Fix MSE GC, make it less aggressive, more spec-compliant (Blink CL)

Source/modules/mediasource/SourceBuffer.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 22 matching lines @@
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMArrayBufferView.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/events/Event.h"
 #include "core/events/GenericEventQueue.h"
 #include "core/fileapi/FileReaderLoader.h"
+#include "core/html/HTMLMediaElement.h"
+#include "core/html/MediaError.h"
 #include "core/html/TimeRanges.h"
 #include "core/streams/Stream.h"
 #include "modules/mediasource/MediaSource.h"
 #include "platform/Logging.h"
 #include "platform/TraceEvent.h"
 #include "public/platform/WebSourceBuffer.h"
 #include "wtf/MathExtras.h"
 
 #include <limits>
 
@@ skipping 208 matching lines @@
     }
 
     m_webSourceBuffer->setAppendWindowEnd(end);
 
     // 5. Update the attribute to the new value.
     m_appendWindowEnd = end;
 }
 
 void SourceBuffer::appendBuffer(PassRefPtr<DOMArrayBuffer> data, ExceptionState& exceptionState)
 {
+    WTF_LOG(Media, "SourceBuffer::appendBuffer %p size=%u", this, data->byteLength());
     // 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
     appendBufferInternal(static_cast<const unsigned char*>(data->data()), data->byteLength(), exceptionState);
 }
 
 void SourceBuffer::appendBuffer(PassRefPtr<DOMArrayBufferView> data, ExceptionState& exceptionState)
 {
+    WTF_LOG(Media, "SourceBuffer::appendBuffer %p size=%u", this, data->byteLength());
     // 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
     appendBufferInternal(static_cast<const unsigned char*>(data->baseAddress()), data->byteLength(), exceptionState);
 }
 
 void SourceBuffer::appendStream(Stream* stream, ExceptionState& exceptionState)
 {
     m_streamMaxSizeValid = false;
     appendStreamInternal(stream, exceptionState);
 }
 
 void SourceBuffer::appendStream(Stream* stream, unsigned long long maxSize, ExceptionState& exceptionState)
 {
+    WTF_LOG(Media, "SourceBuffer::appendStream %p maxSize=%llu", this, maxSize);
     m_streamMaxSizeValid = maxSize > 0;
     if (m_streamMaxSizeValid)
         m_streamMaxSize = maxSize;
     appendStreamInternal(stream, exceptionState);
 }
 
 void SourceBuffer::abort(ExceptionState& exceptionState)
 {
     // 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
@@ skipping 18 matching lines @@
 
     // 5. Set appendWindowStart to 0.
     setAppendWindowStart(0, exceptionState);
 
     // 6. Set appendWindowEnd to positive Infinity.
     setAppendWindowEnd(std::numeric_limits<double>::infinity(), exceptionState);
 }
 
 void SourceBuffer::remove(double start, double end, ExceptionState& exceptionState)
 {
+    WTF_LOG(Media, "SourceBuffer::remove %p start=%f end=%f", this, start, end);
+
     // Section 3.2 remove() method steps.
     // 1. If duration equals NaN, then throw an InvalidAccessError exception and abort these steps.
     // 2. If start is negative or greater than duration, then throw an InvalidAccessError exception and abort these steps.
 
     if (start < 0 || (m_source && (std::isnan(m_source->duration()) || start > m_source->duration()))) {
         exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::indexOutsideRange("start", start, 0.0, ExceptionMessages::ExclusiveBound, !m_source || std::isnan(m_source->duration()) ? 0 : m_source->duration(), ExceptionMessages::ExclusiveBound));
         return;
     }
 
     // 3. If end is less than or equal to start or end equals NaN, then throw an InvalidAccessError exception and abort these steps.
@@ skipping 167 matching lines @@
 void SourceBuffer::scheduleEvent(const AtomicString& eventName)
 {
     ASSERT(m_asyncEventQueue);
 
     RefPtrWillBeRawPtr<Event> event = Event::create(eventName);
     event->setTarget(this);
 
     m_asyncEventQueue->enqueueEvent(event.release());
 }
 
+bool SourceBuffer::prepareAppend(size_t newDataSize, ExceptionState& exceptionState)
+{
+    TRACE_EVENT_ASYNC_BEGIN0("media", "SourceBuffer::prepareAppend", this);
+    // http://w3c.github.io/media-source/#sourcebuffer-prepare-append
+    // 3.5.4 Prepare Append Algorithm
+    // 1. If the SourceBuffer has been removed from the sourceBuffers attribute of the parent media source then throw an InvalidStateError exception and abort these steps.
+    // 2. If the updating attribute equals true, then throw an InvalidStateError exception and abort these steps.
+    if (throwExceptionIfRemovedOrUpdating(isRemoved(), m_updating, exceptionState)) {
+        TRACE_EVENT_ASYNC_END0("media", "SourceBuffer::prepareAppend", this);
+        return false;
+    }
+
+    // 3. If the HTMLMediaElement.error attribute is not null, then throw an InvalidStateError exception and abort these steps.
+    ASSERT(m_source);
+    ASSERT(m_source->mediaElement());
+    if (m_source->mediaElement()->error()) {
+        exceptionState.throwDOMException(InvalidStateError, "The HTMLMediaElement.error attribute is not null.");
+        TRACE_EVENT_ASYNC_END0("media", "SourceBuffer::prepareAppend", this);
+        return false;
+    }
+
+    // 4. If the readyState attribute of the parent media source is in the "ended" state then run the following steps:
+    //    1. Set the readyState attribute of the parent media source to "open"
+    //    2. Queue a task to fire a simple event named sourceopen at the parent media source.
+    m_source->openIfInEndedState();
+
+    // 5. Run the coded frame eviction algorithm.
+    if (!evictCodedFrames(newDataSize)) {
+        // 6. If the buffer full flag equals true, then throw a QUOTA_EXCEEDED_ERR exception and abort these steps.
+        WTF_LOG(Media, "SourceBuffer::prepareAppend %p -> throw QuotaExceededError", this);
+        exceptionState.throwDOMException(QuotaExceededError, "The SourceBuffer is full, and cannot free space to append additional buffers.");
+        TRACE_EVENT_ASYNC_END0("media", "SourceBuffer::prepareAppend", this);
+        return false;
+    }
+
+    TRACE_EVENT_ASYNC_END0("media", "SourceBuffer::prepareAppend", this);
+    return true;
+}
+
+bool SourceBuffer::evictCodedFrames(size_t newDataSize)
+{
+    ASSERT(m_source);
+    ASSERT(m_source->mediaElement());
+    double currentTime = m_source->mediaElement()->currentTime();
+    return m_webSourceBuffer->evictCodedFrames(currentTime, newDataSize);
+}
+
 void SourceBuffer::appendBufferInternal(const unsigned char* data, unsigned size, ExceptionState& exceptionState)
 {
+    TRACE_EVENT_ASYNC_BEGIN1("media", "SourceBuffer::appendBuffer", this, "size", size);
     // 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. Run the prepare append algorithm.
-    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#sourcebuffer-prepare-append
-    //  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 updating attribute equals true, then throw an InvalidStateError exception and abort these steps.
-    if (throwExceptionIfRemovedOrUpdating(isRemoved(), m_updating, exceptionState))
+    if (!prepareAppend(size, exceptionState)) {
+        TRACE_EVENT_ASYNC_END0("media", "SourceBuffer::appendBuffer", this);
         return;
-
-    TRACE_EVENT_ASYNC_BEGIN1("media", "SourceBuffer::appendBuffer", this, "size", size);
-
-    //  3. If the readyState attribute of the parent media source is in the "ended" state then run the following steps: ...
-    m_source->openIfInEndedState();
-
-    //  Steps 4-5 - end "prepare append" algorithm.
+    }
+    TRACE_EVENT_ASYNC_STEP_INTO0("media", "SourceBuffer::appendBuffer", this, "prepareAppend");
 
     // 2. Add data to the end of the input buffer.
     ASSERT(data || size == 0);
     if (data)
         m_pendingAppendData.append(data, size);
     m_pendingAppendDataOffset = 0;
 
     // 3. Set the updating attribute to true.
     m_updating = true;
 
@@ skipping 79 matching lines @@
 
     // 11. Queue a task to fire a simple event named update at this SourceBuffer object.
     scheduleEvent(EventTypeNames::update);
 
     // 12. Queue a task to fire a simple event named updateend at this SourceBuffer object.
     scheduleEvent(EventTypeNames::updateend);
 }
 
 void SourceBuffer::appendStreamInternal(Stream* stream, ExceptionState& exceptionState)
 {
+    TRACE_EVENT_ASYNC_BEGIN0("media", "SourceBuffer::appendStream", this);
+
     // Section 3.2 appendStream()
-    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#widl-SourceBuffer-appendStream-void-Stream-stream-unsigned-long-long-maxSize
+    // http://w3c.github.io/media-source/#widl-SourceBuffer-appendStream-void-ReadableStream-stream-unsigned-long-long-maxSize
     // (0. If the stream has been neutered, then throw an InvalidAccessError exception and abort these steps.)
     if (stream->isNeutered()) {
         exceptionState.throwDOMException(InvalidAccessError, "The stream provided has been neutered.");
+        TRACE_EVENT_ASYNC_END0("media", "SourceBuffer::appendStream", this);
         return;
     }
 
     // 1. Run the prepare append algorithm.
-    //  Section 3.5.4 Prepare Append Algorithm.
-    //  https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#sourcebuffer-prepare-append
-    //  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 updating attribute equals true, then throw an InvalidStateError exception and abort these steps.
-    if (throwExceptionIfRemovedOrUpdating(isRemoved(), m_updating, exceptionState))
+    size_t newDataSize = m_streamMaxSizeValid ? m_streamMaxSize : 0;
+    if (!prepareAppend(newDataSize, exceptionState)) {
+        TRACE_EVENT_ASYNC_END0("media", "SourceBuffer::appendStream", this);
         return;
-
-    TRACE_EVENT_ASYNC_BEGIN0("media", "SourceBuffer::appendStream", this);
-
-    //  3. If the readyState attribute of the parent media source is in the "ended" state then run the following steps: ...
-    m_source->openIfInEndedState();
-
-    // Steps 4-5 of the prepare append algorithm are handled by m_webSourceBuffer.
+    }
 
     // 2. Set the updating attribute to true.
     m_updating = true;
 
     // 3. Queue a task to fire a simple event named updatestart at this SourceBuffer object.
     scheduleEvent(EventTypeNames::updatestart);
 
     // 4. Asynchronously run the stream append loop algorithm with stream and maxSize.
-
     stream->neuter();
     m_loader = FileReaderLoader::create(FileReaderLoader::ReadByClient, this);
     m_stream = stream;
     m_appendStreamAsyncPartRunner.runAsync();
 }
 
 void SourceBuffer::appendStreamAsyncPart()
 {
     ASSERT(m_updating);
     ASSERT(m_loader);
     ASSERT(m_stream);
+    TRACE_EVENT_ASYNC_STEP_INTO0("media", "SourceBuffer::appendStream", this, "appendStreamAsyncPart");
 
     // Section 3.5.6 Stream Append Loop
-    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#sourcebuffer-stream-append-loop
+    // http://w3c.github.io/media-source/#sourcebuffer-stream-append-loop
 
     // 1. If maxSize is set, then let bytesLeft equal maxSize.
     // 2. Loop Top: If maxSize is set and bytesLeft equals 0, then jump to the loop done step below.
     if (m_streamMaxSizeValid && !m_streamMaxSize) {
         appendStreamDone(true);
         return;
     }
 
     // Steps 3-11 are handled by m_loader.
     // Note: Passing 0 here signals that maxSize was not set. (i.e. Read all the data in the stream).
     m_loader->start(executionContext(), *m_stream, m_streamMaxSizeValid ? m_streamMaxSize : 0);
 }
 
 void SourceBuffer::appendStreamDone(bool success)
 {
     ASSERT(m_updating);
     ASSERT(m_loader);
     ASSERT(m_stream);
 
     clearAppendStreamState();
 
     if (!success) {
-        // Section 3.5.3 Append Error Algorithm
-        // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#sourcebuffer-append-error
-        //
-        // 1. Run the reset parser state algorithm. (Handled by caller)
-        // 2. Set the updating attribute to false.
-        m_updating = false;
-
-        // 3. Queue a task to fire a simple event named error at this SourceBuffer object.
-        scheduleEvent(EventTypeNames::error);
-
-        // 4. Queue a task to fire a simple event named updateend at this SourceBuffer object.
-        scheduleEvent(EventTypeNames::updateend);
+        appendError(false);
         TRACE_EVENT_ASYNC_END0("media", "SourceBuffer::appendStream", this);
         return;
     }
 
     // Section 3.5.6 Stream Append Loop
     // Steps 1-11 are handled by appendStreamAsyncPart(), |m_loader|, and |m_webSourceBuffer|.
+
     // 12. Loop Done: Set the updating attribute to false.
     m_updating = false;
 
     // 13. Queue a task to fire a simple event named update at this SourceBuffer object.
     scheduleEvent(EventTypeNames::update);
 
     // 14. Queue a task to fire a simple event named updateend at this SourceBuffer object.
     scheduleEvent(EventTypeNames::updateend);
     TRACE_EVENT_ASYNC_END0("media", "SourceBuffer::appendStream", this);
 }
 
 void SourceBuffer::clearAppendStreamState()
 {
     m_streamMaxSizeValid = false;
     m_streamMaxSize = 0;
     m_loader.clear();
     m_stream = nullptr;
 }
 
+void SourceBuffer::appendError(bool decodeError)
+{
+    // Section 3.5.3 Append Error Algorithm
+    // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#sourcebuffer-append-error
+
+    // 1. Run the reset parser state algorithm.
+    m_webSourceBuffer->abort();
+
+    // 2. Set the updating attribute to false.
+    m_updating = false;
+
+    // 3. Queue a task to fire a simple event named error at this SourceBuffer object.
+    scheduleEvent(EventTypeNames::error);
+
+    // 4. Queue a task to fire a simple event named updateend at this SourceBuffer object.
+    scheduleEvent(EventTypeNames::updateend);
+
+    // 5. If decode error is true, then run the end of stream algorithm with the
+    // error parameter set to "decode".
+    if (decodeError)

[wolenetz, 2015/08/12 22:42:04]

This is interesting that Blink didn't do this previously. Internally in
Chromium, we bubble the error through the pipeline / mediasourcedelegate, Do we
need a new layout test added to confirm failed append does the right thing to
the state of m_source?

[servolk, 2015/08/21 02:51:25]

This is a new method that was introduced in this CL, so currently it is only
going to be invoked from one place (didFinishLoading via appendStreamDone) and
decodeError will always be false for now. But later we can re-route the actual
decode errors, which are handled through a different code path, through
SourceBuffer::appendError as well.

[wolenetz, 2015/08/21 19:33:02]

Acknowledged.

+        m_source->endOfStream("decode", ASSERT_NO_EXCEPTION);
+}
+
 void SourceBuffer::didStartLoading()
 {
     WTF_LOG(Media, "SourceBuffer::didStartLoading() %p", this);
 }
 
 void SourceBuffer::didReceiveDataForClient(const char* data, unsigned dataLength)
 {
     WTF_LOG(Media, "SourceBuffer::didReceiveDataForClient(%d) %p", dataLength, this);
     ASSERT(m_updating);
     ASSERT(m_loader);
     m_webSourceBuffer->append(reinterpret_cast<const unsigned char*>(data), dataLength, &m_timestampOffset);
 }
 
 void SourceBuffer::didFinishLoading()
 {
     WTF_LOG(Media, "SourceBuffer::didFinishLoading() %p", this);
-    appendStreamDone(true);
+    // Section 3.5.6 Stream Append Loop
+    // Steps 1-9 are handled by appendStreamAsyncPart(), |m_loader|, and |m_webSourceBuffer|.
+
+    // 10. Run the coded frame eviction algorithm.
+    bool evictCodedFramesResult = evictCodedFrames(0);

[wolenetz, 2015/08/12 22:42:04]

This needs to be done, instead of here, within the loop, in
didReceiveDataForClient, prior to each m_webSourceBUffer->append(...) in l.803.
Also, that is the precise time at which you'll actually know a real dataLength.

Is the intent of this implementation to try to free enough headroom prior to
stream append loop, or during each iteration of the loop. I suggest the latter,
though the Chromium side CL currently ignores newDataSize in
WSBI::evictCodedFrames().

[servolk, 2015/08/21 02:51:25]

Yeah, you are right, it's actually cleaner to do it in didReceiveDataForClient.
We will only try to free enough headroom in advance if maxSize is specified for
appendStream.

+
+    // (will be done inside appendStreamDone)
+    // 11. If the buffer full flag equals true, then run the append error algorithm with the decode error parameter set to false and abort this algorithm.
+    appendStreamDone(evictCodedFramesResult);
 }
 
 void SourceBuffer::didFail(FileError::ErrorCode errorCode)
 {
     WTF_LOG(Media, "SourceBuffer::didFail(%d) %p", errorCode, this);
     appendStreamDone(false);
 }
 
 DEFINE_TRACE(SourceBuffer)
 {
     visitor->trace(m_source);
     visitor->trace(m_stream);
     visitor->trace(m_trackDefaults);
     visitor->trace(m_asyncEventQueue);
     RefCountedGarbageCollectedEventTargetWithInlineData<SourceBuffer>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink