MSE: Experimental support for customizing live seekable range

third_party/WebKit/Source/modules/mediasource/MediaSource.cpp

 /*
  * 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
@@ skipping 19 matching lines @@
 
 #include "modules/mediasource/MediaSource.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/events/Event.h"
 #include "core/events/GenericEventQueue.h"
 #include "core/html/HTMLMediaElement.h"
-#include "core/html/TimeRanges.h"
 #include "modules/mediasource/MediaSourceRegistry.h"
 #include "platform/ContentType.h"
 #include "platform/Logging.h"
 #include "platform/MIMETypeRegistry.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/TraceEvent.h"
 #include "public/platform/WebMediaSource.h"
 #include "public/platform/WebSourceBuffer.h"
 #include "wtf/PtrUtil.h"
 #include "wtf/text/CString.h"
@@ skipping 46 matching lines @@
 }
 
 MediaSource::MediaSource(ExecutionContext* context)
     : ActiveScriptWrappable(this)
     , ActiveDOMObject(context)
     , m_readyState(closedKeyword())
     , m_asyncEventQueue(GenericEventQueue::create(this))
     , m_attachedElement(nullptr)
     , m_sourceBuffers(SourceBufferList::create(getExecutionContext(), m_asyncEventQueue.get()))
     , m_activeSourceBuffers(SourceBufferList::create(getExecutionContext(), m_asyncEventQueue.get()))
+    , m_liveSeekableRange(TimeRanges::create())
     , m_isAddedToRegistry(false)
 {
     MSLOG << __FUNCTION__ << " this=" << this;
 }
 
 MediaSource::~MediaSource()
 {
     MSLOG << __FUNCTION__ << " this=" << this;
     DCHECK(isClosed());
 }
@@ skipping 159 matching lines @@
 {
     return ActiveDOMObject::getExecutionContext();
 }
 
 DEFINE_TRACE(MediaSource)
 {
     visitor->trace(m_asyncEventQueue);
     visitor->trace(m_attachedElement);
     visitor->trace(m_sourceBuffers);
     visitor->trace(m_activeSourceBuffers);
+    visitor->trace(m_liveSeekableRange);
     EventTargetWithInlineData::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 void MediaSource::setWebMediaSourceAndOpen(std::unique_ptr<WebMediaSource> webMediaSource)
 {
     TRACE_EVENT_ASYNC_END0("media", "MediaSource::attachToElement", this);
     DCHECK(webMediaSource);
     DCHECK(!m_webMediaSource);
     DCHECK(m_attachedElement);
@@ skipping 60 matching lines @@
         // 5.4 Replace the ranges in intersection ranges with the new intersection ranges.
         intersectionRanges->intersectWith(sourceRanges);
     }
 
     return intersectionRanges;
 }
 
 TimeRanges* MediaSource::seekable() const
 {
     // Implements MediaSource algorithm for HTMLMediaElement.seekable.
-    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#htmlmediaelement-extensions
+    // http://w3c.github.io/media-source/#htmlmediaelement-extensions
 
     double sourceDuration = duration();
     // If duration equals NaN: Return an empty TimeRanges object.
     if (std::isnan(sourceDuration))
         return TimeRanges::create();
 
     // If duration equals positive Infinity:
     if (sourceDuration == std::numeric_limits<double>::infinity()) {
         TimeRanges* buffered = m_attachedElement->buffered();
 
-        // 1. If the HTMLMediaElement.buffered attribute returns an empty TimeRanges object, then
-        // return an empty TimeRanges object and abort these steps.
+        // 1. If live seekable range is not empty:
+        if (m_liveSeekableRange->length() != 0) {
+            // 1.1. Let union ranges be the union of live seekable range and the
+            //      HTMLMediaElement.buffered attribute.
+            // 1.2. Return a single range with a start time equal to the
+            //      earliest start time in union ranges and an end time equal to
+            //      the highest end time in union ranges and abort these steps.
+            if (buffered->length() == 0) {
+                return TimeRanges::create(m_liveSeekableRange->start(0, ASSERT_NO_EXCEPTION), m_liveSeekableRange->end(0, ASSERT_NO_EXCEPTION));
+            }
+
+            return TimeRanges::create(std::min(m_liveSeekableRange->start(0, ASSERT_NO_EXCEPTION), buffered->start(0, ASSERT_NO_EXCEPTION)),
+                std::max(m_liveSeekableRange->end(0, ASSERT_NO_EXCEPTION), buffered->end(buffered->length() - 1, ASSERT_NO_EXCEPTION)));
+        }
+        // 2. If the HTMLMediaElement.buffered attribute returns an empty TimeRanges object, then
+        //    return an empty TimeRanges object and abort these steps.
         if (buffered->length() == 0)
             return TimeRanges::create();
 
-        // 2. Return a single range with a start time of 0 and an end time equal to the highest end
-        // time reported by the HTMLMediaElement.buffered attribute.
+        // 3. Return a single range with a start time of 0 and an end time equal to the highest end
+        //    time reported by the HTMLMediaElement.buffered attribute.
         return TimeRanges::create(0, buffered->end(buffered->length() - 1, ASSERT_NO_EXCEPTION));
     }
 
     // 3. Otherwise: Return a single range with a start time of 0 and an end time equal to duration.
     return TimeRanges::create(0, sourceDuration);
 }
 
 void MediaSource::setDuration(double duration, ExceptionState& exceptionState)
 {
     // 2.1 http://www.w3.org/TR/media-source/#widl-MediaSource-duration
@@ skipping 81 matching lines @@
     } else {
         NOTREACHED(); // IDL enforcement should prevent this case.
     }
 }
 
 void MediaSource::endOfStream(ExceptionState& exceptionState)
 {
     endOfStreamInternal(WebMediaSource::EndOfStreamStatusNoError, exceptionState);
 }
 
+void MediaSource::setLiveSeekableRange(double start, double end, ExceptionState& exceptionState)
+{
+    // http://w3c.github.io/media-source/#widl-MediaSource-setLiveSeekableRange-void-double-start-double-end
+    // 1. If the readyState attribute is not "open" then throw an
+    //    InvalidStateError exception and abort these steps.
+    // 2. If the updating attribute equals true on any SourceBuffer in
+    //    SourceBuffers, then throw an InvalidStateError exception and abort
+    //    these steps.
+    if (throwExceptionIfClosedOrUpdating(isOpen(), isUpdating(), exceptionState))
+        return;
+
+    // 3. If start is negative or greater than end, then throw a TypeError
+    //    exception and abort these steps.
+    if (start < 0 || start > end) {
+        exceptionState.throwTypeError(ExceptionMessages::indexOutsideRange("start value", start, 0.0, ExceptionMessages::InclusiveBound, end, ExceptionMessages::InclusiveBound));
+        return;
+    }
+
+    // 4. Set live seekable range to be a new normalized TimeRanges object
+    //    containing a single range whose start position is start and end
+    //    position is end.
+    m_liveSeekableRange = TimeRanges::create(start, end);
+}
+
+void MediaSource::clearLiveSeekableRange(ExceptionState& exceptionState)
+{
+    // http://w3c.github.io/media-source/#widl-MediaSource-clearLiveSeekableRange-void
+    // 1. If the readyState attribute is not "open" then throw an
+    //    InvalidStateError exception and abort these steps.
+    // 2. If the updating attribute equals true on any SourceBuffer in
+    //    SourceBuffers, then throw an InvalidStateError exception and abort
+    //    these steps.
+    if (throwExceptionIfClosedOrUpdating(isOpen(), isUpdating(), exceptionState))
+        return;
+
+    // 3. If live seekable range contains a range, then set live seekable range
+    //    to be a new empty TimeRanges object.
+    if (m_liveSeekableRange->length() != 0)
+        m_liveSeekableRange = TimeRanges::create();
+}
+
 void MediaSource::endOfStreamInternal(const WebMediaSource::EndOfStreamStatus eosStatus, ExceptionState& exceptionState)
 {
     // 2.2 http://www.w3.org/TR/media-source/#widl-MediaSource-endOfStream-void-EndOfStreamError-error
     // 1. If the readyState attribute is not in the "open" state then throw an
     // InvalidStateError exception and abort these steps.
     // 2. If the updating attribute equals true on any SourceBuffer in sourceBuffers, then throw an
     // InvalidStateError exception and abort these steps.
     if (throwExceptionIfClosedOrUpdating(isOpen(), isUpdating(), exceptionState))
         return;
 
@@ skipping 121 matching lines @@
 
     m_asyncEventQueue->enqueueEvent(event);
 }
 
 URLRegistry& MediaSource::registry() const
 {
     return MediaSourceRegistry::registry();
 }
 
 } // namespace blink