Pool::addNextRequest() - Code Metrics - Inspection of "Merge pull request #208 from owncloud/ignore-vendo..." - owncloud/updater - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 2b1385...7c6a84 )

by Thomas

created 2016-01-07 11:44 UTC

Pool::addNextRequest() D

↳ Parent: Project

Complexity

Conditions	9
Paths	0

Size

Total Lines	52
Code Lines	31

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
c	1
b	0
f	0
dl	0
loc	52
rs	4.6098
cc	9
eloc	31
nc	0
nop	0

How to fix Long Method

<?php
namespace GuzzleHttp;

use GuzzleHttp\Event\BeforeEvent;
use GuzzleHttp\Event\RequestEvents;
use GuzzleHttp\Message\RequestInterface;
use GuzzleHttp\Message\ResponseInterface;
use GuzzleHttp\Ring\Core;
use GuzzleHttp\Ring\Future\FutureInterface;
use GuzzleHttp\Event\ListenerAttacherTrait;
use GuzzleHttp\Event\EndEvent;
use React\Promise\Deferred;
use React\Promise\FulfilledPromise;
use React\Promise\PromiseInterface;
use React\Promise\RejectedPromise;

/**
 * Sends and iterator of requests concurrently using a capped pool size.
 *
 * The Pool object implements FutureInterface, meaning it can be used later
 * when necessary, the requests provided to the pool can be cancelled, and
 * you can check the state of the pool to know if it has been dereferenced
 * (sent) or has been cancelled.
 *
 * When sending the pool, keep in mind that no results are returned: callers
 * are expected to handle results asynchronously using Guzzle's event system.
 * When requests complete, more are added to the pool to ensure that the
 * requested pool size is always filled as much as possible.
 *
 * IMPORTANT: Do not provide a pool size greater that what the utilized
 * underlying RingPHP handler can support. This will result is extremely poor
 * performance.
 */
class Pool implements FutureInterface
{
    use ListenerAttacherTrait;

    /** @var \GuzzleHttp\ClientInterface */
    private $client;

    /** @var \Iterator Yields requests */
    private $iter;

    /** @var Deferred */
    private $deferred;

    /** @var PromiseInterface */
    private $promise;

    private $waitQueue = [];
    private $eventListeners = [];
    private $poolSize;
    private $isRealized = false;

    /**
     * The option values for 'before', 'complete', 'error' and 'end' can be a
     * callable, an associative array containing event data, or an array of
     * event data arrays. Event data arrays contain the following keys:
     *
     * - fn: callable to invoke that receives the event
     * - priority: Optional event priority (defaults to 0)
     * - once: Set to true so that the event is removed after it is triggered
     *
     * @param ClientInterface $client   Client used to send the requests.
     * @param array|\Iterator $requests Requests to send in parallel
     * @param array           $options  Associative array of options
     *     - pool_size: (callable|int)   Maximum number of requests to send
     *                                   concurrently, or a callback that receives
     *                                   the current queue size and returns the
     *                                   number of new requests to send
     *     - before:    (callable|array) Receives a BeforeEvent
     *     - complete:  (callable|array) Receives a CompleteEvent
     *     - error:     (callable|array) Receives a ErrorEvent
     *     - end:       (callable|array) Receives an EndEvent
     */
    public function __construct(
        ClientInterface $client,
        $requests,
        array $options = []
    ) {
        $this->client = $client;
        $this->iter = $this->coerceIterable($requests);
        $this->deferred = new Deferred();
        $this->promise = $this->deferred->promise();
        $this->poolSize = isset($options['pool_size'])
            ? $options['pool_size'] : 25;
        $this->eventListeners = $this->prepareListeners(
            $options,
            ['before', 'complete', 'error', 'end']
        );
    }

    /**
     * Sends multiple requests in parallel and returns an array of responses
     * and exceptions that uses the same ordering as the provided requests.
     *
     * IMPORTANT: This method keeps every request and response in memory, and
     * as such, is NOT recommended when sending a large number or an
     * indeterminate number of requests concurrently.
     *
     * @param ClientInterface $client   Client used to send the requests
     * @param array|\Iterator $requests Requests to send in parallel
     * @param array           $options  Passes through the options available in
     *                                  {@see GuzzleHttp\Pool::__construct}
     *
     * @return BatchResults Returns a container for the results.
     * @throws \InvalidArgumentException if the event format is incorrect.
     */
    public static function batch(
        ClientInterface $client,
        $requests,
        array $options = []
    ) {
        $hash = new \SplObjectStorage();
        foreach ($requests as $request) {
            $hash->attach($request);
        }

        // In addition to the normally run events when requests complete, add
        // and event to continuously track the results of transfers in the hash.
        (new self($client, $requests, RequestEvents::convertEventArray(
            $options,
            ['end'],
            [
                'priority' => RequestEvents::LATE,
                'fn'       => function (EndEvent $e) use ($hash) {
                    $hash[$e->getRequest()] = $e->getException()
                        ? $e->getException()
                        : $e->getResponse();
                }
            ]
        )))->wait();

        return new BatchResults($hash);
    }

    /**
     * Creates a Pool and immediately sends the requests.
     *
     * @param ClientInterface $client   Client used to send the requests
     * @param array|\Iterator $requests Requests to send in parallel
     * @param array           $options  Passes through the options available in
     *                                  {@see GuzzleHttp\Pool::__construct}
     */
    public static function send(
        ClientInterface $client,
        $requests,
        array $options = []
    ) {
        $pool = new self($client, $requests, $options);
        $pool->wait();
    }

    private function getPoolSize()
    {
        return is_callable($this->poolSize)
            ? call_user_func($this->poolSize, count($this->waitQueue))
            : $this->poolSize;
    }

    /**
     * Add as many requests as possible up to the current pool limit.
     */
    private function addNextRequests()
    {
        $limit = max($this->getPoolSize() - count($this->waitQueue), 0);
        while ($limit--) {
            if (!$this->addNextRequest()) {
                break;
            }
        }
    }

    public function wait()
    {
        if ($this->isRealized) {
            return false;
        }

        // Seed the pool with N number of requests.
        $this->addNextRequests();

        // Stop if the pool was cancelled while transferring requests.
        if ($this->isRealized) {
            return false;
        }

        // Wait on any outstanding FutureResponse objects.
        while ($response = array_pop($this->waitQueue)) {
            try {
                $response->wait();
            } catch (\Exception $e) {
                // Eat exceptions because they should be handled asynchronously
            }
            $this->addNextRequests();
        }

        // Clean up no longer needed state.
        $this->isRealized = true;
        $this->waitQueue = $this->eventListeners = [];
        $this->client = $this->iter = null;
        $this->deferred->resolve(true);

        return true;
    }

    /**
     * {@inheritdoc}
     *
     * Attempt to cancel all outstanding requests (requests that are queued for
     * dereferencing). Returns true if all outstanding requests can be
     * cancelled.
     *
     * @return bool
     */
    public function cancel()
    {
        if ($this->isRealized) {
            return false;
        }

        $success = $this->isRealized = true;
        foreach ($this->waitQueue as $response) {
            if (!$response->cancel()) {
                $success = false;
            }
        }

        return $success;
    }

    /**
     * Returns a promise that is invoked when the pool completed. There will be
     * no passed value.
     *
     * {@inheritdoc}
     */
    public function then(
        callable $onFulfilled = null,
        callable $onRejected = null,
        callable $onProgress = null
    ) {
        return $this->promise->then($onFulfilled, $onRejected, $onProgress);
    }

    public function promise()
    {
        return $this->promise;
    }

    private function coerceIterable($requests)
    {
        if ($requests instanceof \Iterator) {
            return $requests;
        } elseif (is_array($requests)) {
            return new \ArrayIterator($requests);
        }

        throw new \InvalidArgumentException('Expected Iterator or array. '
            . 'Found ' . Core::describeType($requests));
    }

    /**
     * Adds the next request to pool and tracks what requests need to be
     * dereferenced when completing the pool.
     */
    private function addNextRequest()
    {
        add_next:

        if ($this->isRealized || !$this->iter || !$this->iter->valid()) {
            return false;
        }

        $request = $this->iter->current();
        $this->iter->next();

        if (!($request instanceof RequestInterface)) {
            throw new \InvalidArgumentException(sprintf(
                'All requests in the provided iterator must implement '
                . 'RequestInterface. Found %s',
                Core::describeType($request)
            ));
        }

        // Be sure to use "lazy" futures, meaning they do not send right away.
        $request->getConfig()->set('future', 'lazy');
        $hash = spl_object_hash($request);
        $this->attachListeners($request, $this->eventListeners);
        $request->getEmitter()->on('before', [$this, '_trackRetries'], RequestEvents::EARLY);
        $response = $this->client->send($request);
        $this->waitQueue[$hash] = $response;
        $promise = $response->promise();

        // Don't recursively call itself for completed or rejected responses.
        if ($promise instanceof FulfilledPromise
            || $promise instanceof RejectedPromise
        ) {
            try {
                $this->finishResponse($request, $response->wait(), $hash);
            } catch (\Exception $e) {
                $this->finishResponse($request, $e, $hash);
            }
            goto add_next;
        }

        // Use this function for both resolution and rejection.
        $thenFn = function ($value) use ($request, $hash) {
            $this->finishResponse($request, $value, $hash);
            if (!$request->getConfig()->get('_pool_retries')) {
                $this->addNextRequests();
            }
        };

        $promise->then($thenFn, $thenFn);

        return true;
    }

    public function _trackRetries(BeforeEvent $e)
    {
        $e->getRequest()->getConfig()->set('_pool_retries', $e->getRetryCount());
    }

    private function finishResponse($request, $value, $hash)
    {
        unset($this->waitQueue[$hash]);
        $result = $value instanceof ResponseInterface
            ? ['request' => $request, 'response' => $value, 'error' => null]
            : ['request' => $request, 'response' => null, 'error' => $value];
        $this->deferred->notify($result);
    }
}


1			<?php
2			namespace GuzzleHttp;
3
4			use GuzzleHttp\Event\BeforeEvent;
5			use GuzzleHttp\Event\RequestEvents;
6			use GuzzleHttp\Message\RequestInterface;
7			use GuzzleHttp\Message\ResponseInterface;
8			use GuzzleHttp\Ring\Core;
9			use GuzzleHttp\Ring\Future\FutureInterface;
10			use GuzzleHttp\Event\ListenerAttacherTrait;
11			use GuzzleHttp\Event\EndEvent;
12			use React\Promise\Deferred;
13			use React\Promise\FulfilledPromise;
14			use React\Promise\PromiseInterface;
15			use React\Promise\RejectedPromise;
16
17			/**
18			* Sends and iterator of requests concurrently using a capped pool size.
19			*
20			* The Pool object implements FutureInterface, meaning it can be used later
21			* when necessary, the requests provided to the pool can be cancelled, and
22			* you can check the state of the pool to know if it has been dereferenced
23			* (sent) or has been cancelled.
24			*
25			* When sending the pool, keep in mind that no results are returned: callers
26			* are expected to handle results asynchronously using Guzzle's event system.
27			* When requests complete, more are added to the pool to ensure that the
28			* requested pool size is always filled as much as possible.
29			*
30			* IMPORTANT: Do not provide a pool size greater that what the utilized
31			* underlying RingPHP handler can support. This will result is extremely poor
32			* performance.
33			*/
34			class Pool implements FutureInterface
35			{
36			use ListenerAttacherTrait;
37
38			/** @var \GuzzleHttp\ClientInterface */
39			private $client;
40
41			/** @var \Iterator Yields requests */
42			private $iter;
43
44			/** @var Deferred */
45			private $deferred;
46
47			/** @var PromiseInterface */
48			private $promise;
49
50			private $waitQueue = [];
51			private $eventListeners = [];
52			private $poolSize;
53			private $isRealized = false;
54
55			/**
56			* The option values for 'before', 'complete', 'error' and 'end' can be a
57			* callable, an associative array containing event data, or an array of
58			* event data arrays. Event data arrays contain the following keys:
59			*
60			* - fn: callable to invoke that receives the event
61			* - priority: Optional event priority (defaults to 0)
62			* - once: Set to true so that the event is removed after it is triggered
63			*
64			* @param ClientInterface $client Client used to send the requests.
65			* @param array\|\Iterator $requests Requests to send in parallel
66			* @param array $options Associative array of options
67			* - pool_size: (callable\|int) Maximum number of requests to send
68			* concurrently, or a callback that receives
69			* the current queue size and returns the
70			* number of new requests to send
71			* - before: (callable\|array) Receives a BeforeEvent
72			* - complete: (callable\|array) Receives a CompleteEvent
73			* - error: (callable\|array) Receives a ErrorEvent
74			* - end: (callable\|array) Receives an EndEvent
75			*/
76			public function __construct(
77			ClientInterface $client,
78			$requests,
79			array $options = []
80			) {
81			$this->client = $client;
82			$this->iter = $this->coerceIterable($requests);
83			$this->deferred = new Deferred();
84			$this->promise = $this->deferred->promise();
85			$this->poolSize = isset($options['pool_size'])
86			? $options['pool_size'] : 25;
87			$this->eventListeners = $this->prepareListeners(
88			$options,
89			['before', 'complete', 'error', 'end']
90			);
91			}
92
93			/**
94			* Sends multiple requests in parallel and returns an array of responses
95			* and exceptions that uses the same ordering as the provided requests.
96			*
97			* IMPORTANT: This method keeps every request and response in memory, and
98			* as such, is NOT recommended when sending a large number or an
99			* indeterminate number of requests concurrently.
100			*
101			* @param ClientInterface $client Client used to send the requests
102			* @param array\|\Iterator $requests Requests to send in parallel
103			* @param array $options Passes through the options available in
104			* {@see GuzzleHttp\Pool::__construct}
105			*
106			* @return BatchResults Returns a container for the results.
107			* @throws \InvalidArgumentException if the event format is incorrect.
108			*/
109			public static function batch(
110			ClientInterface $client,
111			$requests,
112			array $options = []
113			) {
114			$hash = new \SplObjectStorage();
115			foreach ($requests as $request) {
116			$hash->attach($request);
117			}
118
119			// In addition to the normally run events when requests complete, add
120			// and event to continuously track the results of transfers in the hash.
121			(new self($client, $requests, RequestEvents::convertEventArray(
122			$options,
123			['end'],
124			[
125			'priority' => RequestEvents::LATE,
126			'fn' => function (EndEvent $e) use ($hash) {
127			$hash[$e->getRequest()] = $e->getException()
128			? $e->getException()
129			: $e->getResponse();
130			}
131			]
132			)))->wait();
133
134			return new BatchResults($hash);
135			}
136
137			/**
138			* Creates a Pool and immediately sends the requests.
139			*
140			* @param ClientInterface $client Client used to send the requests
141			* @param array\|\Iterator $requests Requests to send in parallel
142			* @param array $options Passes through the options available in
143			* {@see GuzzleHttp\Pool::__construct}
144			*/
145			public static function send(
146			ClientInterface $client,
147			$requests,
148			array $options = []
149			) {
150			$pool = new self($client, $requests, $options);
151			$pool->wait();
152			}
153
154			private function getPoolSize()
155			{
156			return is_callable($this->poolSize)
157			? call_user_func($this->poolSize, count($this->waitQueue))
158			: $this->poolSize;
159			}
160
161			/**
162			* Add as many requests as possible up to the current pool limit.
163			*/
164			private function addNextRequests()
165			{
166			$limit = max($this->getPoolSize() - count($this->waitQueue), 0);
167			while ($limit--) {
168			if (!$this->addNextRequest()) {
169			break;
170			}
171			}
172			}
173
174			public function wait()
175			{
176			if ($this->isRealized) {
177			return false;
178			}
179
180			// Seed the pool with N number of requests.
181			$this->addNextRequests();
182
183			// Stop if the pool was cancelled while transferring requests.
184			if ($this->isRealized) {
185			return false;
186			}
187
188			// Wait on any outstanding FutureResponse objects.
189			while ($response = array_pop($this->waitQueue)) {
190			try {
191			$response->wait();
192			} catch (\Exception $e) {
193			// Eat exceptions because they should be handled asynchronously
194			}
195			$this->addNextRequests();
196			}
197
198			// Clean up no longer needed state.
199			$this->isRealized = true;
200			$this->waitQueue = $this->eventListeners = [];
201			$this->client = $this->iter = null;
202			$this->deferred->resolve(true);
203
204			return true;
205			}
206
207			/**
208			* {@inheritdoc}
209			*
210			* Attempt to cancel all outstanding requests (requests that are queued for
211			* dereferencing). Returns true if all outstanding requests can be
212			* cancelled.
213			*
214			* @return bool
215			*/
216			public function cancel()
217			{
218			if ($this->isRealized) {
219			return false;
220			}
221
222			$success = $this->isRealized = true;
223			foreach ($this->waitQueue as $response) {
224			if (!$response->cancel()) {
225			$success = false;
226			}
227			}
228
229			return $success;
230			}
231
232			/**
233			* Returns a promise that is invoked when the pool completed. There will be
234			* no passed value.
235			*
236			* {@inheritdoc}
237			*/
238			public function then(
239			callable $onFulfilled = null,
240			callable $onRejected = null,
241			callable $onProgress = null
242			) {
243			return $this->promise->then($onFulfilled, $onRejected, $onProgress);
244			}
245
246			public function promise()
247			{
248			return $this->promise;
249			}
250
251			private function coerceIterable($requests)
252			{
253			if ($requests instanceof \Iterator) {
254			return $requests;
255			} elseif (is_array($requests)) {
256			return new \ArrayIterator($requests);
257			}
258
259			throw new \InvalidArgumentException('Expected Iterator or array. '
260			. 'Found ' . Core::describeType($requests));
261			}
262
263			/**
264			* Adds the next request to pool and tracks what requests need to be
265			* dereferenced when completing the pool.
266			*/
267			private function addNextRequest()
268			{
269			add_next:
270
271			if ($this->isRealized \|\| !$this->iter \|\| !$this->iter->valid()) {
272			return false;
273			}
274
275			$request = $this->iter->current();
276			$this->iter->next();
277
278			if (!($request instanceof RequestInterface)) {
279			throw new \InvalidArgumentException(sprintf(
280			'All requests in the provided iterator must implement '
281			. 'RequestInterface. Found %s',
282			Core::describeType($request)
283			));
284			}
285
286			// Be sure to use "lazy" futures, meaning they do not send right away.
287			$request->getConfig()->set('future', 'lazy');
288			$hash = spl_object_hash($request);
289			$this->attachListeners($request, $this->eventListeners);
290			$request->getEmitter()->on('before', [$this, '_trackRetries'], RequestEvents::EARLY);
291			$response = $this->client->send($request);
292			$this->waitQueue[$hash] = $response;
293			$promise = $response->promise();
294
295			// Don't recursively call itself for completed or rejected responses.
296			if ($promise instanceof FulfilledPromise
297			\|\| $promise instanceof RejectedPromise
298			) {
299			try {
300			$this->finishResponse($request, $response->wait(), $hash);
301			} catch (\Exception $e) {
302			$this->finishResponse($request, $e, $hash);
303			}
304			goto add_next;
305			}
306
307			// Use this function for both resolution and rejection.
308			$thenFn = function ($value) use ($request, $hash) {
309			$this->finishResponse($request, $value, $hash);
310			if (!$request->getConfig()->get('_pool_retries')) {
311			$this->addNextRequests();
312			}
313			};
314
315			$promise->then($thenFn, $thenFn);
316
317			return true;
318			}
319
320			public function _trackRetries(BeforeEvent $e)
321			{
322			$e->getRequest()->getConfig()->set('_pool_retries', $e->getRetryCount());
323			}
324
325			private function finishResponse($request, $value, $hash)
326			{
327			unset($this->waitQueue[$hash]);
328			$result = $value instanceof ResponseInterface
329			? ['request' => $request, 'response' => $value, 'error' => null]
330			: ['request' => $request, 'response' => null, 'error' => $value];
331			$this->deferred->notify($result);
332			}
333			}
334

owncloud / updater

Push — master ( 2b1385...7c6a84 )

Pool::addNextRequest() D

Complexity

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Duplication

Importance

How to fix Long Method

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