GuzzleRetryMiddleware::deriveTimeoutFromHeader() - Code Metrics - Inspection of "Bugfix to comparison type check" - caseyamcl/guzzle_retry_middleware - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( eeba1a...91793e )

by Casey

created 2019-09-16 15:35 UTC

GuzzleRetryMiddleware::deriveTimeoutFromHeader() A

↳ Parent: GuzzleRetryMiddleware

Complexity

Conditions	3
Paths	3

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	6
CRAP Score	3

Importance

Changes

Metric	Value
dl	0
loc	12
ccs	6
cts	6
cp	1
rs	9.8666
c	0
b	0
f	0
cc	3
nc	3
nop	1
crap	3

<?php
/**
 * Guzzle Retry Middleware Library
 *
 * @license http://opensource.org/licenses/MIT
 * @link https://github.com/caseyamcl/guzzle_retry_middleware
 * @version 2.0
 * @package caseyamcl/guzzle_retry_middleware
 * @author Casey McLaughlin <[email protected]>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * ------------------------------------------------------------------
 */

declare(strict_types=1);

namespace GuzzleRetry;

use Closure;
use DateTime;
use GuzzleHttp\Exception\BadResponseException;
use GuzzleHttp\Exception\ConnectException;
use GuzzleHttp\Promise\Promise;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;
use function call_user_func;
use function call_user_func_array;
use function GuzzleHttp\Promise\rejection_for;
use function in_array;
use function is_callable;

/**
 * Retry After Middleware
 *
 * Guzzle 6 middleware that retries requests when encountering responses
 * with certain conditions (429 or 503).  This middleware also respects
 * the `RetryAfter` header
 *
 * @author Casey McLaughlin <[email protected]>
 */
class GuzzleRetryMiddleware
{
    // HTTP date format
    const DATE_FORMAT = 'D, d M Y H:i:s T';

    // Default retry header (off by default; configurable)
    const RETRY_HEADER = 'X-Retry-Counter';

    /**
     * @var array
     */
    private $defaultOptions = [

        // Retry enabled.  Toggle retry on or off per request
        'retry_enabled'                    => true,

        // If server doesn't provide a Retry-After header, then set a default back-off delay
        // NOTE: This can either be a float, or it can be a callable that returns a (accepts count and response|null)
        'default_retry_multiplier'         => 1.5,

        // Set a maximum number of attempts per request
        'max_retry_attempts'               => 10,

        // Set this to TRUE to retry only if the HTTP Retry-After header is specified
        'retry_only_if_retry_after_header' => false,

        // Only retry when status is equal to these response codes
        'retry_on_status'                  => ['429', '503'],

        // Callback to trigger when delay occurs (accepts count, delay, request, response, options)
        'on_retry_callback'                => null,

        // Retry on connect timeout?
        'retry_on_timeout'                 => false,

        // Add the number of retries to an X-Header
        'expose_retry_header'              => false,

        // The header key
        'retry_header'                     => self::RETRY_HEADER
    ];

    /**
     * @var callable
     */
    private $nextHandler;

    /**
     * Provides a closure that can be pushed onto the handler stack
     *
     * Example:
     * <code>$handlerStack->push(GuzzleRetryMiddleware::factory());</code>
     *
     * @param array $defaultOptions
     * @return Closure
     */
    public static function factory(array $defaultOptions = []): Closure
    {
        return function (callable $handler) use ($defaultOptions) {
            return new static($handler, $defaultOptions);
        };
    }

    /**
     * GuzzleRetryMiddleware constructor.
     *
     * @param callable $nextHandler
     * @param array $defaultOptions
     */
    public function __construct(callable $nextHandler, array $defaultOptions = [])
    {
        $this->nextHandler = $nextHandler;
        $this->defaultOptions = array_replace($this->defaultOptions, $defaultOptions);
    }

    /**
     * @param RequestInterface $request
     * @param array $options
     * @return Promise
     */
    public function __invoke(RequestInterface $request, array $options): Promise
    {
        // Combine options with defaults specified by this middleware
        $options = array_replace($this->defaultOptions, $options);

        // Set the retry count if not already set
        if (! isset($options['retry_count'])) {
            $options['retry_count'] = 0;
        }

        /** @var callable $next */
        $next = $this->nextHandler;
        return $next($request, $options)
            ->then(
                $this->onFulfilled($request, $options),
                $this->onRejected($request, $options)
            );
    }

    /**
     * No exceptions were thrown during processing
     *
     * Depending on where this middleware is in the stack, the response could still
     * be unsuccessful (e.g. 429 or 503), so check to see if it should be retried
     *
     * @param RequestInterface $request
     * @param array $options
     * @return callable
     */
    protected function onFulfilled(RequestInterface $request, array $options): callable
    {
        return function (ResponseInterface $response) use ($request, $options) {
            return $this->shouldRetryHttpResponse($options, $response)
                ? $this->doRetry($request, $options, $response)
                : $this->returnResponse($options, $response);
        };
    }

    /**
     * An exception or error was thrown during processing
     *
     * If the reason is a BadResponseException exception, check to see if
     * the request can be retried.  Otherwise, pass it on.
     *
     * @param RequestInterface $request
     * @param array $options
     * @return callable
     */
    protected function onRejected(RequestInterface $request, array $options): callable
    {
        return function ($reason) use ($request, $options) {
            // If was bad response exception, test if we retry based on the response headers
            if ($reason instanceof BadResponseException) {
                if ($this->shouldRetryHttpResponse($options, $reason->getResponse())) {
/** @return stdClass|null */
function mayReturnNull() { }

function doesNotAcceptNull(stdClass $x) { }

// With potential error.
function withoutCheck() {
    $x = mayReturnNull();
    doesNotAcceptNull($x); // Potential error here.
}

// Safe - Alternative 1
function withCheck1() {
    $x = mayReturnNull();
    if ( ! $x instanceof stdClass) {
        throw new \LogicException('$x must be defined.');
    }
    doesNotAcceptNull($x);
}

// Safe - Alternative 2
function withCheck2() {
    $x = mayReturnNull();
    if ($x instanceof stdClass) {
        doesNotAcceptNull($x);
    }
}
                    return $this->doRetry($request, $options, $reason->getResponse());
                }
            // If this was a connection exception, test to see if we should retry based on connect timeout rules
            } elseif ($reason instanceof ConnectException) {
                // If was another type of exception, test if we should retry based on timeout rules
                if ($this->shouldRetryConnectException($reason, $options)) {
                    return $this->doRetry($request, $options);
                }
            }

            // If made it here, then we have decided not to retry the request
            return rejection_for($reason);
        };
    }

    /**
     * @param ConnectException $e
     * @param array $options
     * @return bool
     */
    protected function shouldRetryConnectException(ConnectException $e, array $options): bool
    {
        switch (true) {
            case $options['retry_enabled'] === false:
            case $this->countRemainingRetries($options) === 0:
                return false;

            // Test if this was a connection or response timeout exception
            case isset($e->getHandlerContext()['errno']) && $e->getHandlerContext()['errno'] == 28:
                return isset($options['retry_on_timeout']) && $options['retry_on_timeout'] === true;

            // No conditions met, so return false
            default:
                return false;
        }
    }

    /**
     * Check to see if a request can be retried
     *
     * This checks two things:
     *
     * 1. The response status code against the status codes that should be retried
     * 2. The number of attempts made thus far for this request
     *
     * @param array $options
     * @param ResponseInterface|null $response
     * @return bool  TRUE if the response should be retried, FALSE if not
     */
    protected function shouldRetryHttpResponse(array $options, ResponseInterface $response): bool
    {
        $statuses = array_map('\intval', (array) $options['retry_on_status']);

        switch (true) {
            case $options['retry_enabled'] === false:
            case $this->countRemainingRetries($options) === 0: // No Retry-After header, and it is required?  Give up
            case (! $response->hasHeader('Retry-After') && $options['retry_only_if_retry_after_header']):
                return false;

            // Conditions met; see if status code matches one that can be retried
            default:
                return in_array($response->getStatusCode(), $statuses, true);
        }
    }

    /**
     * Count the number of retries remaining.  Always returns 0 or greater.
     * @param array $options
     * @return int
     */
    protected function countRemainingRetries(array $options): int
    {
        $retryCount  = isset($options['retry_count']) ? (int) $options['retry_count'] : 0;

        $numAllowed  = isset($options['max_retry_attempts'])
            ? (int) $options['max_retry_attempts']
            : $this->defaultOptions['max_retry_attempts'];

        return max([$numAllowed - $retryCount, 0]);
    }

    /**
     * Retry the request
     *
     * Increments the retry count, determines the delay (timeout), executes callbacks, sleeps, and re-send the request
     *
     * @param RequestInterface $request
     * @param array $options
     * @param ResponseInterface|null $response
     * @return Promise
     */
    protected function doRetry(RequestInterface $request, array $options, ResponseInterface $response = null): Promise
    {
        // Increment the retry count
        ++$options['retry_count'];

        // Determine the delay timeout
        $delayTimeout = $this->determineDelayTimeout($options, $response);

        // Callback?
        if ($options['on_retry_callback']) {
            call_user_func_array(
                $options['on_retry_callback'],
                [
                    (int) $options['retry_count'],
                    (float) $delayTimeout,
                    &$request,
                    &$options,
                    $response
                ]
            );
        }

        // Delay!
        usleep(((int) $delayTimeout) * 1000000);

        // Return
        return $this($request, $options);
    }

    /**
     * @param array $options
     * @param ResponseInterface $response
     * @return ResponseInterface
     */
    protected function returnResponse(array $options, ResponseInterface $response): ResponseInterface
    {
        if ($options['expose_retry_header'] === false
            || $options['retry_count'] === 0
        ) {
            return $response;
        }

        return $response->withHeader($options['retry_header'], $options['retry_count']);
    }

    /**
     * Determine the delay timeout
     *
     * Attempts to read and interpret the HTTP `Retry-After` header, or defaults
     * to a built-in incremental back-off algorithm.
     *
     * @param ResponseInterface $response
     * @param array $options
     * @return float  Delay timeout, in seconds
     */
    protected function determineDelayTimeout(array $options, ResponseInterface $response = null): float
    {
        if (is_callable($options['default_retry_multiplier'])) {
            $defaultDelayTimeout = (float) call_user_func(
                $options['default_retry_multiplier'],
                $options['retry_count'],
                $response
            );
        } else {
            $defaultDelayTimeout = (float) $options['default_retry_multiplier'] * $options['retry_count'];
        }

        // Retry-After can be a delay in seconds or a date
        // (see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Retry-After)
        if ($response && $response->hasHeader('Retry-After')) {
            return
                $this->deriveTimeoutFromHeader($response->getHeader('Retry-After')[0])
                ?: $defaultDelayTimeout;
        }

        return $defaultDelayTimeout;
    }

    /**
     * Attempt to derive the timeout from the HTTP `Retry-After` header
     *
     * The spec allows the header value to either be a number of seconds or a datetime.
     *
     * @param string $headerValue
     * @return float|null  The number of seconds to wait, or NULL if unsuccessful (invalid header)
     */
    protected function deriveTimeoutFromHeader(string $headerValue): ?float
    {
        // The timeout will either be a number or a HTTP-formatted date,
        // or seconds (integer)
        if (trim($headerValue) === (string) (int) $headerValue) {
            return (float) trim($headerValue);
        } elseif ($date = DateTime::createFromFormat(self::DATE_FORMAT, trim($headerValue))) {
            return (float) $date->format('U') - time();
        }

        return null;
    }
}


1		<?php
2		/**
3		* Guzzle Retry Middleware Library
4		*
5		* @license http://opensource.org/licenses/MIT
6		* @link https://github.com/caseyamcl/guzzle_retry_middleware
7		* @version 2.0
8		* @package caseyamcl/guzzle_retry_middleware
9		* @author Casey McLaughlin <[email protected]>
10		*
11		* For the full copyright and license information, please view the LICENSE
12		* file that was distributed with this source code.
13		*
14		* ------------------------------------------------------------------
15		*/
16
17		declare(strict_types=1);
18
19		namespace GuzzleRetry;
20
21		use Closure;
22		use DateTime;
23		use GuzzleHttp\Exception\BadResponseException;
24		use GuzzleHttp\Exception\ConnectException;
25		use GuzzleHttp\Promise\Promise;
26		use Psr\Http\Message\RequestInterface;
27		use Psr\Http\Message\ResponseInterface;
28		use function call_user_func;
29		use function call_user_func_array;
30		use function GuzzleHttp\Promise\rejection_for;
31		use function in_array;
32		use function is_callable;
33
34		/**
35		* Retry After Middleware
36		*
37		* Guzzle 6 middleware that retries requests when encountering responses
38		* with certain conditions (429 or 503). This middleware also respects
39		* the `RetryAfter` header
40		*
41		* @author Casey McLaughlin <[email protected]>
42		*/
43		class GuzzleRetryMiddleware
44		{
45		// HTTP date format
46		const DATE_FORMAT = 'D, d M Y H:i:s T';
47
48		// Default retry header (off by default; configurable)
49		const RETRY_HEADER = 'X-Retry-Counter';
50
51		/**
52		* @var array
53		*/
54		private $defaultOptions = [
55
56		// Retry enabled. Toggle retry on or off per request
57		'retry_enabled' => true,
58
59		// If server doesn't provide a Retry-After header, then set a default back-off delay
60		// NOTE: This can either be a float, or it can be a callable that returns a (accepts count and response\|null)
61		'default_retry_multiplier' => 1.5,
62
63		// Set a maximum number of attempts per request
64		'max_retry_attempts' => 10,
65
66		// Set this to TRUE to retry only if the HTTP Retry-After header is specified
67		'retry_only_if_retry_after_header' => false,
68
69		// Only retry when status is equal to these response codes
70		'retry_on_status' => ['429', '503'],
71
72		// Callback to trigger when delay occurs (accepts count, delay, request, response, options)
73		'on_retry_callback' => null,
74
75		// Retry on connect timeout?
76		'retry_on_timeout' => false,
77
78		// Add the number of retries to an X-Header
79		'expose_retry_header' => false,
80
81		// The header key
82		'retry_header' => self::RETRY_HEADER
83		];
84
85		/**
86		* @var callable
87		*/
88		private $nextHandler;
89
90		/**
91		* Provides a closure that can be pushed onto the handler stack
92		*
93		* Example:
94		* <code>$handlerStack->push(GuzzleRetryMiddleware::factory());</code>
95		*
96		* @param array $defaultOptions
97		* @return Closure
98		*/
99	69	public static function factory(array $defaultOptions = []): Closure
100		{
101		return function (callable $handler) use ($defaultOptions) {
102	69	return new static($handler, $defaultOptions);
103	69	};
104		}
105
106		/**
107		* GuzzleRetryMiddleware constructor.
108		*
109		* @param callable $nextHandler
110		* @param array $defaultOptions
111		*/
112	72	public function __construct(callable $nextHandler, array $defaultOptions = [])
113		{
114	72	$this->nextHandler = $nextHandler;
115	72	$this->defaultOptions = array_replace($this->defaultOptions, $defaultOptions);
116	72	}
117
118		/**
119		* @param RequestInterface $request
120		* @param array $options
121		* @return Promise
122		*/
123	69	public function __invoke(RequestInterface $request, array $options): Promise
124		{
125		// Combine options with defaults specified by this middleware
126	69	$options = array_replace($this->defaultOptions, $options);
127
128		// Set the retry count if not already set
129	69	if (! isset($options['retry_count'])) {
130	69	$options['retry_count'] = 0;
131		}
132
133		/** @var callable $next */
134	69	$next = $this->nextHandler;
135	69	return $next($request, $options)
136	69	->then(
137	69	$this->onFulfilled($request, $options),
138	69	$this->onRejected($request, $options)
139		);
140		}
141
142		/**
143		* No exceptions were thrown during processing
144		*
145		* Depending on where this middleware is in the stack, the response could still
146		* be unsuccessful (e.g. 429 or 503), so check to see if it should be retried
147		*
148		* @param RequestInterface $request
149		* @param array $options
150		* @return callable
151		*/
152	69	protected function onFulfilled(RequestInterface $request, array $options): callable
153		{
154		return function (ResponseInterface $response) use ($request, $options) {
155	57	return $this->shouldRetryHttpResponse($options, $response)
156	42	? $this->doRetry($request, $options, $response)
157	57	: $this->returnResponse($options, $response);
158	69	};
159		}
160
161		/**
162		* An exception or error was thrown during processing
163		*
164		* If the reason is a BadResponseException exception, check to see if
165		* the request can be retried. Otherwise, pass it on.
166		*
167		* @param RequestInterface $request
168		* @param array $options
169		* @return callable
170		*/
171	69	protected function onRejected(RequestInterface $request, array $options): callable
172		{
173		return function ($reason) use ($request, $options) {
174		// If was bad response exception, test if we retry based on the response headers
175	18	if ($reason instanceof BadResponseException) {
176	3	if ($this->shouldRetryHttpResponse($options, $reason->getResponse())) {
		0 ignored issues – show Bug introduced 2017-10-01 14:35 UTC by Report Bug Copy Issue Report It seems like `$reason->getResponse()` can be `null`; however, `shouldRetryHttpResponse()` does not accept `null`, maybe add an additional type check? Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code: /** @return stdClass\|null */ function mayReturnNull() { } function doesNotAcceptNull(stdClass $x) { } // With potential error. function withoutCheck() { $x = mayReturnNull(); doesNotAcceptNull($x); // Potential error here. } // Safe - Alternative 1 function withCheck1() { $x = mayReturnNull(); if ( ! $x instanceof stdClass) { throw new \LogicException('$x must be defined.'); } doesNotAcceptNull($x); } // Safe - Alternative 2 function withCheck2() { $x = mayReturnNull(); if ($x instanceof stdClass) { doesNotAcceptNull($x); } } Loading history...
177	3	return $this->doRetry($request, $options, $reason->getResponse());
178		}
179		// If this was a connection exception, test to see if we should retry based on connect timeout rules
180	15	} elseif ($reason instanceof ConnectException) {
181		// If was another type of exception, test if we should retry based on timeout rules
182	12	if ($this->shouldRetryConnectException($reason, $options)) {
183	6	return $this->doRetry($request, $options);
184		}
185		}
186
187		// If made it here, then we have decided not to retry the request
188	12	return rejection_for($reason);
189	69	};
190		}
191
192		/**
193		* @param ConnectException $e
194		* @param array $options
195		* @return bool
196		*/
197	12	protected function shouldRetryConnectException(ConnectException $e, array $options): bool
198		{
199	8	switch (true) {
200	12	case $options['retry_enabled'] === false:
201	12	case $this->countRemainingRetries($options) === 0:
202	3	return false;
203
204		// Test if this was a connection or response timeout exception
205	12	case isset($e->getHandlerContext()['errno']) && $e->getHandlerContext()['errno'] == 28:
206	9	return isset($options['retry_on_timeout']) && $options['retry_on_timeout'] === true;
207
208		// No conditions met, so return false
209		default:
210	3	return false;
211		}
212		}
213
214		/**
215		* Check to see if a request can be retried
216		*
217		* This checks two things:
218		*
219		* 1. The response status code against the status codes that should be retried
220		* 2. The number of attempts made thus far for this request
221		*
222		* @param array $options
223		* @param ResponseInterface\|null $response
224		* @return bool TRUE if the response should be retried, FALSE if not
225		*/
226	57	protected function shouldRetryHttpResponse(array $options, ResponseInterface $response): bool
227		{
228	57	$statuses = array_map('\intval', (array) $options['retry_on_status']);
229
230	38	switch (true) {
231	57	case $options['retry_enabled'] === false:
232	57	case $this->countRemainingRetries($options) === 0: // No Retry-After header, and it is required? Give up
233	57	case (! $response->hasHeader('Retry-After') && $options['retry_only_if_retry_after_header']):
234	18	return false;
235
236		// Conditions met; see if status code matches one that can be retried
237		default:
238	54	return in_array($response->getStatusCode(), $statuses, true);
239		}
240		}
241
242		/**
243		* Count the number of retries remaining. Always returns 0 or greater.
244		* @param array $options
245		* @return int
246		*/
247	66	protected function countRemainingRetries(array $options): int
248		{
249	66	$retryCount = isset($options['retry_count']) ? (int) $options['retry_count'] : 0;
250
251	66	$numAllowed = isset($options['max_retry_attempts'])
252	66	? (int) $options['max_retry_attempts']
253	66	: $this->defaultOptions['max_retry_attempts'];
254
255	66	return max([$numAllowed - $retryCount, 0]);
256		}
257
258		/**
259		* Retry the request
260		*
261		* Increments the retry count, determines the delay (timeout), executes callbacks, sleeps, and re-send the request
262		*
263		* @param RequestInterface $request
264		* @param array $options
265		* @param ResponseInterface\|null $response
266		* @return Promise
267		*/
268	51	protected function doRetry(RequestInterface $request, array $options, ResponseInterface $response = null): Promise
269		{
270		// Increment the retry count
271	51	++$options['retry_count'];
272
273		// Determine the delay timeout
274	51	$delayTimeout = $this->determineDelayTimeout($options, $response);
275
276		// Callback?
277	51	if ($options['on_retry_callback']) {
278		call_user_func_array(
279	42	$options['on_retry_callback'],
280		[
281	42	(int) $options['retry_count'],
282	42	(float) $delayTimeout,
283	42	&$request,
284	42	&$options,
285	42	$response
286		]
287		);
288		}
289
290		// Delay!
291	51	usleep(((int) $delayTimeout) * 1000000);
292
293		// Return
294	51	return $this($request, $options);
295		}
296
297		/**
298		* @param array $options
299		* @param ResponseInterface $response
300		* @return ResponseInterface
301		*/
302	57	protected function returnResponse(array $options, ResponseInterface $response): ResponseInterface
303		{
304	57	if ($options['expose_retry_header'] === false
305	57	\|\| $options['retry_count'] === 0
306		) {
307	54	return $response;
308		}
309
310	3	return $response->withHeader($options['retry_header'], $options['retry_count']);
311		}
312
313		/**
314		* Determine the delay timeout
315		*
316		* Attempts to read and interpret the HTTP `Retry-After` header, or defaults
317		* to a built-in incremental back-off algorithm.
318		*
319		* @param ResponseInterface $response
320		* @param array $options
321		* @return float Delay timeout, in seconds
322		*/
323	51	protected function determineDelayTimeout(array $options, ResponseInterface $response = null): float
324		{
325	51	if (is_callable($options['default_retry_multiplier'])) {
326		$defaultDelayTimeout = (float) call_user_func(
327	3	$options['default_retry_multiplier'],
328	3	$options['retry_count'],
329	3	$response
330		);
331		} else {
332	48	$defaultDelayTimeout = (float) $options['default_retry_multiplier'] * $options['retry_count'];
333		}
334
335		// Retry-After can be a delay in seconds or a date
336		// (see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Retry-After)
337	51	if ($response && $response->hasHeader('Retry-After')) {
338		return
339	9	$this->deriveTimeoutFromHeader($response->getHeader('Retry-After')[0])
340	9	?: $defaultDelayTimeout;
341		}
342
343	42	return $defaultDelayTimeout;
344		}
345
346		/**
347		* Attempt to derive the timeout from the HTTP `Retry-After` header
348		*
349		* The spec allows the header value to either be a number of seconds or a datetime.
350		*
351		* @param string $headerValue
352		* @return float\|null The number of seconds to wait, or NULL if unsuccessful (invalid header)
353		*/
354	9	protected function deriveTimeoutFromHeader(string $headerValue): ?float
355		{
356		// The timeout will either be a number or a HTTP-formatted date,
357		// or seconds (integer)
358	9	if (trim($headerValue) === (string) (int) $headerValue) {
359	3	return (float) trim($headerValue);
360	6	} elseif ($date = DateTime::createFromFormat(self::DATE_FORMAT, trim($headerValue))) {
361	3	return (float) $date->format('U') - time();
362		}
363
364	3	return null;
365		}
366		}
367

caseyamcl / guzzle_retry_middleware

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GuzzleRetryMiddleware::deriveTimeoutFromHeader() A

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