memcached-client.php

一个用PHP编写的

<?php
//
// +---------------------------------------------------------------------------+
// | memcached client, PHP                                                     |
// +---------------------------------------------------------------------------+
// | Copyright (c) 2003 Ryan T. Dean <[e-mail]>                 |
// | All rights reserved.                                                      |
// |                                                                           |
// | Redistribution and use in source and binary forms, with or without        |
// | modification, are permitted provided that the following conditions        |
// | are met:                                                                  |
// |                                                                           |
// | 1. Redistributions of source code must retain the above copyright         |
// |    notice, this list of conditions and the following disclaimer.          |
// | 2. Redistributions in binary form must reproduce the above copyright      |
// |    notice, this list of conditions and the following disclaimer in the    |
// |    documentation and/or other materials provided with the distribution.   |
// |                                                                           |
// | THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR      |
// | IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
// | OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.   |
// | IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,          |
// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT  |
// | NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
// | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY     |
// | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT       |
// | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF  |
// | THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.         |
// +---------------------------------------------------------------------------+
// | Author: Ryan T. Dean <[e-mail]>                            |
// | Heavily influenced by the Perl memcached client by Brad Fitzpatrick.      |
// |   Permission granted by Brad Fitzpatrick for relicense of ported Perl     |
// |   client logic under 2-clause BSD license.                                |
// +---------------------------------------------------------------------------+
//
// $TCAnet$
//

/**
 * This is the PHP client for memcached - a distributed memory cache daemon.
 * More information is available at http://www.danga.com/memcached/
 *
 * Usage example:
 *
 * require_once 'memcached.php';
 *
 * $mc = new memcached(array(
 *              'servers' => array('127.0.0.1:10000',
 *                                 array('192.0.0.1:10010', 2),
 *                                 '127.0.0.1:10020'),
 *              'debug'   => false,
 *              'compress_threshold' => 10240,
 *              'persistant' => true));
 *
 * $mc->add('key', array('some', 'array'));
 * $mc->replace('key', 'some random string');
 * $val = $mc->get('key');
 *
 * @author  Ryan T. Dean <[e-mail]>
 * @package memcached-client
 * @version 0.1.2
 */

// {{{ requirements
// }}}

// {{{ constants
// {{{ flags

/**
 * Flag: indicates data is serialized
 */
define("MEMCACHE_SERIALIZED", 1<<0);

/**
 * Flag: indicates data is compressed
 */
define("MEMCACHE_COMPRESSED", 1<<1);

// }}}

/**
 * Minimum savings to store data compressed
 */
define("COMPRESSION_SAVINGS", 0.20);

// }}}

// {{{ class memcached
/**
 * memcached client class implemented using (p)fsockopen()
 *
 * @author  Ryan T. Dean <[e-mail]>
 * @package memcached-client
 */
class memcached
{
   // {{{ properties
   // {{{ public

   /**
    * Command statistics
    *
    * @var     array
    * @access  public
    */
   var $stats;

   // }}}
   // {{{ private

   /**
    * Cached Sockets that are connected
    *
    * @var     array
    * @access  private
    */
   var $_cache_sock;

   /**
    * Current debug status; 0 - none to 9 - profiling
    *
    * @var     boolean
    * @access  private
    */
   var $_debug;

   /**
    * Dead hosts, assoc array, 'host'=>'unixtime when ok to check again'
    *
    * @var     array
    * @access  private
    */
   var $_host_dead;

   /**
    * Is compression available?
    *
    * @var     boolean
    * @access  private
    */
   var $_have_zlib;

   /**
    * Do we want to use compression?
    *
    * @var     boolean
    * @access  private
    */
   var $_compress_enable;

   /**
    * At how many bytes should we compress?
    *
    * @var     interger
    * @access  private
    */
   var $_compress_threshold;

   /**
    * Are we using persistant links?
    *
    * @var     boolean
    * @access  private
    */
   var $_persistant;

   /**
    * If only using one server; contains ip:port to connect to
    *
    * @var     string
    * @access  private
    */
   var $_single_sock;

   /**
    * Array containing ip:port or array(ip:port, weight)
    *
    * @var     array
    * @access  private
    */
   var $_servers;

   /**
    * Our bit buckets
    *
    * @var     array
    * @access  private
    */
   var $_buckets;

   /**
    * Total # of bit buckets we have
    *
    * @var     interger
    * @access  private
    */
   var $_bucketcount;

   /**
    * # of total servers we have
    *
    * @var     interger
    * @access  private
    */
   var $_active;

   /**
    * Stream timeout in seconds. Applies for example to fread()
    *
    * @var     integer
    * @access  private
    */
   var $_timeout_seconds;

   /**
    * Stream timeout in microseconds
    *
    * @var     integer
    * @access  private
    */
   var $_timeout_microseconds;

   // }}}
   // }}}
   // {{{ methods
   // {{{ public functions
   // {{{ memcached()

   /**
    * Memcache initializer
    *
    * @param   array    $args    Associative array of settings
    *
    * @return  mixed
    * @access  public
    */
   function memcached ($args)
   {
      $this->set_servers(@$args['servers']);
      $this->_debug = @$args['debug'];
      $this->stats = array();
      $this->_compress_threshold = @$args['compress_threshold'];
      $this->_persistant = array_key_exists('persistant', $args) ? (@$args['persistant']) : false;
      $this->_compress_enable = true;
      $this->_have_zlib = function_exists("gzcompress");

      $this->_cache_sock = array();
      $this->_host_dead = array();

      $this->_timeout_seconds = 1;
      $this->_timeout_microseconds = 0;
   }

   // }}}
   // {{{ add()

   /**
    * Adds a key/value to the memcache server if one isn't already set with
    * that key
    *
    * @param   string   $key     Key to set with data
    * @param   mixed    $val     Value to store
    * @param   interger $exp     (optional) Time to expire data at
    *
    * @return  boolean
    * @access  public
    */
   function add ($key, $val, $exp = 0)
   {
      return $this->_set('add', $key, $val, $exp);
   }

   // }}}
   // {{{ decr()

   /**
    * Decriment a value stored on the memcache server
    *
    * @param   string   $key     Key to decriment
    * @param   interger $amt     (optional) Amount to decriment
    *
    * @return  mixed    FALSE on failure, value on success
    * @access  public
    */
   function decr ($key, $amt=1)
   {
      return $this->_incrdecr('decr', $key, $amt);
   }

   // }}}
   // {{{ delete()

   /**
    * Deletes a key from the server, optionally after $time
    *
    * @param   string   $key     Key to delete
    * @param   interger $time    (optional) How long to wait before deleting
    *
    * @return  boolean  TRUE on success, FALSE on failure
    * @access  public
    */
   function delete ($key, $time = 0)
   {
      if (!$this->_active)
         return false;

      $sock = $this->get_sock($key);
      if (!is_resource($sock))
         return false;

      $key = is_array($key) ? $key[1] : $key;

      @$this->stats['delete']++;
      $cmd = "delete $key $time\r\n";
      if(!$this->_safe_fwrite($sock, $cmd, strlen($cmd)))
      {
         $this->_dead_sock($sock);
         return false;
      }
      $res = trim(fgets($sock));

      if ($this->_debug)
         $this->_debugprint(sprintf("MemCache: delete %s (%s)\n", $key, $res));

      if ($res == "DELETED")
         return true;
      return false;
   }
   
   // }}}
   // {{{ flush_all()

   /**
    * Flush all keys from the server
	*
    * @return  boolean  Always TRUE
    * @access  public
    */
   function flush_all ()
   {
      if (!$this->_active)
         return false;

      foreach ($this->_servers as $server)
      {
         if (is_array($server))
         {
            for ($i=0; $i<$server[1]; $i++)
               $hosts[] = $server[0];
         } else
         {
            $hosts[] = $server;
         }
      }
      
      foreach ($hosts as $host)
      {  
         $sock = $this->sock_to_host($host);
         if (is_resource($sock)) {
            $this->_flush_read_buffer($sock);
      
            @$this->stats['flush_all']++;
            $cmd = "flush_all\r\n";
            if(!$this->_safe_fwrite($sock, $cmd, strlen($cmd)))
            {
               $this->_dead_sock($sock);
               continue;
            }
            $res = trim(fgets($sock));

            if ($this->_debug)
               $this->_debugprint(sprintf("MemCache: flush_all %s (%s)\n", $host, $res));
         }
      }
      return true;
   }

   // }}}
   // {{{ disconnect_all()

   /**
    * Disconnects all connected sockets
    *
    * @access  public
    */
   function disconnect_all ()
   {
      foreach ($this->_cache_sock as $sock)
         fclose($sock);

      $this->_cache_sock = array();
   }

   // }}}
   // {{{ enable_compress()

   /**
    * Enable / Disable compression
    *
    * @param   boolean  $enable  TRUE to enable, FALSE to disable
    *
    * @access  public
    */
   function enable_compress ($enable)
   {
      $this->_compress_enable = $enable;
   }

   // }}}
   // {{{ forget_dead_hosts()

   /**
    * Forget about all of the dead hosts
    *
    * @access  public
    */
   function forget_dead_hosts ()
   {
      $this->_host_dead = array();
   }

   // }}}
   // {{{ get()

   /**
    * Retrieves the value associated with the key from the memcache server
    *
    * @param  string   $key     Key to retrieve
    *
    * @return  mixed
    * @access  public
    */
   function get ($key)
   {
      if (!$this->_active) {
         return false;
      }

      $sock = $this->get_sock($key);

      if (!is_resource($sock)) {
         return false;
      }

      @$this->stats['get']++;

      $cmd = "get $key\r\n";
      if (!$this->_safe_fwrite($sock, $cmd, strlen($cmd)))
      {
         $this->_dead_sock($sock);
         return false;
      }

      $val = array();
      $this->_load_items($sock, $val);

      if ($this->_debug)
         foreach ($val as $k => $v)
            $this->_debugprint(@sprintf("MemCache: sock %s got %s => %s\r\n", serialize($sock), $k, $v));

      return @$val[$key];
   }

   // }}}
   // {{{ get_multi()

   /**
    * Get multiple keys from the server(s)
    *
    * @param   array    $keys    Keys to retrieve
    *
    * @return  array
    * @access  public
    */
   function get_multi ($keys)
   {
      if (!$this->_active)
         return false;

      $this->stats['get_multi']++;

      foreach ($keys as $key)
      {
         $sock = $this->get_sock($key);
         if (!is_resource($sock)) continue;
         $key = is_array($key) ? $key[1] : $key;
         if (!isset($sock_keys[$sock]))
         {
            $sock_keys[$sock] = array();
            $socks[] = $sock;
         }
         $sock_keys[$sock][] = $key;
      }

      // Send out the requests
      foreach ($socks as $sock)
      {
         $cmd = "get";
         foreach ($sock_keys[$sock] as $key)
         {
            $cmd .= " ". $key;
         }
         $cmd .= "\r\n";

         if ($this->_safe_fwrite($sock, $cmd, strlen($cmd)))
         {
            $gather[] = $sock;
         } else
         {
            $this->_dead_sock($sock);
         }
      }

      // Parse responses
      $val = array();
      foreach ($gather as $sock)
      {
         $this->_load_items($sock, $val);
      }

      if ($this->_debug)
         foreach ($val as $k => $v)
            $this->_debugprint(sprintf("MemCache: got %s => %s\r\n", $k, $v));

      return $val;
   }

   // }}}
   // {{{ incr()

   /**
    * Increments $key (optionally) by $amt
    *
    * @param   string   $key     Key to increment
    * @param   interger $amt     (optional) amount to increment
    *
    * @return  interger New key value?
    * @access  public
    */