复制代码 代码如下:
class CacheException extends Exception {}
/**
* 缓存抽象类
*/
abstract class Cache_Abstract {
/**
* 读缓存变量
*
* @param string $key 缓存下标
* @return mixed
*/
abstract public function fetch($key);

/**
* 缓存变量
*
* @param string $key 缓存变量下标
* @param string $value 缓存变量的值
* @return bool
*/
abstract public function store($key, $value);

/**
* 删除缓存变量
*
* @param string $key 缓存下标
* @return Cache_Abstract
*/
abstract public function delete($key);

/**
* 清(删)除所有缓存
*
* @return Cache_Abstract
*/
abstract public function clear();

/**
* 锁定缓存变量
*
* @param string $key 缓存下标
* @return Cache_Abstract
*/
abstract public function lock($key);
/**
* 缓存变量解锁
*
* @param string $key 缓存下标
* @return Cache_Abstract
*/
abstract public function unlock($key);
/**
* 取得缓存变量是否被锁定
*
* @param string $key 缓存下标
* @return bool
*/
abstract public function isLocked($key);
/**
* 确保不是锁定状态
* 最多做$tries次睡眠等待解锁，超时则跳过并解锁
*
* @param string $key 缓存下标
*/
public function checkLock($key) {
if (!$this->isLocked($key)) {
return $this;
}

$tries = 10;
$count = 0;
do {
usleep(200);
$count ++;
} while ($count <= $tries && $this->isLocked($key)); // 最多做十次睡眠等待解锁，超时则跳过并解锁
$this->isLocked($key) && $this->unlock($key);

return $this;
}
}

/**
* APC扩展缓存实现
*
*
* @category Mjie
* @package Cache
* @author 流水孟春
* @copyright Copyright (c) 2008- <cmpan(at)qq.com>
* @license New BSD License
* @version $Id: Cache/Apc.php 版本号 2010-04-18 23:02 cmpan $
*/
class Cache_Apc extends Cache_Abstract {

protected $_prefix = "cache.mjie.net";

public function __construct() {
if (!function_exists("apc_cache_info")) {
throw new CacheException("apc extension didn"t installed");
}
}

/**
* 保存缓存变量
*
* @param string $key
* @param mixed $value
* @return bool
*/
public function store($key, $value) {
return apc_store($this->_storageKey($key), $value);
}

/**
* 读取缓存
*
* @param string $key
* @return mixed
*/
public function fetch($key) {
return apc_fetch($this->_storageKey($key));
}

/**
* 清除缓存
*
* @return Cache_Apc
*/
public function clear() {
apc_clear_cache();
return $this;
}

/**
* 删除缓存单元
*
* @return Cache_Apc
*/
public function delete($key) {
apc_delete($this->_storageKey($key));
return $this;
}

/**
* 缓存单元是否被锁定
*
* @param string $key
* @return bool
*/
public function isLocked($key) {
if ((apc_fetch($this->_storageKey($key) . ".lock")) === false) {
return false;
}

return true;
}

/**
* 锁定缓存单元
*
* @param string $key
* @return Cache_Apc
*/
public function lock($key) {
apc_store($this->_storageKey($key) . ".lock", "", 5);
return $this;
}

/**
* 缓存单元解锁
*
* @param string $key
* @return Cache_Apc
*/
public function unlock($key) {
apc_delete($this->_storageKey($key) . ".lock");
return $this;
}

/**
* 完整缓存名
*
* @param string $key
* @return string
*/
private function _storageKey($key) {
return $this->_prefix . "_" . $key;
}
}
/**
* 文件缓存实现
*
*
* @category Mjie
* @package Cache
* @author 流水孟春
* @copyright Copyright (c) 2008- <cmpan(at)qq.com>
* @license New BSD License
* @version $Id: Cache/File.php 版本号 2010-04-18 16:46 cmpan $
*/
class Cache_File extends Cache_Abstract {

protected $_cachesDir = "cache";

public function __construct() {
if (defined("DATA_DIR")) {
$this->_setCacheDir(DATA_DIR . "/cache");
}
}

/**
* 获取缓存文件
*
* @param string $key
* @return string
*/
protected function _getCacheFile($key) {
return $this->_cachesDir . "/" . substr($key, 0, 2) . "/" . $key . ".php";
}
/**
* 读取缓存变量
* 为防止信息泄露，缓存文件格式为php文件，并以"<?php exit;?>"开头
*
* @param string $key 缓存下标
* @return mixed
*/
public function fetch($key) {
$cacheFile = self::_getCacheFile($key);
if (file_exists($cacheFile) && is_readable($cacheFile)) {
return unserialize(@file_get_contents($cacheFile, false, NULL, 13));
}
return false;
}
/**
* 缓存变量
* 为防止信息泄露，缓存文件格式为php文件，并以"<?php exit;?>"开头
*
* @param string $key 缓存变量下标
* @param string $value 缓存变量的值
* @return bool
*/
public function store($key, $value) {
$cacheFile = self::_getCacheFile($key);
$cacheDir = dirname($cacheFile);
if(!is_dir($cacheDir)) {
if(mkdir($cacheDir" target="_blank">!@mkdir($cacheDir, 0755, true)) {
throw new CacheException("Could not make cache directory");
}
}
return @file_put_contents($cacheFile, "<?php exit;?>" . serialize($value));
}
/**
* 删除缓存变量
*
* @param string $key 缓存下标
* @return Cache_File
*/
public function delete($key) {
if(emptyempty($key)) {
throw new CacheException("Missing argument 1 for Cache_File::delete()");
}

$cacheFile = self::_getCacheFile($key);
if($cacheFile" target="_blank">!@unlink($cacheFile)) {
throw new CacheException("Cache file could not be deleted");
}
return $this;
}
/**
* 缓存单元是否已经锁定
*
* @param string $key
* @return bool
*/
public function isLocked($key) {
$cacheFile = self::_getCacheFile($key);
clearstatcache();
return file_exists($cacheFile . ".lock");
}
/**
* 锁定
*
* @param string $key
* @return Cache_File
*/
public function lock($key) {
$cacheFile = self::_getCacheFile($key);
$cacheDir = dirname($cacheFile);
if(!is_dir($cacheDir)) {
if(mkdir($cacheDir" target="_blank">!@mkdir($cacheDir, 0755, true)) {
if(!is_dir($cacheDir)) {
throw new CacheException("Could not make cache directory");
}
}
}
// 设定缓存锁文件的访问和修改时间
@touch($cacheFile . ".lock");
return $this;
}

/**
* 解锁
*
* @param string $key
* @return Cache_File
*/
public function unlock($key) {
$cacheFile = self::_getCacheFile($key);
@unlink($cacheFile . ".lock");
return $this;
}
/**
* 设置文件缓存目录
* @param string $dir
* @return Cache_File
*/
protected function _setCacheDir($dir) {
$this->_cachesDir = rtrim(str_replace("\", "/", trim($dir)), "/");
clearstatcache();
if(!is_dir($this->_cachesDir)) {
mkdir($this->_cachesDir, 0755, true);
}
//
return $this;
}

/**
* 清空所有缓存
*
* @return Cache_File
*/
public function clear() {
// 遍历目录清除缓存
$cacheDir = $this->_cachesDir;
$d = dir($cacheDir);
while(false !== ($entry = $d->read())) {
if("." == $entry[0]) {
continue;
}

$cacheEntry = $cacheDir . "/" . $entry;
if(is_file($cacheEntry)) {
@unlink($cacheEntry);
} elseif(is_dir($cacheEntry)) {
// 缓存文件夹有两级
$d2 = dir($cacheEntry);
while(false !== ($entry = $d2->read())) {
if("." == $entry[0]) {
continue;
}

$cacheEntry .= "/" . $entry;
if(is_file($cacheEntry)) {
@unlink($cacheEntry);
}
}
$d2->close();
}
}
$d->close();

return $this;
}
}
/**
* 缓存单元的数据结构
* array(
* "time" => time(), // 缓存写入时的时间戳
* "expire" => $expire, // 缓存过期时间
* "valid" => true, // 缓存是否有效
* "data" => $value // 缓存的值
* );
*/
final class Cache {
/**
* 缓存过期时间长度(s)
*
* @var int
*/
private $_expire = 3600;
/**
* 缓存处理类
*
* @var Cache_Abstract
*/
private $_storage = null;
/**
* @return Cache
*/
static public function createCache($cacheClass = "Cache_File") {
return new self($cacheClass);
}
private function __construct($cacheClass) {
$this->_storage = new $cacheClass();
}
/**
* 设置缓存
*
* @param string $key
* @param mixed $value
* @param int $expire
*/
public function set($key, $value, $expire = false) {
if (!$expire) {
$expire = $this->_expire;
}

$this->_storage->checkLock($key);

$data = array("time" => time(), "expire" => $expire, "valid" => true, "data" => $value);
$this->_storage->lock($key);

try {
$this->_storage->store($key, $data);
$this->_storage->unlock($key);
} catch (CacheException $e) {
$this->_storage->unlock($key);
throw $e;
}
}
/**
* 读取缓存
*
* @param string $key
* @return mixed
*/
public function get($key) {
$data = $this->fetch($key);
if ($data && $data["valid"] && !$data["isExpired"]) {
return $data["data"];
}

return false;
}
/**
* 读缓存，包括过期的和无效的，取得完整的存贮结构
*
* @param string $key
*/
public function fetch($key) {
$this->_storage->checkLock($key);
$data = $this->_storage->fetch($key);
if ($data) {
$data["isExpired"] = (time() - $data["time"]) > $data["expire"] ? true : false;
return $data;
}

return false;
}
/**
* 删除缓存
*
* @param string $key
*/
public function delete($key) {
$this->_storage->checkLock($key)
->lock($key)
->delete($key)
->unlock($key);
}

public function clear() {
$this->_storage->clear();
}
/**
* 把缓存设为无效
*
* @param string $key
*/
public function setInvalidate($key) {
$this->_storage->checkLock($key)
->lock($key);
try {
$data = $this->_storage->fetch($key);
if ($data) {
$data["valid"] = false;
$this->_storage->store($key, $data);
}
$this->_storage->unlock($key);
} catch (CacheException $e) {
$this->_storage->unlock($key);
throw $e;
}
}

/**
* 设置缓存过期时间（s）
*
* @param int $expire
*/
public function setExpire($expire) {
$this->_expire = (int) $expire;
return $this;
}
}