3 * Base class for memcached clients.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
25 * Base class for memcached clients.
29 class MemcachedBagOStuff
extends BagOStuff
{
30 /** @var MemcachedClient|Memcached */
33 function __construct( array $params ) {
34 parent
::__construct( $params );
36 $this->attrMap
[self
::ATTR_SYNCWRITES
] = self
::QOS_SYNCWRITES_BE
; // unreliable
40 * Fill in some defaults for missing keys in $params.
42 * @param array $params
45 protected function applyDefaultParams( $params ) {
47 'compress_threshold' => 1500,
48 'connect_timeout' => 0.5,
53 protected function doGet( $key, $flags = 0, &$casToken = null ) {
54 return $this->client
->get( $this->validateKeyEncoding( $key ), $casToken );
57 public function set( $key, $value, $exptime = 0, $flags = 0 ) {
58 return $this->client
->set( $this->validateKeyEncoding( $key ), $value,
59 $this->fixExpiry( $exptime ) );
62 protected function cas( $casToken, $key, $value, $exptime = 0, $flags = 0 ) {
63 return $this->client
->cas( $casToken, $this->validateKeyEncoding( $key ),
64 $value, $this->fixExpiry( $exptime ) );
67 public function delete( $key, $flags = 0 ) {
68 return $this->client
->delete( $this->validateKeyEncoding( $key ) );
71 public function add( $key, $value, $exptime = 0, $flags = 0 ) {
72 return $this->client
->add( $this->validateKeyEncoding( $key ), $value,
73 $this->fixExpiry( $exptime ) );
76 public function incr( $key, $value = 1 ) {
77 $n = $this->client
->incr( $this->validateKeyEncoding( $key ), $value );
79 return ( $n !== false && $n !== null ) ?
$n : false;
82 public function decr( $key, $value = 1 ) {
83 $n = $this->client
->decr( $this->validateKeyEncoding( $key ), $value );
85 return ( $n !== false && $n !== null ) ?
$n : false;
88 public function changeTTL( $key, $exptime = 0, $flags = 0 ) {
89 return $this->client
->touch( $this->validateKeyEncoding( $key ),
90 $this->fixExpiry( $exptime ) );
94 * Get the underlying client object. This is provided for debugging
96 * @return MemcachedClient|Memcached
98 public function getClient() {
103 * Construct a cache key.
106 * @param string $keyspace
110 public function makeKeyInternal( $keyspace, $args ) {
111 // Memcached keys have a maximum length of 255 characters. From that,
112 // subtract the number of characters we need for the keyspace and for
113 // the separator character needed for each argument. To handle some
114 // custom prefixes used by thing like WANObjectCache, limit to 205.
115 $charsLeft = 205 - strlen( $keyspace ) - count( $args );
118 function ( $arg ) use ( &$charsLeft ) {
119 $arg = strtr( $arg, ' ', '_' );
121 // Make sure %, #, and non-ASCII chars are escaped
122 $arg = preg_replace_callback(
123 '/[^\x21-\x22\x24\x26-\x39\x3b-\x7e]+/',
125 return rawurlencode( $m[0] );
130 // 33 = 32 characters for the MD5 + 1 for the '#' prefix.
131 if ( $charsLeft > 33 && strlen( $arg ) > $charsLeft ) {
132 $arg = '#' . md5( $arg );
135 $charsLeft -= strlen( $arg );
141 if ( $charsLeft < 0 ) {
142 return $keyspace . ':BagOStuff-long-key:##' . md5( implode( ':', $args ) );
145 return $keyspace . ':' . implode( ':', $args );
149 * Ensure that a key is safe to use (contains no control characters and no
150 * characters above the ASCII range.)
156 public function validateKeyEncoding( $key ) {
157 if ( preg_match( '/[^\x21-\x7e]+/', $key ) ) {
158 throw new Exception( "Key contains invalid characters: $key" );
164 * TTLs higher than 30 days will be detected as absolute TTLs
165 * (UNIX timestamps), and will result in the cache entry being
166 * discarded immediately because the expiry is in the past.
167 * Clamp expires >30d at 30d, unless they're >=1e9 in which
168 * case they are likely to really be absolute (1e9 = 2011-09-09)
172 function fixExpiry( $expiry ) {
173 if ( $expiry > 2592000 && $expiry < 1000000000 ) {