects->getErrorCode() == RepositoryResult::ERROR_NOERROR ); + + foreach ( $affectedObjects as $expElements ) { + if ( count( $expElements ) > 0 ) { + $turtleName = TurtleSerializer::getTurtleNameForExpElement( reset( $expElements ) ); + $success = $this->delete( "$turtleName ?p ?o", "$turtleName ?p ?o", $extraNamespaces ) && $success; + } + } + + return $success; + } + + /** + * Execute a HTTP-based SPARQL POST request according to + * http://www.w3.org/2009/sparql/docs/http-rdf-update/. + * The method throws exceptions based on + * GenericHttpDatabaseConnector::mapHttpRequestError(). If errors occur and this + * method does not throw anything, then an empty result with an error + * code is returned. + * + * This method is specific to 4Store since it uses POST parameters that + * are not given in the specification. + * + * @param $payload string Turtle serialization of data to send + * + * @return boolean + */ + public function doHttpPost( $payload ) { + + if ( $this->repositoryClient->getDataEndpoint() === '' ) { + throw new BadHttpEndpointResponseException( BadHttpEndpointResponseException::ERROR_NOSERVICE, "SPARQL POST with data: $payload", 'not specified' ); + } + + $this->httpRequest->setOption( CURLOPT_URL, $this->repositoryClient->getDataEndpoint() ); + $this->httpRequest->setOption( CURLOPT_POST, true ); + + $defaultGraph = $this->repositoryClient->getDefaultGraph(); + + $parameterString = "data=" . urlencode( $payload ) . '&graph=' . + ( ( $defaultGraph !== '' )? urlencode( $defaultGraph ) : 'default' ) . + '&mime-type=application/x-turtle'; + + $this->httpRequest->setOption( CURLOPT_POSTFIELDS, $parameterString ); + $this->httpRequest->execute(); + + if ( $this->httpRequest->getLastErrorCode() == 0 ) { + return true; + } + + $this->mapHttpRequestError( $this->repositoryClient->getDataEndpoint(), $payload ); + return false; + } + + /** + * @see GenericHttpDatabaseConnector::doUpdate + * + * @note 4store 1.1.4 breaks on update if charset is set in the Content-Type header + * + * @since 2.0 + */ + public function doUpdate( $sparql ) { + + if ( $this->repositoryClient->getUpdateEndpoint() === '' ) { + throw new BadHttpEndpointResponseException( BadHttpEndpointResponseException::ERROR_NOSERVICE, $sparql, 'not specified' ); + } + + $this->httpRequest->setOption( CURLOPT_URL, $this->repositoryClient->getUpdateEndpoint() ); + $this->httpRequest->setOption( CURLOPT_POST, true ); + + $parameterString = "update=" . urlencode( $sparql ); + + $this->httpRequest->setOption( CURLOPT_POSTFIELDS, $parameterString ); + $this->httpRequest->setOption( CURLOPT_HTTPHEADER, ['Content-Type: application/x-www-form-urlencoded' ] ); + + $this->httpRequest->execute(); + + if ( $this->httpRequest->getLastErrorCode() == 0 ) { + return true; + } + + $this->mapHttpRequestError( $this->repositoryClient->getUpdateEndpoint(), $sparql ); + return false; + } + +} |