bindings: preparation for fixing incorrect dependency of SerializedScriptValue.

Source/bindings/core/v8/ScriptValueSerializer.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ScriptValueSerializer_h
+#define ScriptValueSerializer_h
+
+#include "bindings/core/v8/SerializationTag.h"
+#include "bindings/core/v8/SerializedScriptValue.h"
+#include "bindings/core/v8/V8Binding.h"
+#include "public/platform/WebCrypto.h"
+#include "public/platform/WebCryptoKey.h"
+#include "public/platform/WebCryptoKeyAlgorithm.h"
+#include "wtf/ArrayBufferContents.h"
+#include "wtf/HashMap.h"
+#include "wtf/Noncopyable.h"
+#include "wtf/Vector.h"
+#include "wtf/text/WTFString.h"
+#include <v8.h>
+
+namespace WTF {
+
+class ArrayBuffer;
+class ArrayBufferView;
+
+}
+
+namespace blink {
+
+class File;
+class FileList;
+
+namespace SerializedScriptValueInternal {
+
+typedef Vector<WTF::ArrayBufferContents, 1> ArrayBufferContentsArray;
+
+// V8ObjectMap is a map from V8 objects to arbitrary values of type T.
+// V8 objects (or handles to V8 objects) cannot be used as keys in ordinary wtf::HashMaps;
+// this class should be used instead. GCObject must be a subtype of v8::Object.
+// Suggested usage:
+//     V8ObjectMap<v8::Object, int> map;
+//     v8::Handle<v8::Object> obj = ...;
+//     map.set(obj, 42);
+template<typename GCObject, typename T>
+class V8ObjectMap {
+public:
+    bool contains(const v8::Handle<GCObject>& handle)
+    {
+        return m_map.contains(*handle);
+    }
+
+    bool tryGet(const v8::Handle<GCObject>& handle, T* valueOut)
+    {
+        typename HandleToT::iterator result = m_map.find(*handle);
+        if (result != m_map.end()) {
+            *valueOut = result->value;
+            return true;
+        }
+        return false;
+    }
+
+    void set(const v8::Handle<GCObject>& handle, const T& value)
+    {
+        m_map.set(*handle, value);
+    }
+
+private:
+    // This implementation uses GetIdentityHash(), which sets a hidden property on the object containing
+    // a random integer (or returns the one that had been previously set). This ensures that the table
+    // never needs to be rebuilt across garbage collections at the expense of doing additional allocation
+    // and making more round trips into V8. Note that since GetIdentityHash() is defined only on
+    // v8::Objects, this V8ObjectMap cannot be used to map v8::Strings to T (because the public V8 API
+    // considers a v8::String to be a v8::Primitive).
+
+    // If V8 exposes a way to get at the address of the object held by a handle, then we can produce
+    // an alternate implementation that does not need to do any V8-side allocation; however, it will
+    // need to rehash after every garbage collection because a key object may have been moved.
+    template<typename G>
+    struct V8HandlePtrHash {
+        static v8::Handle<G> unsafeHandleFromRawValue(const G* value)
+        {
+            const v8::Handle<G>* handle = reinterpret_cast<const v8::Handle<G>*>(&value);
+            return *handle;
+        }
+
+        static unsigned hash(const G* key)
+        {
+            return static_cast<unsigned>(unsafeHandleFromRawValue(key)->GetIdentityHash());
+        }
+        static bool equal(const G* a, const G* b)
+        {
+            return unsafeHandleFromRawValue(a) == unsafeHandleFromRawValue(b);
+        }
+        // For HashArg.
+        static const bool safeToCompareToEmptyOrDeleted = false;
+    };
+
+    typedef WTF::HashMap<GCObject*, T, V8HandlePtrHash<GCObject> > HandleToT;
+    HandleToT m_map;
+};
+
+// Writer is responsible for serializing primitive types and storing
+// information used to reconstruct composite types.
+class Writer {
+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(Writer);
+public:
+    typedef UChar BufferValueType;
+
+    Writer()
+        : m_position(0)
+    {
+    }
+
+    // Write functions for primitive types.
+
+    void writeUndefined();
+    void writeNull();
+    void writeTrue();
+    void writeFalse();
+    void writeBooleanObject(bool value);
+    void writeOneByteString(v8::Handle<v8::String>&);
+    void writeUCharString(v8::Handle<v8::String>&);
+    void writeStringObject(const char* data, int length);
+    void writeWebCoreString(const String&);
+    void writeVersion();
+    void writeInt32(int32_t value);
+    void writeUint32(uint32_t value);
+    void writeDate(double numberValue);
+    void writeNumber(double number);
+    void writeNumberObject(double number);
+    void writeBlob(const String& uuid, const String& type, unsigned long long size);
+    void writeBlobIndex(int blobIndex);
+    void writeDOMFileSystem(int type, const String& name, const String& url);
+    void writeFile(const File&);
+    void writeFileIndex(int blobIndex);
+    void writeFileList(const FileList&);
+    void writeFileListIndex(const Vector<int>& blobIndices);
+    bool writeCryptoKey(const WebCryptoKey&);
+    void writeArrayBuffer(const ArrayBuffer&);
+    void writeArrayBufferView(const ArrayBufferView&);
+    void writeImageData(uint32_t width, uint32_t height, const uint8_t* pixelData, uint32_t pixelDataLength);
+    void writeRegExp(v8::Local<v8::String> pattern, v8::RegExp::Flags);
+    void writeTransferredMessagePort(uint32_t index);
+    void writeTransferredArrayBuffer(uint32_t index);
+    void writeObjectReference(uint32_t reference);
+    void writeObject(uint32_t numProperties);
+    void writeSparseArray(uint32_t numProperties, uint32_t length);
+    void writeDenseArray(uint32_t numProperties, uint32_t length);
+    String takeWireString();
+    void writeReferenceCount(uint32_t numberOfReferences);
+    void writeGenerateFreshObject();
+    void writeGenerateFreshSparseArray(uint32_t length);
+    void writeGenerateFreshDenseArray(uint32_t length);
+
+protected:
+    void doWriteFile(const File&);
+    void doWriteArrayBuffer(const ArrayBuffer&);
+    void doWriteString(const char* data, int length);
+    void doWriteWebCoreString(const String&);
+    void doWriteHmacKey(const WebCryptoKey&);
+    void doWriteAesKey(const WebCryptoKey&);
+    void doWriteRsaHashedKey(const WebCryptoKey&);
+    void doWriteAlgorithmId(WebCryptoAlgorithmId);
+    void doWriteKeyUsages(const WebCryptoKeyUsageMask usages, bool extractable);
+    int bytesNeededToWireEncode(uint32_t value);
+
+    template<class T>
+    void doWriteUintHelper(T value)
+    {
+        while (true) {
+            uint8_t b = (value & SerializedScriptValue::varIntMask);
+            value >>= SerializedScriptValue::varIntShift;
+            if (!value) {
+                append(b);
+                break;
+            }
+            append(b | (1 << SerializedScriptValue::varIntShift));
+        }
+    }
+
+    void doWriteUint32(uint32_t value);
+    void doWriteUint64(uint64_t value);
+    void doWriteNumber(double number);
+    void append(SerializationTag);
+    void append(uint8_t b);
+    void append(const uint8_t* data, int length);
+    void ensureSpace(unsigned extra);
+    void fillHole();
+    uint8_t* byteAt(int position);
+    int v8StringWriteOptions();
+
+private:
+    Vector<BufferValueType> m_buffer;
+    unsigned m_position;
+};
+
+class Serializer {
+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(Serializer);
+protected:
+    class StateBase;
+public:
+    enum Status {
+        Success,
+        InputError,
+        DataCloneError,
+        JSException
+    };
+
+    Serializer(Writer&, MessagePortArray* messagePorts, ArrayBufferArray* arrayBuffers, WebBlobInfoArray*, BlobDataHandleMap& blobDataHandles, v8::TryCatch&, ScriptState*);
+    v8::Isolate* isolate() { return m_scriptState->isolate(); }
+
+    Status serialize(v8::Handle<v8::Value>);
+    String errorMessage() { return m_errorMessage; }
+
+    // Functions used by serialization states.
+    Serializer::StateBase* doSerialize(v8::Handle<v8::Value>, Serializer::StateBase* next);
+
+    StateBase* doSerializeArrayBuffer(v8::Handle<v8::Value> arrayBuffer, StateBase* next);
+    StateBase* checkException(StateBase*);
+    StateBase* writeObject(uint32_t numProperties, StateBase*);
+    StateBase* writeSparseArray(uint32_t numProperties, uint32_t length, StateBase*);
+    StateBase* writeDenseArray(uint32_t numProperties, uint32_t length, StateBase*);
+
+protected:
+    class StateBase {
+        WTF_MAKE_NONCOPYABLE(StateBase);
+    public:
+        virtual ~StateBase() { }
+
+        // Link to the next state to form a stack.
+        StateBase* nextState() { return m_next; }
+
+        // Composite object we're processing in this state.
+        v8::Handle<v8::Value> composite() { return m_composite; }
+
+        // Serializes (a part of) the current composite and returns
+        // the next state to process or null when this is the final
+        // state.
+        virtual StateBase* advance(Serializer&) = 0;
+
+    protected:
+        StateBase(v8::Handle<v8::Value> composite, StateBase* next)
+            : m_composite(composite)
+            , m_next(next)
+        {
+        }
+
+    private:
+        v8::Handle<v8::Value> m_composite;
+        StateBase* m_next;
+    };
+
+    // Dummy state that is used to signal serialization errors.
+    class ErrorState final : public StateBase {
+    public:
+        ErrorState()
+            : StateBase(v8Undefined(), 0)
+        {
+        }
+
+        virtual StateBase* advance(Serializer&) override
+        {
+            delete this;
+            return 0;
+        }
+    };
+
+    template <typename T>
+    class State : public StateBase {
+    public:
+        v8::Handle<T> composite() { return v8::Handle<T>::Cast(StateBase::composite()); }
+
+    protected:
+        State(v8::Handle<T> composite, StateBase* next)
+            : StateBase(composite, next)
+        {
+        }
+    };
+
+    class AbstractObjectState : public State<v8::Object> {
+    public:
+        AbstractObjectState(v8::Handle<v8::Object> object, StateBase* next)
+            : State<v8::Object>(object, next)
+            , m_index(0)
+            , m_numSerializedProperties(0)
+            , m_nameDone(false)
+        {
+        }
+
+    protected:
+        virtual StateBase* objectDone(unsigned numProperties, Serializer&) = 0;
+
+        StateBase* serializeProperties(bool ignoreIndexed, Serializer&);
+        v8::Local<v8::Array> m_propertyNames;
+
+    private:
+        v8::Local<v8::Value> m_propertyName;
+        unsigned m_index;
+        unsigned m_numSerializedProperties;
+        bool m_nameDone;
+    };
+
+    class ObjectState final : public AbstractObjectState {
+    public:
+        ObjectState(v8::Handle<v8::Object> object, StateBase* next)
+            : AbstractObjectState(object, next)
+        {
+        }
+
+        virtual StateBase* advance(Serializer&) override;
+
+    protected:
+        virtual StateBase* objectDone(unsigned numProperties, Serializer&) override;
+    };
+
+    class DenseArrayState final : public AbstractObjectState {
+    public:
+        DenseArrayState(v8::Handle<v8::Array> array, v8::Handle<v8::Array> propertyNames, StateBase* next, v8::Isolate* isolate)
+            : AbstractObjectState(array, next)
+            , m_arrayIndex(0)
+            , m_arrayLength(array->Length())
+        {
+            m_propertyNames = v8::Local<v8::Array>::New(isolate, propertyNames);
+        }
+
+        virtual StateBase* advance(Serializer&) override;
+
+    protected:
+        virtual StateBase* objectDone(unsigned numProperties, Serializer&) override;
+
+    private:
+        uint32_t m_arrayIndex;
+        uint32_t m_arrayLength;
+    };
+
+    class SparseArrayState final : public AbstractObjectState {
+    public:
+        SparseArrayState(v8::Handle<v8::Array> array, v8::Handle<v8::Array> propertyNames, StateBase* next, v8::Isolate* isolate)
+            : AbstractObjectState(array, next)
+        {
+            m_propertyNames = v8::Local<v8::Array>::New(isolate, propertyNames);
+        }
+
+        virtual StateBase* advance(Serializer&) override;
+
+    protected:
+        virtual StateBase* objectDone(unsigned numProperties, Serializer&) override;
+    };
+
+private:
+    StateBase* push(StateBase* state)
+    {
+        ASSERT(state);
+        ++m_depth;
+        return checkComposite(state) ? state : handleError(InputError, "Value being cloned is either cyclic or too deeply nested.", state);
+    }
+
+    StateBase* pop(StateBase* state)
+    {
+        ASSERT(state);
+        --m_depth;
+        StateBase* next = state->nextState();
+        delete state;
+        return next;
+    }
+
+    bool checkComposite(StateBase* top);
+    void writeString(v8::Handle<v8::Value>);
+    void writeStringObject(v8::Handle<v8::Value>);
+    void writeNumberObject(v8::Handle<v8::Value>);
+    void writeBooleanObject(v8::Handle<v8::Value>);
+    StateBase* writeBlob(v8::Handle<v8::Value>, StateBase* next);
+    StateBase* writeDOMFileSystem(v8::Handle<v8::Value>, StateBase* next);
+    StateBase* writeFile(v8::Handle<v8::Value>, StateBase* next);
+    StateBase* writeFileList(v8::Handle<v8::Value>, StateBase* next);
+    bool writeCryptoKey(v8::Handle<v8::Value>);
+    void writeImageData(v8::Handle<v8::Value>);
+    void writeRegExp(v8::Handle<v8::Value>);
+    StateBase* writeAndGreyArrayBufferView(v8::Handle<v8::Object>, StateBase* next);
+    StateBase* writeArrayBuffer(v8::Handle<v8::Value>, StateBase* next);
+    StateBase* writeTransferredArrayBuffer(v8::Handle<v8::Value>, uint32_t index, StateBase* next);
+    static bool shouldSerializeDensely(uint32_t length, uint32_t propertyCount);
+
+    StateBase* startArrayState(v8::Handle<v8::Array>, StateBase* next);
+    StateBase* startObjectState(v8::Handle<v8::Object>, StateBase* next);
+
+    // 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>&);
+    bool appendBlobInfo(const String& uuid, const String& type, unsigned long long size, int* index);
+    bool appendFileInfo(const File*, int* index);
+
+protected:
+    StateBase* handleError(Status errorStatus, const String& message, StateBase*);
+
+    Writer& writer() { return m_writer; }
+    uint32_t nextObjectReference() const { return m_nextObjectReference; }
+
+private:
+    RefPtr<ScriptState> m_scriptState;
+    Writer& m_writer;
+    v8::TryCatch& m_tryCatch;
+    int m_depth;
+    Status m_status;
+    String m_errorMessage;
+    typedef V8ObjectMap<v8::Object, uint32_t> ObjectPool;
+    ObjectPool m_objectPool;
+    ObjectPool m_transferredMessagePorts;
+    ObjectPool m_transferredArrayBuffers;
+    uint32_t m_nextObjectReference;
+    WebBlobInfoArray* m_blobInfo;
+    BlobDataHandleMap& m_blobDataHandles;
+};
+
+// Interface used by Reader to create objects of composite types.
+class CompositeCreator {
+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(CompositeCreator);
+public:
+    CompositeCreator() { }
+    virtual ~CompositeCreator() { }
+
+    virtual bool consumeTopOfStack(v8::Handle<v8::Value>*) = 0;
+    virtual uint32_t objectReferenceCount() = 0;
+    virtual void pushObjectReference(const v8::Handle<v8::Value>&) = 0;
+    virtual bool tryGetObjectFromObjectReference(uint32_t reference, v8::Handle<v8::Value>*) = 0;
+    virtual bool tryGetTransferredMessagePort(uint32_t index, v8::Handle<v8::Value>*) = 0;
+    virtual bool tryGetTransferredArrayBuffer(uint32_t index, v8::Handle<v8::Value>*) = 0;
+    virtual bool newSparseArray(uint32_t length) = 0;
+    virtual bool newDenseArray(uint32_t length) = 0;
+    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 {
+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(Reader);
+public:
+    Reader(const uint8_t* buffer, int length, const WebBlobInfoArray* blobInfo, BlobDataHandleMap& blobDataHandles, ScriptState* scriptState)
+        : m_scriptState(scriptState)
+        , m_buffer(buffer)
+        , m_length(length)
+        , m_position(0)
+        , m_version(0)
+        , m_blobInfo(blobInfo)
+        , m_blobDataHandles(blobDataHandles)
+    {
+        ASSERT(!(reinterpret_cast<size_t>(buffer) & 1));
+        ASSERT(length >= 0);
+    }
+
+    bool isEof() const { return m_position >= m_length; }
+
+    ScriptState* scriptState() const { return m_scriptState.get(); }
+
+protected:
+    v8::Isolate* isolate() const { return m_scriptState->isolate(); }
+    unsigned length() const { return m_length; }
+    unsigned position() const { return m_position; }
+
+    const uint8_t* allocate(uint32_t size)
+    {
+        const uint8_t* allocated = m_buffer + m_position;
+        m_position += size;
+        return allocated;
+    }
+
+public:
+    bool read(v8::Handle<v8::Value>*, CompositeCreator&);
+    bool readVersion(uint32_t& version);
+    void setVersion(uint32_t);
+
+private:
+    bool readTag(SerializationTag*);
+    bool readWebCoreString(String*);
+    bool readUint32(v8::Handle<v8::Value>*);
+    void undoReadTag();
+    bool readArrayBufferViewSubTag(ArrayBufferViewSubTag*);
+    bool readString(v8::Handle<v8::Value>*);
+    bool readUCharString(v8::Handle<v8::Value>*);
+    bool readStringObject(v8::Handle<v8::Value>*);
+    bool readInt32(v8::Handle<v8::Value>*);
+    bool readDate(v8::Handle<v8::Value>*);
+    bool readNumber(v8::Handle<v8::Value>*);
+    bool readNumberObject(v8::Handle<v8::Value>*);
+    bool readImageData(v8::Handle<v8::Value>*);
+    PassRefPtr<ArrayBuffer> doReadArrayBuffer();
+    bool readArrayBuffer(v8::Handle<v8::Value>*);
+    bool readArrayBufferView(v8::Handle<v8::Value>*, CompositeCreator&);
+    bool readRegExp(v8::Handle<v8::Value>*);
+    bool readBlob(v8::Handle<v8::Value>*, bool isIndexed);
+    bool readDOMFileSystem(v8::Handle<v8::Value>*);
+    bool readFile(v8::Handle<v8::Value>*, bool isIndexed);
+    bool readFileList(v8::Handle<v8::Value>*, bool isIndexed);
+    bool readCryptoKey(v8::Handle<v8::Value>*);
+    File* readFileHelper();
+    File* readFileIndexHelper();
+
+    template<class T>
+    bool doReadUintHelper(T* value)
+    {
+        *value = 0;
+        uint8_t currentByte;
+        int shift = 0;
+        do {
+            if (m_position >= m_length)
+                return false;
+            currentByte = m_buffer[m_position++];
+            *value |= ((currentByte & SerializedScriptValue::varIntMask) << shift);
+            shift += SerializedScriptValue::varIntShift;
+        } while (currentByte & (1 << SerializedScriptValue::varIntShift));
+        return true;
+    }
+
+    bool doReadUint32(uint32_t* value);
+    bool doReadUint64(uint64_t* value);
+    bool doReadNumber(double* number);
+    PassRefPtr<BlobDataHandle> getOrCreateBlobDataHandle(const String& uuid, const String& type, long long size = -1);
+    bool doReadHmacKey(WebCryptoKeyAlgorithm&, WebCryptoKeyType&);
+    bool doReadAesKey(WebCryptoKeyAlgorithm&, WebCryptoKeyType&);
+    bool doReadRsaHashedKey(WebCryptoKeyAlgorithm&, WebCryptoKeyType&);
+    bool doReadAlgorithmId(WebCryptoAlgorithmId&);
+    bool doReadKeyUsages(WebCryptoKeyUsageMask& usages, bool& extractable);
+
+private:
+    RefPtr<ScriptState> m_scriptState;
+    const uint8_t* m_buffer;
+    const unsigned m_length;
+    unsigned m_position;
+    uint32_t m_version;
+    const WebBlobInfoArray* m_blobInfo;
+    const BlobDataHandleMap& m_blobDataHandles;
+};
+
+class Deserializer : public CompositeCreator {
+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(Deserializer);
+public:
+    Deserializer(Reader& reader, MessagePortArray* messagePorts, ArrayBufferContentsArray* arrayBufferContents)
+        : m_reader(reader)
+        , m_transferredMessagePorts(messagePorts)
+        , m_arrayBufferContents(arrayBufferContents)
+        , m_arrayBuffers(arrayBufferContents ? arrayBufferContents->size() : 0)
+        , m_version(0)
+    {
+    }
+
+    v8::Handle<v8::Value> deserialize();
+    virtual bool newSparseArray(uint32_t) override;
+    virtual bool newDenseArray(uint32_t length) override;
+    virtual bool consumeTopOfStack(v8::Handle<v8::Value>*) override;
+    virtual bool newObject() override;
+    virtual bool completeObject(uint32_t numProperties, v8::Handle<v8::Value>*) override;
+    virtual bool completeSparseArray(uint32_t numProperties, uint32_t length, v8::Handle<v8::Value>*) override;
+    virtual bool completeDenseArray(uint32_t numProperties, uint32_t length, v8::Handle<v8::Value>*) override;
+    virtual void pushObjectReference(const v8::Handle<v8::Value>&) override;
+    virtual bool tryGetTransferredMessagePort(uint32_t index, v8::Handle<v8::Value>*) override;
+    virtual bool tryGetTransferredArrayBuffer(uint32_t index, v8::Handle<v8::Value>*) override;
+    virtual bool tryGetObjectFromObjectReference(uint32_t reference, v8::Handle<v8::Value>*) override;
+    virtual uint32_t objectReferenceCount() override;
+
+protected:
+    Reader& reader() { return m_reader; }
+    bool read(v8::Local<v8::Value>*);
+
+private:
+    bool initializeObject(v8::Handle<v8::Object>, uint32_t numProperties, v8::Handle<v8::Value>*);
+    bool doDeserialize();
+    void push(v8::Local<v8::Value> value) { m_stack.append(value); };
+    void pop(unsigned length)
+    {
+        ASSERT(length <= m_stack.size());
+        m_stack.shrink(m_stack.size() - length);
+    }
+    unsigned stackDepth() const { return m_stack.size(); }
+
+    v8::Local<v8::Value> element(unsigned index);
+    void openComposite(const v8::Local<v8::Value>&);
+    bool closeComposite(v8::Handle<v8::Value>*);
+
+    Reader& m_reader;
+    Vector<v8::Local<v8::Value> > m_stack;
+    Vector<v8::Handle<v8::Value> > m_objectPool;
+    Vector<uint32_t> m_openCompositeReferenceStack;
+    RawPtrWillBeMember<MessagePortArray> m_transferredMessagePorts;
+    ArrayBufferContentsArray* m_arrayBufferContents;
+    Vector<v8::Handle<v8::Object> > m_arrayBuffers;
+    uint32_t m_version;
+};
+
+} // namespace SerializedScriptValueInternal
+
+} // namespace blink
+
+#endif // ScriptValueSerializer_h