<?php
namespace WORKERMAN\Core;
require_once WORKERMAN_ROOT_DIR . 'Core/Events/Select.php';
require_once WORKERMAN_ROOT_DIR . 'Core/AbstractWorker.php';
require_once WORKERMAN_ROOT_DIR . 'Core/Lib/Config.php';

/**
 * SocketWorker 监听某个端口，对外提供网络服务的worker
 * 
* @author walkor <worker-man@qq.com>
* 
 * <b>使用示例:</b>
 * <pre>
 * <code>
 * $worker = new SocketWorker();
 * $worker->start();
 * <code>
 * </pre>
 */

abstract class SocketWorker extends AbstractWorker
{
    
    /**
     * udp最大包长 linux:65507 mac:9216
     * @var integer
     */ 
    const MAX_UDP_PACKEG_SIZE = 65507;
    
    /**
     * 停止服务后等待EXIT_WAIT_TIME秒后还没退出则强制退出
     * @var integer
     */
    const EXIT_WAIT_TIME = 3;
    
    /**
     * 进程意外退出状态码
     * @var integer
     */ 
    const EXIT_UNEXPECT_CODE = 119;
    
    /**
     * worker的传输层协议
     * @var string
     */
    protected $protocol = "tcp";
    
    /**
     * worker监听端口的Socket
     * @var resource
     */
    protected $mainSocket = null;
    
    /**
     * worker接受的所有链接
     * @var array
     */
    protected $connections = array();
    
    /**
     * worker的所有读buffer
     * @var array
     */
    protected $recvBuffers = array();
    
    /**
     * 当前处理的fd
     * @var integer
     */
    protected $currentDealFd = 0;
    
    /**
     * UDP当前处理的客户端地址
     * @var string
     */
    protected $currentClientAddress = '';
    
    /**
     * worker的服务状态
     * @var integer
     */
    protected $workerStatus = self::STATUS_RUNNING;
    
    /**
     * 是否是长链接，(短连接每次请求后服务器主动断开，长连接一般是客户端主动断开)
     * @var bool
     */
    protected $isPersistentConnection = false;
    
    /**
     * 事件轮询库的名称
     * @var string
     */
    protected $eventLoopName ="\\WORKERMAN\\Core\\Events\\Select";
    
    /**
     * 时间轮询库实例
     * @var object
     */
    protected $event = null;
    
    /**
     * worker名称
     * @var string
     */
    protected $workerName = __CLASS__;
    
    /**
     * 该worker进程处理多少请求后退出，0表示不自动退出
     * @var integer
     */
    protected $maxRequests = 0;
    
    /**
     * 预读长度
     * @var integer
     */
    protected $prereadLength = 4;
    
    /**
     * 该进程使用的php文件
     * @var array
     */
    protected $includeFiles = array();
    
    /**
     * 统计信息
     * @var array
     */
    protected $statusInfo = array(
        'start_time'      => 0, // 该进程开始时间戳
        'total_request'   => 0, // 该进程处理的总请求数
        'recv_timeout'    => 0, // 该进程接收数据超时总数
        'proc_timeout'    => 0, // 该进程逻辑处理超时总数
        'packet_err'      => 0, // 该进程收到错误数据包的总数
        'throw_exception' => 0, // 该进程逻辑处理时收到异常的总数
        'thunder_herd'    => 0, // 该进程受惊群效应影响的总数
        'client_close'    => 0, // 客户端提前关闭链接总数
        'send_fail'       => 0, // 发送数据给客户端失败总数
    );
    
    
    /**
     * 用户worker继承此worker类必须实现该方法，根据具体协议和当前收到的数据决定是否继续收包
     * @param string $recv_str 收到的数据包
     * @return int/false 返回0表示接收完毕/>0表示还有多少字节没有接收到/false出错
     */
    abstract public function dealInput($recv_str);
    
    
    /**
     * 用户worker继承此worker类必须实现该方法，根据包中的数据处理逻辑
     * 逻辑处理
     * @param string $recv_str 收到的数据包
     * @return void
     */
    abstract public function dealProcess($recv_str);
    
    
    /**
     * 构造函数
     * @param int $port
     * @param string $ip
     * @param string $protocol
     * @return void
     */
    public function __construct($worker_name = '')
    {
        // worker name
        if(!empty($worker_name))
        {
            $this->workerName = $worker_name;
        }
        else
        {
            $this->workerName = get_class($this);
        }
        
        // 是否开启长连接
        $this->isPersistentConnection = (bool)Lib\Config::get('workers.' . $worker_name . '.socket.persistent');
        // 最大请求数，如果没有配置则使用PHP_INT_MAX
        $this->maxRequests = (int)Lib\Config::get('workers.' . $worker_name . '.max_requests');
        $this->maxRequests = $this->maxRequests <= 0 ? PHP_INT_MAX : $this->maxRequests;

        $preread_length = (int)Lib\Config::get('workers.' . $worker_name . '.preread_length');
        if($preread_length > 0)
        {
            $this->prereadLength = $preread_length;
        }
        elseif(!$this->isPersistentConnection)
        {
            $this->prereadLength = 65535;
        }
        
        // worker启动时间
        $this->statusInfo['start_time'] = time();
        
        //事件轮询库
        if(extension_loaded('libevent'))
        {
            $this->setEventLoopName('Libevent');
        }
        
        // 检查退出状态
        $this->addShutdownHook();
        
        // 初始化事件轮询库
        // $this->event = new Libevent();
        // $this->event = new Select();
        $this->event = new $this->eventLoopName();
    }
    
    
    /**
     * 让该worker实例开始服务
     *
     * @return void
     */
    public function start()
    {
        // 安装信号处理函数
        $this->installSignal();
        
        // 触发该worker进程onStart事件，该进程整个生命周期只触发一次
        if($this->onStart())
        {
            return;
        }

        if($this->protocol == 'udp')
        {
            // 添加读udp事件
            $this->event->add($this->mainSocket,  Events\BaseEvent::EV_READ, array($this, 'recvUdp'));
        }
        else
        {
            // 添加accept事件
            $ret = $this->event->add($this->mainSocket,  Events\BaseEvent::EV_READ, array($this, 'accept'));
        }
        
        // 主体循环,整个子进程会阻塞在这个函数上
        $ret = $this->event->loop();
        $this->notice("evet->loop returned " . var_export($ret, true));
        
        exit(self::EXIT_UNEXPECT_CODE);
    }
    
    /**
     * 停止服务
     * @param bool $exit 是否退出
     * @return void
     */
    public function stop($exit = true)
    {
        // 触发该worker进程onStop事件
        if($this->onStop())
        {
            return;
        }
        
        // 标记这个worker开始停止服务
        if($this->workerStatus != self::STATUS_SHUTDOWN)
        {
            // 停止接收连接
            $this->event->del($this->mainSocket, Events\BaseEvent::EV_READ);
            fclose($this->mainSocket);
            $this->workerStatus = self::STATUS_SHUTDOWN;
        }
        
        // 没有链接要处理了
        if($this->allTaskHasDone())
        {
            if($exit)
            {
                exit(0);
            }
        }
    }
    
    /**
     * 设置worker监听的socket
     * @param resource $socket
     * @return void
     */
    public function setListendSocket($socket)
    {
        // 初始化
        $this->mainSocket = $socket;
        // 设置监听socket非阻塞
        stream_set_blocking($this->mainSocket, 0);
        // 获取协议
        $mata_data = stream_get_meta_data($socket);
        $this->protocol = substr($mata_data['stream_type'], 0, 3);
        
    }
    
    /**
     * 设置worker的事件轮询库的名称
     * @param string 
     * @return void
     */
    public function setEventLoopName($event_loop_name)
    {
        $this->eventLoopName = "\\WORKERMAN\\Core\\Events\\".$event_loop_name;
        require_once WORKERMAN_ROOT_DIR . 'Core/Events/'.ucfirst(str_replace('WORKERMAN', '', $event_loop_name)).'.php';
    }
    
    /**
     * 接受一个链接
     * @param resource $socket
     * @param $null_one $flag
     * @param $null_two $base
     * @return void
     */
    public function accept($socket, $null_one = null, $null_two = null)
    {
        // 获得一个连接
        $new_connection = @stream_socket_accept($socket, 0);
        // 可能是惊群效应
        if(false === $new_connection)
        {
            $this->statusInfo['thunder_herd']++;
            return false;
        }
        
        // 接受请求数加1
        $this->statusInfo['total_request'] ++;
        
        // 连接的fd序号
        $fd = (int) $new_connection;
        $this->connections[$fd] = $new_connection;
        $this->recvBuffers[$fd] = array('buf'=>'', 'remain_len'=>$this->prereadLength);
        
        // 非阻塞
        stream_set_blocking($this->connections[$fd], 0);
        $this->event->add($this->connections[$fd], Events\BaseEvent::EV_READ , array($this, 'dealInputBase'), $fd);
        return $new_connection;
    }
    
    /**
     * 接收Udp数据 
     * 如果数据超过一个udp包长，需要业务自己解析包体，判断数据是否全部到达
     * @param resource $socket
     * @param $null_one $flag
     * @param $null_two $base
     * @return void
     */
    public function recvUdp($socket, $null_one = null, $null_two = null)
    {
         $data = stream_socket_recvfrom($socket , self::MAX_UDP_PACKEG_SIZE, 0, $address);
         // 可能是惊群效应
         if(false === $data || empty($address))
         {
             $this->statusInfo['thunder_herd']++;
             return false;
         }
         
         // 接受请求数加1
         $this->statusInfo['total_request'] ++;
         
         $this->currentClientAddress = $address;
         if(0 === $this->dealInput($data))
         {
             $this->dealProcess($data);
         }
    }
    
    /**
     * 处理受到的数据
     * @param event_buffer $event_buffer
     * @param int $fd
     * @return void
     */
    public function dealInputBase($connection, $flag, $fd = null)
    {
        $this->currentDealFd = $fd;
        $buffer = stream_socket_recvfrom($connection, $this->recvBuffers[$fd]['remain_len']);
        // 出错了
        if('' == $buffer)
        {
            if(feof($connection))
            {
                // 客户端提前断开链接
                $this->statusInfo['client_close']++;
                // 如果该链接对应的buffer有数据，说明放生错误
                if(!empty($this->recvBuffers[$fd]['buf']))
                {
                    $this->notice("CLIENT_CLOSE\nCLIENT_IP:".$this->getRemoteIp()."\nBUFFER:[".var_export($this->recvBuffers[$fd]['buf'],true)."]\n");
                }
            }
            else
            {
                // 超时了
                $this->statusInfo['recv_timeout']++;
                // 如果该链接对应的buffer有数据，说明放生错误
                if(!empty($this->recvBuffers[$fd]['buf']))
                {
                    $this->notice("RECV_TIMEOUT\nCLIENT_IP:".$this->getRemoteIp()."\nBUFFER:[".var_export($this->recvBuffers[$fd]['buf'],true)."]\n");
                }
            }
            
            // 关闭链接
            $this->closeClient($fd);
            if($this->workerStatus == self::STATUS_SHUTDOWN)
            {
                $this->stop();
            }
            return;
        }
        
        $this->recvBuffers[$fd]['buf'] .= $buffer;
        
        $remain_len = $this->dealInput($this->recvBuffers[$fd]['buf']);
        // 包接收完毕
        if(0 === $remain_len)
        {
            // 执行处理
            try{
                // 业务处理
                $this->dealProcess($this->recvBuffers[$fd]['buf']);
            }
            catch(\Exception $e)
            {
                // 关闭闹钟
                //pcntl_alarm(0);
                $this->notice('CODE:' . $e->getCode() . ' MESSAGE:' . $e->getMessage()."\n".$e->getTraceAsString()."\nCLIENT_IP:".$this->getRemoteIp()."\nBUFFER:[".var_export($this->recvBuffers[$fd]['buf'],true)."]\n");
                $this->statusInfo['throw_exception'] ++;
                $this->sendToClient($e->getMessage());
            }
            
            // 是否是长连接
            if($this->isPersistentConnection)
            {
                // 清空缓冲buffer
                $this->recvBuffers[$fd] = array('buf'=>'', 'remain_len'=>$this->prereadLength);
            }
            else
            {
                // 关闭链接
                $this->closeClient($fd);
            }
        }
        // 出错
        else if(false === $remain_len)
        {
            // 出错
            $this->statusInfo['packet_err']++;
            $this->sendToClient('packet_err:'.$this->recvBuffers[$fd]['buf']);
            $this->notice("PACKET_ERROR\nCLIENT_IP:".$this->getRemoteIp()."\nBUFFER:[".var_export($this->recvBuffers[$fd]['buf'],true)."]\n");
            $this->closeClient($fd);
        }
        else 
        {
            $this->recvBuffers[$fd]['remain_len'] = $remain_len;
        }

        // 检查是否是关闭状态或者是否到达请求上限
        if($this->workerStatus == self::STATUS_SHUTDOWN || $this->statusInfo['total_request'] >= $this->maxRequests)
        {
            // 关闭链接
            if($this->isPersistentConnection)
            {
                $this->closeClient($fd);
            }
            // 停止服务
            $this->stop();
            // EXIT_WAIT_TIME秒后退出进程
            pcntl_alarm(self::EXIT_WAIT_TIME);
        }
    }
    
    /**
     * 根据fd关闭链接
     * @param int $fd
     * @return void
     */
    protected function closeClient($fd)
    {
        // udp忽略
        if($this->protocol != 'udp')
        {
            $this->event->del($this->connections[$fd], Events\BaseEvent::EV_READ);
            fclose($this->connections[$fd]);
            unset($this->connections[$fd], $this->recvBuffers[$fd]);
        }
    }
    
    /**
     * 安装信号处理函数
     * @return void
     */
    protected function installSignal()
    {
        // 如果是由worker脚本启动则不安装信号
        if(!defined('WORKERMAN_PID_FILE'))
        {
            return;
        }
        
        // 闹钟信号
        $this->event->add(SIGALRM, Events\BaseEvent::EV_SIGNAL, array($this, 'signalHandler'), SIGALRM);
        // 终止进程信号
        $this->event->add(SIGINT, Events\BaseEvent::EV_SIGNAL, array($this, 'signalHandler'), SIGINT);
        // 平滑重启信号
        $this->event->add(SIGHUP, Events\BaseEvent::EV_SIGNAL, array($this, 'signalHandler'), SIGHUP);
        // 报告进程状态
        $this->event->add(SIGUSR1, Events\BaseEvent::EV_SIGNAL, array($this, 'signalHandler'), SIGUSR1);
        // 报告该进程使用的文件
        $this->event->add(SIGUSR2, Events\BaseEvent::EV_SIGNAL, array($this, 'signalHandler'), SIGUSR2);
        
        // 设置忽略信号
        pcntl_signal(SIGTTIN, SIG_IGN);
        pcntl_signal(SIGTTOU, SIG_IGN);
        pcntl_signal(SIGQUIT, SIG_IGN);
        pcntl_signal(SIGPIPE, SIG_IGN);
        pcntl_signal(SIGCHLD, SIG_IGN);
    }
    
    /**
     * 设置server信号处理函数
     * @param null $null
     * @param int $signal
     */
    public function signalHandler($signal, $null = null, $null = null)
    {
        switch($signal)
        {
            // 时钟处理函数
            case SIGALRM:
                // 停止服务后EXIT_WAIT_TIME秒还没退出则强制退出
                if($this->workerStatus == self::STATUS_SHUTDOWN)
                {
                    exit(0);
                }
                break;
            // 停止该进程
            case SIGINT:
            // 平滑重启
            case SIGHUP:
                $this->stop();
                // EXIT_WAIT_TIME秒后退出进程
                pcntl_alarm(self::EXIT_WAIT_TIME);
                break;
            // 报告进程状态
            case SIGUSR1:
                $this->writeStatusToQueue();
                break;
            // 报告进程使用的php文件
            case SIGUSR2:
                $this->writeFilesListToQueue();
                break;
        }
    }
    
    /**
     * 发送数据到客户端
     * @return bool
     */
    public function sendToClient($str_to_send)
    {
        // tcp
        if($this->protocol != 'udp')
        {
            // tcp 如果一次没写完（一般是缓冲区满的情况），则阻塞写
            if(!$this->blockWrite($this->connections[$this->currentDealFd], $str_to_send, 500))
            {
                $this->notice('sendToClient fail ,Data length = ' . strlen($str_to_send));
                $this->statusInfo['send_fail']++;
                return false;
            }
            return true;
        }
        // udp 直接发送，要求数据包不能超过65515
        $len = stream_socket_sendto($this->mainSocket, $str_to_send, 0, $this->currentClientAddress);
        return $len == strlen($str_to_send);
    }
    
    /**
     * 向fd写数据，如果socket缓冲区满了，则改用阻塞模式写数据
     * @param resource $fd
     * @param string $str_to_write
     * @param int $time_out 单位毫秒
     * @return bool
     */
    protected function blockWrite($fd, $str_to_write, $timeout_ms = 500)
    {
        $send_len = @fwrite($fd, $str_to_write);
        if($send_len == strlen($str_to_write))
        {
            return true;
        }
        
        // 客户端关闭
        if(feof($fd))
        {
            $this->notice("blockWrite client close");
            return false;
        }
        
        // 设置阻塞
        stream_set_blocking($fd, 1);
        // 设置超时
        $timeout_sec = floor($timeout_ms/1000);
        $timeout_ms = $timeout_ms%1000;
        stream_set_timeout($fd, $timeout_sec, $timeout_ms*1000);
        $send_len += @fwrite($fd, substr($str_to_write, $send_len));
        // 改回非阻塞
        stream_set_blocking($fd, 0);
        
        return $send_len == strlen($str_to_write);
    }
    
    /**
     * 获取客户端ip
     * @param int $fd 已经链接的socket id
     * @return string
     */
    public function getRemoteIp($fd = null)
    {
        if(empty($fd))
        {
            if(!isset($this->connections[$this->currentDealFd]))
            {
                return '0.0.0.0';
            }
            $fd = $this->currentDealFd;
        }
        
        $ip = '';
        if($this->protocol == 'udp')
        {
            $sock_name = $this->currentClientAddress;
        }
        else
        {
            $sock_name = stream_socket_get_name($this->connections[$fd], true);
        }
        
        if($sock_name)
        {
            $tmp = explode(':', $sock_name);
            $ip = $tmp[0];
        }
        
        return $ip;
    }
    
    /**
     * 获取本地ip
     * @return string 
     */
    public function getLocalIp()
    {
        $ip = '';
        $sock_name = '';
        if($this->protocol == 'udp' || !isset($this->connections[$this->currentDealFd]))
        {
            $sock_name = stream_socket_get_name($this->mainSocket, false);
        }
        else
        {
            $sock_name = stream_socket_get_name($this->connections[$this->currentDealFd], false);
        }
        
        if($sock_name)
        {
            $tmp = explode(':', $sock_name);
            $ip = $tmp[0];
        }
        
        if(empty($ip) || '127.0.0.1' == $ip)
        {
            $ip = gethostbyname(trim(`hostname`));
        }
        
        return $ip;
    }
    
    /**
     * 将当前worker进程状态写入消息队列
     * @return void
     */
    protected function writeStatusToQueue()
    {
        if(!Master::getQueueId())
        {
            return;
        }
        $error_code = 0;
        msg_send(Master::getQueueId(), self::MSG_TYPE_STATUS, array_merge($this->statusInfo, array('memory'=>memory_get_usage(true), 'pid'=>posix_getpid(), 'worker_name' => $this->workerName)), true, false, $error_code);
    }
    
    /**
     * 开发环境将当前进程使用的文件写入消息队列,用于FileMonitor监控文件更新
     * @return void
     */
    protected function writeFilesListToQueue()
    {
        if(!Master::getQueueId())
        {
            return;
        }
        $error_code = 0;
        $flip_file_list = array_flip(get_included_files());
        $file_list = array_diff_key($flip_file_list, $this->includeFiles);
        $this->includeFiles = $flip_file_list;
        if($file_list)
        {
            msg_send(Master::getQueueId(), self::MSG_TYPE_FILE_MONITOR, array_keys($file_list), true, false, $error_code);
        }
    }
    
    /**
     * 是否所有任务都已经完成
     * @return bool
     */
    protected function allTaskHasDone()
    {
        // 如果是长链接并且没有要处理的数据则是任务都处理完了
        return $this->noConnections() || ($this->isPersistentConnection && $this->allBufferIsEmpty());
    }
    
    /**
     * 检查是否所有的链接的缓冲区都是空
     * @return bool
     */
    protected function allBufferIsEmpty()
    {
        foreach($this->recvBuffers as $fd => $buf)
        {
            if(!empty($buf['buf']))
            {
                return false;
            }
        }
        return true;
    }
    
    /**
     * 该进程收到的任务是否都已经完成，重启进程时需要判断
     * @return bool
     */
    protected function noConnections()
    {
        return empty($this->connections);
    }
    
    
    /**
     * 该worker进程开始服务的时候会触发一次，可以在这里做一些全局的事情
     * @return bool
     */
    protected function onStart()
    {
        return false;
    }
    
    /**
     * 该worker进程停止服务的时候会触发一次，可以在这里做一些全局的事情
     * @return bool
     */
    protected function onStop()
    {
        return false;
    }
    
}