Automatically migrate in-progress transfers after roaming.

Automatically migrate in-progress transfers after roaming to a new
access point for backends that support it. Currently only works for http
transfers that do not upload data (i.e. HTTP GET).

4 files changed, 31 insertions, 47 deletions

diff --git a/src/network/access/qnetworkaccessmanager.cpp b/src/network/access/qnetworkaccessmanager.cpp
index 617e398..8df580d 100644
--- a/src/network/access/qnetworkaccessmanager.cpp
+++ b/src/network/access/qnetworkaccessmanager.cpp
@@ -802,27 +802,6 @@ void QNetworkAccessManagerPrivate::_q_replyFinished()
     QNetworkReply *reply = qobject_cast<QNetworkReply *>(q->sender());
     if (reply)
         emit q->finished(reply);
-
-    if (session && deferredMigration) {
-        foreach (QObject *child, q->children()) {
-            if (child == reply)
-                continue;
-
-            QNetworkReplyImpl *replyImpl = qobject_cast<QNetworkReplyImpl *>(child);
-            if (!replyImpl)
-                continue;
-
-            QNetworkReplyImplPrivate::State state = replyImpl->d_func()->state;
-            if (state == QNetworkReplyImplPrivate::Buffering ||
-                state == QNetworkReplyImplPrivate::Working) {
-                return;
-            }
-        }
-
-        deferredMigration = false;
-        qDebug() << "Migrating as there are no pending replies.";
-        session->migrate();
-    }
 }
 
 void QNetworkAccessManagerPrivate::_q_replySslErrors(const QList<QSslError> &errors)
@@ -1136,6 +1115,7 @@ void QNetworkAccessManagerPrivate::_q_sessionNewConfigurationActivated()
 {
     Q_Q(QNetworkAccessManager);
 
+#if 0
     foreach (QObject *child, q->children()) {
         QNetworkReplyImpl *reply = qobject_cast<QNetworkReplyImpl *>(child);
         if (reply) {
@@ -1151,6 +1131,7 @@ void QNetworkAccessManagerPrivate::_q_sessionNewConfigurationActivated()
             }
         }
     }
+#endif
 
     qDebug() << "Accepting new configuration.";
     session->accept();
@@ -1183,18 +1164,10 @@ void QNetworkAccessManagerPrivate::_q_sessionPreferredConfigurationChanged(const
 
     foreach (QObject *child, q->children()) {
         QNetworkReplyImpl *replyImpl = qobject_cast<QNetworkReplyImpl *>(child);
-        if (replyImpl) {
-            QNetworkReplyImplPrivate::State state = replyImpl->d_func()->state;
-            if (state == QNetworkReplyImplPrivate::Buffering ||
-                state == QNetworkReplyImplPrivate::Working) {
-                deferredMigration = true;
-                return;
-            }
-        }
+        if (replyImpl)
+            replyImpl->migrateBackend();
     }
 
-    deferredMigration = false;
-    qDebug() << "Migrating as there are no pending replies.";
     session->migrate();
 }
 
diff --git a/src/network/access/qnetworkaccessmanager_p.h b/src/network/access/qnetworkaccessmanager_p.h
index 92b2782..e916158 100644
--- a/src/network/access/qnetworkaccessmanager_p.h
+++ b/src/network/access/qnetworkaccessmanager_p.h
@@ -76,8 +76,7 @@ public:
           proxyFactory(0),
 #endif
           cookieJarCreated(false),
-          session(0),
-          deferredMigration(false)
+          session(0)
     { }
     ~QNetworkAccessManagerPrivate();
 
@@ -131,7 +130,6 @@ public:
     bool cookieJarCreated;
 
     QNetworkSession *session;
-    bool deferredMigration;
 
     // this cache can be used by individual backends to cache e.g. their TCP connections to a server
     // and use the connections for multiple requests.
diff --git a/src/network/access/qnetworkreplyimpl.cpp b/src/network/access/qnetworkreplyimpl.cpp
index 0c7aca8..9721e32 100644
--- a/src/network/access/qnetworkreplyimpl.cpp
+++ b/src/network/access/qnetworkreplyimpl.cpp
@@ -477,6 +477,17 @@ void QNetworkReplyImplPrivate::appendDownstreamData(QByteDataBuffer &data)
     QPointer<QNetworkReplyImpl> qq = q;
 
     QVariant totalSize = cookedHeaders.value(QNetworkRequest::ContentLengthHeader);
+    if (totalSize.isNull()) {
+        RawHeadersList::ConstIterator it = findRawHeader("Content-Range");
+        if (it != rawHeaders.constEnd()) {
+            int index = it->second.lastIndexOf('/');
+            if (index != -1)
+                totalSize = it->second.mid(index + 1).toLongLong() - preMigrationDownloaded;
+        } else {
+            qDebug() << "Could not find Content-Length or Content-Range header";
+        }
+    }
+
     if (preMigrationDownloaded != Q_INT64_C(-1))
         totalSize = totalSize.toLongLong() + preMigrationDownloaded;
     pauseNotificationHandling();
@@ -520,7 +531,8 @@ void QNetworkReplyImplPrivate::appendDownstreamData(QIODevice *data)
 void QNetworkReplyImplPrivate::finished()
 {
     Q_Q(QNetworkReplyImpl);
-    if (state == Finished || state == Aborted)
+
+    if (state == Finished || state == Aborted || state == WaitingForSession)
         return;
 
     pauseNotificationHandling();
@@ -540,11 +552,10 @@ void QNetworkReplyImplPrivate::finished()
             } else {
                 qDebug() << "Download hasn't finished";
 
-                if (q->bytesAvailable() == bytesDownloaded) {
-                    qDebug() << "User hasn't read data from reply, we could continue after reconnect.";
-                    error(QNetworkReply::TemporaryNetworkFailureError, q->tr("Temporary network failure."));
-                } else if (q->bytesAvailable() < bytesDownloaded) {
-                    qDebug() << "User has already read data from reply.";
+                if (migrateBackend()) {
+                    return;
+                } else {
+                    qDebug() << "Could not migrate backend, application needs to send another requeset.";
                     error(QNetworkReply::TemporaryNetworkFailureError, q->tr("Temporary network failure."));
                 }
             }
@@ -781,24 +792,24 @@ void QNetworkReplyImpl::migrateBackend()
     d->migrateBackend();
 }
 
-void QNetworkReplyImplPrivate::migrateBackend()
+bool QNetworkReplyImplPrivate::migrateBackend()
 {
     Q_Q(QNetworkReplyImpl);
 
     if (state == QNetworkReplyImplPrivate::Finished ||
         state == QNetworkReplyImplPrivate::Aborted) {
         qDebug() << "Network reply is already finished/aborted.";
-        return;
+        return false;
     }
 
     if (!qobject_cast<QNetworkAccessHttpBackend *>(backend)) {
         qDebug() << "Resume only support by http backend, not migrating.";
-        return;
+        return false;
     }
 
     if (outgoingData) {
         qDebug() << "Request has outgoing data, not migrating.";
-        return;
+        return false;
     }
 
     qDebug() << "Need to check for only cacheable content.";
@@ -812,14 +823,14 @@ void QNetworkReplyImplPrivate::migrateBackend()
     state = QNetworkReplyImplPrivate::Reconnecting;
 
     if (backend) {
-        backend->deleteLater();
+        delete backend;
         backend = 0;
     }
 
     RawHeadersList::ConstIterator it = findRawHeader("Accept-Ranges");
     if (it == rawHeaders.constEnd() || it->second == "none") {
         qDebug() << "Range header not supported by server/resource.";
-        qFatal("Should fail with TemporaryNetworkFailure.");
+        return false;
     }
 
     cookedHeaders.clear();
@@ -841,6 +852,8 @@ void QNetworkReplyImplPrivate::migrateBackend()
     } else {
         QMetaObject::invokeMethod(q, "_q_startOperation", Qt::QueuedConnection);
     }
+
+    return true;
 }
 
 QT_END_NAMESPACE
diff --git a/src/network/access/qnetworkreplyimpl_p.h b/src/network/access/qnetworkreplyimpl_p.h
index ac82ca0..89b976f 100644
--- a/src/network/access/qnetworkreplyimpl_p.h
+++ b/src/network/access/qnetworkreplyimpl_p.h
@@ -165,7 +165,7 @@ public:
     QIODevice *copyDevice;
     QAbstractNetworkCache *networkCache() const;
 
-    void migrateBackend();
+    bool migrateBackend();
 
     bool cacheEnabled;
     QIODevice *cacheSaveDevice;