Remove waitForReadyRead from QWebSocketFrame::readFrame

Asynchronously process socket frame in QWebSocketDataProcessor::process.
If the processing of QWebSocketFrame is not done and waiting for more
data, QWebSocketDataProcessor::process will return the control and wait
for next readyRead signal to continue processing the unfinished socket
frame. QWebSocketDataProcessor::process gets timeout after 5 seconds,
and then an errorEncountered signal will be emitted.

Fixes: QTBUG-74464
Change-Id: I03b7f874c1c266617e7eadf59c59ae43fa8540ce
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

5 files changed, 56 insertions, 36 deletions

diff --git a/src/websockets/qwebsocket_p.cpp b/src/websockets/qwebsocket_p.cpp
index 6965731..9b94d04 100644
--- a/src/websockets/qwebsocket_p.cpp
+++ b/src/websockets/qwebsocket_p.cpp
@@ -1173,10 +1173,10 @@ void QWebSocketPrivate::processData()
 {
     if (!m_pSocket) // disconnected with data still in-bound
         return;
-    while (m_pSocket->bytesAvailable()) {
+    if (m_pSocket->bytesAvailable()) {
         if (state() == QAbstractSocket::ConnectingState) {
             if (!m_pSocket->canReadLine())
-                break;
+                return;
             processHandshake(m_pSocket);
         } else {
             m_dataProcessor.process(m_pSocket);
diff --git a/src/websockets/qwebsocketdataprocessor.cpp b/src/websockets/qwebsocketdataprocessor.cpp
index ee28969..39287d4 100644
--- a/src/websockets/qwebsocketdataprocessor.cpp
+++ b/src/websockets/qwebsocketdataprocessor.cpp
@@ -87,6 +87,10 @@ QWebSocketDataProcessor::QWebSocketDataProcessor(QObject *parent) :
     m_pTextCodec(QTextCodec::codecForName("UTF-8"))
 {
     clear();
+    // initialize the internal timeout timer
+    waitTimer.setInterval(5000);
+    waitTimer.setSingleShot(true);
+    waitTimer.callOnTimeout(this, &QWebSocketDataProcessor::timeout);
 }
 
 /*!
@@ -126,7 +130,13 @@ void QWebSocketDataProcessor::process(QIODevice *pIoDevice)
 
     while (!isDone) {
         frame.readFrame(pIoDevice);
-        if (Q_LIKELY(frame.isValid())) {
+        if (!frame.isDone()) {
+            // waiting for more data available
+            QObject::connect(pIoDevice, &QIODevice::readyRead,
+                             &waitTimer, &QTimer::stop, Qt::UniqueConnection);
+            waitTimer.start();
+            return;
+        } else if (Q_LIKELY(frame.isValid())) {
             if (frame.isControlFrame()) {
                 isDone = processControlFrame(frame);
             } else {
@@ -302,4 +312,14 @@ bool QWebSocketDataProcessor::processControlFrame(const QWebSocketFrame &frame)
     return mustStopProcessing;
 }
 
+/*!
+    \internal
+ */
+void QWebSocketDataProcessor::timeout()
+{
+    clear();
+    Q_EMIT errorEncountered(QWebSocketProtocol::CloseCodeGoingAway,
+                            tr("Timeout when reading data from socket."));
+}
+
 QT_END_NAMESPACE
diff --git a/src/websockets/qwebsocketdataprocessor_p.h b/src/websockets/qwebsocketdataprocessor_p.h
index 1d8024e..41226d6 100644
--- a/src/websockets/qwebsocketdataprocessor_p.h
+++ b/src/websockets/qwebsocketdataprocessor_p.h
@@ -55,6 +55,7 @@
 #include <QtCore/QByteArray>
 #include <QtCore/QString>
 #include <QtCore/QTextCodec>
+#include <QTimer>
 #include "qwebsocketframe_p.h"
 #include "qwebsocketprotocol.h"
 #include "qwebsocketprotocol_p.h"
@@ -113,8 +114,10 @@ private:
     QTextCodec::ConverterState *m_pConverterState;
     QTextCodec *m_pTextCodec;
     QWebSocketFrame frame;
+    QTimer waitTimer;
 
     bool processControlFrame(const QWebSocketFrame &frame);
+    void timeout();
 };
 
 QT_END_NAMESPACE
diff --git a/src/websockets/qwebsocketframe.cpp b/src/websockets/qwebsocketframe.cpp
index 5b10e02..11373a7 100644
--- a/src/websockets/qwebsocketframe.cpp
+++ b/src/websockets/qwebsocketframe.cpp
@@ -188,7 +188,7 @@ void QWebSocketFrame::swap(QWebSocketFrame &other)
  */
 QWebSocketProtocol::CloseCode QWebSocketFrame::closeCode() const
 {
-    return m_closeCode;
+    return isDone() ? m_closeCode : QWebSocketProtocol::CloseCodeGoingAway;
 }
 
 /*!
@@ -196,7 +196,7 @@ QWebSocketProtocol::CloseCode QWebSocketFrame::closeCode() const
  */
 QString QWebSocketFrame::closeReason() const
 {
-    return m_closeReason;
+    return isDone() ? m_closeReason : tr("Waiting for more data from socket.");
 }
 
 /*!
@@ -289,67 +289,63 @@ void QWebSocketFrame::clear()
  */
 bool QWebSocketFrame::isValid() const
 {
-    return m_isValid;
+    return isDone() && m_isValid;
 }
 
-#define WAIT_FOR_MORE_DATA(returnState)  \
-    { needMoreData = true; \
-      m_processingState = (returnState); }
+/*!
+    \internal
+ */
+bool QWebSocketFrame::isDone() const
+{
+    return m_processingState == PS_DISPATCH_RESULT;
+}
 
 /*!
     \internal
  */
 void QWebSocketFrame::readFrame(QIODevice *pIoDevice)
 {
-    bool isDone = false;
-    while (!isDone)
+    while (true)
     {
-        bool needMoreData = false;
         switch (m_processingState) {
         case PS_READ_HEADER:
             m_processingState = readFrameHeader(pIoDevice);
-            if (m_processingState == PS_WAIT_FOR_MORE_DATA)
-                WAIT_FOR_MORE_DATA(PS_READ_HEADER);
+            if (m_processingState == PS_WAIT_FOR_MORE_DATA) {
+                m_processingState = PS_READ_HEADER;
+                return;
+            }
             break;
 
         case PS_READ_PAYLOAD_LENGTH:
             m_processingState = readFramePayloadLength(pIoDevice);
-            if (m_processingState == PS_WAIT_FOR_MORE_DATA)
-                WAIT_FOR_MORE_DATA(PS_READ_PAYLOAD_LENGTH);
+            if (m_processingState == PS_WAIT_FOR_MORE_DATA) {
+                m_processingState = PS_READ_PAYLOAD_LENGTH;
+                return;
+            }
             break;
 
         case PS_READ_MASK:
             m_processingState = readFrameMask(pIoDevice);
-            if (m_processingState == PS_WAIT_FOR_MORE_DATA)
-                WAIT_FOR_MORE_DATA(PS_READ_MASK);
+            if (m_processingState == PS_WAIT_FOR_MORE_DATA) {
+                m_processingState = PS_READ_MASK;
+                return;
+            }
             break;
 
         case PS_READ_PAYLOAD:
             m_processingState = readFramePayload(pIoDevice);
-            if (m_processingState == PS_WAIT_FOR_MORE_DATA)
-                WAIT_FOR_MORE_DATA(PS_READ_PAYLOAD);
+            if (m_processingState == PS_WAIT_FOR_MORE_DATA) {
+                m_processingState = PS_READ_PAYLOAD;
+                return;
+            }
             break;
 
         case PS_DISPATCH_RESULT:
-            m_processingState = PS_DISPATCH_RESULT;
-            isDone = true;
-            break;
+            return;
 
         default:
             Q_UNREACHABLE();
-            break;
-        }
-
-        if (needMoreData) {
-            // TODO: waitForReadyRead should really be changed
-            // now, when a WebSocket is used in a GUI thread
-            // the GUI will hang for at most 5 seconds
-            // maybe, a QStateMachine should be used
-            if (!pIoDevice->waitForReadyRead(5000)) {
-                setError(QWebSocketProtocol::CloseCodeGoingAway,
-                         tr("Timeout when reading data from socket."));
-                m_processingState = PS_DISPATCH_RESULT;
-            }
+            return;
         }
     }
 }
diff --git a/src/websockets/qwebsocketframe_p.h b/src/websockets/qwebsocketframe_p.h
index be79a6e..e2b4e9f 100644
--- a/src/websockets/qwebsocketframe_p.h
+++ b/src/websockets/qwebsocketframe_p.h
@@ -101,6 +101,7 @@ public:
     void clear();
 
     bool isValid() const;
+    bool isDone() const;
 
     void readFrame(QIODevice *pIoDevice);