<?php
/**
 * 记录日志,默认目录 myoa/webroot/
 * new log($logName，$size=2)
 * 默认 2mb 大小，超过后自动重命名
 */
class log{
    
private $logName;
private $logPath;
private $logSize = 2;
private $link;

//创建日志并检测日志大小
public function  __construct($logName,$size=null){
    $this->logName = $logName;
    $this->logPath = $_SERVER['DOCUMENT_ROOT']."/$this->logName.txt";
    if($size != null and $size>0){
        $this->logSize = $size;
    }
    
    if(!$this->exist()){
        $this->link = fopen($this->logPath, "a+");
        if(!$this->link){
            exit('无法创建文件');
        }
    }else{
        if($this->getSize() > $this->logSize){
            if(!$this->rename()){
                echo "日志文件过大且无法重命名会导致性能下降";
            }
        }
        $this->link = fopen($this->logPath, "a+");
    }
}

//检测文件是否存在
private function exist(){
    if(is_file($this->logPath)){
        return true;
    }else{
        return false;
    }
}

//返回文件的大小 mb
public function getSize(){
    if($this->exist()){
        $size = filesize($this->logPath);
    }else{
        return -1;
    }
    
    if($size<1024){
        return 0.01;
    }else if($size>1024 and $size<=1048576){
        return 0.1;
    }else if($size>1048576){
        return round(($size/1024)/1024,2);
    }
    
}

public function rename (){
    if($this->exist()){
        $newName = $_SERVER['DOCUMENT_ROOT']."/$this->logName".time().".txt";
        return rename($this->logPath, $newName);
    }else{
        return false;
    }
}

public function add($str){
    $str = $str."------".date('Y-m-d H:i:s').PHP_EOL;
    if($this->exist()){
        $num = fwrite($this->link, $str);
    }
    if($num == false){
        exit('写入日志失败!');
    }
}

public function __destruct(){
   fclose($this->link); 
}

}
?>