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Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like MemcachedClient often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use MemcachedClient, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 79 | class MemcachedClient { |
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| 80 | // {{{ properties |
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| 81 | // {{{ public |
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| 82 | |||
| 83 | // {{{ constants |
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| 84 | // {{{ flags |
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| 85 | |||
| 86 | /** |
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| 87 | * Flag: indicates data is serialized |
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| 88 | */ |
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| 89 | const SERIALIZED = 1; |
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| 90 | |||
| 91 | /** |
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| 92 | * Flag: indicates data is compressed |
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| 93 | */ |
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| 94 | const COMPRESSED = 2; |
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| 95 | |||
| 96 | /** |
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| 97 | * Flag: indicates data is an integer |
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| 98 | */ |
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| 99 | const INTVAL = 4; |
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| 100 | |||
| 101 | // }}} |
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| 102 | |||
| 103 | /** |
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| 104 | * Minimum savings to store data compressed |
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| 105 | */ |
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| 106 | const COMPRESSION_SAVINGS = 0.20; |
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| 107 | |||
| 108 | // }}} |
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| 109 | |||
| 110 | /** |
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| 111 | * Command statistics |
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| 112 | * |
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| 113 | * @var array |
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| 114 | * @access public |
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| 115 | */ |
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| 116 | public $stats; |
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| 117 | |||
| 118 | // }}} |
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| 119 | // {{{ private |
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| 120 | |||
| 121 | /** |
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| 122 | * Cached Sockets that are connected |
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| 123 | * |
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| 124 | * @var array |
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| 125 | * @access private |
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| 126 | */ |
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| 127 | public $_cache_sock; |
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| 128 | |||
| 129 | /** |
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| 130 | * Current debug status; 0 - none to 9 - profiling |
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| 131 | * |
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| 132 | * @var bool |
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| 133 | * @access private |
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| 134 | */ |
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| 135 | public $_debug; |
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| 136 | |||
| 137 | /** |
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| 138 | * Dead hosts, assoc array, 'host'=>'unixtime when ok to check again' |
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| 139 | * |
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| 140 | * @var array |
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| 141 | * @access private |
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| 142 | */ |
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| 143 | public $_host_dead; |
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| 144 | |||
| 145 | /** |
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| 146 | * Is compression available? |
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| 147 | * |
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| 148 | * @var bool |
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| 149 | * @access private |
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| 150 | */ |
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| 151 | public $_have_zlib; |
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| 152 | |||
| 153 | /** |
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| 154 | * Do we want to use compression? |
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| 155 | * |
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| 156 | * @var bool |
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| 157 | * @access private |
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| 158 | */ |
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| 159 | public $_compress_enable; |
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| 160 | |||
| 161 | /** |
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| 162 | * At how many bytes should we compress? |
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| 163 | * |
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| 164 | * @var int |
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| 165 | * @access private |
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| 166 | */ |
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| 167 | public $_compress_threshold; |
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| 168 | |||
| 169 | /** |
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| 170 | * Are we using persistent links? |
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| 171 | * |
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| 172 | * @var bool |
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| 173 | * @access private |
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| 174 | */ |
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| 175 | public $_persistent; |
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| 176 | |||
| 177 | /** |
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| 178 | * If only using one server; contains ip:port to connect to |
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| 179 | * |
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| 180 | * @var string |
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| 181 | * @access private |
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| 182 | */ |
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| 183 | public $_single_sock; |
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| 184 | |||
| 185 | /** |
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| 186 | * Array containing ip:port or array(ip:port, weight) |
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| 187 | * |
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| 188 | * @var array |
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| 189 | * @access private |
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| 190 | */ |
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| 191 | public $_servers; |
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| 192 | |||
| 193 | /** |
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| 194 | * Our bit buckets |
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| 195 | * |
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| 196 | * @var array |
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| 197 | * @access private |
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| 198 | */ |
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| 199 | public $_buckets; |
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| 200 | |||
| 201 | /** |
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| 202 | * Total # of bit buckets we have |
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| 203 | * |
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| 204 | * @var int |
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| 205 | * @access private |
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| 206 | */ |
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| 207 | public $_bucketcount; |
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| 208 | |||
| 209 | /** |
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| 210 | * # of total servers we have |
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| 211 | * |
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| 212 | * @var int |
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| 213 | * @access private |
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| 214 | */ |
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| 215 | public $_active; |
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| 216 | |||
| 217 | /** |
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| 218 | * Stream timeout in seconds. Applies for example to fread() |
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| 219 | * |
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| 220 | * @var int |
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| 221 | * @access private |
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| 222 | */ |
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| 223 | public $_timeout_seconds; |
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| 224 | |||
| 225 | /** |
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| 226 | * Stream timeout in microseconds |
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| 227 | * |
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| 228 | * @var int |
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| 229 | * @access private |
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| 230 | */ |
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| 231 | public $_timeout_microseconds; |
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| 232 | |||
| 233 | /** |
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| 234 | * Connect timeout in seconds |
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| 235 | */ |
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| 236 | public $_connect_timeout; |
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| 237 | |||
| 238 | /** |
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| 239 | * Number of connection attempts for each server |
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| 240 | */ |
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| 241 | public $_connect_attempts; |
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| 242 | |||
| 243 | /** |
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| 244 | * @var LoggerInterface |
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| 245 | */ |
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| 246 | private $_logger; |
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| 247 | |||
| 248 | // }}} |
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| 249 | // }}} |
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| 250 | // {{{ methods |
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| 251 | // {{{ public functions |
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| 252 | // {{{ memcached() |
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| 253 | |||
| 254 | /** |
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| 255 | * Memcache initializer |
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| 256 | * |
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| 257 | * @param array $args Associative array of settings |
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| 258 | * |
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| 259 | * @return mixed |
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|
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| 260 | */ |
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| 261 | public function __construct( $args ) { |
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| 281 | |||
| 282 | // }}} |
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| 283 | // {{{ add() |
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| 284 | |||
| 285 | /** |
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| 286 | * Adds a key/value to the memcache server if one isn't already set with |
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| 287 | * that key |
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| 288 | * |
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| 289 | * @param string $key Key to set with data |
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| 290 | * @param mixed $val Value to store |
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| 291 | * @param int $exp (optional) Expiration time. This can be a number of seconds |
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| 292 | * to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or |
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| 293 | * longer must be the timestamp of the time at which the mapping should expire. It |
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| 294 | * is safe to use timestamps in all cases, regardless of expiration |
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| 295 | * eg: strtotime("+3 hour") |
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| 296 | * |
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| 297 | * @return bool |
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| 298 | */ |
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| 299 | public function add( $key, $val, $exp = 0 ) { |
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| 302 | |||
| 303 | // }}} |
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| 304 | // {{{ decr() |
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| 305 | |||
| 306 | /** |
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| 307 | * Decrease a value stored on the memcache server |
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| 308 | * |
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| 309 | * @param string $key Key to decrease |
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| 310 | * @param int $amt (optional) amount to decrease |
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| 311 | * |
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| 312 | * @return mixed False on failure, value on success |
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| 313 | */ |
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| 314 | public function decr( $key, $amt = 1 ) { |
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| 317 | |||
| 318 | // }}} |
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| 319 | // {{{ delete() |
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| 320 | |||
| 321 | /** |
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| 322 | * Deletes a key from the server, optionally after $time |
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| 323 | * |
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| 324 | * @param string $key Key to delete |
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| 325 | * @param int $time (optional) how long to wait before deleting |
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| 326 | * |
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| 327 | * @return bool True on success, false on failure |
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| 328 | */ |
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| 329 | View Code Duplication | public function delete( $key, $time = 0 ) { |
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| 362 | |||
| 363 | /** |
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| 364 | * Changes the TTL on a key from the server to $time |
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| 365 | * |
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| 366 | * @param string $key Key |
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| 367 | * @param int $time TTL in seconds |
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| 368 | * |
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| 369 | * @return bool True on success, false on failure |
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| 370 | */ |
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| 371 | View Code Duplication | public function touch( $key, $time = 0 ) { |
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| 404 | |||
| 405 | /** |
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| 406 | * @param string $key |
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| 407 | * @param int $timeout |
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| 408 | * @return bool |
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| 409 | */ |
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| 410 | public function lock( $key, $timeout = 0 ) { |
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| 414 | |||
| 415 | /** |
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| 416 | * @param string $key |
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| 417 | * @return bool |
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| 418 | */ |
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| 419 | public function unlock( $key ) { |
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| 423 | |||
| 424 | // }}} |
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| 425 | // {{{ disconnect_all() |
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| 426 | |||
| 427 | /** |
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| 428 | * Disconnects all connected sockets |
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| 429 | */ |
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| 430 | public function disconnect_all() { |
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| 437 | |||
| 438 | // }}} |
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| 439 | // {{{ enable_compress() |
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| 440 | |||
| 441 | /** |
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| 442 | * Enable / Disable compression |
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| 443 | * |
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| 444 | * @param bool $enable True to enable, false to disable |
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| 445 | */ |
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| 446 | public function enable_compress( $enable ) { |
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| 449 | |||
| 450 | // }}} |
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| 451 | // {{{ forget_dead_hosts() |
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| 452 | |||
| 453 | /** |
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| 454 | * Forget about all of the dead hosts |
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| 455 | */ |
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| 456 | public function forget_dead_hosts() { |
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| 459 | |||
| 460 | // }}} |
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| 461 | // {{{ get() |
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| 462 | |||
| 463 | /** |
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| 464 | * Retrieves the value associated with the key from the memcache server |
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| 465 | * |
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| 466 | * @param array|string $key key to retrieve |
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| 467 | * @param float $casToken [optional] |
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| 468 | * |
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| 469 | * @return mixed |
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| 470 | */ |
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| 471 | public function get( $key, &$casToken = null ) { |
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| 519 | |||
| 520 | // }}} |
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| 521 | // {{{ get_multi() |
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| 522 | |||
| 523 | /** |
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| 524 | * Get multiple keys from the server(s) |
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| 525 | * |
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| 526 | * @param array $keys Keys to retrieve |
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| 527 | * |
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| 528 | * @return array |
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| 529 | */ |
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| 530 | public function get_multi( $keys ) { |
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| 583 | |||
| 584 | // }}} |
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| 585 | // {{{ incr() |
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| 586 | |||
| 587 | /** |
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| 588 | * Increments $key (optionally) by $amt |
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| 589 | * |
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| 590 | * @param string $key Key to increment |
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| 591 | * @param int $amt (optional) amount to increment |
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| 592 | * |
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| 593 | * @return int|null Null if the key does not exist yet (this does NOT |
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| 594 | * create new mappings if the key does not exist). If the key does |
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| 595 | * exist, this returns the new value for that key. |
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| 596 | */ |
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| 597 | public function incr( $key, $amt = 1 ) { |
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| 600 | |||
| 601 | // }}} |
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| 602 | // {{{ replace() |
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| 603 | |||
| 604 | /** |
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| 605 | * Overwrites an existing value for key; only works if key is already set |
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| 606 | * |
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| 607 | * @param string $key Key to set value as |
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| 608 | * @param mixed $value Value to store |
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| 609 | * @param int $exp (optional) Expiration time. This can be a number of seconds |
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| 610 | * to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or |
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| 611 | * longer must be the timestamp of the time at which the mapping should expire. It |
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| 612 | * is safe to use timestamps in all cases, regardless of exipration |
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| 613 | * eg: strtotime("+3 hour") |
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| 614 | * |
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| 615 | * @return bool |
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| 616 | */ |
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| 617 | public function replace( $key, $value, $exp = 0 ) { |
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| 620 | |||
| 621 | // }}} |
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| 622 | // {{{ run_command() |
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| 623 | |||
| 624 | /** |
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| 625 | * Passes through $cmd to the memcache server connected by $sock; returns |
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| 626 | * output as an array (null array if no output) |
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| 627 | * |
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| 628 | * @param Resource $sock Socket to send command on |
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| 629 | * @param string $cmd Command to run |
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| 630 | * |
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| 631 | * @return array Output array |
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| 632 | */ |
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| 633 | public function run_command( $sock, $cmd ) { |
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| 655 | |||
| 656 | // }}} |
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| 657 | // {{{ set() |
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| 658 | |||
| 659 | /** |
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| 660 | * Unconditionally sets a key to a given value in the memcache. Returns true |
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| 661 | * if set successfully. |
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| 662 | * |
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| 663 | * @param string $key Key to set value as |
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| 664 | * @param mixed $value Value to set |
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| 665 | * @param int $exp (optional) Expiration time. This can be a number of seconds |
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| 666 | * to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or |
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| 667 | * longer must be the timestamp of the time at which the mapping should expire. It |
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| 668 | * is safe to use timestamps in all cases, regardless of exipration |
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| 669 | * eg: strtotime("+3 hour") |
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| 670 | * |
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| 671 | * @return bool True on success |
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| 672 | */ |
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| 673 | public function set( $key, $value, $exp = 0 ) { |
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| 676 | |||
| 677 | // }}} |
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| 678 | // {{{ cas() |
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| 679 | |||
| 680 | /** |
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| 681 | * Sets a key to a given value in the memcache if the current value still corresponds |
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| 682 | * to a known, given value. Returns true if set successfully. |
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| 683 | * |
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| 684 | * @param float $casToken Current known value |
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| 685 | * @param string $key Key to set value as |
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| 686 | * @param mixed $value Value to set |
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| 687 | * @param int $exp (optional) Expiration time. This can be a number of seconds |
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| 688 | * to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or |
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| 689 | * longer must be the timestamp of the time at which the mapping should expire. It |
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| 690 | * is safe to use timestamps in all cases, regardless of exipration |
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| 691 | * eg: strtotime("+3 hour") |
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| 692 | * |
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| 693 | * @return bool True on success |
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| 694 | */ |
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| 695 | public function cas( $casToken, $key, $value, $exp = 0 ) { |
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| 698 | |||
| 699 | // }}} |
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| 700 | // {{{ set_compress_threshold() |
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| 701 | |||
| 702 | /** |
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| 703 | * Set the compression threshold |
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| 704 | * |
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| 705 | * @param int $thresh Threshold to compress if larger than |
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| 706 | */ |
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| 707 | public function set_compress_threshold( $thresh ) { |
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| 710 | |||
| 711 | // }}} |
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| 712 | // {{{ set_debug() |
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| 713 | |||
| 714 | /** |
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| 715 | * Set the debug flag |
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| 716 | * |
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| 717 | * @see __construct() |
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| 718 | * @param bool $dbg True for debugging, false otherwise |
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| 719 | */ |
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| 720 | public function set_debug( $dbg ) { |
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| 723 | |||
| 724 | // }}} |
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| 725 | // {{{ set_servers() |
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| 726 | |||
| 727 | /** |
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| 728 | * Set the server list to distribute key gets and puts between |
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| 729 | * |
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| 730 | * @see __construct() |
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| 731 | * @param array $list Array of servers to connect to |
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| 732 | */ |
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| 733 | public function set_servers( $list ) { |
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| 744 | |||
| 745 | /** |
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| 746 | * Sets the timeout for new connections |
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| 747 | * |
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| 748 | * @param int $seconds Number of seconds |
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| 749 | * @param int $microseconds Number of microseconds |
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| 750 | */ |
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| 751 | public function set_timeout( $seconds, $microseconds ) { |
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| 755 | |||
| 756 | // }}} |
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| 757 | // }}} |
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| 758 | // {{{ private methods |
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| 759 | // {{{ _close_sock() |
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| 760 | |||
| 761 | /** |
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| 762 | * Close the specified socket |
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| 763 | * |
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| 764 | * @param string $sock Socket to close |
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| 765 | * |
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| 766 | * @access private |
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| 767 | */ |
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| 768 | function _close_sock( $sock ) { |
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| 773 | |||
| 774 | // }}} |
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| 775 | // {{{ _connect_sock() |
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| 776 | |||
| 777 | /** |
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| 778 | * Connects $sock to $host, timing out after $timeout |
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| 779 | * |
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| 780 | * @param int $sock Socket to connect |
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| 781 | * @param string $host Host:IP to connect to |
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| 782 | * |
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| 783 | * @return bool |
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| 784 | * @access private |
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| 785 | */ |
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| 786 | function _connect_sock( &$sock, $host ) { |
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| 816 | |||
| 817 | // }}} |
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| 818 | // {{{ _dead_sock() |
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| 819 | |||
| 820 | /** |
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| 821 | * Marks a host as dead until 30-40 seconds in the future |
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| 822 | * |
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| 823 | * @param string $sock Socket to mark as dead |
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| 824 | * |
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| 825 | * @access private |
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| 826 | */ |
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| 827 | function _dead_sock( $sock ) { |
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| 831 | |||
| 832 | /** |
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| 833 | * @param string $host |
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| 834 | */ |
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| 835 | function _dead_host( $host ) { |
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| 841 | |||
| 842 | // }}} |
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| 843 | // {{{ get_sock() |
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| 844 | |||
| 845 | /** |
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| 846 | * get_sock |
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| 847 | * |
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| 848 | * @param string $key Key to retrieve value for; |
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| 849 | * |
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| 850 | * @return Resource|bool Resource on success, false on failure |
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| 851 | * @access private |
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| 852 | */ |
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| 853 | function get_sock( $key ) { |
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| 890 | |||
| 891 | // }}} |
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| 892 | // {{{ _hashfunc() |
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| 893 | |||
| 894 | /** |
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| 895 | * Creates a hash integer based on the $key |
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| 896 | * |
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| 897 | * @param string $key Key to hash |
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| 898 | * |
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| 899 | * @return int Hash value |
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| 900 | * @access private |
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| 901 | */ |
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| 902 | function _hashfunc( $key ) { |
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| 908 | |||
| 909 | // }}} |
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| 910 | // {{{ _incrdecr() |
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| 911 | |||
| 912 | /** |
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| 913 | * Perform increment/decriment on $key |
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| 914 | * |
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| 915 | * @param string $cmd Command to perform |
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| 916 | * @param string|array $key Key to perform it on |
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| 917 | * @param int $amt Amount to adjust |
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| 918 | * |
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| 919 | * @return int New value of $key |
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| 920 | * @access private |
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| 921 | */ |
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| 922 | function _incrdecr( $cmd, $key, $amt = 1 ) { |
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| 949 | |||
| 950 | // }}} |
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| 951 | // {{{ _load_items() |
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| 952 | |||
| 953 | /** |
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| 954 | * Load items into $ret from $sock |
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| 955 | * |
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| 956 | * @param Resource $sock Socket to read from |
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| 957 | * @param array $ret returned values |
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| 958 | * @param float $casToken [optional] |
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| 959 | * @return bool True for success, false for failure |
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| 960 | * |
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| 961 | * @access private |
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| 962 | */ |
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| 963 | function _load_items( $sock, &$ret, &$casToken = null ) { |
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| 1037 | |||
| 1038 | // }}} |
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| 1039 | // {{{ _set() |
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| 1040 | |||
| 1041 | /** |
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| 1042 | * Performs the requested storage operation to the memcache server |
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| 1043 | * |
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| 1044 | * @param string $cmd Command to perform |
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| 1045 | * @param string $key Key to act on |
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| 1046 | * @param mixed $val What we need to store |
||
| 1047 | * @param int $exp (optional) Expiration time. This can be a number of seconds |
||
| 1048 | * to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or |
||
| 1049 | * longer must be the timestamp of the time at which the mapping should expire. It |
||
| 1050 | * is safe to use timestamps in all cases, regardless of exipration |
||
| 1051 | * eg: strtotime("+3 hour") |
||
| 1052 | * @param float $casToken [optional] |
||
| 1053 | * |
||
| 1054 | * @return bool |
||
| 1055 | * @access private |
||
| 1056 | */ |
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| 1057 | function _set( $cmd, $key, $val, $exp, $casToken = null ) { |
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| 1122 | |||
| 1123 | // }}} |
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| 1124 | // {{{ sock_to_host() |
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| 1125 | |||
| 1126 | /** |
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| 1127 | * Returns the socket for the host |
||
| 1128 | * |
||
| 1129 | * @param string $host Host:IP to get socket for |
||
| 1130 | * |
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| 1131 | * @return Resource|bool IO Stream or false |
||
| 1132 | * @access private |
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| 1133 | */ |
||
| 1134 | function sock_to_host( $host ) { |
||
| 1159 | |||
| 1160 | /** |
||
| 1161 | * @param string $text |
||
| 1162 | */ |
||
| 1163 | function _debugprint( $text ) { |
||
| 1166 | |||
| 1167 | /** |
||
| 1168 | * @param string $text |
||
| 1169 | */ |
||
| 1170 | function _error_log( $text ) { |
||
| 1173 | |||
| 1174 | /** |
||
| 1175 | * Write to a stream. If there is an error, mark the socket dead. |
||
| 1176 | * |
||
| 1177 | * @param Resource $sock The socket |
||
| 1178 | * @param string $buf The string to write |
||
| 1179 | * @return bool True on success, false on failure |
||
| 1180 | */ |
||
| 1181 | function _fwrite( $sock, $buf ) { |
||
| 1201 | |||
| 1202 | /** |
||
| 1203 | * Handle an I/O error. Mark the socket dead and log an error. |
||
| 1204 | * |
||
| 1205 | * @param Resource $sock |
||
| 1206 | * @param string $msg |
||
| 1207 | */ |
||
| 1208 | function _handle_error( $sock, $msg ) { |
||
| 1220 | |||
| 1221 | /** |
||
| 1222 | * Read the specified number of bytes from a stream. If there is an error, |
||
| 1223 | * mark the socket dead. |
||
| 1224 | * |
||
| 1225 | * @param Resource $sock The socket |
||
| 1226 | * @param int $len The number of bytes to read |
||
| 1227 | * @return string|bool The string on success, false on failure. |
||
| 1228 | */ |
||
| 1229 | function _fread( $sock, $len ) { |
||
| 1252 | |||
| 1253 | /** |
||
| 1254 | * Read a line from a stream. If there is an error, mark the socket dead. |
||
| 1255 | * The \r\n line ending is stripped from the response. |
||
| 1256 | * |
||
| 1257 | * @param Resource $sock The socket |
||
| 1258 | * @return string|bool The string on success, false on failure |
||
| 1259 | */ |
||
| 1260 | function _fgets( $sock ) { |
||
| 1284 | |||
| 1285 | /** |
||
| 1286 | * Flush the read buffer of a stream |
||
| 1287 | * @param Resource $f |
||
| 1288 | */ |
||
| 1289 | function _flush_read_buffer( $f ) { |
||
| 1305 | |||
| 1306 | // }}} |
||
| 1307 | // }}} |
||
| 1308 | // }}} |
||
| 1309 | } |
||
| 1310 | |||
| 1312 |
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Adding a
@returnannotation to a constructor is not recommended, since a constructor does not have a meaningful return value.Please refer to the PHP core documentation on constructors.