Question

http://cn2.php.net/manual/en/class.memcache.php

API 如下，

// add
bool Memcache::add (string $key , mixed $var [, int $flag [, int $expire]])
/*
//stores variable *var* with *key* only if such key doesn't exist at the server yet.
//flag : Use MEMCACHE_COMPRESSED to store the item compressed (uses zlib).
*/

// get
string Memcache::get ( string $key [, int &$flags ] )
array Memcache::get ( array $keys [, array &$flags ] )
Memcache::get() returns previously stored data if an item with such *key* exists on the server at this moment. can get string or array.

// del
bool Memcache::delete ( string $key [, int $timeout ] )

// replace
bool Memcache::replace ( string $key , mixed $var [, int $flag [, int $expire ]] )
//Memcache::replace() should be used to replace value of existing item with *key*. In case if item with such key doesn't exists, //Memcache::replace() returns **FALSE**.

// set — Store data at the server
bool Memcache::set ( string $key , mixed $var [, int $flag [, int $expire ]] )

// connect + addServer
bool Memcache::connect ( string $host [, int $port [, int $timeout ]] )
bool Memcache::addServer ( string $host [, int $port = 11211 [, bool $persistent [, int $weight [, int $timeout [, int $retry_interval [, bool $status [, callback $failure_callback [, int $timeoutms ]]]]]]]] )

$mem->addServer ("192.168.220.30",5555,false,1,0); //false: persistent;0:timeout
//说明：上述 delete, addServer 都有带 timeout 参数即本次操作的超时时间; add 带有存储项的过期时间，最多 30days;


// flush — Flush all existing items at the server
bool Memcache::flush ( void )
//说明：flush 不是马上就看到数据，flush 操作只是标记了所有数据是过期数据，但要在有新的 get 请求时，才相应删除对应项。 （评价：典型的延迟删除策略，好!!!）