diff --git a/library/think/cache/driver/Apc.php b/library/think/cache/driver/Apc.php
index ebe163cc..b622762a 100644
--- a/library/think/cache/driver/Apc.php
+++ b/library/think/cache/driver/Apc.php
@@ -23,7 +23,6 @@ class Apc
     protected $options = [
         'expire' => 0,
         'prefix' => '',
-        'length' => 0,
     ];
     /*****************************
     需要支持apc_cli模式
diff --git a/library/think/cache/driver/File.php b/library/think/cache/driver/File.php
index d8487102..267fabdd 100644
--- a/library/think/cache/driver/File.php
+++ b/library/think/cache/driver/File.php
@@ -25,7 +25,6 @@ class File
         'cache_subdir'  => false,
         'path_level'    => 1,
         'prefix'        => '',
-        'length'        => 0,
         'path'          => CACHE_PATH,
         'data_compress' => false,
     ];
diff --git a/library/think/cache/driver/Memcache.php b/library/think/cache/driver/Memcache.php
index fbfbb08a..370c6415 100644
--- a/library/think/cache/driver/Memcache.php
+++ b/library/think/cache/driver/Memcache.php
@@ -23,7 +23,6 @@ class Memcache
         'expire'     => 0,
         'timeout'    => 0, // 超时时间（单位：毫秒）
         'persistent' => true,
-        'length'     => 0,
         'prefix'     => '',
     ];
 
diff --git a/library/think/cache/driver/Memcached.php b/library/think/cache/driver/Memcached.php
index f82500f5..e413b06f 100644
--- a/library/think/cache/driver/Memcached.php
+++ b/library/think/cache/driver/Memcached.php
@@ -22,7 +22,6 @@ class Memcached
         'port'    => 11211,
         'expire'  => 0,
         'timeout' => 0, // 超时时间（单位：毫秒）
-        'length'  => 0,
         'prefix'  => '',
     ];
 
diff --git a/library/think/cache/driver/Redis.php b/library/think/cache/driver/Redis.php
index 23455a1d..403229ff 100644
--- a/library/think/cache/driver/Redis.php
+++ b/library/think/cache/driver/Redis.php
@@ -17,7 +17,7 @@ use think\Exception;
 /**
  * Redis缓存驱动，适合单机部署、有前端代理实现高可用的场景，性能最好
  * 有需要在业务层实现读写分离、或者使用RedisCluster的需求，请使用Redisd驱动
- * 
+ *
  * 要求安装phpredis扩展：https://github.com/nicolasff/phpredis
  * @author    尘缘 <130775@qq.com>
  */
@@ -31,7 +31,6 @@ class Redis
         'timeout'    => 0,
         'expire'     => 0,
         'persistent' => false,
-        'length'     => 0,
         'prefix'     => '',
     ];
 
diff --git a/library/think/cache/driver/Redisd.php b/library/think/cache/driver/Redisd.php
index 67058975..d32dbaca 100644
--- a/library/think/cache/driver/Redisd.php
+++ b/library/think/cache/driver/Redisd.php
@@ -18,21 +18,21 @@ use think\Log;
 /**
 配置参数:
 'cache' => [
-    'type'       => 'Redisd'
-    'host'       => 'A:6379,B:6379', //redis服务器ip，多台用逗号隔开；读写分离开启时，默认写A，当A主挂时，再尝试写B
-    'slave'      => 'B:6379,C:6379', //redis服务器ip，多台用逗号隔开；读写分离开启时，所有IP随机读，其中一台挂时，尝试读其它节点，可以配置权重
-    'port'       => 6379,    //默认的端口号
-    'password'   => '',      //AUTH认证密码，当redis服务直接暴露在外网时推荐
-    'timeout'    => 10,      //连接超时时间
-    'expire'     => false,   //默认过期时间，默认为永不过期
-    'prefix'     => '',      //缓存前缀，不宜过长
-    'persistent' => false,   //是否长连接 false=短连接，推荐长连接
+'type'       => 'Redisd'
+'host'       => 'A:6379,B:6379', //redis服务器ip，多台用逗号隔开；读写分离开启时，默认写A，当A主挂时，再尝试写B
+'slave'      => 'B:6379,C:6379', //redis服务器ip，多台用逗号隔开；读写分离开启时，所有IP随机读，其中一台挂时，尝试读其它节点，可以配置权重
+'port'       => 6379,    //默认的端口号
+'password'   => '',      //AUTH认证密码，当redis服务直接暴露在外网时推荐
+'timeout'    => 10,      //连接超时时间
+'expire'     => false,   //默认过期时间，默认为永不过期
+'prefix'     => '',      //缓存前缀，不宜过长
+'persistent' => false,   //是否长连接 false=短连接，推荐长连接
 ],
 
 单例获取:
-    $redis = \think\Cache::connect(Config::get('cache'));
-    $redis->master(true)->setnx('key');
-    $redis->master(false)->get('key');
+$redis = \think\Cache::connect(Config::get('cache'));
+$redis->master(true)->setnx('key');
+$redis->master(false)->get('key');
  */
 
 /**
@@ -70,7 +70,6 @@ class Redisd
         'timeout'    => 10,
         'expire'     => false,
         'persistent' => false,
-        'length'     => 0,
         'prefix'     => '',
         'serialize'  => \Redis::SERIALIZER_PHP,
     ];
@@ -136,7 +135,7 @@ class Redisd
         //发生错误则摘掉当前节点
         try {
             $result = $this->handler->$func($host, $port, $this->options['timeout']);
-            if($result === false) {
+            if (false === $result) {
                 $this->handler->getLastError();
             }
 
@@ -145,7 +144,7 @@ class Redisd
             }
 
             $this->handler->setOption(\Redis::OPT_SERIALIZER, $this->options['serialize']);
-            if(strlen($this->options['prefix'])) {
+            if (strlen($this->options['prefix'])) {
                 $this->handler->setOption(\Redis::OPT_PREFIX, $this->options['prefix']);
             }
 
@@ -288,7 +287,7 @@ class Redisd
         $this->master(true);
         return $this->handler->flushDB();
     }
-    
+
     /**
      * 返回句柄对象，可执行其它高级方法
      * 需要先执行 $redis->master() 连接到 DB
diff --git a/library/think/cache/driver/Sae.php b/library/think/cache/driver/Sae.php
index 4bead286..03b70735 100644
--- a/library/think/cache/driver/Sae.php
+++ b/library/think/cache/driver/Sae.php
@@ -27,7 +27,6 @@ class Sae
         'expire'     => 0,
         'timeout'    => false,
         'persistent' => false,
-        'length'     => 0,
         'prefix'     => '',
     ];
 
diff --git a/library/think/cache/driver/Secache.php b/library/think/cache/driver/Secache.php
index 13613bfe..67966f21 100644
--- a/library/think/cache/driver/Secache.php
+++ b/library/think/cache/driver/Secache.php
@@ -25,7 +25,6 @@ class Secache
         'path'    => '',
         'expire'  => 0,
         'prefix'  => '',
-        'length'  => 0,
     ];
 
     /**
diff --git a/library/think/cache/driver/Sqlite.php b/library/think/cache/driver/Sqlite.php
index 89a24e96..6144a366 100644
--- a/library/think/cache/driver/Sqlite.php
+++ b/library/think/cache/driver/Sqlite.php
@@ -26,7 +26,6 @@ class Sqlite implements CacheInterface
         'table'      => 'sharedmemory',
         'prefix'     => '',
         'expire'     => 0,
-        'length'     => 0,
         'persistent' => false,
     ];
 
diff --git a/library/think/cache/driver/Wincache.php b/library/think/cache/driver/Wincache.php
index e77b53a2..66972a48 100644
--- a/library/think/cache/driver/Wincache.php
+++ b/library/think/cache/driver/Wincache.php
@@ -23,7 +23,6 @@ class Wincache
     protected $options = [
         'prefix' => '',
         'expire' => 0,
-        'length' => 0,
     ];
 
     /**
diff --git a/library/think/cache/driver/Xcache.php b/library/think/cache/driver/Xcache.php
index 00a0483f..3fea3296 100644
--- a/library/think/cache/driver/Xcache.php
+++ b/library/think/cache/driver/Xcache.php
@@ -23,7 +23,6 @@ class Xcache
     protected $options = [
         'prefix' => '',
         'expire' => 0,
-        'length' => 0,
     ];
 
     /**