Stream scripts to V8 as they load - Blink side.

Source/core/dom/PendingScript.cpp

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 #include "config.h"
 #include "core/dom/PendingScript.h"
 
+#include "bindings/core/v8/ScriptStreamer.h"
 #include "core/dom/Element.h"
 #include "core/fetch/ScriptResource.h"
 
 namespace blink {
 
 PendingScript::~PendingScript()
 {
 }
 
-void PendingScript::watchForLoad(ResourceClient* client)
+void PendingScript::watchForLoad(ScriptResourceClient* client)
 {
     ASSERT(!m_watchingForLoad);
     ASSERT(!resource()->isLoaded());
-    // addClient() will call notifyFinished() if the load is complete. Callers
-    // do not expect to be re-entered from this call, so they should not become
-    // a client of an already-loaded Resource.
-    resource()->addClient(client);
+    if (m_streamer) {
+        m_streamer->addClient(client);
+    } else {
+        // addClient() will call notifyFinished() if the load is
+        // complete. Callers do not expect to be re-entered from this call, so
+        // they should not become a client of an already-loaded Resource.
+        resource()->addClient(client);
+    }
     m_watchingForLoad = true;
 }
 
-void PendingScript::stopWatchingForLoad(ResourceClient* client)
+void PendingScript::stopWatchingForLoad(ScriptResourceClient* client)
 {
-    if (resource() && m_watchingForLoad) {
+    if (!m_watchingForLoad) {
+        return;
+    }
+    ASSERT(resource());
+    if (m_streamer) {
+        m_streamer->cancel();
+        m_streamer->removeClient(client);

[haraken, 2014/09/11 16:12:30]

Shall we clear m_streamer ?

[marja, 2014/09/15 17:45:27]

Yeah, we cancel() it here anyway, so why not. Done.

+    } else {
         resource()->removeClient(client);
-        m_watchingForLoad = false;
     }
+    m_watchingForLoad = false;
 }
 
 PassRefPtrWillBeRawPtr<Element> PendingScript::releaseElementAndClear()
 {
     setScriptResource(0);
     m_watchingForLoad = false;
     m_startingPosition = TextPosition::belowRangePosition();
     return m_element.release();
 }
 
 void PendingScript::setScriptResource(ScriptResource* resource)
 {
     setResource(resource);
+    // This function is only called 1) during construction (we're not yet
+    // streaming) 2) after loading has completed (and streaming too, if we were
+    // streaming).
+    ASSERT(!isStreaming());
+    ASSERT(!m_watchingForLoad);
+    m_streamer.release();
 }
 
-void PendingScript::notifyFinished(Resource*)
+void PendingScript::notifyFinished(Resource* resource)
 {
+    if (m_streamer) {
+        m_streamer->notifyFinished(resource);
+    }
+}
+
+void PendingScript::notifyAppendData(ScriptResource* resource)
+{
+    if (m_streamer) {
+        m_streamer->notifyAppendData(resource);
+    }
 }
 
 void PendingScript::trace(Visitor* visitor)
 {
     visitor->trace(m_element);
 }
 
 ScriptSourceCode PendingScript::getSource(const KURL& documentURL, bool& errorOccurred) const
 {
     if (resource()) {
         errorOccurred = resource()->errorOccurred();
         ASSERT(resource()->isLoaded());
+        if (m_streamer && !m_streamer->streamingSuppressed()) {

[haraken, 2014/09/11 16:12:30]

Just to confirm: Is it possible that the streaming is not suppressed at this
point but is suppressed later when V8ScriptRunner::compileScript tries to
compile the ScriptSourceCode. I think the answer is no. If the answer is yes, it
should be problematic.

[marja, 2014/09/15 17:45:27]

You're correct, the answer is no. The streaming cannot be suppressed once it has
completed. Or if it is, it has no effect and makes no sense for anyone to call
suppress when we have already parsed.

+            return ScriptSourceCode(m_streamer, resource());
+        }
         return ScriptSourceCode(resource());
     }
     errorOccurred = false;
     return ScriptSourceCode(m_element->textContent(), documentURL, startingPosition());
 }
 
+bool PendingScript::isStreaming() const
+{
+    return m_streamer && m_streamer->streamingInProgress();
 }
+
+}