media-cloud-sync / includes / sdk / google / google / cloud-storage / src / Connection / RetryTrait.php

RetryTrait.php in Media Cloud Sync 1.2.10, at includes/sdk/google/google/cloud-storage/src/Connection/RetryTrait.php

174 lines 7.2 KB

Raw Download Zip

1	<?php
2
3	/**
4	* Copyright 2022 Google Inc. All Rights Reserved.
5	*
6	* Licensed under the Apache License, Version 2.0 (the "License");
7	* you may not use this file except in compliance with the License.
8	* You may obtain a copy of the License at
9	*
10	* http://www.apache.org/licenses/LICENSE-2.0
11	*
12	* Unless required by applicable law or agreed to in writing, software
13	* distributed under the License is distributed on an "AS IS" BASIS,
14	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15	* See the License for the specific language governing permissions and
16	* limitations under the License.
17	*/
18	namespace Dudlewebs\WPMCS\Google\Cloud\Storage\Connection;
19
20	use Dudlewebs\WPMCS\Google\Cloud\Storage\StorageClient;
21	/**
22	* Trait which provides helper methods for retry logic.
23	*
24	* @internal
25	*/
26	trait RetryTrait
27	{
28	/**
29	* The HTTP codes that will be retried by our custom retry function.
30	* @var array
31	*/
32	private static $httpRetryCodes = [
33	0,
34	// connetion-refused OR connection-reset gives status code of 0
35	200,
36	// partial download cases
37	408,
38	429,
39	500,
40	502,
41	503,
42	504,
43	];
44	/**
45	* The operations which can be retried without any conditions
46	* (Idempotent)
47	* @var array
48	*/
49	private static $idempotentOps = ['bucket_acl.get', 'bucket_acl.list', 'buckets.delete', 'buckets.get', 'buckets.getIamPolicy', 'buckets.insert', 'buckets.list', 'buckets.lockRetentionPolicy', 'buckets.testIamPermissions', 'default_object_acl.get', 'default_object_acl.list', 'hmacKey.delete', 'hmacKey.get', 'hmacKey.list', 'notifications.delete', 'notifications.get', 'notifications.list', 'object_acl.get', 'object_acl.list', 'objects.get', 'objects.list', 'serviceaccount.get'];
50	/**
51	* The operations which can be retried with specific conditions
52	* (Conditionally idempotent)
53	* @var array
54	*/
55	private static $condIdempotentOps = [
56	'buckets.patch' => ['ifMetagenerationMatch', 'etag'],
57	// Currently etag is not supported, so this preCondition never available
58	'buckets.setIamPolicy' => ['etag'],
59	'buckets.update' => ['ifMetagenerationMatch', 'etag'],
60	'hmacKey.update' => ['etag'],
61	'objects.compose' => ['ifGenerationMatch'],
62	'objects.copy' => ['ifGenerationMatch'],
63	'objects.delete' => ['ifGenerationMatch'],
64	'objects.insert' => ['ifGenerationMatch', 'ifGenerationNotMatch'],
65	'objects.patch' => ['ifMetagenerationMatch', 'etag'],
66	'objects.rewrite' => ['ifGenerationMatch'],
67	'objects.update' => ['ifMetagenerationMatch'],
68	];
69	/**
70	* Retry strategies which enforce certain behaviour like:
71	* - Always retrying a call when an exception occurs(within the limits of 'max retries').
72	* - Never retrying a call when an exception occurs.
73	* - Retrying only when the operation is considered idempotent(default).
74	* These configurations are supplied for per api call basis.
75	*
76	*/
77	/**
78	* Header that identifies a specific request hash. The
79	* hash needs to stay the same for multiple retries.
80	*/
81	private static $INVOCATION_ID_HEADER = 'gccl-invocation-id';
82	/**
83	* Header that identifies the attempt count for a request. The
84	* value will increment by 1 with every retry.
85	*/
86	private static $ATTEMPT_COUNT_HEADER = 'gccl-attempt-count';
87	/**
88	* Return a retry decider function.
89	*
90	* @param string $resource resource name, eg: buckets.
91	* @param string $method method name, eg: get
92	* @param array $args
93	* @return callable
94	*/
95	private function getRestRetryFunction($resource, $method, array $args)
96	{
97	if (isset($args['restRetryFunction'])) {
98	return $args['restRetryFunction'];
99	}
100	$methodName = sprintf('%s.%s', $resource, $method);
101	$isOpIdempotent = in_array($methodName, self::$idempotentOps);
102	$preconditionNeeded = array_key_exists($methodName, self::$condIdempotentOps);
103	$preconditionSupplied = $this->isPreConditionSupplied($methodName, $args);
104	$retryStrategy = isset($args['retryStrategy']) ? $args['retryStrategy'] : StorageClient::RETRY_IDEMPOTENT;
105	return function (\Exception $exception) use ($isOpIdempotent, $preconditionNeeded, $preconditionSupplied, $retryStrategy) {
106	return $this->retryDeciderFunction($exception, $isOpIdempotent, $preconditionNeeded, $preconditionSupplied, $retryStrategy);
107	};
108	}
109	/**
110	* This function returns true when the user given
111	* precondtions ($preConditions) has values that are present
112	* in the precondition map ($this->condIdempotentMap) for that method.
113	* eg: condIdempotentMap has entry 'objects.copy' => ['ifGenerationMatch'],
114	* if the user has given 'ifGenerationMatch' in the 'objects.copy' operation,
115	* it will be available in the $preConditions
116	* as an array ['ifGenerationMatch']. This makes the array_intersect
117	* function return a non empty result and this function returns true.
118	*
119	* @param string $methodName method name, eg: buckets.get.
120	* @param array $args arguments which include preconditions provided,
121	* eg: ['ifGenerationMatch' => 0].
122	* @return bool
123	*/
124	private function isPreConditionSupplied($methodName, array $args)
125	{
126	if (isset(self::$condIdempotentOps[$methodName])) {
127	// return true if required precondition are given.
128	return !empty(array_intersect(self::$condIdempotentOps[$methodName], array_keys($args)));
129	}
130	return \false;
131	}
132	/**
133	* Decide whether the op needs to be retried or not.
134	*
135	* @param \Exception $exception The exception object received
136	* while sending the request.
137	* @param int $currentAttempt Current retry attempt.
138	* @param bool $isIdempotent
139	* @param bool $preconditionNeeded
140	* @param bool $preconditionSupplied
141	* @param int $maxRetries
142	* @return bool
143	*/
144	private function retryDeciderFunction(\Exception $exception, $isIdempotent, $preconditionNeeded, $preconditionSupplied, $retryStrategy)
145	{
146	if ($retryStrategy == StorageClient::RETRY_NEVER) {
147	return \false;
148	}
149	$statusCode = $exception->getCode();
150	// Retry if the exception status code matches
151	// with one of the retriable status code and
152	// the operation is either idempotent or conditionally
153	// idempotent with preconditions supplied.
154	if (in_array($statusCode, self::$httpRetryCodes)) {
155	if ($retryStrategy == StorageClient::RETRY_ALWAYS) {
156	return \true;
157	} elseif ($isIdempotent) {
158	return \true;
159	} elseif ($preconditionNeeded) {
160	return $preconditionSupplied;
161	}
162	}
163	return \false;
164	}
165	/**
166	* Utility func that returns the list of headers that need to be
167	* attached to every request and its retries.
168	*/
169	private static function getRetryHeaders($invocationId, $attemptCount)
170	{
171	return [sprintf('%s/%s', self::$INVOCATION_ID_HEADER, $invocationId), sprintf('%s/%d', self::$ATTEMPT_COUNT_HEADER, $attemptCount)];
172	}
173	}
174