关于CI框架中Session.php源码分析

Session类并不使用PHP本身的session，而是使用类自己的session，这样做，可以给开发者提供更大的弹性。下面我们就来仔细分析下CI框架的Session类Session.php文件

CI的Session并不是原生的session，正是我前面所有的cookie based session,另外，CI可以根据用户选择配置是否将session存入数据库中，本人很喜欢这个功能，还有就是“闪出数据”的功能，既闪出数据只是对下次服务器请求可以，之后就会被自动清除。常见使用方法有：

$this- session- set_userdata( some_name , some_html' target='_blank'>value //设置session数据

$this- session- userdata( item //获取session数据

$this- session- unset_userdata( some_name //删除session数据

$this- session- sess_destroy(); //销毁session数据

$this- session- set_flashdata( item , value //设置闪存数据

$this- session- flashdata( item //获取闪存数据

$this- session- keep_flashdata( item //保留闪存数据

/** * CI是 session based cookieclass CI_Session { var $sess_encrypt_cookie = FALSE; //是否对session加密 var $sess_use_database = FALSE; //是否将session存入数据库 var $sess_table_name = //session存入数据的表名 var $sess_expiration = 7200; //session的过期时间 var $sess_expire_on_close = FALSE; //当浏览器窗口关闭时是否自动使session过期 var $sess_match_ip = FALSE;//是否通过用户的IP地址来读取 session 的数据 var $sess_match_useragent = TRUE; //是否要按照对应的 User Agent 来读取 session 数据。 var $sess_cookie_name = ci_session //cookie名称 var $cookie_prefix = //cookie前缀 var $cookie_path = //cookie路径 var $cookie_domain = //cookie作用域 var $cookie_secure = FALSE; //是否在安全的https协议下才有效 var $sess_time_to_update = 300; //session cookie多久更新一次 var $encryption_key = //加密key var $flashdata_key = flash  var $time_reference = time  var $gc_probability = 5; //回收session的能力 var $userdata = array(); //用户session数据保存变量 var $CI; //CI超级句柄 var $now; //当前时间 public function __construct($params = array()) log_message( debug , Session Class Initialized  // 获取CI超级类 $this- CI = get_instance(); // 获取config文件中的配置数据 foreach (array( sess_encrypt_cookie , sess_use_database , sess_table_name , sess_expiration , sess_expire_on_close , sess_match_ip , sess_match_useragent , sess_cookie_name , cookie_path , cookie_domain , cookie_secure , sess_time_to_update , time_reference , cookie_prefix , encryption_key ) as $key) $this- $key = (isset($params[$key])) ? $params[$key] : $this- CI- config- item($key); //必须设置encryption_key if ($this- encryption_key == ) show_error( In order to use the Session class you are required to set an encryption key in your config file.  // 加载string helper函数 $this- CI- load- helper( string  // D如果对cookie进行加密，则引入加密类 if ($this- sess_encrypt_cookie == TRUE) $this- CI- load- library( encrypt  // 如果session计入数据库，则引入db if ($this- sess_use_database === TRUE AND $this- sess_table_name != ) $this- CI- load- database(); // 获取当前时间 $this- now = $this- _get_time(); // 如果没有设置session的有效时间，默认两年 if ($this- sess_expiration == 0) $this- sess_expiration = (60*60*24*365*2); // 获取cookie名称 $this- sess_cookie_name = $this- cookie_prefix.$this- sess_cookie_name; // 如果session不存在，创建新会话 if ( ! $this- sess_read()) $this- sess_create(); else $this- sess_update(); // 闪出标记old的闪出数据 $this- _flashdata_sweep(); //将新的闪出数据标记成old 标记成old的数据的数据将会在下次请求时闪出 $this- _flashdata_mark(); //回收/删除 过期的session $this- _sess_gc(); log_message( debug , Session routines successfully run  // -------------------------------------------------------------------- * 读取session数据 function sess_read() // 获取session $session = $this- CI- input- cookie($this- sess_cookie_name); // 没有session 拜拜 if ($session === FALSE) log_message( debug , A session cookie was not found.  return FALSE; // 如果加密了cookie if ($this- sess_encrypt_cookie == TRUE) $session = $this- CI- encrypt- decode($session); else // encryption was not used, so we need to check the md5 hash $hash = substr($session, strlen($session)-32); // get last 32 chars $session = substr($session, 0, strlen($session)-32); // Does the md5 hash match? This is to prevent manipulation of session data in userspace if ($hash !== md5($session.$this- encryption_key)) log_message( error , The session cookie data did not match what was expected. This could be a possible hacking attempt.  $this- sess_destroy(); return FALSE; // 反序列化存入cookie的session数组 $session = $this- _unserialize($session); // 检测session的数据 if ( ! is_array($session) OR ! isset($session[ session_id ]) OR ! isset($session[ ip_address ]) OR ! isset($session[ user_agent ]) OR ! isset($session[ last_activity ])) $this- sess_destroy(); return FALSE; // session数据过期了吗 if (($session[ last_activity ] + $this- sess_expiration) $this- now) $this- sess_destroy(); return FALSE; // 是否是根据用户ip来读取session数据 if ($this- sess_match_ip == TRUE AND $session[ ip_address ] != $this- CI- input- ip_address()) $this- sess_destroy(); return FALSE; // 是否根据ua来匹配session数据 if ($this- sess_match_useragent == TRUE AND trim($session[ user_agent ]) != trim(substr($this- CI- input- user_agent(), 0, 120))) $this- sess_destroy(); return FALSE; // 如果session入库了，这种方式应该更安全点，当然负载大时，就不建议了，数据库读写压力大 if ($this- sess_use_database === TRUE) $this- CI- db- where( session_id , $session[ session_id  if ($this- sess_match_ip == TRUE) $this- CI- db- where( ip_address , $session[ ip_address  if ($this- sess_match_useragent == TRUE) $this- CI- db- where( user_agent , $session[ user_agent  $query = $this- CI- db- get($this- sess_table_name); // No result? Kill it! if ($query- num_rows() == 0) $this- sess_destroy(); return FALSE; // Is there custom data? If so, add it to the main session array $row = $query- row(); if (isset($row- user_data) AND $row- user_data != ) $custom_data = $this- _unserialize($row- user_data); if (is_array($custom_data)) foreach ($custom_data as $key = $val) $session[$key] = $val; // Session is valid! $this- userdata = $session; unset($session); return TRUE; // -------------------------------------------------------------------- * 将读取的session数据写入 function sess_write() // 是否写入db if ($this- sess_use_database === FALSE) $this- _set_cookie(); return; // set the custom userdata, the session data we will set in a second $custom_userdata = $this- userdata; $cookie_userdata = array(); // Before continuing, we need to determine if there is any custom data to deal with. // Let s determine this by removing the default indexes to see if there s anything left in the array // and set the session data while we re at it foreach (array( session_id , ip_address , user_agent , last_activity ) as $val) unset($custom_userdata[$val]); $cookie_userdata[$val] = $this- userdata[$val]; // Did we find any custom data? If not, we turn the empty array into a string // since there s no reason to serialize and store an empty array in the DB if (count($custom_userdata) === 0) $custom_userdata =  else // Serialize the custom data array so we can store it $custom_userdata = $this- _serialize($custom_userdata); // 更新session记录 $this- CI- db- where( session_id , $this- userdata[ session_id  $this- CI- db- update($this- sess_table_name, array( last_activity = $this- userdata[ last_activity ], user_data = $custom_userdata)); // Write the cookie. Notice that we manually pass the cookie data array to the // _set_cookie() function. Normally that function will store $this- userdata, but // in this case that array contains custom data, which we do not want in the cookie. $this- _set_cookie($cookie_userdata); // -------------------------------------------------------------------- * 创建一个新的session function sess_create() //保证sessid 安全唯一 $sessid =  while (strlen($sessid) 32) $sessid .= mt_rand(0, mt_getrandmax()); $sessid .= $this- CI- input- ip_address(); $this- userdata = array( session_id = md5(uniqid($sessid, TRUE)), ip_address = $this- CI- input- ip_address(), user_agent = substr($this- CI- input- user_agent(), 0, 120), last_activity = $this- now, user_data =  // Save the data to the DB if needed if ($this- sess_use_database === TRUE) $this- CI- db- query($this- CI- db- insert_string($this- sess_table_name, $this- userdata)); // Write the cookie $this- _set_cookie(); // -------------------------------------------------------------------- * 更新session function sess_update() // 默认五分钟更新 if (($this- userdata[ last_activity ] + $this- sess_time_to_update) = $this- now) return; // Save the old session id so we know which record to // update in the database if we need it $old_sessid = $this- userdata[ session_id  $new_sessid =  while (strlen($new_sessid) 32) $new_sessid .= mt_rand(0, mt_getrandmax()); // To make the session ID even more secure we ll combine it with the user s IP $new_sessid .= $this- CI- input- ip_address(); // Turn it into a hash $new_sessid = md5(uniqid($new_sessid, TRUE)); // Update the session data in the session data array $this- userdata[ session_id ] = $new_sessid; $this- userdata[ last_activity ] = $this-  // _set_cookie() will handle this for us if we aren t using database sessions // by pushing all userdata to the cookie. $cookie_data = NULL; // 更新数据库中几率 if ($this- sess_use_database === TRUE) // set cookie explicitly to only have our session data $cookie_data = array(); foreach (array( session_id , ip_address , user_agent , last_activity ) as $val) $cookie_data[$val] = $this- userdata[$val]; $this- CI- db- query($this- CI- db- update_string($this- sess_table_name, array( last_activity = $this- now, session_id = $new_sessid), array( session_id = $old_sessid))); // 重新写入session $this- _set_cookie($cookie_data); // -------------------------------------------------------------------- *销毁当前所有session数据 function sess_destroy() // Kill the session DB row if ($this- sess_use_database === TRUE isset($this- userdata[ session_id ])) $this- CI- db- where( session_id , $this- userdata[ session_id  $this- CI- db- delete($this- sess_table_name); // Kill the cookie setcookie( $this- sess_cookie_name, addslashes(serialize(array())), ($this- now - 31500000), $this- cookie_path, $this- cookie_domain, // Kill session data $this- userdata = array(); // -------------------------------------------------------------------- * 获取session数组指定元素的值 function userdata($item) return ( ! isset($this- userdata[$item])) ? FALSE : $this- userdata[$item]; // -------------------------------------------------------------------- * 获取所有session数据 function all_userdata() return $this- userdata; // -------------------------------------------------------------------- * 添加和修改自定义的session数据 function set_userdata($newdata = array(), $newval = ) if (is_string($newdata)) $newdata = array($newdata = $newval); //支持数组组合方式 if (count($newdata) 0) foreach ($newdata as $key = $val) $this- userdata[$key] = $val; $this- sess_write(); // -------------------------------------------------------------------- * 删除session数组中的元素， function unset_userdata($newdata = array()) if (is_string($newdata)) $newdata = array($newdata =  if (count($newdata) 0) foreach ($newdata as $key = $val) unset($this- userdata[$key]); $this- sess_write(); // ------------------------------------------------------------------------ * Add or change flashdata, only available * until the next request * @access public * @param mixed * @param string * @return void function set_flashdata($newdata = array(), $newval = ) if (is_string($newdata)) $newdata = array($newdata = $newval); if (count($newdata) 0) foreach ($newdata as $key = $val) $flashdata_key = $this- flashdata_key. :new: .$key; $this- set_userdata($flashdata_key, $val); // ------------------------------------------------------------------------ * CI支持闪出数据也就是说 Session数据只对下次服务器请求可用,有时候如果你还想在下个请求后的请求还有效。。。 * keep_flashdata功能就是讲持续保持闪出数据，使其在下个请求也有效 function keep_flashdata($key) //将闪出数据标记成new $old_flashdata_key = $this- flashdata_key. :old: .$key; $value = $this- userdata($old_flashdata_key); $new_flashdata_key = $this- flashdata_key. :new: .$key; $this- set_userdata($new_flashdata_key, $value); // ------------------------------------------------------------------------ * 获取闪出数据 function flashdata($key) $flashdata_key = $this- flashdata_key. :old: .$key; return $this- userdata($flashdata_key); // ------------------------------------------------------------------------ * 将闪出数据标记成old，以便_flashdata_sweep清除数据 function _flashdata_mark() $userdata = $this- all_userdata(); foreach ($userdata as $name = $value) $parts = explode( :new: , $name); if (is_array($parts) count($parts) === 2) $new_name = $this- flashdata_key. :old: .$parts[1]; $this- set_userdata($new_name, $value); $this- unset_userdata($name); // ------------------------------------------------------------------------ * 将标记成old的闪出数据闪出 function _flashdata_sweep() $userdata = $this- all_userdata(); foreach ($userdata as $key = $value) if (strpos($key, :old: )) $this- unset_userdata($key); //获取当前时间 function _get_time() if (strtolower($this- time_reference) == gmt ) $now = time(); $time = mktime(gmdate( H , $now), gmdate( i , $now), gmdate( s , $now), gmdate( m , $now), gmdate( d , $now), gmdate( Y , $now)); else $time = time(); return $time; // -------------------------------------------------------------------- * 写入session cookie function _set_cookie($cookie_data = NULL) if (is_null($cookie_data)) $cookie_data = $this- userdata; // 序列化数组 $cookie_data = $this- _serialize($cookie_data); //加密数据 if ($this- sess_encrypt_cookie == TRUE) $cookie_data = $this- CI- encrypt- encode($cookie_data); else // if encryption is not used, we provide an md5 hash to prevent userside tampering $cookie_data = $cookie_data.md5($cookie_data.$this- encryption_key); //sess_expire_on_close为TRUE则，浏览器关闭，session失效 $expire = ($this- sess_expire_on_close === TRUE) ? 0 : $this- sess_expiration + time(); // Set the cookie setcookie( $this- sess_cookie_name, $cookie_data, $expire, $this- cookie_path, $this- cookie_domain, $this- cookie_secure // -------------------------------------------------------------------- * 序列化数组 function _serialize($data) if (is_array($data)) foreach ($data as $key = $val) if (is_string($val)) $data[$key] = str_replace( // , {{slash}} , $val); else if (is_string($data)) $data = str_replace( // , {{slash}} , $data); return serialize($data); // -------------------------------------------------------------------- * 反序列化数组 function _unserialize($data) $data = @unserialize(strip_slashes($data)); if (is_array($data)) foreach ($data as $key = $val) if (is_string($val)) $data[$key] = str_replace( {{slash}} , // , $val); return $data; return (is_string($data)) ? str_replace( {{slash}} , // , $data) : $data; // -------------------------------------------------------------------- * 回收/删除数据库中失效的session信息 function _sess_gc() if ($this- sess_use_database != TRUE) return; srand(time()); if ((rand() % 100) $this- gc_probability) $expire = $this- now - $this- sess_expiration; $this- CI- db- where( last_activity {$expire}  $this- CI- db- delete($this- sess_table_name); log_message( debug , Session garbage collection performed. }

以上就是本文的全部内容，希望对大家的学习有所帮助，更多相关内容请关注PHP ！

相关推荐：

关于CI框架开发新浪微博登录接口的源码分析

关于CI框架扩展系统核心类的方法分析

CI框架的公共模型类定义与用法

以上就是关于CI框架中Session.php源码分析的详细内容，PHP教程

郑重声明：本文版权归原作者所有，转载文章仅为传播更多信息之目的，如作者信息标记有误，请第一时间联系我们修改或删除，多谢。