--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/server/src/app/Libraries/Sparql/GuzzleSparqlClient.php Fri Jun 09 15:22:02 2017 +0200
@@ -0,0 +1,284 @@
+<?php
+namespace CorpusParole\Libraries\Sparql;
+
+use EasyRdf\Sparql\Client;
+use EasyRdf\Sparql\Result;
+use EasyRdf\Exception;
+use EasyRdf\Format;
+use EasyRdf\RdfNamespace;
+
+/**
+ * Wraps a Guzzle psr7 response into a EasyRdf\Http\Response interface
+ **/
+class ResponseWrapper {
+
+ /**
+ * Constructor.
+ *
+ * @param Response Guzzle psr7 response
+ */
+ public function __construct($response) {
+ $this->response = $response;
+ }
+
+ /**
+ * Check whether the response in successful
+ *
+ * @return boolean
+ */
+ public function isSuccessful()
+ {
+ $status = $this->getStatus();
+ return ($status >= 200 && $status < 300);
+ }
+
+ /**
+ * Check whether the response is an error
+ *
+ * @return boolean
+ */
+ public function isError()
+ {
+ $status = $this->getStatus();
+ return ($status >= 400 && $status < 600);
+ }
+
+ /**
+ * Check whether the response is a redirection
+ *
+ * @return boolean
+ */
+ public function isRedirect()
+ {
+ $status = $this->getStatus();
+ return ($status >= 300 && $status < 400);
+ }
+
+ /**
+ * Get the HTTP response status code
+ *
+ * @return int
+ */
+ public function getStatus()
+ {
+ return $this->response->getStatusCode();
+ }
+
+ /**
+ * Return a message describing the HTTP response code
+ * (Eg. "OK", "Not Found", "Moved Permanently")
+ *
+ * @return string
+ */
+ public function getMessage()
+ {
+ return $this->response->getReasonPhrase();
+ }
+
+ /**
+ * Get the response body as string
+ *
+ * @return string
+ */
+ public function getBody()
+ {
+ return $this->response->getBody();
+ }
+
+ /**
+ * Get the raw response body (as transfered "on wire") as string
+ *
+ * If the body is encoded (with Transfer-Encoding, not content-encoding -
+ * IE "chunked" body), gzip compressed, etc. it will not be decoded.
+ *
+ * @return string
+ */
+ public function getRawBody()
+ {
+ return $this->getBody();
+ }
+
+ /**
+ * Get the HTTP version of the response
+ *
+ * @return string
+ */
+ public function getVersion()
+ {
+ return $this->response->getProtocolVersion();
+ }
+
+ /**
+ * Get the response headers
+ *
+ * @return array
+ */
+ public function getHeaders()
+ {
+ return $this->response->getHeaders();
+ }
+
+ /**
+ * Get a specific header as string, or null if it is not set
+ *
+ * @param string$header
+ *
+ * @return string|array|null
+ */
+ public function getHeader($header)
+ {
+ $header = $this->response->getHeader($header);
+ if(is_array($header) && count($header) == 1) {
+ return $header[0];
+ } else {
+ return $header;
+ }
+ }
+
+ /**
+ * Get all headers as string
+ *
+ * @param boolean $statusLine Whether to return the first status line (ie "HTTP 200 OK")
+ * @param string $br Line breaks (eg. "\n", "\r\n", "<br />")
+ *
+ * @return string
+ */
+ public function getHeadersAsString($statusLine = true, $br = "\n")
+ {
+ $str = '';
+
+ if ($statusLine) {
+ $version = $this->getVersion();
+ $status = $this->getStatus();
+ $message = $this->getMessage();
+ $str = "HTTP/{$version} {$status} {$message}{$br}";
+ }
+
+ // Iterate over the headers and stringify them
+ foreach ($this->getHeaders() as $name => $value) {
+ if (is_string($value)) {
+ $str .= "{$name}: {$value}{$br}";
+ } elseif (is_array($value)) {
+ foreach ($value as $subval) {
+ $str .= "{$name}: {$subval}{$br}";
+ }
+ }
+ }
+
+ return $str;
+ }
+
+ /**
+ * Get the entire response as string
+ *
+ * @param string $br Line breaks (eg. "\n", "\r\n", "<br />")
+ *
+ * @return string
+ */
+ public function asString($br = "\n")
+ {
+ return $this->getHeadersAsString(true, $br) . $br . $this->getRawBody();
+ }
+
+ /**
+ * Implements magic __toString()
+ *
+ * @return string
+ */
+ public function __toString()
+ {
+ return $this->asString();
+ }
+}
+
+class GuzzleSparqlClient extends Client {
+
+ public function __construct($httpClient, $queryUri, $updateUri = null) {
+ parent::__construct($queryUri, $updateUri);
+ $this->httpClient = $httpClient;
+ }
+
+ private function queryUriHasParams() {
+ return strlen(parse_url($this->getQueryUri(), PHP_URL_QUERY)) > 0;
+ }
+
+ /**
+ * Build http-client object, execute request and return a response
+ *
+ * @param string $processed_query
+ * @param string $type Should be either "query" or "update"
+ *
+ * @return Http\Response|\Zend\Http\Response
+ * @throws Exception
+ */
+ protected function executeQuery($processed_query, $type)
+ {
+ // Tell the server which response formats we can parse
+ $sparql_results_types = array(
+ 'application/sparql-results+json' => 1.0,
+ 'application/sparql-results+xml' => 0.8
+ );
+ $request_options = [];
+ $uri = null;
+ $method = 'GET';
+ if ($type == 'update') {
+ // accept anything, as "response body of a […] update request is implementation defined"
+ // @see http://www.w3.org/TR/sparql11-protocol/#update-success
+ $accept = Format::getHttpAcceptHeader($sparql_results_types);
+ $request_options['headers'] = [
+ 'Accept' => $accept,
+ 'Content-Type' => 'application/sparql-update'
+ ];
+ $uri = $this->getUpdateUri();
+ $method = 'POST';
+ $request_options['body'] = $processed_query;
+ } elseif ($type == 'query') {
+ $re = '(?:(?:\s*BASE\s*<.*?>\s*)|(?:\s*PREFIX\s+.+:\s*<.*?>\s*))*'.
+ '(CONSTRUCT|SELECT|ASK|DESCRIBE)[\W]';
+ $result = null;
+ $matched = mb_eregi($re, $processed_query, $result);
+ if (false === $matched or count($result) !== 2) {
+ // non-standard query. is this something non-standard?
+ $query_verb = null;
+ } else {
+ $query_verb = strtoupper($result[1]);
+ }
+ if ($query_verb === 'SELECT' or $query_verb === 'ASK') {
+ // only "results"
+ $accept = Format::formatAcceptHeader($sparql_results_types);
+ } elseif ($query_verb === 'CONSTRUCT' or $query_verb === 'DESCRIBE') {
+ // only "graph"
+ $accept = Format::getHttpAcceptHeader();
+ } else {
+ // both
+ $accept = Format::getHttpAcceptHeader($sparql_results_types);
+ }
+ $encodedQuery = 'query=' . urlencode($processed_query);
+ // Use GET if the query is less than 2kB
+ // 2046 = 2kB minus 1 for '?' and 1 for NULL-terminated string on server
+ if (strlen($encodedQuery) + strlen($this->getQueryUri()) <= 2046) {
+ $delimiter = $this->queryUriHasParams() ? '&' : '?';
+ $request_options['headers'] = [
+ 'Accept' => $accept,
+ ];
+ $method = 'GET';
+ $uri = $this->getQueryUri() . $delimiter . $encodedQuery;
+ } else {
+ $request_options['headers'] = [
+ 'Accept' => $accept,
+ 'Content-Type' => 'application/x-www-form-urlencoded'
+ ];
+ // Fall back to POST instead (which is un-cacheable)
+ $method = 'POST';
+ $uri = $this->getQueryUri();
+ $request_options['body'] = $encodedQuery;
+ }
+ } else {
+ throw new Exception('unexpected request-type: '.$type);
+ }
+ $response = $this->httpClient->request($method, $uri, $request_options);
+ return new ResponseWrapper($response);
+ }
+
+}
+