Refactor duplicated error handler

For extensions of qdb the default error handler (start server and try again)
which was used for askDevices and watchDevices is used very often. In order
to not duplicate this function for every additional command the same function
is reused.

Change-Id: I469ccf6955c5590e295d9182a80cdfb3a4dfbcd0
Reviewed-by: Kari Oikarinen <kari.oikarinen@qt.io>
Reviewed-by: Samuli Piippo <samuli.piippo@qt.io>

2 files changed, 8 insertions, 31 deletions

diff --git a/qdb/client/client.cpp b/qdb/client/client.cpp
index 953919f..f3687a2 100644
--- a/qdb/client/client.cpp
+++ b/qdb/client/client.cpp
@@ -85,7 +85,7 @@ void Client::ignoreErrors(bool ignoreErrors)
 
 void Client::askDevices()
 {
-    setupSocketAndConnect(&Client::handleDevicesConnection, &Client::handleDevicesError);
+    setupSocketAndConnect(&Client::handleDevicesConnection, std::bind(&Client::handleErrorWithRetry, this, std::placeholders::_1, &Client::askDevices));
 }
 
 void Client::startServer()
@@ -96,12 +96,12 @@ void Client::startServer()
 
 void Client::stopServer()
 {
-    setupSocketAndConnect(&Client::handleStopConnection, &Client::handleStopError);
+    setupSocketAndConnect(&Client::handleStopConnection, std::bind(&Client::handleStopError, this, std::placeholders::_1));
 }
 
 void Client::watchDevices()
 {
-    setupSocketAndConnect(&Client::handleWatchConnection, &Client::handleWatchError);
+    setupSocketAndConnect(&Client::handleWatchConnection, std::bind(&Client::handleErrorWithRetry, this, std::placeholders::_1, &Client::watchDevices));
 }
 
 void Client::handleDevicesConnection()
@@ -121,7 +121,7 @@ void Client::handleDevicesConnection()
     shutdown(0);
 }
 
-void Client::handleDevicesError(QLocalSocket::LocalSocketError error)
+void Client::handleErrorWithRetry(QLocalSocket::LocalSocketError error, ConnectedSlot repeatFunction)
 {
     if (error == QLocalSocket::PeerClosedError)
         return;
@@ -141,7 +141,7 @@ void Client::handleDevicesError(QLocalSocket::LocalSocketError error)
     std::cout << "Starting QDB host server\n";
     m_triedToStart = true;
     forkHostServer();
-    QTimer::singleShot(startupDelay, this, &Client::askDevices);
+    QTimer::singleShot(startupDelay, this, repeatFunction);
 }
 
 void Client::handleStopConnection()
@@ -180,29 +180,6 @@ void Client::handleWatchConnection()
     m_socket->write(createRequest(RequestType::WatchDevices));
 }
 
-void Client::handleWatchError(QLocalSocket::LocalSocketError error)
-{
-    if (error == QLocalSocket::PeerClosedError)
-        return;
-    if (error != QLocalSocket::ServerNotFoundError &&
-            error != QLocalSocket::ConnectionRefusedError) {
-        std::cerr << "Unexpected QLocalSocket error:" << qUtf8Printable(m_socket->errorString())
-                  << std::endl;
-        shutdown(1);
-        return;
-    }
-
-    if (m_triedToStart) {
-        std::cerr << "Could not connect QDB host server even after trying to start it\n";
-        shutdown(1);
-        return;
-    }
-    std::cout << "Starting QDB host server\n";
-    m_triedToStart = true;
-    forkHostServer();
-    QTimer::singleShot(startupDelay, this, &Client::watchDevices);
-}
-
 void Client::handleWatchMessage()
 {
     while (m_socket->bytesAvailable() > 0) {
diff --git a/qdb/client/client.h b/qdb/client/client.h
index eccc607..482641c 100644
--- a/qdb/client/client.h
+++ b/qdb/client/client.h
@@ -36,6 +36,7 @@ class QCoreApplication;
 QT_END_NAMESPACE
 
 #include <memory>
+#include <functional>
 
 int execClient(const QCoreApplication &app, const QString &command, const QCommandLineParser &parser);
 
@@ -55,14 +56,13 @@ public slots:
 
 private:
     using ConnectedSlot = void (Client::*)();
-    using ErrorSlot = void (Client::*)(QLocalSocket::LocalSocketError);
+    using ErrorSlot = std::function<void(QLocalSocket::LocalSocketError)>;
 
     void handleDevicesConnection();
-    void handleDevicesError(QLocalSocket::LocalSocketError error);
+    void handleErrorWithRetry(QLocalSocket::LocalSocketError error, ConnectedSlot repeatFunction);
     void handleStopConnection();
     void handleStopError(QLocalSocket::LocalSocketError error);
     void handleWatchConnection();
-    void handleWatchError(QLocalSocket::LocalSocketError error);
     void handleWatchMessage();
     void setupSocketAndConnect(ConnectedSlot handleConnection, ErrorSlot handleError);
     void shutdown(int exitCode);