/*

 * Copyright (C) 2006, 2007, 2008 Apple Inc. All Rights Reserved.

 * Copyright (C) 2008 Collabora, Ltd. 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. ``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

 * 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.

 */

#include "config.h"

#include "PluginMessageThrottlerWin.h"

#include "PluginView.h"

#include <wtf/ASCIICType.h>

#include <wtf/CurrentTime.h>

using namespace WTF;

namespace WebCore {

// Set a timer to make sure we process any queued messages at least every 16ms.

// This value allows Flash 60 messages/second, which should be enough for video

// playback, and also gets us over the limit for kicking into high-resolution

// timer mode (see SharedTimerWin.cpp).

static const double MessageThrottleTimeInterval = 0.016;

// During a continuous stream of messages, process one every 5ms.

static const double MessageDirectProcessingInterval = 0.005;

PluginMessageThrottlerWin::PluginMessageThrottlerWin(PluginView* pluginView)

    : m_pluginView(pluginView)

    , m_back(0)

    , m_front(0)

    , m_lastMessageTime(0)

    , m_messageThrottleTimer(this, &PluginMessageThrottlerWin::messageThrottleTimerFired)

{

    // Initialize the free list with our inline messages

    for (unsigned i = 0; i < NumInlineMessages - 1; i++)

        m_inlineMessages[i].next = &m_inlineMessages[i + 1];

    m_inlineMessages[NumInlineMessages - 1].next = 0;

    m_freeInlineMessages = &m_inlineMessages[0];

}

PluginMessageThrottlerWin::~PluginMessageThrottlerWin()

{

    PluginMessage* next;

    for (PluginMessage* message = m_front; message; message = next) {

        next = message->next;

        freeMessage(message);

    }

}

void PluginMessageThrottlerWin::appendMessage(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)

{

    PluginMessage* message = allocateMessage();

    message->hWnd = hWnd;

    message->msg = msg;

    message->wParam = wParam;

    message->lParam = lParam;

    message->next = 0;

    if (m_back)

        m_back->next = message;

    m_back = message;

    if (!m_front)

        m_front = message;

    // If it has been more than MessageDirectProcessingInterval between throttled messages,

    // go ahead and process a message directly.

    double currentTime = WTF::currentTime();

    if (currentTime - m_lastMessageTime > MessageDirectProcessingInterval) {

        processQueuedMessage();

        m_lastMessageTime = currentTime;

        if (!m_front)

            return;

    }

    if (!m_messageThrottleTimer.isActive())

        m_messageThrottleTimer.startOneShot(MessageThrottleTimeInterval);

}

void PluginMessageThrottlerWin::processQueuedMessage()

{

    PluginMessage* message = m_front;

    m_front = m_front->next;

    if (message == m_back)

        m_back = 0;

    // Protect the PluginView from destruction while calling its window proc.

    // <rdar://problem/6930280>

    RefPtr<PluginView> protect(m_pluginView);

    ::CallWindowProc(m_pluginView->pluginWndProc(), message->hWnd, message->msg, message->wParam, message->lParam);

    freeMessage(message);

}

void PluginMessageThrottlerWin::messageThrottleTimerFired(Timer<PluginMessageThrottlerWin>*)

{

    processQueuedMessage();

    if (m_front)

        m_messageThrottleTimer.startOneShot(MessageThrottleTimeInterval);

}

PluginMessage* PluginMessageThrottlerWin::allocateMessage()

{

    PluginMessage *message;

    if (m_freeInlineMessages) {

        message = m_freeInlineMessages;

        m_freeInlineMessages = message->next;

    } else

        message = new PluginMessage;

    return message;

}

bool PluginMessageThrottlerWin::isInlineMessage(PluginMessage* message)

{

    return message >= &m_inlineMessages[0] && message <= &m_inlineMessages[NumInlineMessages - 1];

}

void PluginMessageThrottlerWin::freeMessage(PluginMessage* message)

{

    if (isInlineMessage(message)) {

        message->next = m_freeInlineMessages;

        m_freeInlineMessages = message;

    } else

        delete message;

}

} // namespace WebCore