V8Binding/binding/V8MessagePortCustom.cpp

/*
* Copyright (C) 2009 Google Inc. All rights reserved.
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* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
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*     * Redistributions of source code must retain the above copyright
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* in the documentation and/or other materials provided with the
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*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "config.h"

#include "v8_binding.h"
#include "v8_custom.h"
#include "v8_proxy.h"

#include "V8Document.h"
#include "V8HTMLDocument.h"
#include "V8ObjectEventListener.h"

#include "ExceptionCode.h"
#include "MessagePort.h"

namespace WebCore {

// FIXME: merge these with XHR's CreateHiddenXHRDependency

// Use an array to hold dependents. It works like a ref-counted scheme.
// A value can be added more than once to the xhr object.
static void CreateHiddenDependency(v8::Local<v8::Object> object,
                                   v8::Local<v8::Value> value)
{
    ASSERT(V8Proxy::GetDOMWrapperType(object) == V8ClassIndex::MESSAGEPORT);
    v8::Local<v8::Value> cache = object->GetInternalField(V8Custom::kMessagePortRequestCacheIndex);
    if (cache->IsNull() || cache->IsUndefined()) {
        cache = v8::Array::New();
        object->SetInternalField(V8Custom::kMessagePortRequestCacheIndex, cache);
    }

    v8::Local<v8::Array> cacheArray = v8::Local<v8::Array>::Cast(cache);
    cacheArray->Set(v8::Integer::New(cacheArray->Length()), value);
}

static void RemoveHiddenDependency(v8::Local<v8::Object> object,
                                   v8::Local<v8::Value> value)
{
    ASSERT(V8Proxy::GetDOMWrapperType(object) == V8ClassIndex::MESSAGEPORT);
    v8::Local<v8::Value> cache = object->GetInternalField(V8Custom::kMessagePortRequestCacheIndex);
    ASSERT(cache->IsArray());
    v8::Local<v8::Array> cacheArray = v8::Local<v8::Array>::Cast(cache);
    for (int i = cacheArray->Length() - 1; i >= 0; i--) {
        v8::Local<v8::Value> cached = cacheArray->Get(v8::Integer::New(i));
        if (cached->StrictEquals(value)) {
            cacheArray->Delete(i);
            return;
        }
    }

  // We should only get here if we try to remove an event listener that was
  // never added.
}

ACCESSOR_GETTER(MessagePortOnmessage)
{
    INC_STATS("DOM.MessagePort.onmessage._get");
    MessagePort* messagePort = V8Proxy::ToNativeObject<MessagePort>(
        V8ClassIndex::MESSAGEPORT, info.Holder());
    if (messagePort->onmessage()) {
        V8ObjectEventListener* listener =
            static_cast<V8ObjectEventListener*>(messagePort->onmessage());
        v8::Local<v8::Object> v8Listener = listener->getListenerObject();
        return v8Listener;
    }
    return v8::Undefined();
}

ACCESSOR_SETTER(MessagePortOnmessage)
{
    INC_STATS("DOM.MessagePort.onmessage._set");
    MessagePort* messagePort = V8Proxy::ToNativeObject<MessagePort>(
        V8ClassIndex::MESSAGEPORT, info.Holder());
    if (value->IsNull()) {
        if (messagePort->onmessage()) {
            V8ObjectEventListener* listener =
                static_cast<V8ObjectEventListener*>(messagePort->onmessage());
            v8::Local<v8::Object> v8Listener = listener->getListenerObject();
            RemoveHiddenDependency(info.Holder(), v8Listener);
        }

        // Clear the listener
        messagePort->setOnmessage(0);

    } else {
        V8Proxy* proxy = V8Proxy::retrieve(messagePort->scriptExecutionContext());
        if (!proxy)
            return;

        RefPtr<EventListener> listener =
            proxy->FindOrCreateObjectEventListener(value, false);
        if (listener) {
            messagePort->setOnmessage(listener);
            CreateHiddenDependency(info.Holder(), value);
        }
    }
}

ACCESSOR_GETTER(MessagePortOnclose)
{
    INC_STATS("DOM.MessagePort.onclose._get");
    MessagePort* messagePort = V8Proxy::ToNativeObject<MessagePort>(
        V8ClassIndex::MESSAGEPORT, info.Holder());
    if (messagePort->onclose()) {
        V8ObjectEventListener* listener =
            static_cast<V8ObjectEventListener*>(messagePort->onclose());
        v8::Local<v8::Object> v8Listener = listener->getListenerObject();
        return v8Listener;
    }
    return v8::Undefined();
}

ACCESSOR_SETTER(MessagePortOnclose)
{
    INC_STATS("DOM.MessagePort.onclose._set");
    MessagePort* messagePort = V8Proxy::ToNativeObject<MessagePort>(
        V8ClassIndex::MESSAGEPORT, info.Holder());
    if (value->IsNull()) {
        if (messagePort->onclose()) {
            V8ObjectEventListener* listener =
                static_cast<V8ObjectEventListener*>(messagePort->onclose());
            v8::Local<v8::Object> v8Listener = listener->getListenerObject();
            RemoveHiddenDependency(info.Holder(), v8Listener);
        }

        // Clear the listener
        messagePort->setOnclose(0);
    } else {
        V8Proxy* proxy = V8Proxy::retrieve(messagePort->scriptExecutionContext());
        if (!proxy)
            return;

        RefPtr<EventListener> listener =
            proxy->FindOrCreateObjectEventListener(value, false);
        if (listener) {
            messagePort->setOnclose(listener);
            CreateHiddenDependency(info.Holder(), value);
        }
    }
}

CALLBACK_FUNC_DECL(MessagePortStartConversation)
{
    INC_STATS("DOM.MessagePort.StartConversation()");
    if (args.Length() < 1) {
        V8Proxy::ThrowError(V8Proxy::SYNTAX_ERROR, "Not enough arguments");
        return v8::Undefined();
    }

    MessagePort* messagePort = V8Proxy::ToNativeObject<MessagePort>(
        V8ClassIndex::MESSAGEPORT, args.Holder());

    V8Proxy* proxy = V8Proxy::retrieve(messagePort->scriptExecutionContext());
    if (!proxy)
        return v8::Undefined();

    RefPtr<MessagePort> port =
        messagePort->startConversation(messagePort->scriptExecutionContext(),
        ToWebCoreString(args[0]));
    v8::Handle<v8::Value> wrapper =
        V8Proxy::ToV8Object(V8ClassIndex::MESSAGEPORT, port.get());
    return wrapper;
}

CALLBACK_FUNC_DECL(MessagePortAddEventListener)
{
    INC_STATS("DOM.MessagePort.AddEventListener()");
    MessagePort* messagePort = V8Proxy::ToNativeObject<MessagePort>(
        V8ClassIndex::MESSAGEPORT, args.Holder());

    V8Proxy* proxy = V8Proxy::retrieve(messagePort->scriptExecutionContext());
    if (!proxy)
        return v8::Undefined();

    RefPtr<EventListener> listener =
        proxy->FindOrCreateObjectEventListener(args[1], false);
    if (listener) {
        String type = ToWebCoreString(args[0]);
        bool useCapture = args[2]->BooleanValue();
        messagePort->addEventListener(type, listener, useCapture);

        CreateHiddenDependency(args.Holder(), args[1]);
    }
    return v8::Undefined();
}

CALLBACK_FUNC_DECL(MessagePortRemoveEventListener)
{
    INC_STATS("DOM.MessagePort.RemoveEventListener()");
    MessagePort* messagePort = V8Proxy::ToNativeObject<MessagePort>(
        V8ClassIndex::MESSAGEPORT, args.Holder());

    V8Proxy* proxy = V8Proxy::retrieve(messagePort->scriptExecutionContext());
    if (!proxy)
        return v8::Undefined();  // probably leaked

    RefPtr<EventListener> listener =
        proxy->FindObjectEventListener(args[1], false);

    if (listener) {
        String type = ToWebCoreString(args[0]);
        bool useCapture = args[2]->BooleanValue();
        messagePort->removeEventListener(type, listener.get(), useCapture);

        RemoveHiddenDependency(args.Holder(), args[1]);
    }

    return v8::Undefined();
}

} // namespace WebCore