MediaWiki REL1_39
MemcachedBagOStuff.php
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1<?php
31 protected $routingPrefix;
32
42 public function __construct( array $params ) {
43 $params['segmentationSize'] = $params['segmentationSize'] ?? 917504; // < 1MiB
44 parent::__construct( $params );
45
46 $this->routingPrefix = $params['routingPrefix'] ?? '';
47
48 // ...and does not use special disk-cache plugins
50 }
51
60 public function makeKeyInternal( $keyspace, $components ) {
61 // Memcached keys have a maximum length of 255 characters. From that,
62 // subtract the number of characters we need for the keyspace and for
63 // the separator character needed for each argument. To handle some
64 // custom prefixes used by thing like WANObjectCache, limit to 205.
65 $charsLeft = 205 - strlen( $keyspace ) - count( $components );
66
67 foreach ( $components as &$component ) {
68 $component = strtr( $component, ' ', '_' );
69
70 // Make sure %, #, and non-ASCII chars are escaped
71 $component = preg_replace_callback(
72 '/[^\x21-\x22\x24\x26-\x39\x3b-\x7e]+/',
73 static function ( $m ) {
74 return rawurlencode( $m[0] );
75 },
76 $component
77 );
78
79 // 33 = 32 characters for the MD5 + 1 for the '#' prefix.
80 if ( $charsLeft > 33 && strlen( $component ) > $charsLeft ) {
81 $component = '#' . md5( $component );
82 }
83
84 $charsLeft -= strlen( $component );
85 }
86
87 if ( $charsLeft < 0 ) {
88 return $keyspace . ':BagOStuff-long-key:##' . md5( implode( ':', $components ) );
89 }
90
91 return $keyspace . ':' . implode( ':', $components );
92 }
93
102 public function validateKeyEncoding( $key ) {
103 if ( preg_match( '/[^\x21-\x7e]+/', $key ) ) {
104 throw new Exception( "Key contains invalid characters: $key" );
105 }
106
107 return $key;
108 }
109
114 protected function validateKeyAndPrependRoute( $key ) {
115 $this->validateKeyEncoding( $key );
116
117 if ( $this->routingPrefix === '' ) {
118 return $key;
119 }
120
121 if ( $key[0] === '/' ) {
122 throw new RuntimeException( "Key '$key' already contains a route." );
123 }
124
125 return $this->routingPrefix . $key;
126 }
127
132 protected function stripRouteFromKey( $key ) {
133 if ( $this->routingPrefix === '' ) {
134 return $key;
135 }
136
137 $prefixLength = strlen( $this->routingPrefix );
138 if ( substr( $key, 0, $prefixLength ) === $this->routingPrefix ) {
139 return substr( $key, $prefixLength );
140 }
141
142 return $key;
143 }
144
149 protected function fixExpiry( $exptime ) {
150 if ( $exptime < 0 ) {
151 // The PECL driver does not seem to like negative relative values
152 $expiresAt = $this->getCurrentTime() + $exptime;
153 } elseif ( $this->isRelativeExpiration( $exptime ) ) {
154 // TTLs higher than 30 days will be detected as absolute TTLs
155 // (UNIX timestamps), and will result in the cache entry being
156 // discarded immediately because the expiry is in the past.
157 // Clamp expires >30d at 30d, unless they're >=1e9 in which
158 // case they are likely to really be absolute (1e9 = 2011-09-09)
159 $expiresAt = min( $exptime, self::TTL_MONTH );
160 } else {
161 $expiresAt = $exptime;
162 }
163
164 return (int)$expiresAt;
165 }
166
167 protected function doIncrWithInit( $key, $exptime, $step, $init, $flags ) {
168 if ( $flags & self::WRITE_BACKGROUND ) {
169 return $this->doIncrWithInitAsync( $key, $exptime, $step, $init );
170 } else {
171 return $this->doIncrWithInitSync( $key, $exptime, $step, $init );
172 }
173 }
174
182 abstract protected function doIncrWithInitAsync( $key, $exptime, $step, $init );
183
191 abstract protected function doIncrWithInitSync( $key, $exptime, $step, $init );
192}
string $keyspace
Default keyspace; used by makeKey()
Storage medium specific cache for storing items (e.g.
Base class for memcached clients.
doIncrWithInit( $key, $exptime, $step, $init, $flags)
validateKeyEncoding( $key)
Ensure that a key is safe to use (contains no control characters and no characters above the ASCII ra...
__construct(array $params)
doIncrWithInitSync( $key, $exptime, $step, $init)
makeKeyInternal( $keyspace, $components)
Construct a cache key.
string $routingPrefix
Routing prefix appended to keys during operations.
doIncrWithInitAsync( $key, $exptime, $step, $init)
const QOS_DURABILITY_SERVICE
Data is lost once the service storing the data restarts.
const ATTR_DURABILITY
Durability of writes; see QOS_DURABILITY_* (higher means stronger)