gecko-dev/image/IDecodingTask.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "IDecodingTask.h"
#include "gfxPrefs.h"
#include "nsThreadUtils.h"
#include "Decoder.h"
#include "DecodePool.h"
#include "RasterImage.h"
#include "SurfaceCache.h"
namespace mozilla {
using gfx::IntRect;
namespace image {
///////////////////////////////////////////////////////////////////////////////
// Helpers for sending notifications to the image associated with a decoder.
///////////////////////////////////////////////////////////////////////////////
/* static */ void
IDecodingTask::NotifyProgress(NotNull<RasterImage*> aImage,
NotNull<Decoder*> aDecoder)
{
MOZ_ASSERT(aDecoder->HasProgress() && !aDecoder->IsMetadataDecode());
// Capture the decoder's state. If we need to notify asynchronously, it's
// important that we don't wait until the lambda actually runs to capture the
// state that we're going to notify. That would both introduce data races on
// the decoder's state and cause inconsistencies between the NotifyProgress()
// calls we make off-main-thread and the notifications that RasterImage
// actually receives, which would cause bugs.
Progress progress = aDecoder->TakeProgress();
IntRect invalidRect = aDecoder->TakeInvalidRect();
Maybe<uint32_t> frameCount = aDecoder->TakeCompleteFrameCount();
DecoderFlags decoderFlags = aDecoder->GetDecoderFlags();
SurfaceFlags surfaceFlags = aDecoder->GetSurfaceFlags();
// Synchronously notify if we can.
if (NS_IsMainThread() && !(decoderFlags & DecoderFlags::ASYNC_NOTIFY)) {
aImage->NotifyProgress(progress, invalidRect, frameCount,
decoderFlags, surfaceFlags);
return;
}
// We're forced to notify asynchronously.
NotNull<RefPtr<RasterImage>> image = aImage;
NS_DispatchToMainThread(NS_NewRunnableFunction([=]() -> void {
image->NotifyProgress(progress, invalidRect, frameCount,
decoderFlags, surfaceFlags);
}));
}
/* static */ void
IDecodingTask::NotifyDecodeComplete(NotNull<RasterImage*> aImage,
NotNull<Decoder*> aDecoder)
{
MOZ_ASSERT(aDecoder->HasError() || !aDecoder->InFrame(),
"Decode complete in the middle of a frame?");
// Capture the decoder's state.
DecoderFinalStatus finalStatus = aDecoder->FinalStatus();
ImageMetadata metadata = aDecoder->GetImageMetadata();
DecoderTelemetry telemetry = aDecoder->Telemetry();
Progress progress = aDecoder->TakeProgress();
IntRect invalidRect = aDecoder->TakeInvalidRect();
Maybe<uint32_t> frameCount = aDecoder->TakeCompleteFrameCount();
DecoderFlags decoderFlags = aDecoder->GetDecoderFlags();
SurfaceFlags surfaceFlags = aDecoder->GetSurfaceFlags();
// Synchronously notify if we can.
if (NS_IsMainThread() && !(decoderFlags & DecoderFlags::ASYNC_NOTIFY)) {
aImage->NotifyDecodeComplete(finalStatus, metadata, telemetry, progress,
invalidRect, frameCount, decoderFlags,
surfaceFlags);
return;
}
// We're forced to notify asynchronously.
NotNull<RefPtr<RasterImage>> image = aImage;
NS_DispatchToMainThread(NS_NewRunnableFunction([=]() -> void {
image->NotifyDecodeComplete(finalStatus, metadata, telemetry, progress,
invalidRect, frameCount, decoderFlags,
surfaceFlags);
}));
}
///////////////////////////////////////////////////////////////////////////////
// IDecodingTask implementation.
///////////////////////////////////////////////////////////////////////////////
void
IDecodingTask::Resume()
{
DecodePool::Singleton()->AsyncRun(this);
}
///////////////////////////////////////////////////////////////////////////////
// MetadataDecodingTask implementation.
///////////////////////////////////////////////////////////////////////////////
MetadataDecodingTask::MetadataDecodingTask(NotNull<Decoder*> aDecoder)
: mMutex("mozilla::image::MetadataDecodingTask")
, mDecoder(aDecoder)
{
MOZ_ASSERT(mDecoder->IsMetadataDecode(),
"Use DecodingTask for non-metadata decodes");
}
void
MetadataDecodingTask::Run()
{
MutexAutoLock lock(mMutex);
LexerResult result = mDecoder->Decode(WrapNotNull(this));
if (result.is<TerminalState>()) {
NotifyDecodeComplete(mDecoder->GetImage(), mDecoder);
return; // We're done.
}
if (result == LexerResult(Yield::NEED_MORE_DATA)) {
// We can't make any more progress right now. We also don't want to report
// any progress, because it's important that metadata decode results are
// delivered atomically. The decoder itself will ensure that we get
// reenqueued when more data is available; just return for now.
return;
}
MOZ_ASSERT_UNREACHABLE("Metadata decode yielded for an unexpected reason");
}
///////////////////////////////////////////////////////////////////////////////
// AnonymousDecodingTask implementation.
///////////////////////////////////////////////////////////////////////////////
AnonymousDecodingTask::AnonymousDecodingTask(NotNull<Decoder*> aDecoder)
: mDecoder(aDecoder)
{ }
void
AnonymousDecodingTask::Run()
{
while (true) {
LexerResult result = mDecoder->Decode(WrapNotNull(this));
if (result.is<TerminalState>()) {
return; // We're done.
}
if (result == LexerResult(Yield::NEED_MORE_DATA)) {
// We can't make any more progress right now. Let the caller decide how to
// handle it.
return;
}
// Right now we don't do anything special for other kinds of yields, so just
// keep working.
MOZ_ASSERT(result.is<Yield>());
}
}
} // namespace image
} // namespace mozilla