modules/mediasource/WebKitSourceBuffer.cpp

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#include "config.h"
#include "modules/mediasource/WebKitSourceBuffer.h"

#include "bindings/v8/ExceptionState.h"
#include "core/dom/ExceptionCode.h"
#include "core/html/TimeRanges.h"
#include "modules/mediasource/WebKitMediaSource.h"
#include "platform/TraceEvent.h"
#include "public/platform/WebSourceBuffer.h"
#include "wtf/Uint8Array.h"

using blink::WebSourceBuffer;

namespace WebCore {

PassRefPtr<WebKitSourceBuffer> WebKitSourceBuffer::create(PassOwnPtr<WebSourceBuffer> webSourceBuffer, PassRefPtr<WebKitMediaSource> source)
{
    return adoptRef(new WebKitSourceBuffer(webSourceBuffer, source));
}

WebKitSourceBuffer::WebKitSourceBuffer(PassOwnPtr<WebSourceBuffer> webSourceBuffer, PassRefPtr<WebKitMediaSource> source)
    : m_webSourceBuffer(webSourceBuffer)
    , m_source(source)
    , m_timestampOffset(0)
{
    ASSERT(m_webSourceBuffer);
    ASSERT(m_source);
    ScriptWrappable::init(this);
}

WebKitSourceBuffer::~WebKitSourceBuffer()
{
}

PassRefPtr<TimeRanges> WebKitSourceBuffer::buffered(ExceptionState& exceptionState) const
{
    // Section 3.1 buffered attribute steps.
    // 1. If this object has been removed from the sourceBuffers attribute of the parent media source then throw an
    //    InvalidStateError exception and abort these steps.
    if (isRemoved()) {
        exceptionState.throwUninformativeAndGenericDOMException(InvalidStateError);
        return 0;
    }

    // 2. Return a new static normalized TimeRanges object for the media segments buffered.
    return TimeRanges::create(m_webSourceBuffer->buffered());
}

double WebKitSourceBuffer::timestampOffset() const
{
    return m_timestampOffset;
}

void WebKitSourceBuffer::setTimestampOffset(double offset, ExceptionState& exceptionState)
{
    // Section 3.1 timestampOffset attribute setter steps.
    // 1. If this object has been removed from the sourceBuffers attribute of the parent media source then throw an
    //    InvalidStateError exception and abort these steps.
    if (isRemoved()) {
        exceptionState.throwUninformativeAndGenericDOMException(InvalidStateError);
        return;
    }

    // 4. If the readyState attribute of the parent media source is in the "ended" state then run the following steps:
    // 4.1 Set the readyState attribute of the parent media source to "open"
    // 4.2 Queue a task to fire a simple event named sourceopen at the parent media source.
    m_source->openIfInEndedState();

    // 5. If this object is waiting for the end of a media segment to be appended, then throw an InvalidStateError
    // and abort these steps.
    if (!m_webSourceBuffer->setTimestampOffset(offset)) {
        exceptionState.throwUninformativeAndGenericDOMException(InvalidStateError);
        return;
    }

    // 6. Update the attribute to the new value.
    m_timestampOffset = offset;
}

void WebKitSourceBuffer::append(PassRefPtr<Uint8Array> data, ExceptionState& exceptionState)
{
    TRACE_EVENT0("media", "SourceBuffer::append");

    // SourceBuffer.append() steps from October 1st version of the Media Source Extensions spec.
    // https://dvcs.w3.org/hg/html-media/raw-file/7bab66368f2c/media-source/media-source.html#dom-append

    // 2. If data is null then throw an InvalidAccessError exception and abort these steps.
    if (!data) {
        exceptionState.throwUninformativeAndGenericDOMException(InvalidAccessError);
        return;
    }

    // 3. If this object has been removed from the sourceBuffers attribute of media source then throw
    //    an InvalidStateError exception and abort these steps.
    if (isRemoved()) {
        exceptionState.throwUninformativeAndGenericDOMException(InvalidStateError);
        return;
    }

    // 5. If the readyState attribute of media source is in the "ended" state then run the following steps:
    // 5.1. Set the readyState attribute of media source to "open"
    // 5.2. Queue a task to fire a simple event named sourceopen at media source.
    m_source->openIfInEndedState();

    // Steps 6 & beyond are handled by m_webSourceBuffer.
    m_webSourceBuffer->append(data->data(), data->length());
}

void WebKitSourceBuffer::abort(ExceptionState& exceptionState)
{
    // Section 3.2 abort() method steps.
    // 1. If this object has been removed from the sourceBuffers attribute of the parent media source
    //    then throw an InvalidStateError exception and abort these steps.
    // 2. If the readyState attribute of the parent media source is not in the "open" state
    //    then throw an InvalidStateError exception and abort these steps.
    if (isRemoved() || !m_source->isOpen()) {
        exceptionState.throwUninformativeAndGenericDOMException(InvalidStateError);
        return;
    }

    // 4. Run the reset parser state algorithm.
    m_webSourceBuffer->abort();
}

void WebKitSourceBuffer::removedFromMediaSource()
{
    if (isRemoved())
        return;

    m_webSourceBuffer->removedFromMediaSource();
    m_source.clear();
}

bool WebKitSourceBuffer::isRemoved() const
{
    return !m_source;
}

} // namespace WebCore