spaces.php

aws/Aws/WrappedHttpHandler.php

@@ -0,0 +1,204 @@
+<?php
+namespace Aws;
+
+use Aws\Api\Parser\Exception\ParserException;
+use GuzzleHttp\Promise;
+use GuzzleHttp\Promise\FulfilledPromise;
+use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ResponseInterface;
+
+/**
+ * Converts an HTTP handler into a Command HTTP handler.
+ *
+ * HTTP handlers have the following signature:
+ *     function(RequestInterface $request, array $options) : PromiseInterface
+ *
+ * The promise returned form an HTTP handler must resolve to a PSR-7 response
+ * object when fulfilled or an error array when rejected. The error array
+ * can contain the following data:
+ *
+ * - exception: (required, Exception) Exception that was encountered.
+ * - response: (ResponseInterface) PSR-7 response that was received (if a
+ *   response) was received.
+ * - connection_error: (bool) True if the error is the result of failing to
+ *   connect.
+ */
+class WrappedHttpHandler
+{
+    private $httpHandler;
+    private $parser;
+    private $errorParser;
+    private $exceptionClass;
+    private $collectStats;
+
+    /**
+     * @param callable $httpHandler    Function that accepts a request and array
+     *                                 of request options and returns a promise
+     *                                 that fulfills with a response or rejects
+     *                                 with an error array.
+     * @param callable $parser         Function that accepts a response object
+     *                                 and returns an AWS result object.
+     * @param callable $errorParser    Function that parses a response object
+     *                                 into AWS error data.
+     * @param string   $exceptionClass Exception class to throw.
+     * @param bool     $collectStats   Whether to collect HTTP transfer
+     *                                 information.
+     */
+    public function __construct(
+        callable $httpHandler,
+        callable $parser,
+        callable $errorParser,
+        $exceptionClass = 'Aws\Exception\AwsException',
+        $collectStats = false
+    ) {
+        $this->httpHandler = $httpHandler;
+        $this->parser = $parser;
+        $this->errorParser = $errorParser;
+        $this->exceptionClass = $exceptionClass;
+        $this->collectStats = $collectStats;
+    }
+
+    /**
+     * Calls the simpler HTTP specific handler and wraps the returned promise
+     * with AWS specific values (e.g., a result object or AWS exception).
+     *
+     * @param CommandInterface $command Command being executed.
+     * @param RequestInterface $request Request to send.
+     *
+     * @return Promise\PromiseInterface
+     */
+    public function __invoke(
+        CommandInterface $command,
+        RequestInterface $request
+    ) {
+        $fn = $this->httpHandler;
+        $options = $command['@http'] ?: [];
+        $stats = [];
+        if ($this->collectStats) {
+            $options['http_stats_receiver'] = static function (
+                array $transferStats
+            ) use (&$stats) {
+                $stats = $transferStats;
+            };
+        } elseif (isset($options['http_stats_receiver'])) {
+            throw new \InvalidArgumentException('Providing a custom HTTP stats'
+                . ' receiver to Aws\WrappedHttpHandler is not supported.');
+        }
+
+        return Promise\promise_for($fn($request, $options))
+            ->then(
+                function (
+                    ResponseInterface $res
+                ) use ($command, $request, &$stats) {
+                    return $this->parseResponse($command, $request, $res, $stats);
+                },
+                function ($err) use ($request, $command, &$stats) {
+                    if (is_array($err)) {
+                        $err = $this->parseError(
+                            $err,
+                            $request,
+                            $command,
+                            $stats
+                        );
+                    }
+                    return new Promise\RejectedPromise($err);
+                }
+            );
+    }
+
+    /**
+     * @param CommandInterface  $command
+     * @param RequestInterface  $request
+     * @param ResponseInterface $response
+     * @param array             $stats
+     *
+     * @return ResultInterface
+     */
+    private function parseResponse(
+        CommandInterface $command,
+        RequestInterface $request,
+        ResponseInterface $response,
+        array $stats
+    ) {
+        $parser = $this->parser;
+        $status = $response->getStatusCode();
+        $result = $status < 300
+            ? $parser($command, $response)
+            : new Result();
+
+        $metadata = [
+            'statusCode'    => $status,
+            'effectiveUri'  => (string) $request->getUri(),
+            'headers'       => [],
+            'transferStats' => [],
+        ];
+        if (!empty($stats)) {
+            $metadata['transferStats']['http'] = [$stats];
+        }
+
+        // Bring headers into the metadata array.
+        foreach ($response->getHeaders() as $name => $values) {
+            $metadata['headers'][strtolower($name)] = $values[0];
+        }
+
+        $result['@metadata'] = $metadata;
+
+        return $result;
+    }
+
+    /**
+     * Parses a rejection into an AWS error.
+     *
+     * @param array            $err     Rejection error array.
+     * @param RequestInterface $request Request that was sent.
+     * @param CommandInterface $command Command being sent.
+     * @param array            $stats   Transfer statistics
+     *
+     * @return \Exception
+     */
+    private function parseError(
+        array $err,
+        RequestInterface $request,
+        CommandInterface $command,
+        array $stats
+    ) {
+        if (!isset($err['exception'])) {
+            throw new \RuntimeException('The HTTP handler was rejected without an "exception" key value pair.');
+        }
+
+        $serviceError = "AWS HTTP error: " . $err['exception']->getMessage();
+
+        if (!isset($err['response'])) {
+            $parts = ['response' => null];
+        } else {
+            try {
+                $parts = call_user_func($this->errorParser, $err['response']);
+                $serviceError .= " {$parts['code']} ({$parts['type']}): "
+                    . "{$parts['message']} - " . $err['response']->getBody();
+            } catch (ParserException $e) {
+                $parts = [];
+                $serviceError .= ' Unable to parse error information from '
+                    . "response - {$e->getMessage()}";
+            }
+
+            $parts['response'] = $err['response'];
+        }
+
+        $parts['exception'] = $err['exception'];
+        $parts['request'] = $request;
+        $parts['connection_error'] = !empty($err['connection_error']);
+        $parts['transfer_stats'] = $stats;
+
+        return new $this->exceptionClass(
+            sprintf(
+                'Error executing "%s" on "%s"; %s',
+                $command->getName(),
+                $request->getUri(),
+                $serviceError
+            ),
+            $command,
+            $parts,
+            $err['exception']
+        );
+    }
+}