php写的带缓存数据功能的mysqli类

<?php
/**
* mysqli类
*/
class db_mysqli {
protected $mysqli;
protected $sql;
protected $rs;
protected $query_num = 0;
protected $fetch_mode = mysqli_assoc;
protected $cache_dir = './cache/';
protected $cache_time = 1800;
public function __construct($dbhost, $dbuser, $dbpass, $dbname) {
$this->mysqli = new mysqli($dbhost, $dbuser, $dbpass, $dbname);
if(mysqli_connect_errno()) {
$this->mysqli = false;
echo '<h2>'.mysqli_connect_error().'</h2>';
die();
} else {
$this->mysqli->set_charset("utf8");
}
}
public function __destruct() {
$this->free();
$this->close();
}
protected function free() {
@$this->rs->free();
}
protected function close() {
$this->mysqli->close();
}
protected function fetch() {
return $this->rs->fetch_array($this->fetch_mode);
}
protected function getquerysql($sql, $limit = null) {
if (@preg_match("/[0-9]+(,[ ]?[0-9]+)?/is", $limit) && !preg_match("/ limit [0-9]+(,[ ]?[0-9]+)?$/is", $sql)) {
$sql .= " limit " . $limit;
}
return $sql;
}
protected function get_cache($sql,$method) {
include_once './cache.php';//若框架中使用__autoload()，这里可以不用加载文件
$cache = new cache($this->cache_dir,$this->cache_time);
$cache_file = md5($sql.$method);
$res = $cache->get_cache($cache_file);
if(!$res) {
$res = $this->$method($sql);
$cache->set_cache($cache_file, $res);
}
return $res;
}
public function query_num() {
return $this->query_num;
}
public function set_cache_dir($cache_dir) {
$this->cache_dir = $cache_dir;
}
public function set_cache_time($cache_time) {
$this->cache_time = $cache_time;
}
public function query($sql, $limit = null) {
$sql = $this->getquerysql($sql, $limit);
$this->sql = $sql;
$this->rs = $this->mysqli->query($sql);
if (!$this->rs) {
echo "<h2>".$this->mysqli->error."</h2>";
die();
} else {
$this->query_num++;
return $this->rs;
}
}
public function getone($sql) {
$this->query($sql, 1);
$this->fetch_mode = mysqli_num;
$row = $this->fetch();
$this->free();
return $row[0];
}
public function get_one($sql) {
return $this->getone($sql);
}
public function cache_one($sql) {
$sql = $this->getquerysql($sql, 1);
return $this->get_cache($sql, 'getone');
}
public function getrow($sql, $fetch_mode = mysqli_assoc) {
$this->query($sql, 1);
$this->fetch_mode = $fetch_mode;
$row = $this->fetch();
$this->free();
return $row;
}
public function get_row($sql, $fetch_mode = mysqli_assoc) {
return $this->getrow($sql);
}
public function cache_row($sql) {
$sql = $this->getquerysql($sql, 1);
return $this->get_cache($sql, 'getrow');
}
public function getall($sql, $limit = null, $fetch_mode = mysqli_assoc) {
$this->query($sql, $limit);
$all_rows = array();
$this->fetch_mode = $fetch_mode;
while($rows = $this->fetch()) {
$all_rows[] = $rows;
}
$this->free();
return $all_rows;
}
public function get_all($sql, $limit = null, $fetch_mode = mysqli_assoc) {
return $this->getall($sql);
}
public function cache_all($sql, $limit = null) {
$sql = $this->getquerysql($sql, $limit);
return $this->get_cache($sql, 'getall');
}
public function insert_id() {
return $this->mysqli->insert_id();
}
public function escape($str) {
if(is_array($str)) {
foreach($str as $key=>$val) {
$str[$key] = $this->escape($val);
}
} else {
$str = addslashes(trim($str));
}
return $str;
}
}
//用法
$db = new db_mysqli('localhost', 'root', 111222, 'dict');
$db->set_cache_time(10);
$db->set_cache_dir('./cache/sql/');
$sql = "select * from words order by word_id limit 10,10";
$res1 = $db->get_all($sql);
$res2 = $db->cache_all($sql);
echo $db->query_num(),'<br>';
?>