root/Source/modules/encryptedmedia/MediaKeySession.h

INCLUDED FROM

/*
 * Copyright (C) 2013 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 INC. AND ITS CONTRIBUTORS ``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 INC. OR ITS 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 MediaKeySession_h
#define MediaKeySession_h

#include "bindings/v8/ScriptWrappable.h"
#include "core/dom/ActiveDOMObject.h"
#include "core/events/EventTarget.h"
#include "heap/Handle.h"
#include "platform/Timer.h"
#include "public/platform/WebContentDecryptionModuleSession.h"
#include "wtf/Deque.h"
#include "wtf/PassRefPtr.h"
#include "wtf/RefCounted.h"
#include "wtf/Uint8Array.h"
#include "wtf/WeakPtr.h"
#include "wtf/text/WTFString.h"

namespace blink {
class WebContentDecryptionModule;
}

namespace WebCore {

class ExceptionState;
class GenericEventQueue;
class MediaKeyError;
class MediaKeys;

// References are held by JS only. However, even if all JS references are
// dropped, it won't be garbage collected until close event received or
// MediaKeys goes away (as determined by the validity of a WeakPtr). This allows
// the CDM to continue to fire events for this session, as long as the session
// is open.
//
// WeakPtr<MediaKeys> is used instead of having MediaKeys and MediaKeySession
// keep references to each other, and then having to inform the other object
// when it gets destroyed.
//
// Because this object controls the lifetime of the WebContentDecryptionModuleSession,
// it may outlive any JavaScript references as long as the MediaKeys object is alive.
// The WebContentDecryptionModuleSession has the same lifetime as this object.
class MediaKeySession FINAL
    : public RefCountedWillBeRefCountedGarbageCollected<MediaKeySession>, public ActiveDOMObject, public ScriptWrappable, public EventTargetWithInlineData
    , private blink::WebContentDecryptionModuleSession::Client {
    DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<MediaKeySession>);
public:
    static PassRefPtrWillBeRawPtr<MediaKeySession> create(ExecutionContext*, blink::WebContentDecryptionModule*, WeakPtr<MediaKeys>);
    virtual ~MediaKeySession();

    const String& keySystem() const { return m_keySystem; }
    String sessionId() const;

    void setError(MediaKeyError*);
    MediaKeyError* error() { return m_error.get(); }

    void initializeNewSession(const String& mimeType, const Uint8Array& initData);
    void update(Uint8Array* response, ExceptionState&);
    void release(ExceptionState&);

    void enqueueEvent(PassRefPtrWillBeRawPtr<Event>);

    // EventTarget
    virtual const AtomicString& interfaceName() const OVERRIDE;
    virtual ExecutionContext* executionContext() const OVERRIDE;

    // ActiveDOMObject
    virtual bool hasPendingActivity() const OVERRIDE;
    virtual void stop() OVERRIDE;

    void trace(Visitor*) { }

private:
    // A struct holding the pending action.
    struct PendingAction {
        enum Type {
            Update,
            Release
        };
        const Type type;
        const RefPtr<Uint8Array> data;

        static PassOwnPtr<PendingAction> CreatePendingUpdate(PassRefPtr<Uint8Array> data);
        static PassOwnPtr<PendingAction> CreatePendingRelease();
        ~PendingAction();

    private:
        PendingAction(Type, PassRefPtr<Uint8Array> data);
    };

    MediaKeySession(ExecutionContext*, blink::WebContentDecryptionModule*, WeakPtr<MediaKeys>);
    void actionTimerFired(Timer<MediaKeySession>*);

    // blink::WebContentDecryptionModuleSession::Client
    virtual void message(const unsigned char* message, size_t messageLength, const blink::WebURL& destinationURL) OVERRIDE;
    virtual void ready() OVERRIDE;
    virtual void close() OVERRIDE;
    virtual void error(MediaKeyErrorCode, unsigned long systemCode) OVERRIDE;

    String m_keySystem;
    RefPtr<MediaKeyError> m_error;
    OwnPtr<GenericEventQueue> m_asyncEventQueue;
    OwnPtr<blink::WebContentDecryptionModuleSession> m_session;

    // Used to determine if MediaKeys is still active.
    WeakPtr<MediaKeys> m_keys;

    // Is the CDM finished with this session?
    bool m_isClosed;

    Deque<OwnPtr<PendingAction> > m_pendingActions;
    Timer<MediaKeySession> m_actionTimer;
};

}

#endif // MediaKeySession_h