media-cloud-sync / includes / sdk / s3 / Aws / ResultPaginator.php

ResultPaginator.php in Media Cloud Sync 1.4.1, at includes/sdk/s3/Aws/ResultPaginator.php

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1	<?php
2
3	namespace Dudlewebs\WPMCS\s3\Aws;
4
5	use Dudlewebs\WPMCS\s3\GuzzleHttp\Promise;
6	/**
7	* Iterator that yields each page of results of a pageable operation.
8	*/
9	class ResultPaginator implements \Iterator
10	{
11	/** @var AwsClientInterface Client performing operations. */
12	private $client;
13	/** @var string Name of the operation being paginated. */
14	private $operation;
15	/** @var array Args for the operation. */
16	private $args;
17	/** @var array Configuration for the paginator. */
18	private $config;
19	/** @var Result Most recent result from the client. */
20	private $result;
21	/** @var string\|array Next token to use for pagination. */
22	private $nextToken;
23	/** @var int Number of operations/requests performed. */
24	private $requestCount = 0;
25	/**
26	* @param AwsClientInterface $client
27	* @param string $operation
28	* @param array $args
29	* @param array $config
30	*/
31	public function __construct(AwsClientInterface $client, $operation, array $args, array $config)
32	{
33	$this->client = $client;
34	$this->operation = $operation;
35	$this->args = $args;
36	$this->config = $config;
37	MetricsBuilder::appendMetricsCaptureMiddleware($this->client->getHandlerList(), MetricsBuilder::PAGINATOR);
38	}
39	/**
40	* Runs a paginator asynchronously and uses a callback to handle results.
41	*
42	* The callback should have the signature: function (Aws\Result $result).
43	* A non-null return value from the callback will be yielded by the
44	* promise. This means that you can return promises from the callback that
45	* will need to be resolved before continuing iteration over the remaining
46	* items, essentially merging in other promises to the iteration. The last
47	* non-null value returned by the callback will be the result that fulfills
48	* the promise to any downstream promises.
49	*
50	* @param callable $handleResult Callback for handling each page of results.
51	* The callback accepts the result that was
52	* yielded as a single argument. If the
53	* callback returns a promise, the promise
54	* will be merged into the coroutine.
55	*
56	* @return Promise\Promise
57	*/
58	public function each(callable $handleResult)
59	{
60	return Promise\Coroutine::of(function () use($handleResult) {
61	$nextToken = null;
62	do {
63	$command = $this->createNextCommand($this->args, $nextToken);
64	$result = (yield $this->client->executeAsync($command));
65	$nextToken = $this->determineNextToken($result);
66	$retVal = $handleResult($result);
67	if ($retVal !== null) {
68	(yield Promise\Create::promiseFor($retVal));
69	}
70	} while ($nextToken);
71	});
72	}
73	/**
74	* Returns an iterator that iterates over the values of applying a JMESPath
75	* search to each result yielded by the iterator as a flat sequence.
76	*
77	* @param string $expression JMESPath expression to apply to each result.
78	*
79	* @return \Iterator
80	*/
81	public function search($expression)
82	{
83	// Apply JMESPath expression on each result, but as a flat sequence.
84	return flatmap($this, function (Result $result) use($expression) {
85	return (array) $result->search($expression);
86	});
87	}
88	/**
89	* @return Result
90	*/
91	#[\ReturnTypeWillChange]
92	public function current()
93	{
94	return $this->valid() ? $this->result : \false;
95	}
96	/**
97	* @return mixed
98	*/
99	#[\ReturnTypeWillChange]
100	public function key()
101	{
102	return $this->valid() ? $this->requestCount - 1 : null;
103	}
104	/**
105	* @return void
106	*/
107	#[\ReturnTypeWillChange]
108	public function next()
109	{
110	$this->result = null;
111	}
112	/**
113	* @return bool
114	*/
115	#[\ReturnTypeWillChange]
116	public function valid()
117	{
118	if ($this->result) {
119	return \true;
120	}
121	if ($this->nextToken \|\| !$this->requestCount) {
122	//Forward/backward paging can result in a case where the last page's nextforwardtoken
123	//is the same as the one that came before it. This can cause an infinite loop.
124	$hasBidirectionalPaging = $this->config['output_token'] === 'nextForwardToken';
125	if ($hasBidirectionalPaging && $this->nextToken) {
126	$tokenKey = $this->config['input_token'];
127	$previousToken = $this->nextToken[$tokenKey];
128	}
129	$this->result = $this->client->execute($this->createNextCommand($this->args, $this->nextToken));
130	$this->nextToken = $this->determineNextToken($this->result);
131	if (isset($previousToken) && $previousToken === $this->nextToken[$tokenKey]) {
132	return \false;
133	}
134	$this->requestCount++;
135	return \true;
136	}
137	return \false;
138	}
139	/**
140	* @return void
141	*/
142	#[\ReturnTypeWillChange]
143	public function rewind()
144	{
145	$this->requestCount = 0;
146	$this->nextToken = null;
147	$this->result = null;
148	}
149	private function createNextCommand(array $args, ?array $nextToken = null)
150	{
151	return $this->client->getCommand($this->operation, \array_merge($args, $nextToken ?: []));
152	}
153	private function determineNextToken(Result $result)
154	{
155	if (!$this->config['output_token']) {
156	return null;
157	}
158	if ($this->config['more_results'] && !$result->search($this->config['more_results'])) {
159	return null;
160	}
161	$nextToken = \is_scalar($this->config['output_token']) ? [$this->config['input_token'] => $this->config['output_token']] : \array_combine($this->config['input_token'], $this->config['output_token']);
162	return \array_filter(\array_map(function ($outputToken) use($result) {
163	return $result->search($outputToken);
164	}, $nextToken));
165	}
166	}
167