wp-stateless / lib / Google / vendor / google / auth / src / Cache / SysVCacheItemPool.php

SysVCacheItemPool.php in WP-Stateless – Google Cloud Storage 3.0.3, at lib/Google/vendor/google/auth/src/Cache/SysVCacheItemPool.php

242 lines 5.9 KB

Raw Download Zip

1	<?php
2	/**
3	* Copyright 2018 Google Inc. All Rights Reserved.
4	*
5	* Licensed under the Apache License, Version 2.0 (the "License");
6	* you may not use this file except in compliance with the License.
7	* You may obtain a copy of the License at
8	*
9	* http://www.apache.org/licenses/LICENSE-2.0
10	*
11	* Unless required by applicable law or agreed to in writing, software
12	* distributed under the License is distributed on an "AS IS" BASIS,
13	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14	* See the License for the specific language governing permissions and
15	* limitations under the License.
16	*/
17	namespace Google\Auth\Cache;
18
19	use Psr\Cache\CacheItemInterface;
20	use Psr\Cache\CacheItemPoolInterface;
21
22	/**
23	* SystemV shared memory based CacheItemPool implementation.
24	*
25	* This CacheItemPool implementation can be used among multiple processes, but
26	* it doesn't provide any locking mechanism. If multiple processes write to
27	* this ItemPool, you have to avoid race condition manually in your code.
28	*/
29	class SysVCacheItemPool implements CacheItemPoolInterface
30	{
31	const VAR_KEY = 1;
32
33	const DEFAULT_PROJ = 'A';
34
35	const DEFAULT_MEMSIZE = 10000;
36
37	const DEFAULT_PERM = 0600;
38
39	/** @var int */
40	private $sysvKey;
41
42	/**
43	* @var CacheItemInterface[]
44	*/
45	private $items;
46
47	/**
48	* @var CacheItemInterface[]
49	*/
50	private $deferredItems;
51
52	/**
53	* @var array
54	*/
55	private $options;
56
57	/*
58	* @var bool
59	*/
60	private $hasLoadedItems = false;
61
62	/**
63	* Create a SystemV shared memory based CacheItemPool.
64	*
65	* @param array $options [optional] Configuration options.
66	* @param int $options.variableKey The variable key for getting the data from
67	* the shared memory. Defaults to 1.
68	* @param $options.proj string The project identifier for ftok. This needs to
69	* be a one character string. Defaults to 'A'.
70	* @param $options.memsize int The memory size in bytes for shm_attach.
71	* Defaults to 10000.
72	* @param $options.perm int The permission for shm_attach. Defaults to
73	* 0600.
74	*/
75	public function __construct($options = [])
76	{
77	if (! extension_loaded('sysvshm')) {
78	throw new \RuntimeException(
79	'sysvshm extension is required to use this ItemPool'
80	);
81	}
82	$this->options = $options + [
83	'variableKey' => self::VAR_KEY,
84	'proj' => self::DEFAULT_PROJ,
85	'memsize' => self::DEFAULT_MEMSIZE,
86	'perm' => self::DEFAULT_PERM
87	];
88	$this->items = [];
89	$this->deferredItems = [];
90	$this->sysvKey = ftok(__FILE__, $this->options['proj']);
91	}
92
93	public function getItem($key)
94	{
95	$this->loadItems();
96	return current($this->getItems([$key]));
97	}
98
99	/**
100	* {@inheritdoc}
101	*/
102	public function getItems(array $keys = [])
103	{
104	$this->loadItems();
105	$items = [];
106	foreach ($keys as $key) {
107	$items[$key] = $this->hasItem($key) ?
108	clone $this->items[$key] :
109	new Item($key);
110	}
111	return $items;
112	}
113
114	/**
115	* {@inheritdoc}
116	*/
117	public function hasItem($key)
118	{
119	$this->loadItems();
120	return isset($this->items[$key]) && $this->items[$key]->isHit();
121	}
122
123	/**
124	* {@inheritdoc}
125	*/
126	public function clear()
127	{
128	$this->items = [];
129	$this->deferredItems = [];
130	return $this->saveCurrentItems();
131	}
132
133	/**
134	* {@inheritdoc}
135	*/
136	public function deleteItem($key)
137	{
138	return $this->deleteItems([$key]);
139	}
140
141	/**
142	* {@inheritdoc}
143	*/
144	public function deleteItems(array $keys)
145	{
146	if (!$this->hasLoadedItems) {
147	$this->loadItems();
148	}
149
150	foreach ($keys as $key) {
151	unset($this->items[$key]);
152	}
153	return $this->saveCurrentItems();
154	}
155
156	/**
157	* {@inheritdoc}
158	*/
159	public function save(CacheItemInterface $item)
160	{
161	if (!$this->hasLoadedItems) {
162	$this->loadItems();
163	}
164
165	$this->items[$item->getKey()] = $item;
166	return $this->saveCurrentItems();
167	}
168
169	/**
170	* {@inheritdoc}
171	*/
172	public function saveDeferred(CacheItemInterface $item)
173	{
174	$this->deferredItems[$item->getKey()] = $item;
175	return true;
176	}
177
178	/**
179	* {@inheritdoc}
180	*/
181	public function commit()
182	{
183	foreach ($this->deferredItems as $item) {
184	if ($this->save($item) === false) {
185	return false;
186	}
187	}
188	$this->deferredItems = [];
189	return true;
190	}
191
192	/**
193	* Save the current items.
194	*
195	* @return bool true when success, false upon failure
196	*/
197	private function saveCurrentItems()
198	{
199	$shmid = shm_attach(
200	$this->sysvKey,
201	$this->options['memsize'],
202	$this->options['perm']
203	);
204	if ($shmid !== false) {
205	$ret = shm_put_var(
206	$shmid,
207	$this->options['variableKey'],
208	$this->items
209	);
210	shm_detach($shmid);
211	return $ret;
212	}
213	return false;
214	}
215
216	/**
217	* Load the items from the shared memory.
218	*
219	* @return bool true when success, false upon failure
220	*/
221	private function loadItems()
222	{
223	$shmid = shm_attach(
224	$this->sysvKey,
225	$this->options['memsize'],
226	$this->options['perm']
227	);
228	if ($shmid !== false) {
229	$data = @shm_get_var($shmid, $this->options['variableKey']);
230	if (!empty($data)) {
231	$this->items = $data;
232	} else {
233	$this->items = [];
234	}
235	shm_detach($shmid);
236	$this->hasLoadedItems = true;
237	return true;
238	}
239	return false;
240	}
241	}
242