From 7b673a0d57c1e6604088d1d5642945c386facf4b Mon Sep 17 00:00:00 2001
From: "Srivats P." <pstavirs@gmail.com>
Date: Sat, 25 Dec 2010 12:02:14 +0530
Subject: [PATCH] Implemented auto-reconnect for portgroups

---
 client/mainwindow.cpp |  2 --
 client/portgroup.cpp  | 32 ++++++++++++++++++++++++++++++++
 client/portgroup.h    | 13 ++++++++++---
 3 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/client/mainwindow.cpp b/client/mainwindow.cpp
index 291865f..623624f 100644
--- a/client/mainwindow.cpp
+++ b/client/mainwindow.cpp
@@ -56,8 +56,6 @@ MainWindow::MainWindow(QWidget *parent)
     localServer_ = new QProcess(this);
     localServer_->setProcessChannelMode(QProcess::ForwardedChannels);
     localServer_->start(serverApp, QStringList());
-    // TODO: waitForReadyRead() is a kludge till we implement auto-retry!
-    localServer_->waitForReadyRead(1000);
 
     pgl = new PortGroupList;
 
diff --git a/client/portgroup.cpp b/client/portgroup.cpp
index faa1f0a..43e68a3 100644
--- a/client/portgroup.cpp
+++ b/client/portgroup.cpp
@@ -27,6 +27,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 #include <QMessageBox>
 #include <QProcess>
 #include <QTemporaryFile>
+#include <QTimer>
 #include <QtGlobal>
 
 using ::google::protobuf::NewCallback;
@@ -46,6 +47,13 @@ PortGroup::PortGroup(QHostAddress ip, quint16 port)
     statsController = new PbRpcController(portIdList_, portStatsList_);
     isGetStatsPending_ = false;
 
+    reconnect = false;
+    reconnectAfter = kMinReconnectWaitTime;
+    reconnectTimer = new QTimer(this);
+    reconnectTimer->setSingleShot(true);
+    connect(reconnectTimer, SIGNAL(timeout()), 
+        this, SLOT(on_reconnectTimer_timeout()));
+
     rpcChannel = new PbRpcChannel(ip, port);
     serviceStub = new OstProto::OstService::Stub(rpcChannel);
 
@@ -75,6 +83,15 @@ PortGroup::~PortGroup()
 // ------------------------------------------------
 //                      Slots
 // ------------------------------------------------
+void PortGroup::on_reconnectTimer_timeout()
+{
+    reconnectAfter *= 2;
+    if (reconnectAfter > kMaxReconnectWaitTime)
+        reconnectAfter = kMaxReconnectWaitTime;
+
+    connectToHost();
+}
+
 void PortGroup::on_rpcChannel_stateChanged(QAbstractSocket::SocketState state)
 {
     qDebug("state changed %d", state);
@@ -98,6 +115,8 @@ void PortGroup::on_rpcChannel_connected()
     qDebug("connected\n");
     emit portGroupDataChanged(mPortGroupId);
 
+    reconnectAfter = kMinReconnectWaitTime;
+
     qDebug("requesting portlist ...");
     
     PbRpcController *controller = new PbRpcController(void_, portIdList);
@@ -115,12 +134,25 @@ void PortGroup::on_rpcChannel_disconnected()
 
     emit portListChanged(mPortGroupId);
     emit portGroupDataChanged(mPortGroupId);
+
+    if (reconnect)
+    {
+        qDebug("starting reconnect timer for %d ms ...", reconnectAfter);
+        reconnectTimer->start(reconnectAfter);
+    }
 }
 
 void PortGroup::on_rpcChannel_error(QAbstractSocket::SocketError socketError)
 {
     qDebug("%s: error %d", __FUNCTION__, socketError);
     emit portGroupDataChanged(mPortGroupId);
+
+    qDebug("%s: state %d", __FUNCTION__, rpcChannel->state());
+    if ((rpcChannel->state() == QAbstractSocket::UnconnectedState) && reconnect)
+    {
+        qDebug("starting reconnect timer for %d ms...", reconnectAfter);
+        reconnectTimer->start(reconnectAfter);
+    }
 }
 
 void PortGroup::processPortIdList(PbRpcController *controller)
diff --git a/client/portgroup.h b/client/portgroup.h
index dbf831c..8261576 100644
--- a/client/portgroup.h
+++ b/client/portgroup.h
@@ -37,6 +37,7 @@ LOW
 #define DEFAULT_SERVER_PORT        7878
 
 class QFile;
+class QTimer;
 
 class PortGroup : public QObject {
     Q_OBJECT
@@ -46,6 +47,11 @@ private:
     quint32        mPortGroupId;
     QString        mUserAlias;            // user defined
 
+    bool            reconnect;
+    int             reconnectAfter;     // time in milliseconds
+    static const int kMinReconnectWaitTime = 2000; // ms
+    static const int kMaxReconnectWaitTime = 60000; // ms
+    QTimer          *reconnectTimer;
     PbRpcChannel    *rpcChannel;
     PbRpcController *statsController;
     bool            isGetStatsPending_;
@@ -63,10 +69,10 @@ public:
         quint16 port = DEFAULT_SERVER_PORT); 
     ~PortGroup();
 
-    void connectToHost() { rpcChannel->establish(); }
+    void connectToHost() { reconnect = true; rpcChannel->establish(); }
     void connectToHost(QHostAddress ip, quint16 port) 
-        { rpcChannel->establish(ip, port); }
-    void disconnectFromHost() { rpcChannel->tearDown(); }
+        { reconnect = true; rpcChannel->establish(ip, port); }
+    void disconnectFromHost() { reconnect = false; rpcChannel->tearDown(); }
 
     int numPorts() const { return mPorts.size(); }
     quint32 id() const { return mPortGroupId; } 
@@ -123,6 +129,7 @@ signals:
     void statsChanged(quint32 portGroupId);
 
 private slots:
+    void on_reconnectTimer_timeout();
     void on_rpcChannel_stateChanged(QAbstractSocket::SocketState state);
     void on_rpcChannel_connected();
     void on_rpcChannel_disconnected();