[PresentationAPI] Plumbing send(Blob) from PresentationSession IDL to platform/.

Source/modules/presentation/PresentationSession.cpp

Index: Source/modules/presentation/PresentationSession.cpp
diff --git a/Source/modules/presentation/PresentationSession.cpp b/Source/modules/presentation/PresentationSession.cpp
index 6c6e9380d43916753372d614e9046f7806214c83..dbdab89bf43e31e4fd5cd21503e2dfd7073b4534 100644
--- a/Source/modules/presentation/PresentationSession.cpp
+++ b/Source/modules/presentation/PresentationSession.cpp
@@ -11,6 +11,8 @@
 #include "core/dom/ExceptionCode.h"
 #include "core/events/Event.h"
 #include "core/events/MessageEvent.h"
+#include "core/fileapi/FileReaderLoader.h"
+#include "core/fileapi/FileReaderLoaderClient.h"
 #include "core/frame/LocalFrame.h"
 #include "modules/EventTargetModules.h"
 #include "modules/presentation/Presentation.h"
@@ -47,6 +49,43 @@ void throwPresentationDisconnectedError(ExceptionState& exceptionState)
 
 } // namespace
 
+class PresentationSession::BlobLoader final : public GarbageCollectedFinalized<PresentationSession::BlobLoader>, public FileReaderLoaderClient {
+public:
+    BlobLoader(PassRefPtr<BlobDataHandle> blobDataHandle, PresentationSession* presentationSession)
+        : m_presentationSession(presentationSession)
+        , m_loader(FileReaderLoader::ReadAsArrayBuffer, this)
+    {
+        m_loader.start(m_presentationSession->executionContext(), blobDataHandle);
+    }
+    ~BlobLoader() override { }
+
+    // FileReaderLoaderClient functions.
+    void didStartLoading() override { }
+    void didReceiveData() override { }
+    void didFinishLoading() override
+    {
+        m_presentationSession->didFinishLoadingBlob(m_loader.arrayBufferResult());
+    }
+    void didFail(FileError::ErrorCode errorCode) override
+    {
+        m_presentationSession->didFailLoadingBlob(errorCode);
+    }
+
+    void cancel()
+    {
+        m_loader.cancel();
+    }
+
+    DEFINE_INLINE_TRACE()
+    {
+        visitor->trace(m_presentationSession);
+    }
+
+private:
+    Member<PresentationSession> m_presentationSession;
+    FileReaderLoader m_loader;
+};
+
 PresentationSession::PresentationSession(LocalFrame* frame, const String& id, const String& url)
     : DOMWindowProperty(frame)
     , m_id(id)
@@ -57,6 +96,7 @@ PresentationSession::PresentationSession(LocalFrame* frame, const String& id, co
 
 PresentationSession::~PresentationSession()
 {
+    ASSERT(!m_blobLoader);
 }
 
 // static
@@ -90,6 +130,7 @@ ExecutionContext* PresentationSession::executionContext() const
 
 DEFINE_TRACE(PresentationSession)
 {
+    visitor->trace(m_blobLoader);
     RefCountedGarbageCollectedEventTargetWithInlineData<PresentationSession>::trace(visitor);
     DOMWindowProperty::trace(visitor);
 }
@@ -101,39 +142,81 @@ const AtomicString& PresentationSession::state() const
 
 void PresentationSession::send(const String& message, ExceptionState& exceptionState)
 {
-    if (m_state == WebPresentationSessionState::Disconnected) {
-        throwPresentationDisconnectedError(exceptionState);
+    if (!canSendMessage(exceptionState))
         return;
-    }
 
-    PresentationController* controller = presentationController();
-    if (controller)
-        controller->send(m_url, m_id, message);
+    m_messages.append(adoptPtr(new Message(message)));
+    handleMessageQueue();
 }
 
-void PresentationSession::send(PassRefPtr<DOMArrayBuffer> data, ExceptionState& exceptionState)
+void PresentationSession::send(PassRefPtr<DOMArrayBuffer> arrayBuffer, ExceptionState& exceptionState)
 {
-    ASSERT(data && data->buffer());
-    sendInternal(static_cast<const uint8_t*>(data->data()), data->byteLength(), exceptionState);
+    ASSERT(arrayBuffer && arrayBuffer->buffer());
+    if (!canSendMessage(exceptionState))
+        return;
+
+    m_messages.append(adoptPtr(new Message(arrayBuffer)));
+    handleMessageQueue();
 }
 
-void PresentationSession::send(PassRefPtr<DOMArrayBufferView> data, ExceptionState& exceptionState)
+void PresentationSession::send(PassRefPtr<DOMArrayBufferView> arrayBufferView, ExceptionState& exceptionState)
 {
-    ASSERT(data);
-    sendInternal(static_cast<const uint8_t*>(data->baseAddress()), data->byteLength(), exceptionState);
+    ASSERT(arrayBufferView);
+    if (!canSendMessage(exceptionState))
+        return;
+
+    m_messages.append(adoptPtr(new Message(arrayBufferView->buffer())));
+    handleMessageQueue();
 }
 
-void PresentationSession::sendInternal(const uint8_t* data, size_t size, ExceptionState& exceptionState)
+void PresentationSession::send(Blob* data, ExceptionState& exceptionState)
 {
     ASSERT(data);
+    if (!canSendMessage(exceptionState))
+        return;
+
+    m_messages.append(adoptPtr(new Message(data->blobDataHandle())));
+    handleMessageQueue();
+}
+
+bool PresentationSession::canSendMessage(ExceptionState& exceptionState)
+{
     if (m_state == WebPresentationSessionState::Disconnected) {
         throwPresentationDisconnectedError(exceptionState);
-        return;
+        return false;
     }
 
     PresentationController* controller = presentationController();
-    if (controller)
-        controller->send(m_url, m_id, data, size);
+    if (!controller)
+        return false;
+
+    return true;
+}
+
+void PresentationSession::handleMessageQueue()
+{
+    PresentationController* controller = presentationController();
+    // Extra check just in case.
+    if (!controller)
+        return;
+
+    while (!m_messages.isEmpty() && !m_blobLoader) {
+        Message* message = m_messages.first().get();
+        switch (message->type) {
+        case MessageTypeText:
+            controller->send(m_url, m_id, message->text);
+            m_messages.removeFirst();
+            break;
+        case MessageTypeArrayBuffer:
+            controller->send(m_url, m_id, static_cast<const uint8_t*>(message->arrayBuffer->data()), message->arrayBuffer->byteLength());
+            m_messages.removeFirst();
+            break;
+        case MessageTypeBlob:
+            ASSERT(!m_blobLoader);
+            m_blobLoader = new BlobLoader(message->blobDataHandle, this);
+            break;
+        }
+    }
 }
 
 void PresentationSession::didReceiveTextMessage(const String& message)
@@ -148,6 +231,16 @@ void PresentationSession::close()
     PresentationController* controller = presentationController();
     if (controller)
         controller->closeSession(m_url, m_id);
+
+    // Cancel current Blob loading if any.
+    if (m_blobLoader) {
+        m_blobLoader->cancel();
+        m_blobLoader.clear();
+    }
+
+    // Clear message queue.
+    Deque<OwnPtr<Message>> empty;
+    m_messages.swap(empty);
 }
 
 bool PresentationSession::matches(WebPresentationSessionClient* client) const
@@ -171,4 +264,30 @@ PresentationController* PresentationSession::presentationController()
     return PresentationController::from(*frame());
 }
 
+void PresentationSession::didFinishLoadingBlob(PassRefPtr<DOMArrayBuffer> buffer)
+{
+    m_blobLoader.clear();
+    ASSERT(!m_messages.isEmpty() && m_messages.first()->type == MessageTypeBlob);
+    ASSERT(buffer && buffer->buffer());
+
+    // Send the loaded blob immediately here and continue processing the queue.
+    PresentationController* controller = presentationController();
+    if (controller)
+        controller->sendBlobData(m_url, m_id, static_cast<const uint8_t*>(buffer->data()), buffer->byteLength());
+
+    m_messages.removeFirst();
+    // TODO(s.singapati): Is it more safe to call m_blobLoader.clear() here?

[mark a. foltz, 2015/06/01 17:39:28]

Where is clear() defined?  I don't see it here, or on
GarbageCollectedFinalized<> or FileReaderLoaderClient.

[USE s.singapati at gmail.com, 2015/06/01 19:51:36]

Member::clear(),
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

I was thinking that between the execution of lines 269 and 278, is there any
possibility that handleMessageQueue() is invoked and lead to incorrect behavior.
well at least there won't be any problem moving m_blobLoader.clear() here. I
will update the patch if there is no other concerns with this.

+    handleMessageQueue();
+}
+
+void PresentationSession::didFailLoadingBlob(FileError::ErrorCode errorCode)
+{
+    ASSERT(!m_messages.isEmpty() && m_messages.first()->type == MessageTypeBlob);
+    m_blobLoader.clear();
+    // FIXME: generate error message?
+    // Ignore the current failed blob item and continue with next items.
+    m_messages.removeFirst();
+    handleMessageQueue();
+}
+
 } // namespace blink