Ganesh: images upload to GPU performance fix (skip copying encoded data)

third_party/WebKit/Source/platform/graphics/ThreadSafeDataTransport.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 14 matching lines @@
 
 #include "config.h"
 
 #include "platform/graphics/ThreadSafeDataTransport.h"
 
 #include "platform/SharedBuffer.h"
 
 namespace blink {
 
 ThreadSafeDataTransport::ThreadSafeDataTransport()
-    : m_readBuffer(SharedBuffer::create())
+    : m_newAllDataReceived(false)
+    , m_readBuffer(SharedBuffer::create())
     , m_allDataReceived(false)
     , m_readPosition(0)
 {
 }
 
 ThreadSafeDataTransport::~ThreadSafeDataTransport()
 {
 }
 
 void ThreadSafeDataTransport::setData(SharedBuffer* buffer, bool allDataReceived)
 {
     ASSERT(buffer->size() >= m_readPosition);
     Vector<RefPtr<SharedBuffer>> newBufferQueue;
 
     const char* segment = 0;
     while (size_t length = buffer->getSomeData(segment, m_readPosition)) {
         m_readPosition += length;
         newBufferQueue.append(SharedBuffer::create(segment, length));
     }
 
     MutexLocker locker(m_mutex);
     m_newBufferQueue.appendVector(newBufferQueue);
     newBufferQueue.clear();
-    m_allDataReceived = allDataReceived;
+    m_newAllDataReceived = allDataReceived;
 }
 
 void ThreadSafeDataTransport::data(SharedBuffer** buffer, bool* allDataReceived)
 {
     ASSERT(buffer);
     ASSERT(allDataReceived);
     Vector<RefPtr<SharedBuffer>> newBufferQueue;
     {
         MutexLocker lock(m_mutex);
         m_newBufferQueue.swap(newBufferQueue);
-        *allDataReceived = m_allDataReceived;
+        if (m_allDataReceived && newBufferQueue.size()) {

[aleksandar.stojiljkovic, 2015/12/02 20:33:34]

Nice find. This was handled here, but after ref counting
ThreadSafeDataTransport, it is better to just disable appending data to already
fully downloaded content.

+            // This prevents from unexisting use case now - if alldata was previously
+            // received, don't append but start new buffer and leave reference counting
+            // to handle previous buffer disposal.
+            ASSERT(false);
+            m_readBuffer = SharedBuffer::create();
+        }
+        *allDataReceived = m_allDataReceived = m_newAllDataReceived;
     }
     for (size_t i = 0; i < newBufferQueue.size(); ++i)
         m_readBuffer->append(newBufferQueue[i].get());
     *buffer = m_readBuffer.get();
 }
 
 bool ThreadSafeDataTransport::hasNewData()
 {
     MutexLocker lock(m_mutex);
     return !m_newBufferQueue.isEmpty();
 }
 
 } // namespace blink