Revert of Eliminate copies of encoded image data

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

+/*
+ * 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
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef ThreadSafeDataTransport_h
+#define ThreadSafeDataTransport_h
+
+#include "platform/PlatformExport.h"
+#include "wtf/Allocator.h"
+#include "wtf/Noncopyable.h"
+#include "wtf/OwnPtr.h"
+#include "wtf/PassOwnPtr.h"
+#include "wtf/RefPtr.h"
+#include "wtf/ThreadSafeRefCounted.h"
+#include "wtf/ThreadingPrimitives.h"
+#include "wtf/Vector.h"
+
+namespace blink {
+
+class SharedBuffer;
+
+// The purpose of this class is to allow the transfer of data stored in
+// SharedBuffer in a thread-safe manner, and to minimize memory copies
+// and thread contention.
+//
+// This class is designed such that there is only one producer and
+// one consumer.
+
+class PLATFORM_EXPORT ThreadSafeDataTransport final : public ThreadSafeRefCounted<ThreadSafeDataTransport> {
+    WTF_MAKE_NONCOPYABLE(ThreadSafeDataTransport);
+public:
+    ThreadSafeDataTransport();
+    ~ThreadSafeDataTransport();
+
+    // This method is being called subsequently with an expanding
+    // SharedBuffer.
+    void setData(SharedBuffer*, bool allDataReceived);
+
+    // Get the data submitted to this class so far.
+    void data(SharedBuffer**, bool* allDataReceived);
+
+    // Return true of there is new data submitted to this class
+    // since last time data() was called.
+    bool hasNewData();
+
+private:
+    Mutex m_mutex;
+
+    Vector<RefPtr<SharedBuffer>> m_newBufferQueue;
+    RefPtr<SharedBuffer> m_readBuffer;
+    bool m_allDataReceived;
+    size_t m_readPosition;
+};
+
+} // namespace blink
+
+#endif