Source/WebCore/Modules/mediasource/SourceBufferList.cpp

/*
 * Copyright (C) 2012 Google 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
 * OWNER 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
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "SourceBufferList.h"

#if ENABLE(MEDIA_SOURCE)

#include "Event.h"
#include "SourceBuffer.h"

namespace WebCore {

SourceBufferList::SourceBufferList(ScriptExecutionContext* context,
                                   GenericEventQueue* asyncEventQueue)
    : m_scriptExecutionContext(context)
    , m_asyncEventQueue(asyncEventQueue)
    , m_lastSourceBufferId(0)
{
}

unsigned long SourceBufferList::length() const
{
    return m_list.size();
}

SourceBuffer* SourceBufferList::item(unsigned index) const
{
    if (index >= m_list.size())
        return 0;
    return m_list[index].get();
}

void SourceBufferList::add(PassRefPtr<SourceBuffer> buffer)
{
    m_list.append(buffer);
    createAndFireEvent(eventNames().webkitaddsourcebufferEvent);
}

bool SourceBufferList::remove(SourceBuffer* buffer)
{
    size_t index = m_list.find(buffer);
    if (index == notFound)
        return false;

    buffer->clear();
    m_list.remove(index);
    createAndFireEvent(eventNames().webkitremovesourcebufferEvent);
    return true;
}

void SourceBufferList::clear()
{
    for (size_t i = 0; i < m_list.size(); ++i)
        remove(m_list[i].get());
}

String SourceBufferList::generateUniqueId()
{
    // Ensure a unique id. Until m_lastSourceBufferId wraps around (very unlikely),
    // this loop will exit after one check. If m_lastSourceBufferId does wrap,
    // this loop may run as many times as the size of m_list, but in most
    // cases that should be less than 10. We may want to investigate a more
    // efficient approach if many more SourceBuffers are allowed in the future.
    size_t nextSourceBufferId = m_lastSourceBufferId + 1;

    while (contains(nextSourceBufferId)) {
        if (nextSourceBufferId == m_lastSourceBufferId)
            return emptyString();
        nextSourceBufferId++;
    }
    m_lastSourceBufferId = nextSourceBufferId;

    return String::number(nextSourceBufferId);
}

bool SourceBufferList::contains(size_t id) const
{
    for (size_t i = 0; i < m_list.size(); ++i) {
        if (m_list[i]->id() == String::number(id))
            return true;
    }
    return false;
}

void SourceBufferList::createAndFireEvent(const AtomicString& eventName)
{
    ASSERT(m_asyncEventQueue);

    RefPtr<Event> event = Event::create(eventName, false, false);
    event->setTarget(this);

    m_asyncEventQueue->enqueueEvent(event.release());
}

const AtomicString& SourceBufferList::interfaceName() const
{
    return eventNames().interfaceForSourceBufferList;
}

ScriptExecutionContext* SourceBufferList::scriptExecutionContext() const
{
    return m_scriptExecutionContext;
}

EventTargetData* SourceBufferList::eventTargetData()
{
    return &m_eventTargetData;
}

EventTargetData* SourceBufferList::ensureEventTargetData()
{
    return &m_eventTargetData;
}

} // namespace WebCore

#endif