blob hacking webcore style

Source/bindings/v8/SerializedScriptValue.h

 /*
  * Copyright (C) 2009, 2010 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 15 matching lines @@
  * 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 SerializedScriptValue_h
 #define SerializedScriptValue_h
 
 #include "bindings/v8/ScriptValue.h"
 
+#include "wtf/HashMap.h"
 #include "wtf/ThreadSafeRefCounted.h"
 #include <v8.h>
 
 namespace WTF {
 
 class ArrayBuffer;
 class ArrayBufferContents;
 
 }
 
 namespace WebCore {
 
+class BlobDataHandle;
 class MessagePort;
 
 typedef Vector<RefPtr<MessagePort>, 1> MessagePortArray;
 typedef Vector<RefPtr<WTF::ArrayBuffer>, 1> ArrayBufferArray;
+typedef HashMap<String, RefPtr<BlobDataHandle> > BlobDataHandleMap;
 
 class SerializedScriptValue : public ThreadSafeRefCounted<SerializedScriptValue> {
 public:
     // Increment this for each incompatible change to the wire format.
     // Version 2: Added StringUCharTag for UChar v8 strings.
-    static const uint32_t wireFormatVersion = 2;
+    // Version 3: Switched to using uuids as blob data identifiers.
+    static const uint32_t wireFormatVersion = 3;
 
     virtual ~SerializedScriptValue();
 
     // If a serialization error occurs (e.g., cyclic input value) this
     // function returns an empty representation, schedules a V8 exception to
     // be thrown using v8::ThrowException(), and sets |didThrow|. In this case
     // the caller must not invoke any V8 operations until control returns to
     // V8. When serialization is successful, |didThrow| is false.
     static PassRefPtr<SerializedScriptValue> create(v8::Handle<v8::Value>, MessagePortArray*, ArrayBufferArray*, bool& didThrow, v8::Isolate*);
     static PassRefPtr<SerializedScriptValue> create(v8::Handle<v8::Value>, v8::Isolate*);
@@ skipping 20 matching lines @@
     String toWireString() const { return m_data; }
     void toWireBytes(Vector<char>&) const;
 
     // Deserializes the value (in the current context). Returns a null value in
     // case of failure.
     v8::Handle<v8::Value> deserialize(MessagePortArray* = 0);
     v8::Handle<v8::Value> deserialize(v8::Isolate*, MessagePortArray* = 0);
 
     ScriptValue deserializeForInspector(ScriptState*);
 
-    const Vector<String>& blobURLs() const { return m_blobURLs; }
+    // Only reflects the truth if the SSV was created by walking a v8 value, not reliable

[jsbell, 2013/10/02 22:24:41]

I think the only callers of this basically do:

SSV ssv = myvalue.serialize();
if (ssv.containsBlobs()) { throw; }

Perhaps the API should be that callers pass in the BlobDataHandleMap? I think I
made a similar comment on ericu@'s patch, since in that case the array is
promptly grabbed and passed data in parallel with the SSV wire data.

It's probably safe to wait until ericu@'s changes go in, since that will clarify
how this is used.

+    // if the SSV was created createdFromWire(data).
+    bool containsBlobs() const { return !m_blobDataHandles.isEmpty(); }
 
     // Informs the V8 about external memory allocated and owned by this object. Large values should contribute
     // to GC counters to eventually trigger a GC, otherwise flood of postMessage() can cause OOM.
     // Ok to invoke multiple times (only adds memory once).
     // The memory registration is revoked automatically in destructor.
     void registerMemoryAllocatedWithCurrentScriptContext();
 
 private:
     enum StringDataMode {
         StringValue,
         WireData
     };
     enum ExceptionPolicy {
         ThrowExceptions,
         DoNotThrowExceptions
     };
     typedef Vector<WTF::ArrayBufferContents, 1> ArrayBufferContentsArray;
 
     SerializedScriptValue();
     SerializedScriptValue(v8::Handle<v8::Value>, MessagePortArray*, ArrayBufferArray*, bool& didThrow, v8::Isolate*, ExceptionPolicy = ThrowExceptions);
     explicit SerializedScriptValue(const String& wireData);
 
     static PassOwnPtr<ArrayBufferContentsArray> transferArrayBuffers(ArrayBufferArray&, bool& didThrow, v8::Isolate*);
 
     String m_data;
     OwnPtr<ArrayBufferContentsArray> m_arrayBufferContentsArray;
-    Vector<String> m_blobURLs;
+    BlobDataHandleMap m_blobDataHandles;
     intptr_t m_externallyAllocatedMemory;
 };
 
 } // namespace WebCore
 
 #endif // SerializedScriptValue_h