/*

 * Copyright (C) 2008 Apple 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:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 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 MessagePort_h

#define MessagePort_h

#include "AtomicStringHash.h"

#include "EventListener.h"

#include "EventTarget.h"

#include "MessagePortChannel.h"

#include <wtf/OwnPtr.h>

#include <wtf/PassOwnPtr.h>

#include <wtf/PassRefPtr.h>

#include <wtf/RefPtr.h>

#include <wtf/Vector.h>

namespace WebCore {

    class AtomicStringImpl;

    class Event;

    class Frame;

    class MessagePort;

    class ScriptExecutionContext;

    class String;

    // The overwhelmingly common case is sending a single port, so handle that efficiently with an inline buffer of size 1.

    typedef Vector<RefPtr<MessagePort>, 1> MessagePortArray;

    class MessagePort : public RefCounted<MessagePort>, public EventTarget {

    public:

        static PassRefPtr<MessagePort> create(ScriptExecutionContext& scriptExecutionContext) { return adoptRef(new MessagePort(scriptExecutionContext)); }

        ~MessagePort();

        void postMessage(PassRefPtr<SerializedScriptValue> message, ExceptionCode&);

        void postMessage(PassRefPtr<SerializedScriptValue> message, const MessagePortArray*, ExceptionCode&);

        // FIXME: remove this when we update the ObjC bindings (bug #28774).

        void postMessage(PassRefPtr<SerializedScriptValue> message, MessagePort*, ExceptionCode&);

        void start();

        void close();

        void entangle(PassOwnPtr<MessagePortChannel>);

        PassOwnPtr<MessagePortChannel> disentangle(ExceptionCode&);

        // Disentangle an array of ports, returning the entangled channels.

        // Per section 8.3.3 of the HTML5 spec, generates an INVALID_STATE_ERR exception if any of the passed ports are null or not entangled.

        // Returns 0 if there is an exception, or if the passed-in array is 0/empty.

        static PassOwnPtr<MessagePortChannelArray> disentanglePorts(const MessagePortArray*, ExceptionCode&);

        // Entangles an array of channels, returning an array of MessagePorts in matching order.

        // Returns 0 if the passed array is 0/empty.

        static PassOwnPtr<MessagePortArray> entanglePorts(ScriptExecutionContext&, PassOwnPtr<MessagePortChannelArray>);

        void messageAvailable();

        bool started() const { return m_started; }

        void contextDestroyed();

        virtual ScriptExecutionContext* scriptExecutionContext() const;

        virtual MessagePort* toMessagePort() { return this; }

        void dispatchMessages();

        using RefCounted<MessagePort>::ref;

        using RefCounted<MessagePort>::deref;

        bool hasPendingActivity();

        void setOnmessage(PassRefPtr<EventListener> listener)

        {

            setAttributeEventListener(eventNames().messageEvent, listener);

            start();

        }

        EventListener* onmessage() { return getAttributeEventListener(eventNames().messageEvent); }

        // Returns null if there is no entangled port, or if the entangled port is run by a different thread.

        // Returns null otherwise.

        // NOTE: This is used solely to enable a GC optimization. Some platforms may not be able to determine ownership of the remote port (since it may live cross-process) - those platforms may always return null.

        MessagePort* locallyEntangledPort();

        // A port starts out its life entangled, and remains entangled until it is closed or is cloned.

        bool isEntangled() { return !m_closed && !isCloned(); }

        // A port is cloned if its entangled channel has been removed and sent to a new owner via postMessage().

        bool isCloned() { return !m_entangledChannel; }

    private:

        MessagePort(ScriptExecutionContext&);

        virtual void refEventTarget() { ref(); }

        virtual void derefEventTarget() { deref(); }

        virtual EventTargetData* eventTargetData();

        virtual EventTargetData* ensureEventTargetData();

        OwnPtr<MessagePortChannel> m_entangledChannel;

        bool m_started;

        bool m_closed;

        ScriptExecutionContext* m_scriptExecutionContext;

        EventTargetData m_eventTargetData;

    };

} // namespace WebCore

#endif // MessagePort_h