Blob support for IDB [Blink]

Source/bindings/v8/SerializedScriptValue.cpp

 /*
  * Copyright (C) 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 43 matching lines @@
 #include "bindings/v8/custom/V8Uint8ArrayCustom.h"
 #include "bindings/v8/custom/V8Uint8ClampedArrayCustom.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/MessagePort.h"
 #include "core/fileapi/Blob.h"
 #include "core/fileapi/File.h"
 #include "core/fileapi/FileList.h"
 #include "core/html/ImageData.h"
 #include "core/html/canvas/DataView.h"
 #include "platform/SharedBuffer.h"
+#include "platform/blob/BlobInfo.h"
 #include "wtf/ArrayBuffer.h"
 #include "wtf/ArrayBufferContents.h"
 #include "wtf/ArrayBufferView.h"
 #include "wtf/Assertions.h"
 #include "wtf/ByteOrder.h"
 #include "wtf/Float32Array.h"
 #include "wtf/Float64Array.h"
 #include "wtf/Int16Array.h"
 #include "wtf/Int32Array.h"
 #include "wtf/Int8Array.h"
@@ skipping 105 matching lines @@
     NullTag = '0', // -> <null>
     TrueTag = 'T', // -> <true>
     FalseTag = 'F', // -> <false>
     StringTag = 'S', // string:RawString -> string
     StringUCharTag = 'c', // string:RawUCharString -> string
     Int32Tag = 'I', // value:ZigZag-encoded int32 -> Integer
     Uint32Tag = 'U', // value:uint32_t -> Integer
     DateTag = 'D', // value:double -> Date (ref)
     MessagePortTag = 'M', // index:int -> MessagePort. Fills the result with transferred MessagePort.
     NumberTag = 'N', // value:double -> Number
-    BlobTag = 'b', // url:WebCoreString, type:WebCoreString, size:uint64_t -> Blob (ref)
+    BlobTag = 'b', // uuid:WebCoreString, type:WebCoreString, size:uint64_t -> Blob (ref)
     FileTag = 'f', // file:RawFile -> File (ref)
-    DOMFileSystemTag = 'd', // type:int32_t, name:WebCoreString, url:WebCoreString -> FileSystem (ref)
+    DOMFileSystemTag = 'd', // type:int32_t, name:WebCoreString, uuid:WebCoreString -> FileSystem (ref)
     FileListTag = 'l', // length:uint32_t, files:RawFile[length] -> FileList (ref)
     ImageDataTag = '#', // width:uint32_t, height:uint32_t, pixelDataLength:uint32_t, data:byte[pixelDataLength] -> ImageData (ref)
     ObjectTag = '{', // numProperties:uint32_t -> pops the last object from the open stack;
                      //                           fills it with the last numProperties name,value pairs pushed onto the deserialization stack
     SparseArrayTag = '@', // numProperties:uint32_t, length:uint32_t -> pops the last object from the open stack;
                           //                                            fills it with the last numProperties name,value pairs pushed onto the deserialization stack
     DenseArrayTag = '$', // numProperties:uint32_t, length:uint32_t -> pops the last object from the open stack;
                          //                                            fills it with the last length elements and numProperties name,value pairs pushed onto deserialization stack
     RegExpTag = 'R', // pattern:RawString, flags:uint32_t -> RegExp (ref)
     ArrayBufferTag = 'B', // byteLength:uint32_t, data:byte[byteLength] -> ArrayBuffer (ref)
@@ skipping 183 matching lines @@
     }
 
     void writeBlob(const String& uuid, const String& type, unsigned long long size)
     {
         append(BlobTag);
         doWriteWebCoreString(uuid);
         doWriteWebCoreString(type);
         doWriteUint64(size);
     }
 
+    void writeBlob(int blobIndex)
+    {
+        append(BlobTag);
+        doWriteUint32(blobIndex);
+    }
+
     void writeDOMFileSystem(int type, const String& name, const String& url)
     {
         append(DOMFileSystemTag);
         doWriteUint32(type);
         doWriteWebCoreString(name);
         doWriteWebCoreString(url);
     }
 
     void writeFile(const File& file)
     {
         append(FileTag);
         doWriteFile(file);
     }
 
+    void writeFile(int blobIndex)
+    {
+        append(FileTag);
+        doWriteUint32(blobIndex);
+    }
+
+    // Note: We could dedupe the files in this list, but it's probably
+    // pretty rare that there are any duplicates.
     void writeFileList(const FileList& fileList)
     {
         append(FileListTag);
         uint32_t length = fileList.length();
         doWriteUint32(length);
         for (unsigned i = 0; i < length; ++i)
             doWriteFile(*fileList.item(i));
     }
 
+    void writeFileList(const Vector<int>& blobIndices)
+    {
+        append(FileListTag);
+        uint32_t length = blobIndices.size();
+        doWriteUint32(length);
+        for (unsigned i = 0; i < length; ++i) {
+            doWriteUint32(blobIndices[i]);
+        }
+    }
+
     void writeArrayBuffer(const ArrayBuffer& arrayBuffer)
     {
         append(ArrayBufferTag);
         doWriteArrayBuffer(arrayBuffer);
     }
 
     void writeArrayBufferView(const ArrayBufferView& arrayBufferView)
     {
         append(ArrayBufferViewTag);
 #ifndef NDEBUG
@@ skipping 258 matching lines @@
 public:
     enum Status {
         Success,
         InputError,
         DataCloneError,
         InvalidStateError,
         JSException,
         JSFailure
     };
 
-    Serializer(Writer& writer, MessagePortArray* messagePorts, ArrayBufferArray* arrayBuffers, BlobDataHandleMap& blobDataHandles, v8::TryCatch& tryCatch, v8::Isolate* isolate)
+    Serializer(Writer& writer, MessagePortArray* messagePorts, ArrayBufferArray* arrayBuffers, Vector<BlobInfo>* blobInfo, BlobDataHandleMap& blobDataHandles, v8::TryCatch& tryCatch, v8::Isolate* isolate)
         : m_writer(writer)
         , m_tryCatch(tryCatch)
         , m_depth(0)
         , m_execDepth(0)
         , m_status(Success)
         , m_nextObjectReference(0)
+        , m_blobInfo(blobInfo)
         , m_blobDataHandles(blobDataHandles)
         , m_isolate(isolate)
     {
         ASSERT(!tryCatch.HasCaught());
         if (messagePorts) {
             for (size_t i = 0; i < messagePorts->size(); i++)
                 m_transferredMessagePorts.set(toV8Object(messagePorts->at(i).get(), m_writer.getIsolate()), i);
         }
         if (arrayBuffers) {
             for (size_t i = 0; i < arrayBuffers->size(); i++)  {
@@ skipping 351 matching lines @@
     {
         v8::Handle<v8::BooleanObject> booleanObject = value.As<v8::BooleanObject>();
         m_writer.writeBooleanObject(booleanObject->BooleanValue());
     }
 
     void writeBlob(v8::Handle<v8::Value> value)
     {
         Blob* blob = V8Blob::toNative(value.As<v8::Object>());
         if (!blob)
             return;
-        m_writer.writeBlob(blob->uuid(), blob->type(), blob->size());
+        int blobIndex = -1;
         m_blobDataHandles.add(blob->uuid(), blob->blobDataHandle());
+        if (appendBlobInfo(blob->uuid(), blob->type(), blob->size(), &blobIndex)) {
+            ASSERT(blobIndex >= 0);
+            m_writer.writeBlob(blobIndex);
+        } else {
+            m_writer.writeBlob(blob->uuid(), blob->type(), blob->size());
+        }
     }
 
     StateBase* writeDOMFileSystem(v8::Handle<v8::Value> value, StateBase* next)
     {
         DOMFileSystem* fs = V8DOMFileSystem::toNative(value.As<v8::Object>());
         if (!fs)
             return 0;
         if (!fs->clonable())
             return handleError(DataCloneError, next);
         m_writer.writeDOMFileSystem(fs->type(), fs->name(), fs->rootURL().string());
         return 0;
     }
 
     void writeFile(v8::Handle<v8::Value> value)
     {
         File* file = V8File::toNative(value.As<v8::Object>());
         if (!file)
             return;
-        m_writer.writeFile(*file);
+        int blobIndex = -1;
         m_blobDataHandles.add(file->uuid(), file->blobDataHandle());
+        if (appendFileInfo(file->uuid(), file->path(), file->name(), file->type(), &blobIndex)) {
+            ASSERT(blobIndex >= 0);
+            m_writer.writeFile(blobIndex);
+        } else {
+            m_writer.writeFile(*file);
+        }
     }
 
     void writeFileList(v8::Handle<v8::Value> value)
     {
         FileList* fileList = V8FileList::toNative(value.As<v8::Object>());
         if (!fileList)
             return;
-        m_writer.writeFileList(*fileList);
         unsigned length = fileList->length();
-        for (unsigned i = 0; i < length; ++i)
-            m_blobDataHandles.add(fileList->item(i)->uuid(), fileList->item(i)->blobDataHandle());
+        Vector<int> blobIndices;
+        bool useBlobIndices = false;
+        for (unsigned i = 0; i < length; ++i) {
+            int blobIndex = -1;
+            const File* file = fileList->item(i);
+            m_blobDataHandles.add(file->uuid(), file->blobDataHandle());
+            if (appendFileInfo(file->uuid(), file->path(), file->name(), file->type(), &blobIndex)) {
+                ASSERT(!i || useBlobIndices);
+                ASSERT(blobIndex >= 0);
+                useBlobIndices = true;
+                blobIndices.append(blobIndex);
+            }
+        }
+        if (useBlobIndices) {
+            m_writer.writeFileList(blobIndices);
+        } else {
+            m_writer.writeFileList(*fileList);
+        }
     }
 
     void writeImageData(v8::Handle<v8::Value> value)
     {
         ImageData* imageData = V8ImageData::toNative(value.As<v8::Object>());
         if (!imageData)
             return;
         Uint8ClampedArray* pixelArray = imageData->data();
         m_writer.writeImageData(imageData->width(), imageData->height(), pixelArray->data(), pixelArray->length());
     }
@@ skipping 90 matching lines @@
 
     // Marks object as having been visited by the serializer and assigns it a unique object reference ID.
     // An object may only be greyed once.
     void greyObject(const v8::Handle<v8::Object>& object)
     {
         ASSERT(!m_objectPool.contains(object));
         uint32_t objectReference = m_nextObjectReference++;
         m_objectPool.set(object, objectReference);
     }
 
+    bool appendBlobInfo(const String& uuid, const String& type, unsigned long long size, int* index)
+    {
+        if (!m_blobInfo)
+            return false;
+        *index = m_blobInfo->size();
+        m_blobInfo->append(BlobInfo(uuid, type, size));
+        return true;
+    }
+
+    bool appendFileInfo(const String& uuid, const String& filePath, const String& fileName, const String& type, int* index)
+    {
+        if (!m_blobInfo)
+            return false;
+        *index = m_blobInfo->size();
+        m_blobInfo->append(BlobInfo(uuid, filePath, fileName, type));
+        return true;
+    }
+
     Writer& m_writer;
     v8::TryCatch& m_tryCatch;
     int m_depth;
     int m_execDepth;
     Status m_status;
     typedef V8ObjectMap<v8::Object, uint32_t> ObjectPool;
     ObjectPool m_objectPool;
     ObjectPool m_transferredMessagePorts;
     ObjectPool m_transferredArrayBuffers;
     uint32_t m_nextObjectReference;
+    Vector<BlobInfo>* m_blobInfo;
     BlobDataHandleMap& m_blobDataHandles;
     v8::Isolate* m_isolate;
 };
 
 Serializer::StateBase* Serializer::doSerializeImpl(v8::Handle<v8::Value> value, StateBase* next)
 {
     m_writer.writeReferenceCount(m_nextObjectReference);
     uint32_t objectReference;
     uint32_t arrayBufferIndex;
     WrapperWorldType currentWorldType = worldType(m_isolate);
@@ skipping 95 matching lines @@
     virtual bool newObject() = 0;
     virtual bool completeObject(uint32_t numProperties, v8::Handle<v8::Value>*) = 0;
     virtual bool completeSparseArray(uint32_t numProperties, uint32_t length, v8::Handle<v8::Value>*) = 0;
     virtual bool completeDenseArray(uint32_t numProperties, uint32_t length, v8::Handle<v8::Value>*) = 0;
 };
 
 // Reader is responsible for deserializing primitive types and
 // restoring information about saved objects of composite types.
 class Reader {
 public:
-    Reader(const uint8_t* buffer, int length, v8::Isolate* isolate,  const BlobDataHandleMap& blobDataHandles)
+    Reader(const uint8_t* buffer, int length, v8::Isolate* isolate, const Vector<BlobInfo>* blobInfo, BlobDataHandleMap& blobDataHandles)
         : m_buffer(buffer)
         , m_length(length)
         , m_position(0)
         , m_version(0)
         , m_isolate(isolate)
+        , m_blobInfo(blobInfo)
         , m_blobDataHandles(blobDataHandles)
     {
         ASSERT(!(reinterpret_cast<size_t>(buffer) & 1));
         ASSERT(length >= 0);
     }
 
     bool isEof() const { return m_position >= m_length; }
 
     bool read(v8::Handle<v8::Value>* value, CompositeCreator& creator)
     {
@@ skipping 495 matching lines @@
         return true;
     }
 
     bool readBlob(v8::Handle<v8::Value>* value)
     {
         if (m_version < 3)
             return false;
         String uuid;
         String type;
         uint64_t size;
-        if (!readWebCoreString(&uuid))
-            return false;
-        if (!readWebCoreString(&type))
-            return false;
-        if (!doReadUint64(&size))
-            return false;
+        if (m_blobInfo) {
+            uint32_t index;
+            if (!doReadUint32(&index) || index >= m_blobInfo->size())
+                return false;
+            const BlobInfo& info = (*m_blobInfo)[index];
+            uuid = info.uuid();
+            type = info.type();
+            size = info.size();
+        } else {
+            if (!readWebCoreString(&uuid))
+                return false;
+            if (!readWebCoreString(&type))
+                return false;
+            if (!doReadUint64(&size))
+                return false;
+        }
         RefPtr<Blob> blob = Blob::create(getOrCreateBlobDataHandle(uuid, type, size));
         *value = toV8(blob.release(), v8::Handle<v8::Object>(), m_isolate);
         return true;
     }
 
     bool readDOMFileSystem(v8::Handle<v8::Value>* value)
     {
         uint32_t type;
         String name;
         String url;
         if (!doReadUint32(&type))
             return false;
         if (!readWebCoreString(&name))
             return false;
         if (!readWebCoreString(&url))
             return false;
         RefPtr<DOMFileSystem> fs = DOMFileSystem::create(getExecutionContext(), name, static_cast<WebCore::FileSystemType>(type), KURL(ParsedURLString, url));
         *value = toV8(fs.release(), v8::Handle<v8::Object>(), m_isolate);
         return true;
     }
 
     bool readFile(v8::Handle<v8::Value>* value)
     {
-        RefPtr<File> file = doReadFileHelper();
+        RefPtr<File> file = readSingleFile();
         if (!file)
             return false;
+
         *value = toV8(file.release(), v8::Handle<v8::Object>(), m_isolate);
         return true;
     }
 
     bool readFileList(v8::Handle<v8::Value>* value)
     {
         if (m_version < 3)
             return false;
         uint32_t length;
         if (!doReadUint32(&length))
             return false;
         RefPtr<FileList> fileList = FileList::create();
         for (unsigned i = 0; i < length; ++i) {
-            RefPtr<File> file = doReadFileHelper();
+            RefPtr<File> file = readSingleFile();
             if (!file)
                 return false;
-            fileList->append(file.release());
+            fileList->append(file.get());
         }
         *value = toV8(fileList.release(), v8::Handle<v8::Object>(), m_isolate);
         return true;
     }
 
-    PassRefPtr<File> doReadFileHelper()
+    PassRefPtr<File> readSingleFile()
     {
-        if (m_version < 3)
-            return 0;
+        RefPtr<File> file;
+        if (m_blobInfo) {
+            uint32_t index;
+            if (!doReadUint32(&index) || index >= m_blobInfo->size())
+                return file;
+            const BlobInfo& info = (*m_blobInfo)[index];
+            file = File::create(info.filePath(), info.fileName(), getOrCreateBlobDataHandle(info.uuid(), info.type(), info.size()), info.lastModified(), info.size());
+            return file;
+        }
         String path;
         String uuid;
         String type;
         if (!readWebCoreString(&path))
-            return 0;
+            return file;
         if (!readWebCoreString(&uuid))
-            return 0;
+            return file;
         if (!readWebCoreString(&type))
-            return 0;
+            return file;
         return File::create(path, getOrCreateBlobDataHandle(uuid, type));
     }
 
     template<class T>
     bool doReadUintHelper(T* value)
     {
         *value = 0;
         uint8_t currentByte;
         int shift = 0;
         do {
@@ skipping 30 matching lines @@
     {
         // The containing ssv may have a BDH for this uuid if this ssv is just being
         // passed from main to worker thread (for example). We use those values when creating
         // the new blob instead of cons'ing up a new BDH.
         //
         // FIXME: Maybe we should require that it work that way where the ssv must have a BDH for any
         // blobs it comes across during deserialization. Would require callers to explicitly populate
         // the collection of BDH's for blobs to work, which would encourage lifetimes to be considered
         // when passing ssv's around cross process. At present, we get 'lucky' in some cases because
         // the blob in the src process happens to still exist at the time the dest process is deserializing.
-        // For example in sharedWorker.postMesssage(...).
+        // For example in sharedWorker.postMessage(...).
         BlobDataHandleMap::const_iterator it = m_blobDataHandles.find(uuid);
         if (it != m_blobDataHandles.end()) {
             // make assertions about type and size?
             return it->value;
         }
         return BlobDataHandle::create(uuid, type, size);
     }
 
     const uint8_t* m_buffer;
     const unsigned m_length;
     unsigned m_position;
     uint32_t m_version;
     v8::Isolate* m_isolate;
-    const BlobDataHandleMap& m_blobDataHandles;
+    const Vector<BlobInfo>* m_blobInfo;
+    BlobDataHandleMap m_blobDataHandles;
 };
 
 
 typedef Vector<WTF::ArrayBufferContents, 1> ArrayBufferContentsArray;
 
 class Deserializer : public CompositeCreator {
 public:
     Deserializer(Reader& reader, MessagePortArray* messagePorts, ArrayBufferContentsArray* arrayBufferContents)
         : m_reader(reader)
         , m_transferredMessagePorts(messagePorts)
@@ skipping 242 matching lines @@
     MessagePortArray* m_transferredMessagePorts;
     ArrayBufferContentsArray* m_arrayBufferContents;
     Vector<v8::Handle<v8::Object> > m_arrayBuffers;
     uint32_t m_version;
 };
 
 } // namespace
 
 PassRefPtr<SerializedScriptValue> SerializedScriptValue::create(v8::Handle<v8::Value> value, MessagePortArray* messagePorts, ArrayBufferArray* arrayBuffers, bool& didThrow, v8::Isolate* isolate)
 {
-    return adoptRef(new SerializedScriptValue(value, messagePorts, arrayBuffers, didThrow, isolate));
+    return adoptRef(new SerializedScriptValue(value, messagePorts, arrayBuffers, 0, didThrow, isolate));
+}
+
+PassRefPtr<SerializedScriptValue> SerializedScriptValue::create(v8::Handle<v8::Value> value, MessagePortArray* messagePorts, ArrayBufferArray* arrayBuffers, Vector<BlobInfo>* blobInfo, bool& didThrow, v8::Isolate* isolate)
+{
+    return adoptRef(new SerializedScriptValue(value, messagePorts, arrayBuffers, blobInfo, didThrow, isolate));
 }
 
 PassRefPtr<SerializedScriptValue> SerializedScriptValue::createAndSwallowExceptions(v8::Handle<v8::Value> value, v8::Isolate* isolate)
 {
     bool didThrow;
-    return adoptRef(new SerializedScriptValue(value, 0, 0, didThrow, isolate, DoNotThrowExceptions));
+    return adoptRef(new SerializedScriptValue(value, 0, 0, 0, didThrow, isolate, DoNotThrowExceptions));
 }
 
-PassRefPtr<SerializedScriptValue> SerializedScriptValue::create(const ScriptValue& value, bool& didThrow, ScriptState* state)
+PassRefPtr<SerializedScriptValue> SerializedScriptValue::create(const ScriptValue& value, Vector<BlobInfo>* blobInfo, bool& didThrow, ScriptState* state)
 {
     ScriptScope scope(state);
-    return adoptRef(new SerializedScriptValue(value.v8Value(), 0, 0, didThrow, state->isolate()));
+    return adoptRef(new SerializedScriptValue(value.v8Value(), 0, 0, blobInfo, didThrow, state->isolate()));
 }
 
 PassRefPtr<SerializedScriptValue> SerializedScriptValue::createFromWire(const String& data)
 {
     return adoptRef(new SerializedScriptValue(data));
 }
 
 PassRefPtr<SerializedScriptValue> SerializedScriptValue::createFromWireBytes(const Vector<uint8_t>& data)
 {
     // Decode wire data from big endian to host byte order.
@@ skipping 116 matching lines @@
             return nullptr;
         }
 
         neuterBinding(arrayBuffers[i].get());
         for (size_t j = 0; j < neuteredViews.size(); j++)
             neuterBinding(neuteredViews[j].get());
     }
     return contents.release();
 }
 
-SerializedScriptValue::SerializedScriptValue(v8::Handle<v8::Value> value, MessagePortArray* messagePorts, ArrayBufferArray* arrayBuffers, bool& didThrow, v8::Isolate* isolate, ExceptionPolicy policy)
+SerializedScriptValue::SerializedScriptValue(v8::Handle<v8::Value> value, MessagePortArray* messagePorts, ArrayBufferArray* arrayBuffers, Vector<BlobInfo>* blobInfo, bool& didThrow, v8::Isolate* isolate, ExceptionPolicy policy)
     : m_externallyAllocatedMemory(0)
 {
     didThrow = false;
     Writer writer(isolate);
     Serializer::Status status;
     {
         v8::TryCatch tryCatch;
-        Serializer serializer(writer, messagePorts, arrayBuffers, m_blobDataHandles, tryCatch, isolate);
+        Serializer serializer(writer, messagePorts, arrayBuffers, blobInfo, m_blobDataHandles, tryCatch, isolate);
         status = serializer.serialize(value);
         if (status == Serializer::JSException) {
             didThrow = true;
             // If there was a JS exception thrown, re-throw it.
             if (policy == ThrowExceptions)
                 tryCatch.ReThrow();
             return;
         }
     }
     switch (status) {
@@ skipping 30 matching lines @@
 }
 
 SerializedScriptValue::SerializedScriptValue(const String& wireData)
     : m_externallyAllocatedMemory(0)
 {
     m_data = wireData.isolatedCopy();
 }
 
 v8::Handle<v8::Value> SerializedScriptValue::deserialize(MessagePortArray* messagePorts)
 {
-    return deserialize(v8::Isolate::GetCurrent(), messagePorts);
+    return deserialize(v8::Isolate::GetCurrent(), messagePorts, 0);
 }
 
-v8::Handle<v8::Value> SerializedScriptValue::deserialize(v8::Isolate* isolate, MessagePortArray* messagePorts)
+v8::Handle<v8::Value> SerializedScriptValue::deserialize(v8::Isolate* isolate, MessagePortArray* messagePorts, const Vector<BlobInfo>* blobInfo)
 {
     if (!m_data.impl())
         return v8NullWithCheck(isolate);
     COMPILE_ASSERT(sizeof(BufferValueType) == 2, BufferValueTypeIsTwoBytes);
     m_data.ensure16Bit();
     // FIXME: SerializedScriptValue shouldn't use String for its underlying
     // storage. Instead, it should use SharedBuffer or Vector<uint8_t>. The
     // information stored in m_data isn't even encoded in UTF-16. Instead,
     // unicode characters are encoded as UTF-8 with two code units per UChar.
-    Reader reader(reinterpret_cast<const uint8_t*>(m_data.impl()->characters16()), 2 * m_data.length(), isolate, m_blobDataHandles);
+    Reader reader(reinterpret_cast<const uint8_t*>(m_data.impl()->characters16()), 2 * m_data.length(), isolate, blobInfo, m_blobDataHandles);
     Deserializer deserializer(reader, messagePorts, m_arrayBufferContentsArray.get());
 
     // deserialize() can run arbitrary script (e.g., setters), which could result in |this| being destroyed.
     // Holding a RefPtr ensures we are alive (along with our internal data) throughout the operation.
     RefPtr<SerializedScriptValue> protect(this);
     return deserializer.deserialize();
 }
 
 void SerializedScriptValue::registerMemoryAllocatedWithCurrentScriptContext()
 {
     if (m_externallyAllocatedMemory)
         return;
     m_externallyAllocatedMemory = static_cast<intptr_t>(m_data.length());
     v8::V8::AdjustAmountOfExternalAllocatedMemory(m_externallyAllocatedMemory);
 }
 
 SerializedScriptValue::~SerializedScriptValue()
 {
     // If the allocated memory was not registered before, then this class is likely
     // used in a context other then Worker's onmessage environment and the presence of
     // current v8 context is not guaranteed. Avoid calling v8 then.
     if (m_externallyAllocatedMemory) {
         ASSERT(v8::Isolate::GetCurrent());
         v8::V8::AdjustAmountOfExternalAllocatedMemory(-m_externallyAllocatedMemory);
     }
 }
 
 } // namespace WebCore