下图为文件结构：
核心为件为ShinowLog.php,以下为该文件代码
<?phpdefined('BASEPATH') OR exit('No direct script access allowed');/*** ShinowCMS日志系统* 采用驱动配置的调用模式，日志写入模式包括文件、数据库、远程写入三种* @author LIUTAO 2016/1/19*/
class ShinowLog extends CI_Driver_Library {/*** 验证驱动类型属性*/protected $valid_drivers = array('file', 'db', 'remote');/*** 默认适配器名称*/protected $_adapter = 'file';/*** 日志前缀索引，用于区别不同站点日志*/public $key_prefix = DOMAIN;/*** 存储配置文件中内容* @var type ARRAY*/ protected $cfg = array();/*** 日志构造器* 根据配置文件初始化成员变量*/public function __construct($config = array()) {$this->cfg = &get_shinowlog();if (isset($config['adapter']) && in_array($config['adapter'], $this->valid_drivers)) {$this->_adapter = $config['adapter'];} else { if (isset($this->cfg['shinowlog_adapter']) && in_array($this->cfg['shinowlog_adapter'], $this->valid_drivers)) {$this->_adapter = $this->cfg['shinowlog_adapter'];} else {throw new Exception('非法的适配器！');}}}/*** * @param type $level* @param type $msg* @param type $runtime* @return boolean* @comment 写入日志统一入口*/public function write_log($level, $msg, $runtime = null) {if($this->_is_needed($level)){if($this->_adapter!="file"){$return_msg = $this->{$this->_adapter}->write_log($level, $msg, $runtime);if($return_msg!="ok"){$this->_adapter = 'file';$this->{$this->_adapter}->write_log($level, $msg, $runtime);}return true;}else{$return_msg = $this->{$this->_adapter}->write_log($level, $msg, $runtime);}} else {return false;} }/*** 根据配置文件判断是否需要写入日志*/private function _is_needed($level){// print_r($this->cfg);$level = strtoupper($level);if(isset($this->cfg['shinowlog_threshold']) && isset($this->cfg['levels'])){//echo "aaa";if(is_array($this->cfg['shinowlog_threshold'])){$diff = array_diff($this->cfg['shinowlog_threshold'],$this->cfg['levels']);if(empty($diff)){if(in_array($this->cfg['levels'][$level],$this->cfg['levels'])&& in_array($this->cfg['levels'][$level],$this->cfg['shinowlog_threshold'])){return true;}else {return false;}}else {return false;}}else {// var_dump($level == $this->cfg['levels'][$level]);if($this->cfg['shinowlog_threshold']==$this->cfg['levels']['ALL']){return true;}else if(in_array($this->cfg['shinowlog_threshold'],$this->cfg['levels'])){return true;}else {return false;}}}else {return false;}}}这是适配器drivers文件
<?php
defined('BASEPATH') OR exit('No direct script access allowed');
/* ** ShinowLog文件日志适配器*/
class CI_ShinowLog_file extends CI_Driver {/*** 保存日志的路径** @var string*/protected $_shinowlog_path;/*** 日志文件权限** @var int*/protected $_file_permissions = 0644;/*** 日志级别** @var int*/protected $_threshold = 5;/*** 日志级别数组** @var array*/protected $_threshold_array = array();/*** 文件日志保存的时间格式** @var string*/protected $_date_fmt = 'Y-m-d H:i:s';/*** 文件方扩展名** @var string*/protected $_file_ext;/*** 是否确定写入日志，主要依赖于所配置的日志级别** @var bool*/protected $_enabled = TRUE;/*** 日志级别信息** @var array*/protected $_levels = null;/*** 服务器编号* 注：如果值为null,则写入日志时，值不可见*/protected $_serverID = 'NULL';// --------------------------------------------------------------------/***类的初始化** @return void*/public function __construct(){$config =& get_shinowlog();$this->_levels = $config['levels'];$this->_shinowlog_path = ($config['shinowlog_path'] !== '') ? $config['shinowlog_path'] : APPPATH.'logs/';$this->_serverID = isset($config['server_id'])?$config['server_id']:'NULL';$this->_file_ext = (isset($config['shinowlog_file_extension']) && $config['shinowlog_file_extension'] !== '')? ltrim($config['shinowlog_file_extension'], '.') : 'php';file_exists($this->_shinowlog_path) OR mkdir($this->_shinowlog_path, 0755, TRUE);if ( ! is_dir($this->_shinowlog_path) OR ! is_really_writable($this->_shinowlog_path)){$this->_enabled = FALSE;}if (is_numeric($config['shinowlog_threshold'])){$this->_threshold = (int) $config['shinowlog_threshold'];}elseif (is_array($config['shinowlog_threshold'])){$this->_threshold = 0;$this->_threshold_array = array_flip($config['shinowlog_threshold']);}if ( ! empty($config['shinowlog_date_format'])){$this->_date_fmt = $config['shinowlog_date_format'];}if ( ! empty($config['shinowlog_file_permissions']) && is_int($config['shinowlog_file_permissions'])){$this->_file_permissions = $config['shinowlog_file_permissions'];}}// --------------------------------------------------------------------/*** 日志写入** 一般情况下日志会在全局函数shinowlog_message()中调用** @return bool*/public function write_log($level, $msg,$runtime=null){if ($this->_enabled === FALSE){return FALSE;}$level = strtoupper($level);if (( ! isset($this->_levels[$level]) OR ($this->_levels[$level] > $this->_threshold))&& ! isset($this->_threshold_array[$this->_levels[$level]])){return FALSE;}$filepath = $this->_shinowlog_path.'sys-'.date('Y-m-d').'.'.$this->_file_ext;$message = '';if ( ! file_exists($filepath)){$newfile = TRUE;// Only add protection to php filesif ($this->_file_ext === 'php'){$message .= "<?php defined('BASEPATH') OR exit('No direct script access allowed'); ?>\n\n";}}if ( ! $fp = @fopen($filepath, 'ab')){return FALSE;}// Instantiating DateTime with microseconds appended to initial date is needed for proper support of this formatif (strpos($this->_date_fmt, 'u') !== FALSE){$microtime_full = microtime(TRUE);$microtime_short = sprintf("%06d", ($microtime_full - floor($microtime_full)) * 1000000);$date = new DateTime(date('Y-m-d H:i:s.'.$microtime_short, $microtime_full));$date = $date->format($this->_date_fmt);}else{$date = date($this->_date_fmt);}$runtime = $runtime==null?'NULL':$runtime;$message .= DOMAIN.'|'.$this->_serverID.'|'.$level.' | '.APPURI.'|'.REFERER.'|'.$runtime.'|'.$date.' --> '.$msg."\n";flock($fp, LOCK_EX);for ($written = 0, $length = strlen($message); $written < $length; $written += $result){if (($result = fwrite($fp, substr($message, $written))) === FALSE){break;}}flock($fp, LOCK_UN);fclose($fp);if (isset($newfile) && $newfile === TRUE){chmod($filepath, $this->_file_permissions);}return is_int($result);}}