PHP使用Redis实现Session共享的实现示例

# 使用 redis 作为存储方案
session.save_handler = redis
session.save_path = "tcp://127.0.0.1:6379"
# 若设置了连接密码, 则使用如下
session.save_path = "tcp://127.0.0.1:6379?auth=密码"

<?php
ini_set("session.save_handler", "redis");
ini_set("session.save_path", "tcp://127.0.0.1:6379");

session_start();
echo "<pre>";
$_SESSION['usertest'.rand(1,5)]=1;
var_dump($_SESSION);

echo "</pre>";

session_set_save_handler ( callable $open , callable $close , callable $read , callable $write , callable $destroy , callable $gc [, callable $create_sid [, callable $validate_sid [, callable $update_timestamp ]]] ) : bool
  
# >= php5.4
session_set_save_handler ( object $sessionhandler [, bool $register_shutdown = TRUE ] ) : bool

<?php

/
  This file is part of the Symfony package.
 
  (c) Fabien Potencier <fabien@symfony.>
 
  For the full copyright and license information, please view the LICENSE
  file that was distributed with this source code.
 /

namespace Symfony\Component\HttpFoundation\Session\Storage\Handler;

/
  MemcacheSessionHandler.
 
  @author Drak <drak@zikula.>
 /
class MemcacheSessionHandler implements \SessionHandlerInterface
{
  /
    @var \Memcache Memcache driver.
   /
  private $memcache;

  /
    @var int Time to live in seconds
   /
  private $ttl;

  /
    @var string Key prefix for shared environments.
   /
  private $prefix;

  /
    Constructor.
   
    List of available options:
     prefix: The prefix to use for the memcache keys in order to avoid collision
     expiretime: The time to live in seconds
   
    @param \Memcache $memcache A \Memcache instance
    @param array   $options An associative array of Memcache options
   
    @throws \InvalidArgumentException When unsupported options are passed
   /
  public function __construct(\Memcache $memcache, array $options = array())
  {
    if ($diff = array_diff(array_keys($options), array('prefix', 'expiretime'))) {
      throw new \InvalidArgumentException(sprintf(
        'The following options are not supported "%s"', implode(', ', $diff)
      ));
    }

    $this->memcache = $memcache;
    $this->ttl = isset($options['expiretime']) ? (int) $options['expiretime'] : 86400;
    $this->prefix = isset($options['prefix']) ? $options['prefix'] : 'sf2s';
  }

  /
    {@inheritdoc}
   /
  public function open($savePath, $sessionName)
  {
    return true;
  }

  /
    {@inheritdoc}
   /
  public function close()
  {
    return $this->memcache->close();
  }

  /
    {@inheritdoc}
   /
  public function read($sessionId)
  {
    return $this->memcache->get($this->prefix.$sessionId) ?: '';
  }

  /
    {@inheritdoc}
   /
  public function write($sessionId, $data)
  {
    return $this->memcache->set($this->prefix.$sessionId, $data, 0, time() + $this->ttl);
  }

  /
    {@inheritdoc}
   /
  public function destroy($sessionId)
  {
    return $this->memcache->delete($this->prefix.$sessionId);
  }

  /
    {@inheritdoc}
   /
  public function gc($maxlifetime)
  {
    // not required here because memcache will auto expire the records anyhow.
    return true;
  }

  /
    Return a Memcache instance
   
    @return \Memcache
   /
  protected function getMemcache()
  {
    return $this->memcache;
  }
}