Reland of Split PendingScript into PendingScript and ClassicPendingScript

third_party/WebKit/Source/core/dom/ScriptLoader.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "core/dom/ScriptLoader.h"
 
 #include "bindings/core/v8/ScriptController.h"
 #include "bindings/core/v8/ScriptSourceCode.h"
-#include "bindings/core/v8/V8Binding.h"
 #include "core/HTMLNames.h"
 #include "core/SVGNames.h"
+#include "core/dom/ClassicPendingScript.h"
 #include "core/dom/ClassicScript.h"
 #include "core/dom/Document.h"
 #include "core/dom/DocumentParserTiming.h"
 #include "core/dom/IgnoreDestructiveWriteCountIncrementer.h"
 #include "core/dom/Script.h"
 #include "core/dom/ScriptElementBase.h"
 #include "core/dom/ScriptRunner.h"
 #include "core/dom/ScriptableDocumentParser.h"
 #include "core/dom/Text.h"
 #include "core/events/Event.h"
@@ skipping 274 matching lines @@
   // 22.2. "Switch on the script's type:"
   // TODO(hiroshige): Clarify how Step 22.2 is implemented for "classic".
   // TODO(hiroshige): Implement Step 22.2 for "module".
 
   // [Intervention]
   // Since the asynchronous, low priority fetch for doc.written blocked
   // script is not for execution, return early from here. Watch for its
   // completion to be able to remove it from the memory cache.
   if (m_documentWriteIntervention ==
       DocumentWriteIntervention::FetchDocWrittenScriptDeferIdle) {
-    m_pendingScript = PendingScript::create(m_element.get(), m_resource.get());
+    m_pendingScript =
+        ClassicPendingScript::create(m_element.get(), m_resource.get());
     m_pendingScript->watchForLoad(this);
     return true;
   }
 
   // 23. "Then, follow the first of the following options that describes the
   //      situation:"
 
   // Three flags are used to instruct the caller of prepareScript() to execute
   // a part of Step 23, when |m_willBeParserExecuted| is true:
   // - |m_willBeParserExecuted|
@@ skipping 65 matching lines @@
   // - "If the script's type is "classic",
   //    and the element has a src attribute,
   //    and the element does not have an async attribute,
   //    and the element does not have the "non-blocking" flag set"
   // TODO(hiroshige): Check the script's type and implement "module" case.
   if (m_element->hasSourceAttribute() && !m_element->asyncAttributeValue() &&
       !m_nonBlocking) {
     // "Add the element to the end of the list of scripts that will execute
     // in order as soon as possible associated with the node document of the
     // script element at the time the prepare a script algorithm started."
-    m_pendingScript = PendingScript::create(m_element.get(), m_resource.get());
+    m_pendingScript =
+        ClassicPendingScript::create(m_element.get(), m_resource.get());
     m_asyncExecType = ScriptRunner::InOrder;
     // TODO(hiroshige): Here |contextDocument| is used as "node document"
     // while Step 14 uses |elementDocument| as "node document". Fix this.
     contextDocument->scriptRunner()->queueScriptForExecution(this,
                                                              m_asyncExecType);
     // Note that watchForLoad can immediately call pendingScriptFinished.
     m_pendingScript->watchForLoad(this);
     // The part "When the script is ready..." is implemented in
     // ScriptRunner::notifyScriptReady().
     // TODO(hiroshige): Annotate it.
 
     return true;
   }
 
   // 4th Clause:
   // - "If the script's type is "classic", and the element has a src attribute"
   // TODO(hiroshige): Check the script's type and implement "module" case.
   if (m_element->hasSourceAttribute()) {
     // "The element must be added to the set of scripts that will execute
     //  as soon as possible of the node document of the script element at the
     //  time the prepare a script algorithm started."
-    m_pendingScript = PendingScript::create(m_element.get(), m_resource.get());
+    m_pendingScript =
+        ClassicPendingScript::create(m_element.get(), m_resource.get());
     m_asyncExecType = ScriptRunner::Async;
     m_pendingScript->startStreamingIfPossible(&m_element->document(),
                                               ScriptStreamer::Async);
     // TODO(hiroshige): Here |contextDocument| is used as "node document"
     // while Step 14 uses |elementDocument| as "node document". Fix this.
     contextDocument->scriptRunner()->queueScriptForExecution(this,
                                                              m_asyncExecType);
     // Note that watchForLoad can immediately call pendingScriptFinished.
     m_pendingScript->watchForLoad(this);
     // The part "When the script is ready..." is implemented in
@@ skipping 239 matching lines @@
   return true;
 
   // 7. "Decrement the ignore-destructive-writes counter of neutralized doc,
   //     if it was incremented in the earlier step."
   // Implemented as the scope out of IgnoreDestructiveWriteCountIncrementer.
 }
 
 void ScriptLoader::execute() {
   DCHECK(!m_willBeParserExecuted);
   DCHECK(m_asyncExecType != ScriptRunner::None);
-  DCHECK(m_pendingScript->resource());
+  DCHECK(m_pendingScript->isExternal());
   bool errorOccurred = false;
   Script* script = m_pendingScript->getSource(KURL(), errorOccurred);
+  const bool wasCanceled = m_pendingScript->wasCanceled();
   detachPendingScript();
   if (errorOccurred) {
     dispatchErrorEvent();
-  } else if (!m_resource->wasCanceled()) {
+  } else if (!wasCanceled) {
     if (executeScript(script))
       dispatchLoadEvent();
     else
       dispatchErrorEvent();
   }
   m_resource = nullptr;
 }
 
 void ScriptLoader::pendingScriptFinished(PendingScript* pendingScript) {
   DCHECK(!m_willBeParserExecuted);
   DCHECK_EQ(m_pendingScript, pendingScript);
-  DCHECK_EQ(pendingScript->resource(), m_resource);
+  // DCHECK_EQ(pendingScript->resource(), m_resource);

[hiroshige, 2017/04/07 22:40:40]

Previously I thought this has a slight chance of failure (e.g. after m_resource
is cleared after execute()) but now I think this is not necessary (after
execute() both m_pendingScript and m_resource are null, causing the DCHECK_EQ()
above to fail).

 
   // We do not need this script in the memory cache. The primary goals of
   // sending this fetch request are to let the third party server know
   // about the document.write scripts intervention and populate the http
   // cache for subsequent uses.
   if (m_documentWriteIntervention ==
       DocumentWriteIntervention::FetchDocWrittenScriptDeferIdle) {
-    memoryCache()->remove(m_pendingScript->resource());
+    // memoryCache()->remove(m_pendingScript->resource());
     m_pendingScript->stopWatchingForLoad();
     return;
   }
 
   DCHECK(m_asyncExecType != ScriptRunner::None);
 
   Document* contextDocument = m_element->document().contextDocument();
   if (!contextDocument) {
     detachPendingScript();
     return;
@@ skipping 41 matching lines @@
   //     then abort these steps at this point. The script is not executed.
   return equalIgnoringCase(eventAttribute, "onload") ||
          equalIgnoringCase(eventAttribute, "onload()");
 }
 
 String ScriptLoader::scriptContent() const {
   return m_element->textFromChildren();
 }
 
 }  // namespace blink