http服务器实现后台线程读取数据

src/Http/HttpSession.cpp

@@ -308,6 +308,79 @@ static string dateStr() {
     return buf;
 }
 
+class AsyncSenderData {
+public:
+    friend class AsyncSender;
+    typedef std::shared_ptr<AsyncSenderData> Ptr;
+    AsyncSenderData(const TcpSession::Ptr &session, const HttpBody::Ptr &body, bool close_when_complete) {
+        _session = dynamic_pointer_cast<HttpSession>(session);
+        _body = body;
+        _close_when_complete = close_when_complete;
+    }
+    ~AsyncSenderData() = default;
+private:
+    std::weak_ptr<HttpSession> _session;
+    HttpBody::Ptr _body;
+    bool _close_when_complete;
+    bool _read_complete = false;
+};
+
+class AsyncSender {
+public:
+    typedef std::shared_ptr<AsyncSender> Ptr;
+    static bool onSocketFlushed(const AsyncSenderData::Ptr &data) {
+        if (data->_read_complete) {
+            if (data->_close_when_complete) {
+                //发送完毕需要关闭socket
+                shutdown(data->_session.lock());
+            }
+            return false;
+        }
+
+        GET_CONFIG(uint32_t, sendBufSize, Http::kSendBufSize);
+        data->_body->readDataAsync(sendBufSize, [data](const Buffer::Ptr &sendBuf) {
+            auto session = data->_session.lock();
+            if (!session) {
+                //本对象已经销毁
+                return;
+            }
+            session->async([data, sendBuf]() {
+                auto session = data->_session.lock();
+                if (!session) {
+                    //本对象已经销毁
+                    return;
+                }
+                onRequestData(data, session, sendBuf);
+            }, false);
+        });
+        return true;
+    }
+
+private:
+    static void onRequestData(const AsyncSenderData::Ptr &data, const std::shared_ptr<HttpSession> &session, const Buffer::Ptr &sendBuf) {
+        session->_ticker.resetTime();
+        if (sendBuf && session->send(sendBuf) != -1) {
+            //文件还未读完，还需要继续发送
+            if (!session->isSocketBusy()) {
+                //socket还可写，继续请求数据
+                onSocketFlushed(data);
+            }
+            return;
+        }
+        //文件写完了
+        data->_read_complete = true;
+        if (!session->isSocketBusy() && data->_close_when_complete) {
+            shutdown(session);
+        }
+    }
+
+    static void shutdown(const std::shared_ptr<HttpSession> &session) {
+        if(session){
+            session->shutdown(SockException(Err_shutdown, StrPrinter << "close connection after send http body completed."));
+        }
+    }
+};
+
 static const string kDate = "Date";
 static const string kServer = "Server";
 static const string kConnection = "Connection";
@@ -401,60 +474,18 @@ void HttpSession::sendResponse(const char *pcStatus,
         return;
     }
 
-    //发送http body
-    GET_CONFIG(uint32_t,sendBufSize,Http::kSendBufSize);
-    weak_ptr<HttpSession> weakSelf = dynamic_pointer_cast<HttpSession>(shared_from_this());
-
-    string status_code = pcStatus;
-    auto onFlush = [body,bClose,weakSelf,status_code]() {
-        auto strongSelf = weakSelf.lock();
-        if(!strongSelf){
-            //本对象已经销毁
-            return false;
-        }
-        while(true){
-            //更新超时计时器
-            strongSelf->_ticker.resetTime();
-            //读取文件
-            auto sendBuf = body->readData(sendBufSize);
-            if (!sendBuf) {
-                //文件读完
-                if(strongSelf->isSocketBusy() && bClose){
-                    //套接字忙,我们等待触发下一次onFlush事件
-                    //待所有数据flush到socket fd再移除onFlush事件监听
-                    //标记文件读写完毕
-                    return true;
-                }
-                //文件全部flush到socket fd，可以直接关闭socket了
-                break;
-            }
-
-            //文件还未读完
-            if(strongSelf->send(sendBuf) == -1) {
-                //socket已经销毁，不再监听onFlush事件
-                return false;
-            }
-            if(strongSelf->isSocketBusy()){
-                //socket忙，那么停止继续写,等待下一次onFlush事件，然后再读文件写socket
-                return true;
-            }
-            //socket还可写，继续写socket
-        }
-
-        if(bClose) {
-            //最后一次flush事件，文件也发送完毕了，可以关闭socket了
-            strongSelf->shutdown(SockException(Err_shutdown, StrPrinter << "close connection after send http body completed with status code:" << status_code));
-        }
-        //不再监听onFlush事件
-        return false;
-    };
-
+    GET_CONFIG(uint32_t, sendBufSize, Http::kSendBufSize);
     if(body->remainSize() > sendBufSize){
         //文件下载提升发送性能
         setSocketFlags();
     }
-    onFlush();
-    _sock->setOnFlush(onFlush);
+
+    //发送http body
+    AsyncSenderData::Ptr data = std::make_shared<AsyncSenderData>(shared_from_this(),body,bClose);
+    _sock->setOnFlush([data](){
+        return AsyncSender::onSocketFlushed(data);
+    });
+    AsyncSender::onSocketFlushed(data);
 }
 
 string HttpSession::urlDecode(const string &str){