Oilpan: move MHTML objects to the heap.

Source/platform/mhtml/MHTMLArchive.cpp

 /*
  * Copyright (C) 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "platform/mhtml/MHTMLArchive.h"
 
 #include "platform/DateComponents.h"
 #include "platform/MIMETypeRegistry.h"
 #include "platform/SerializedResource.h"
 #include "platform/SharedBuffer.h"
+#include "platform/mhtml/ArchiveResource.h"
 #include "platform/mhtml/MHTMLParser.h"
 #include "platform/text/QuotedPrintable.h"
 #include "platform/weborigin/SchemeRegistry.h"
 #include "wtf/CryptographicallyRandomNumber.h"
 #include "wtf/DateMath.h"
 #include "wtf/text/Base64.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace WebCore {
 
@@ skipping 31 matching lines @@
     }
     return stringBuilder.toString();
 }
 
 MHTMLArchive::MHTMLArchive()
 {
 }
 
 MHTMLArchive::~MHTMLArchive()
 {
+#if !ENABLE(OILPAN)
     // Because all frames know about each other we need to perform a deep clearing of the archives graph.
     clearAllSubframeArchives();
+#endif
 }
 
-PassRefPtr<MHTMLArchive> MHTMLArchive::create()
+PassRefPtrWillBeRawPtr<MHTMLArchive> MHTMLArchive::create()
 {
-    return adoptRef(new MHTMLArchive);
+    return adoptRefWillBeNoop(new MHTMLArchive);
 }
 
-PassRefPtr<MHTMLArchive> MHTMLArchive::create(const KURL& url, SharedBuffer* data)
+PassRefPtrWillBeRawPtr<MHTMLArchive> MHTMLArchive::create(const KURL& url, SharedBuffer* data)
 {
     // For security reasons we only load MHTML pages from local URLs.
     if (!SchemeRegistry::shouldTreatURLSchemeAsLocal(url.protocol()))
         return nullptr;
 
     MHTMLParser parser(data);
-    RefPtr<MHTMLArchive> mainArchive = parser.parseArchive();
+    RefPtrWillBeRawPtr<MHTMLArchive> mainArchive = parser.parseArchive();
     if (!mainArchive)
         return nullptr; // Invalid MHTML file.
 
     // Since MHTML is a flat format, we need to make all frames aware of all resources.
     for (size_t i = 0; i < parser.frameCount(); ++i) {
-        RefPtr<MHTMLArchive> archive = parser.frameAt(i);
+        RefPtrWillBeRawPtr<MHTMLArchive> archive = parser.frameAt(i);
         for (size_t j = 1; j < parser.frameCount(); ++j) {
             if (i != j)
                 archive->addSubframeArchive(parser.frameAt(j));
         }
         for (size_t j = 0; j < parser.subResourceCount(); ++j)
             archive->addSubresource(parser.subResourceAt(j));
     }
     return mainArchive.release();
 }
 
@@ skipping 85 matching lines @@
             }
         }
     }
 
     asciiString = String("--" + boundary + "--\r\n").utf8();
     mhtmlData->append(asciiString.data(), asciiString.length());
 
     return mhtmlData.release();
 }
 
 void MHTMLArchive::clearAllSubframeArchives()

[haraken, 2014/07/08 08:50:08]

I'm curious why we need to call clearAllSubframeArchives() even in non-oilpan
builds. What clearAllSubframeArchives() does is just to call
m_subframeArchives.clear() for all subframes. I don't think this is needed,
because m_subframeArchives.clear() will be called in the destructor of the
subframes.

In other words, if we really need to call clearAllSubframeArchives() in
non-oilpan builds for some reason (e.g., we want to forcibly clear archives of
the subframes even though there are other retainers of the subframes somewhere),
won't it mean that we want to call clearAllSubframeArchives() in oilpan builds
as well?

[haraken, 2014/07/08 08:50:08]

Can we add #if !ENABLE(OILPAN) to this method?

[sof, 2014/07/08 09:10:00]

I think you're right, I didn't see the point of this operation either, but
didn't want to upset the apple cart. The operation being to DFS visit all
archives and then deref() them all in the end.

The deref() storm that will happen when the vector is destructed should take
care of this already. The comment in the dtor makes me uncertain if the thinking
is that there might be loops here needing this..in which case we'll never get
here due to the use of RefPtrs.

 {
-    Vector<RefPtr<MHTMLArchive> > clearedArchives;
+    SubFrameArchives clearedArchives;
     clearAllSubframeArchivesImpl(&clearedArchives);
 }
 
-void MHTMLArchive::clearAllSubframeArchivesImpl(Vector<RefPtr<MHTMLArchive> >* clearedArchives)
+void MHTMLArchive::clearAllSubframeArchivesImpl(SubFrameArchives* clearedArchives)

[haraken, 2014/07/08 08:50:07]

Ditto.

 {
-    for (Vector<RefPtr<MHTMLArchive> >::iterator it = m_subframeArchives.begin(); it != m_subframeArchives.end(); ++it) {
+    for (SubFrameArchives::iterator it = m_subframeArchives.begin(); it != m_subframeArchives.end(); ++it) {
         if (!clearedArchives->contains(*it)) {
             clearedArchives->append(*it);
             (*it)->clearAllSubframeArchivesImpl(clearedArchives);
         }
     }
     m_subframeArchives.clear();
 }
 
+void MHTMLArchive::trace(Visitor* visitor)
+{
+    visitor->trace(m_mainResource);
+    visitor->trace(m_subresources);
+    visitor->trace(m_subframeArchives);
 }
+
+}