QNetworkAccessManager: HTTP download performance improvements

Better usage of move semantics with implicit sharing to avoid
detaching (=malloc/memcpy). Also some other improvements.
Download performance improvement is around 20% according
to the httpDownloadPerformance autotest.

Reviewed-by: Thiago Macieira

1 files changed, 5 insertions, 1 deletions

diff --git a/src/network/access/qnetworkaccessfilebackend.cpp b/src/network/access/qnetworkaccessfilebackend.cpp
index e3fc8bf..533fc75 100644
--- a/src/network/access/qnetworkaccessfilebackend.cpp
+++ b/src/network/access/qnetworkaccessfilebackend.cpp
@@ -263,7 +263,11 @@ bool QNetworkAccessFileBackend::readMoreFromFile()
 
         data.resize(actuallyRead);
         totalBytes += actuallyRead;
-        writeDownstreamData(data);
+
+        QByteDataBuffer list;
+        list.append(data);
+        data.clear(); // important because of implicit sharing!
+        writeDownstreamData(list);
     }
     return true;
 }