Implementation of delta-sync support on client-side.

This commit adds client-side support for delta-sync, this adds a new
3rdparty submodule `gh:ahmedammar/zsync`. This zsync tree is a modified
version of upstream, adding some needed support for the upload path and
other requirements.

If the server does not announce the required zsync capability then a
full upload/download is fallen back to. Delta synchronization can be
enabled/disabled using command line, config, or gui options.

On both upload and download paths, a check is made for the existance of
a zsync metadata file on the server for a given path. This is provided
by a dav property called `zsync`, found during discovery phase. If it
doesn't exist the code reverts back to a complete upload or download,
i.e. previous implementations. In the case of upload, a new zsync
metadata file will be uploaded as part of the chunked upload and future
synchronizations will be delta-sync capable.

Chunked uploads no longer use sequential file names for each chunk id,
instead, they are named as the byte offset into the remote file, this is
a minimally intrusive modification to allow fo delta-sync and legacy
code paths to run seamlessly. A new http header OC-Total-File-Length is
sent, which informs the server of the final expected size of the file
not just the total transmitted bytes as reported by OC-Total-Length.

The seeding and generation of the zsync metadata file is done in a
separate thread since this is a cpu intensive task, ensuring main thread
is not blocked.

This commit closes owncloud/client#179.

1 files changed, 4 insertions, 4 deletions

diff --git a/src/libsync/bandwidthmanager.h b/src/libsync/bandwidthmanager.h
index 691e11162..33a3cdece 100644
--- a/src/libsync/bandwidthmanager.h
+++ b/src/libsync/bandwidthmanager.h
@@ -23,7 +23,7 @@
 namespace OCC {
 
 class UploadDevice;
-class GETFileJob;
+class GETJob;
 class OwncloudPropagator;
 
 /**
@@ -47,7 +47,7 @@ public slots:
     void registerUploadDevice(UploadDevice *);
     void unregisterUploadDevice(QObject *);
 
-    void registerDownloadJob(GETFileJob *);
+    void registerDownloadJob(GETJob *);
     void unregisterDownloadJob(QObject *);
 
     void absoluteLimitTimerExpired();
@@ -86,14 +86,14 @@ private:
     qint64 _relativeUploadLimitProgressAtMeasuringRestart;
     qint64 _currentUploadLimit;
 
-    QLinkedList<GETFileJob *> _downloadJobList;
+    QLinkedList<GETJob *> _downloadJobList;
     QTimer _relativeDownloadMeasuringTimer;
 
     // for relative bw limiting, we need to wait this amount before measuring again
     QTimer _relativeDownloadDelayTimer;
 
     // the device measured
-    GETFileJob *_relativeLimitCurrentMeasuredJob;
+    GETJob *_relativeLimitCurrentMeasuredJob;
 
     // for measuring how much progress we made at start
     qint64 _relativeDownloadLimitProgressAtMeasuringRestart;