php专区

		
		

			class Cache {
			

				 private $dirCache; //缓存目录,用相对目录
				

					 private $lifeTime; //缓存生存生存时间单位秒
					

						 private $fileName; //缓存文件(包括相对路径)
						

							 private $cacheFlg; //是否开启缓存
							

								 private $fileExt; //缓存文件的扩展名
								

									 public function __construct() {
									

										 $this->dirCache = DIRTMP . '/webcache';
										

											 $this->lifeTime = 0; //默认为60秒
											

												 $this->cacheFlg = false; //默认为开启
												

													 $this->fileExt = '.htm';
													

														 $this->setFileName();
														

															 }
															

																 //获取缓存文件名
																

																	 private function setFileName() {
																	

																		 $this->fileName = md5($_SERVER['REQUEST_URI']) . $this->fileExt;
																		

																			 }
																			

																				 //开始缓存
																				

																					 public function startCache() {
																					

																						 if ($this->cacheFlg) {
																						

																							 if (file_exists($this->dirCache .
																							

																								 '/' . $this->fileName) //检查文件是否存在
																								

																									 && filesize($this->dirCache . '/' . $this->fileName) > 0 //检查文件大小即文件缓存是否保存成功
																									

																										 && $this->checkCacheExpire() && $this->checkCacheLife()) {
																										

																											 echo file_get_contents($this->dirCache . '/' . $this->fileName); //读取缓存内容
																											

																												 $this->cacheFlg = false; //关闭生成缓存
																												

																													 exit ();
																													

																														 } else {
																														

																															 ob_start(); //开始缓存
																															

																																 }
																																

																																	 }
																																	

																																		 }
																																		

																																			 //检查被请求文件在缓存未过期时间内是否被修改
																																			

																																				 private function checkCacheExpire() {
																																				

																																					 if (filemtime($this->dirCache . '/' . $this->fileName) > filemtime($_SERVER['SCRIPT_FILENAME'])) {
																																					

																																						 return true;
																																						

																																							 } else {
																																							

																																								 return false;
																																								

																																									 }
																																									

																																										 }
																																										

																																											 //检查缓存是否过期
																																											

																																												 private function checkCacheLife() {
																																												

																																													 if ($this->lifeTime == 0)
																																													

																																														 return true;
																																														

																																															 if (time() - filemtime($this->dirCache . '/' . $this->fileName) < $this->lifeTime) {
																																															

																																																 return true;
																																																

																																																	 } else {
																																																	

																																																		 return false;
																																																		

																																																			 }
																																																			

																																																				 }
																																																				

																																																					 //缓存页面结束
																																																					

																																																						 public function endCache() {
																																																						

																																																							 if ($this->cacheFlg && $this->makeDir()) {
																																																							

																																																								 $contents = ob_get_contents(); //得到页面要缓存的内容
																																																								

																																																									 ob_end_flush();
																																																									

																																																										 if (!$this->createFile($contents)) {
																																																										

																																																											 @ unlink($this->dirCache . '/' . $this->fileName);
																																																											

																																																												 }
																																																												

																																																													 }
																																																													

																																																														 }
																																																														

																																																															 //创建缓存文件
																																																															

																																																																 private function createFile($contents) {
																																																																

																																																																	 $fp = @ fopen($this->dirCache . '/' . $this->fileName, 'w');
																																																																	

																																																																		 if (@ fwrite($fp, $contents)) {
																																																																		

																																																																			 @ fclose($fp);
																																																																			

																																																																				 return true;
																																																																				

																																																																					 } else {
																																																																					

																																																																						 @ fclose($fp);
																																																																						

																																																																							 return false;
																																																																							

																																																																								 }
																																																																								

																																																																									 }
																																																																									

																																																																										 //创建缓存目录
																																																																										

																																																																											 function makeDir() {
																																																																											

																																																																												 if (file_exists($this->dirCache))
																																																																												

																																																																													 return true;
																																																																													

																																																																														 $dir = explode('/', str_replace("\", '/', $this->dirCache));
																																																																														

																																																																															 $mdir = '';
																																																																															

																																																																																 foreach ($dir as $val) {
																																																																																

																																																																																	 $mdir .= $val . "/";
																																																																																	

																																																																																		 if ($val == '..' || $val == '.' || emptyempty($val))
																																																																																		

																																																																																			 continue;
																																																																																			

																																																																																				 if (!file_exists($mdir)) {
																																																																																				

																																																																																					 if (!@ mkdir($mdir, '0777')) {
																																																																																					

																																																																																						 return false;
																																																																																						

																																																																																							 }
																																																																																							

																																																																																								 }
																																																																																								

																																																																																									 }
																																																																																									

																																																																																										 return true;
																																																																																										

																																																																																											 }
																																																																																											

																																																																																												 //清除缓存
																																																																																												

																																																																																													 function clearCache($getFile = '') {
																																																																																													

																																																																																														 if (emptyempty($getFile)) {
																																																																																														

																																																																																															 $getFile = $this->dirCache;
																																																																																															

																																																																																																 }
																																																																																																

																																																																																																	 if (file_exists($getFile) && is_dir($getFile)) {
																																																																																																	

																																																																																																		 $handle = opendir($getFile);
																																																																																																		

																																																																																																			 while (false != $file = readdir($handle)) {
																																																																																																			

																																																																																																				 if ($file == '..' || $file == '.' || emptyempty($file))
																																																																																																				

																																																																																																					 continue;
																																																																																																					

																																																																																																						 if (strrchr($file, '.') == $this->fileExt) {
																																																																																																						

																																																																																																							 @ unlink($getFile . $file);
																																																																																																							

																																																																																																								 }
																																																																																																								

																																																																																																									 if (is_dir($getFile . $file)) {
																																																																																																									

																																																																																																										 if (!@ rmdir($getFile . $file)) {
																																																																																																										

																																																																																																											 $this->ClearCache($getFile . $file . '/');
																																																																																																											

																																																																																																												 }
																																																																																																												

																																																																																																													 }
																																																																																																													

																																																																																																														 }
																																																																																																														

																																																																																																															 closedir($handle);
																																																																																																															

																																																																																																																 $result = @ rmdir($getFile);
																																																																																																																

																																																																																																																	 } else {
																																																																																																																	

																																																																																																																		 $result = true;
																																																																																																																		

																																																																																																																			 
																																																																																																																			

																																																																																																																				 }
																																																																																																																				

																																																																																																																					 if (is_file($file))
																																																																																																																					

																																																																																																																						 @ unlink($file);
																																																																																																																						

																																																																																																																							 return $result;
																																																																																																																							

																																																																																																																								 }
																																																																																																																								

																																																																																																																									}
																																																																																																																									

																																																																																																																										?>