PHP文件缓存如何应用于长尾关键词优化？
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本文共计353个文字，预计阅读时间需要2分钟。
在Web开发中，可以利用文件缓存来减轻数据库压力。以下是一个PHP中使用文件缓存的示例代码：
phpclass CacheLayer{ protected $root=; protected $cache=; protected $key=;}
在web开发中，可以通过文件缓存，大大缓解数据库的压力。 如下代码是php中使用文件缓存的例子。
CacheLayer.php
<?php
class CacheLayer{
protected $root = "";
protected $cache = "";
protected $key = "";
protected $life = 0;
public function __construct($key, $root = "/cachelayer"){
$this->root = $_SERVER["DOCUMENT_ROOT"].$root;
$this->key = $key;
}
public function expired($life_span){
$this->life = $life_span;
$file = $this->root."/".$this->key.".cachelayer";
if(is_file($file)){
$mtime = filemtime($file);
return (time() >= ($mtime + $this->life));
}else{
return true;
}
}
public function put($content){
$file = $this->root."/".$this->key.".cachelayer";
if(!is_dir(dirname($this->root))){
return false;
}
$this->delete();
$content = json_encode($content);
return (bool)file_put_contents($file, $content);
}
public function get(){
$file = $this->root."/".$this->key.".cachelayer";
if(is_file($file)){
return json_decode(file_get_contents($file), true);
}
return array();
}
public function delete(){
$file = $this->root."/".$this->key.".cachelayer";
if(is_file($file)){
unlink($file);
return true;
}
return false;
}
}
example.php
<?php // Load the cachelayer and the database connection (db connection is optional) require_once "CacheLayer.php"; require_once "db_connection.php"; // Create a instance of the cachelayer $cl_nav = new CacheLayer("navigation"); // Check to see if the cache is expired (60 * 10 = 10 minutes) if($cl_nav->expired(60 * 10)){ echo "Cache doesn't exist or is expired. Rebuilding...<br />"; // if the cache is expired rebuild it $result = mysql_query("select id, title from navigation"); $new_cache = array(); while($row = mysql_fetch_assoc($result)){ $new_cache[] = $row; } // Save the array into the cache $cl_nav->put($new_cache); } echo "Loading from cache...<br />"; // Get the cache $cache = $cl_nav->get(); // Display the cache foreach($cache as $row){ $id = $row["id"]; $title = $row["title"]; echo "<a href='/$id/$title'>$title</a><br />"; }
本文共计353个文字，预计阅读时间需要2分钟。
在Web开发中，可以利用文件缓存来减轻数据库压力。以下是一个PHP中使用文件缓存的示例代码：
phpclass CacheLayer{ protected $root=; protected $cache=; protected $key=;}
在web开发中，可以通过文件缓存，大大缓解数据库的压力。 如下代码是php中使用文件缓存的例子。
CacheLayer.php
<?php
class CacheLayer{
protected $root = "";
protected $cache = "";
protected $key = "";
protected $life = 0;
public function __construct($key, $root = "/cachelayer"){
$this->root = $_SERVER["DOCUMENT_ROOT"].$root;
$this->key = $key;
}
public function expired($life_span){
$this->life = $life_span;
$file = $this->root."/".$this->key.".cachelayer";
if(is_file($file)){
$mtime = filemtime($file);
return (time() >= ($mtime + $this->life));
}else{
return true;
}
}
public function put($content){
$file = $this->root."/".$this->key.".cachelayer";
if(!is_dir(dirname($this->root))){
return false;
}
$this->delete();
$content = json_encode($content);
return (bool)file_put_contents($file, $content);
}
public function get(){
$file = $this->root."/".$this->key.".cachelayer";
if(is_file($file)){
return json_decode(file_get_contents($file), true);
}
return array();
}
public function delete(){
$file = $this->root."/".$this->key.".cachelayer";
if(is_file($file)){
unlink($file);
return true;
}
return false;
}
}
example.php
<?php // Load the cachelayer and the database connection (db connection is optional) require_once "CacheLayer.php"; require_once "db_connection.php"; // Create a instance of the cachelayer $cl_nav = new CacheLayer("navigation"); // Check to see if the cache is expired (60 * 10 = 10 minutes) if($cl_nav->expired(60 * 10)){ echo "Cache doesn't exist or is expired. Rebuilding...<br />"; // if the cache is expired rebuild it $result = mysql_query("select id, title from navigation"); $new_cache = array(); while($row = mysql_fetch_assoc($result)){ $new_cache[] = $row; } // Save the array into the cache $cl_nav->put($new_cache); } echo "Loading from cache...<br />"; // Get the cache $cache = $cl_nav->get(); // Display the cache foreach($cache as $row){ $id = $row["id"]; $title = $row["title"]; echo "<a href='/$id/$title'>$title</a><br />"; }