Add minimal implementation of unprefixed MediaSource API that has feature parity with prefixed API

Source/modules/mediasource/SourceBuffer.cpp

Index: Source/modules/mediasource/SourceBuffer.cpp
diff --git a/Source/modules/mediasource/SourceBuffer.cpp b/Source/modules/mediasource/SourceBuffer.cpp
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+/*
+ * Copyright (C) 2013 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.
+ *     * Neither the name of Google Inc. nor the names of its
+ * 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
+ * (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 "modules/mediasource/SourceBuffer.h"
+
+#include "core/dom/Event.h"
+#include "core/dom/GenericEventQueue.h"
+#include "core/html/TimeRanges.h"
+#include "core/platform/Logging.h"
+#include "core/platform/graphics/SourceBufferPrivate.h"
+#include "modules/mediasource/MediaSource.h"
+#include "wtf/ArrayBuffer.h"
+#include "wtf/ArrayBufferView.h"
+
+namespace WebCore {
+
+PassRefPtr<SourceBuffer> SourceBuffer::create(PassOwnPtr<SourceBufferPrivate> sourceBufferPrivate, MediaSource* source, GenericEventQueue* asyncEventQueue)
+{
+    RefPtr<SourceBuffer> sourceBuffer(adoptRef(new SourceBuffer(sourceBufferPrivate, source, asyncEventQueue)));
+    sourceBuffer->suspendIfNeeded();
+    return sourceBuffer.release();
+}
+
+SourceBuffer::SourceBuffer(PassOwnPtr<SourceBufferPrivate> sourceBufferPrivate, MediaSource* source, GenericEventQueue* asyncEventQueue)
+    : ActiveDOMObject(source->scriptExecutionContext())
+    , m_private(sourceBufferPrivate)
+    , m_source(source)
+    , m_asyncEventQueue(asyncEventQueue)
+    , m_updating(false)
+    , m_timestampOffset(0)
+    , m_appendBufferTimer(this, &SourceBuffer::appendBufferTimerFired)
+{
+    ASSERT(m_private);
+    ASSERT(m_source);
+    ScriptWrappable::init(this);
+}
+
+SourceBuffer::~SourceBuffer()

[adamk, 2013/06/11 18:19:26]

Would it be useful to ASSERT(isRemoved()) here?

[acolwell GONE FROM CHROMIUM, 2013/06/12 01:14:04]

Done.

+{
+}
+
+PassRefPtr<TimeRanges> SourceBuffer::buffered(ExceptionCode& ec) 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
+    //    INVALID_STATE_ERR exception and abort these steps.
+    if (isRemoved()) {
+        ec = INVALID_STATE_ERR;
+        return 0;
+    }
+
+    // 2. Return a new static normalized TimeRanges object for the media segments buffered.
+    return m_private->buffered();
+}
+
+double SourceBuffer::timestampOffset() const
+{
+    return m_timestampOffset;
+}
+
+void SourceBuffer::setTimestampOffset(double offset, ExceptionCode& ec)
+{
+    // 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
+    //    INVALID_STATE_ERR exception and abort these steps.
+    if (isRemoved()) {
+        ec = INVALID_STATE_ERR;
+        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 INVALID_STATE_ERR
+    // and abort these steps.
+    if (!m_private->setTimestampOffset(offset)) {
+        ec = INVALID_STATE_ERR;
+        return;
+    }
+
+    // 6. Update the attribute to the new value.
+    m_timestampOffset = offset;
+}
+
+void SourceBuffer::appendBuffer(PassRefPtr<ArrayBuffer> data, ExceptionCode& ec)
+{
+    // Section 3.2 appendBuffer()
+    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#widl-SourceBuffer-appendBuffer-void-ArrayBufferView-data
+    // 1. If data is null then throw an INVALID_ACCESS_ERR exception and abort these steps.
+    if (!data) {
+        ec = INVALID_ACCESS_ERR;
+        return;
+    }
+
+    appendBufferInternal(reinterpret_cast<unsigned char*>(data->data()), data->byteLength(), ec);

[adamk, 2013/06/11 18:19:26]

This can just be a static_cast, can't it (since data is void*)?

[acolwell GONE FROM CHROMIUM, 2013/06/12 01:14:04]

Done.

+}
+
+void SourceBuffer::appendBuffer(PassRefPtr<ArrayBufferView> data, ExceptionCode& ec)
+{
+    // Section 3.2 appendBuffer()
+    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#widl-SourceBuffer-appendBuffer-void-ArrayBufferView-data
+    // 1. If data is null then throw an INVALID_ACCESS_ERR exception and abort these steps.
+    if (!data) {
+        ec = INVALID_ACCESS_ERR;
+        return;
+    }
+
+    appendBufferInternal(reinterpret_cast<unsigned char*>(data->baseAddress()), data->byteLength(), ec);

[adamk, 2013/06/11 18:19:26]

Same here, prefer static_cast when possible.

[acolwell GONE FROM CHROMIUM, 2013/06/12 01:14:04]

Done.

+}
+
+void SourceBuffer::abort(ExceptionCode& ec)
+{
+    // Section 3.2 abort() method steps.
+    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#widl-SourceBuffer-abort-void
+    // 1. If this object has been removed from the sourceBuffers attribute of the parent media source
+    //    then throw an INVALID_STATE_ERR exception and abort these steps.
+    // 2. If the readyState attribute of the parent media source is not in the "open" state
+    //    then throw an INVALID_STATE_ERR exception and abort these steps.
+    if (isRemoved() || !m_source->isOpen()) {
+        ec = INVALID_STATE_ERR;
+        return;
+    }
+
+    // 3. If the sourceBuffer.updating attribute equals true, then run the following steps: ...
+    abortIfUpdating();
+
+    // 4. Run the reset parser state algorithm.
+    m_private->abort();
+
+    // FIXME(229408) Add steps 5-6 update appendWindowStart & appendWindowEnd.
+}
+
+
+void SourceBuffer::abortIfUpdating()
+{
+    // Section 3.2 abort() method step 3 substeps.
+    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#widl-SourceBuffer-abort-void
+
+    if (!m_updating)
+        return;
+
+    // 3.1. Abort the buffer append and stream append loop algorithms if they are running.
+    m_appendBufferTimer.stop();
+    m_pendingAppendData.clear();
+
+    // 3.2. Set the updating attribute to false.
+    m_updating = false;
+
+    // 3.3. Queue a task to fire a simple event named abort at this SourceBuffer object.
+    scheduleEvent(eventNames().abortEvent);
+
+    // 3.4. Queue a task to fire a simple event named updateend at this SourceBuffer object.
+    scheduleEvent(eventNames().updateendEvent);
+}
+
+void SourceBuffer::removedFromMediaSource()
+{
+    if (isRemoved())
+        return;
+
+    m_private->removedFromMediaSource();
+    m_source = 0;
+    m_asyncEventQueue = 0;
+}
+
+bool SourceBuffer::hasPendingActivity() const
+{
+    return m_source;
+}
+
+void SourceBuffer::stop()
+{
+    m_appendBufferTimer.stop();
+}
+
+ScriptExecutionContext* SourceBuffer::scriptExecutionContext() const
+{
+    return ActiveDOMObject::scriptExecutionContext();
+}
+
+const AtomicString& SourceBuffer::interfaceName() const
+{
+    return eventNames().interfaceForSourceBuffer;
+}
+
+

[adamk, 2013/06/11 18:19:26]

Nit: extra blank line.

[acolwell GONE FROM CHROMIUM, 2013/06/12 01:14:04]

Done.

+EventTargetData* SourceBuffer::eventTargetData()
+{
+    return &m_eventTargetData;
+}
+
+EventTargetData* SourceBuffer::ensureEventTargetData()
+{
+    return &m_eventTargetData;
+}
+
+bool SourceBuffer::isRemoved() const
+{
+    return !m_source;
+}
+
+void SourceBuffer::scheduleEvent(const AtomicString& eventName)
+{
+    ASSERT(m_asyncEventQueue);
+
+    RefPtr<Event> event = Event::create(eventName, false, false);
+    event->setTarget(this);
+
+    m_asyncEventQueue->enqueueEvent(event.release());
+}
+
+void SourceBuffer::appendBufferInternal(unsigned char* data, unsigned size, ExceptionCode& ec)
+{
+    // Section 3.2 appendBuffer()
+    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#widl-SourceBuffer-appendBuffer-void-ArrayBufferView-data
+
+    // Step 1 is enforced by the caller.
+    // 2. If this object has been removed from the sourceBuffers attribute of the parent media source then throw an INVALID_STATE_ERR exception and abort these steps.
+    // 3. If the updating attribute equals true, then throw an INVALID_STATE_ERR exception and abort these steps.
+    if (isRemoved() || m_updating) {
+        ec = INVALID_STATE_ERR;
+        return;
+    }
+
+    // 4. If the readyState attribute of the parent media source is in the "ended" state then run the following steps: ...
+    m_source->openIfInEndedState();
+
+    // Steps 5-6
+
+    // 7. Add data to the end of the input buffer.
+    m_pendingAppendData.append(data, size);
+
+    // 8. Set the updating attribute to true.
+    m_updating = true;
+
+    // 9. Queue a task to fire a simple event named updatestart at this SourceBuffer object.
+    scheduleEvent(eventNames().updatestartEvent);
+
+    // 10. Asynchronously run the buffer append algorithm.
+    m_appendBufferTimer.startOneShot(0);
+}
+
+void SourceBuffer::appendBufferTimerFired(Timer<SourceBuffer>*)
+{
+    ASSERT(m_updating);
+
+    // Section 3.5.4 Buffer Append Algorithm
+    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#sourcebuffer-buffer-append
+
+    // 1. Run the segment parser loop algorithm.
+    // Step 2 doesn't apply since we run Step 1 synchronously here.
+    m_private->append(&m_pendingAppendData[0], m_pendingAppendData.size());
+
+
+    // 3. Set the updating attribute to false.
+    m_updating = false;
+    m_pendingAppendData.clear();
+
+    // 4. Queue a task to fire a simple event named update at this SourceBuffer object.
+    scheduleEvent(eventNames().updateEvent);
+
+    // 5. Queue a task to fire a simple event named updateend at this SourceBuffer object.
+    scheduleEvent(eventNames().updateendEvent);
+}
+
+} // namespace WebCore