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-rw-r--r--image/AnimationFrameBuffer.cpp471
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diff --git a/image/AnimationFrameBuffer.cpp b/image/AnimationFrameBuffer.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 "AnimationFrameBuffer.h"
+
+#include <utility> // for Move
+
+namespace mozilla {
+namespace image {
+
+AnimationFrameRetainedBuffer::AnimationFrameRetainedBuffer(size_t aThreshold,
+ size_t aBatch,
+ size_t aStartFrame)
+ : AnimationFrameBuffer(aBatch, aStartFrame), mThreshold(aThreshold) {
+ // To simplify the code, we have the assumption that the threshold for
+ // entering discard-after-display mode is at least twice the batch size (since
+ // that is the most frames-pending-decode we will request) + 1 for the current
+ // frame. That way the redecoded frames being inserted will never risk
+ // overlapping the frames we will discard due to the animation progressing.
+ // That may cause us to use a little more memory than we want but that is an
+ // acceptable tradeoff for simplicity.
+ size_t minThreshold = 2 * mBatch + 1;
+ if (mThreshold < minThreshold) {
+ mThreshold = minThreshold;
+ }
+
+ // The maximum number of frames we should ever have decoded at one time is
+ // twice the batch. That is a good as number as any to start our decoding at.
+ mPending = mBatch * 2;
+}
+
+bool AnimationFrameRetainedBuffer::InsertInternal(RefPtr<imgFrame>&& aFrame) {
+ // We should only insert new frames if we actually asked for them.
+ MOZ_ASSERT(!mSizeKnown);
+ MOZ_ASSERT(mFrames.Length() < mThreshold);
+
+ ++mSize;
+ mFrames.AppendElement(std::move(aFrame));
+ MOZ_ASSERT(mSize == mFrames.Length());
+ return mSize < mThreshold;
+}
+
+bool AnimationFrameRetainedBuffer::ResetInternal() {
+ // If we haven't crossed the threshold, then we know by definition we have
+ // not discarded any frames. If we previously requested more frames, but
+ // it would have been more than we would have buffered otherwise, we can
+ // stop the decoding after one more frame.
+ if (mPending > 1 && mSize >= mBatch * 2 + 1) {
+ MOZ_ASSERT(!mSizeKnown);
+ mPending = 1;
+ }
+
+ // Either the decoder is still running, or we have enough frames already.
+ // No need for us to restart it.
+ return false;
+}
+
+bool AnimationFrameRetainedBuffer::MarkComplete(
+ const gfx::IntRect& aFirstFrameRefreshArea) {
+ MOZ_ASSERT(!mSizeKnown);
+ mFirstFrameRefreshArea = aFirstFrameRefreshArea;
+ mSizeKnown = true;
+ mPending = 0;
+ mFrames.Compact();
+ return false;
+}
+
+void AnimationFrameRetainedBuffer::AdvanceInternal() {
+ // We should not have advanced if we never inserted.
+ MOZ_ASSERT(!mFrames.IsEmpty());
+ // We only want to change the current frame index if we have advanced. This
+ // means either a higher frame index, or going back to the beginning.
+ size_t framesLength = mFrames.Length();
+ // We should never have advanced beyond the frame buffer.
+ MOZ_ASSERT(mGetIndex < framesLength);
+ // We should never advance if the current frame is null -- it needs to know
+ // the timeout from it at least to know when to advance.
+ MOZ_ASSERT_IF(mGetIndex > 0, mFrames[mGetIndex - 1]);
+ MOZ_ASSERT_IF(mGetIndex == 0, mFrames[framesLength - 1]);
+ // The owner should have already accessed the next frame, so it should also
+ // be available.
+ MOZ_ASSERT(mFrames[mGetIndex]);
+
+ if (!mSizeKnown) {
+ // Calculate how many frames we have requested ahead of the current frame.
+ size_t buffered = mPending + framesLength - mGetIndex - 1;
+ if (buffered < mBatch) {
+ // If we have fewer frames than the batch size, then ask for more. If we
+ // do not have any pending, then we know that there is no active decoding.
+ mPending += mBatch;
+ }
+ }
+}
+
+imgFrame* AnimationFrameRetainedBuffer::Get(size_t aFrame, bool aForDisplay) {
+ // We should not have asked for a frame if we never inserted.
+ if (mFrames.IsEmpty()) {
+ MOZ_ASSERT_UNREACHABLE("Calling Get() when we have no frames");
+ return nullptr;
+ }
+
+ // If we don't have that frame, return an empty frame ref.
+ if (aFrame >= mFrames.Length()) {
+ return nullptr;
+ }
+
+ // If we have space for the frame, it should always be available.
+ if (!mFrames[aFrame]) {
+ MOZ_ASSERT_UNREACHABLE("Calling Get() when frame is unavailable");
+ return nullptr;
+ }
+
+ // If we are advancing on behalf of the animation, we don't expect it to be
+ // getting any frames (besides the first) until we get the desired frame.
+ MOZ_ASSERT(aFrame == 0 || mAdvance == 0);
+ return mFrames[aFrame].get();
+}
+
+bool AnimationFrameRetainedBuffer::IsFirstFrameFinished() const {
+ return !mFrames.IsEmpty() && mFrames[0]->IsFinished();
+}
+
+bool AnimationFrameRetainedBuffer::IsLastInsertedFrame(imgFrame* aFrame) const {
+ return !mFrames.IsEmpty() && mFrames.LastElement().get() == aFrame;
+}
+
+void AnimationFrameRetainedBuffer::AddSizeOfExcludingThis(
+ MallocSizeOf aMallocSizeOf, const AddSizeOfCb& aCallback) {
+ size_t i = 0;
+ for (const RefPtr<imgFrame>& frame : mFrames) {
+ ++i;
+ frame->AddSizeOfExcludingThis(aMallocSizeOf,
+ [&](AddSizeOfCbData& aMetadata) {
+ aMetadata.mIndex = i;
+ aCallback(aMetadata);
+ });
+ }
+}
+
+AnimationFrameDiscardingQueue::AnimationFrameDiscardingQueue(
+ AnimationFrameRetainedBuffer&& aQueue)
+ : AnimationFrameBuffer(aQueue),
+ mInsertIndex(aQueue.mFrames.Length()),
+ mFirstFrame(aQueue.mFrames[0]) {
+ MOZ_ASSERT(!mSizeKnown);
+ MOZ_ASSERT(!mRedecodeError);
+ MOZ_ASSERT(mInsertIndex > 0);
+ mMayDiscard = true;
+
+ // We avoided moving aQueue.mFrames[0] for mFirstFrame above because it is
+ // possible the animation was reset back to the beginning, and then we crossed
+ // the threshold without advancing further. That would mean mGetIndex is 0.
+ for (size_t i = mGetIndex; i < mInsertIndex; ++i) {
+ MOZ_ASSERT(aQueue.mFrames[i]);
+ mDisplay.push_back(std::move(aQueue.mFrames[i]));
+ }
+}
+
+bool AnimationFrameDiscardingQueue::InsertInternal(RefPtr<imgFrame>&& aFrame) {
+ if (mInsertIndex == mSize) {
+ if (mSizeKnown) {
+ // We produced more frames on a subsequent decode than on the first pass.
+ mRedecodeError = true;
+ mPending = 0;
+ return true;
+ }
+ ++mSize;
+ }
+
+ // Even though we don't use redecoded first frames for display purposes, we
+ // will still use them for recycling, so we still need to insert it.
+ mDisplay.push_back(std::move(aFrame));
+ ++mInsertIndex;
+ MOZ_ASSERT(mInsertIndex <= mSize);
+ return true;
+}
+
+bool AnimationFrameDiscardingQueue::ResetInternal() {
+ mDisplay.clear();
+ mInsertIndex = 0;
+
+ bool restartDecoder = mPending == 0;
+ mPending = 2 * mBatch;
+ return restartDecoder;
+}
+
+bool AnimationFrameDiscardingQueue::MarkComplete(
+ const gfx::IntRect& aFirstFrameRefreshArea) {
+ if (NS_WARN_IF(mInsertIndex != mSize)) {
+ mRedecodeError = true;
+ mPending = 0;
+ }
+
+ // If we encounter a redecode error, just make the first frame refresh area to
+ // be the full frame, because we don't really know what we can safely recycle.
+ mFirstFrameRefreshArea =
+ mRedecodeError ? mFirstFrame->GetRect() : aFirstFrameRefreshArea;
+
+ // We reached the end of the animation, the next frame we get, if we get
+ // another, will be the first frame again.
+ mInsertIndex = 0;
+ mSizeKnown = true;
+
+ // Since we only request advancing when we want to resume at a certain point
+ // in the animation, we should never exceed the number of frames.
+ MOZ_ASSERT(mAdvance == 0);
+ return mPending > 0;
+}
+
+void AnimationFrameDiscardingQueue::AdvanceInternal() {
+ // We only want to change the current frame index if we have advanced. This
+ // means either a higher frame index, or going back to the beginning.
+ // We should never have advanced beyond the frame buffer.
+ MOZ_ASSERT(mGetIndex < mSize);
+
+ // We should have the current frame still in the display queue. Either way,
+ // we should at least have an entry in the queue which we need to consume.
+ MOZ_ASSERT(!mDisplay.empty());
+ MOZ_ASSERT(mDisplay.front());
+ mDisplay.pop_front();
+ MOZ_ASSERT(!mDisplay.empty());
+ MOZ_ASSERT(mDisplay.front());
+
+ if (mDisplay.size() + mPending - 1 < mBatch) {
+ // If we have fewer frames than the batch size, then ask for more. If we
+ // do not have any pending, then we know that there is no active decoding.
+ mPending += mBatch;
+ }
+}
+
+imgFrame* AnimationFrameDiscardingQueue::Get(size_t aFrame, bool aForDisplay) {
+ // The first frame is stored separately. If we only need the frame for
+ // display purposes, we can return it right away. If we need it for advancing
+ // the animation, we want to verify the recreated first frame is available
+ // before allowing it continue.
+ if (aForDisplay && aFrame == 0) {
+ return mFirstFrame.get();
+ }
+
+ // If we don't have that frame, return an empty frame ref.
+ if (aFrame >= mSize) {
+ return nullptr;
+ }
+
+ size_t offset;
+ if (aFrame >= mGetIndex) {
+ offset = aFrame - mGetIndex;
+ } else if (!mSizeKnown) {
+ MOZ_ASSERT_UNREACHABLE("Requesting previous frame after we have advanced!");
+ return nullptr;
+ } else {
+ offset = mSize - mGetIndex + aFrame;
+ }
+
+ if (offset >= mDisplay.size()) {
+ return nullptr;
+ }
+
+ // If we are advancing on behalf of the animation, we don't expect it to be
+ // getting any frames (besides the first) until we get the desired frame.
+ MOZ_ASSERT(aFrame == 0 || mAdvance == 0);
+
+ // If we have space for the frame, it should always be available.
+ MOZ_ASSERT(mDisplay[offset]);
+ return mDisplay[offset].get();
+}
+
+bool AnimationFrameDiscardingQueue::IsFirstFrameFinished() const {
+ MOZ_ASSERT(mFirstFrame);
+ MOZ_ASSERT(mFirstFrame->IsFinished());
+ return true;
+}
+
+bool AnimationFrameDiscardingQueue::IsLastInsertedFrame(
+ imgFrame* aFrame) const {
+ return !mDisplay.empty() && mDisplay.back().get() == aFrame;
+}
+
+void AnimationFrameDiscardingQueue::AddSizeOfExcludingThis(
+ MallocSizeOf aMallocSizeOf, const AddSizeOfCb& aCallback) {
+ mFirstFrame->AddSizeOfExcludingThis(aMallocSizeOf,
+ [&](AddSizeOfCbData& aMetadata) {
+ aMetadata.mIndex = 1;
+ aCallback(aMetadata);
+ });
+
+ size_t i = mGetIndex;
+ for (const RefPtr<imgFrame>& frame : mDisplay) {
+ ++i;
+ if (mSize < i) {
+ i = 1;
+ if (mFirstFrame.get() == frame.get()) {
+ // First frame again, we already covered it above. We can have a
+ // different frame in the first frame position in the discard queue
+ // on subsequent passes of the animation. This is useful for recycling.
+ continue;
+ }
+ }
+
+ frame->AddSizeOfExcludingThis(aMallocSizeOf,
+ [&](AddSizeOfCbData& aMetadata) {
+ aMetadata.mIndex = i;
+ aCallback(aMetadata);
+ });
+ }
+}
+
+AnimationFrameRecyclingQueue::AnimationFrameRecyclingQueue(
+ AnimationFrameRetainedBuffer&& aQueue)
+ : AnimationFrameDiscardingQueue(std::move(aQueue)),
+ mForceUseFirstFrameRefreshArea(false) {
+ // In an ideal world, we would always save the already displayed frames for
+ // recycling but none of the frames were marked as recyclable. We will incur
+ // the extra allocation cost for a few more frames.
+ mRecycling = true;
+
+ // Until we reach the end of the animation, set the first frame refresh area
+ // to match that of the full area of the first frame.
+ mFirstFrameRefreshArea = mFirstFrame->GetRect();
+}
+
+void AnimationFrameRecyclingQueue::AddSizeOfExcludingThis(
+ MallocSizeOf aMallocSizeOf, const AddSizeOfCb& aCallback) {
+ AnimationFrameDiscardingQueue::AddSizeOfExcludingThis(aMallocSizeOf,
+ aCallback);
+
+ for (const RecycleEntry& entry : mRecycle) {
+ if (entry.mFrame) {
+ entry.mFrame->AddSizeOfExcludingThis(
+ aMallocSizeOf, [&](AddSizeOfCbData& aMetadata) {
+ aMetadata.mIndex = 0; // Frame is not applicable
+ aCallback(aMetadata);
+ });
+ }
+ }
+}
+
+void AnimationFrameRecyclingQueue::AdvanceInternal() {
+ // We only want to change the current frame index if we have advanced. This
+ // means either a higher frame index, or going back to the beginning.
+ // We should never have advanced beyond the frame buffer.
+ MOZ_ASSERT(mGetIndex < mSize);
+
+ MOZ_ASSERT(!mDisplay.empty());
+ MOZ_ASSERT(mDisplay.front());
+
+ // We have advanced past the first frame. That means the next frame we are
+ // putting in the queue to recycling is the first frame in the animation,
+ // and we no longer need to worry about having looped around.
+ if (mGetIndex == 1) {
+ mForceUseFirstFrameRefreshArea = false;
+ }
+
+ RefPtr<imgFrame>& front = mDisplay.front();
+ RecycleEntry newEntry(mForceUseFirstFrameRefreshArea ? mFirstFrameRefreshArea
+ : front->GetDirtyRect());
+
+ // If we are allowed to recycle the frame, then we should save it before the
+ // base class's AdvanceInternal discards it.
+ newEntry.mFrame = std::move(front);
+
+ // Even if the frame itself isn't saved, we want the dirty rect to calculate
+ // the recycle rect for future recycled frames.
+ mRecycle.push_back(std::move(newEntry));
+ mDisplay.pop_front();
+ MOZ_ASSERT(!mDisplay.empty());
+ MOZ_ASSERT(mDisplay.front());
+
+ if (mDisplay.size() + mPending - 1 < mBatch) {
+ // If we have fewer frames than the batch size, then ask for more. If we
+ // do not have any pending, then we know that there is no active decoding.
+ //
+ // We limit the batch to avoid using the frame we just added to the queue.
+ // This gives other parts of the system time to switch to the new current
+ // frame, and maximize buffer reuse. In particular this is useful for
+ // WebRender which holds onto the previous frame for much longer.
+ size_t newPending = std::min(mPending + mBatch, mRecycle.size() - 1);
+ if (newPending == 0 && (mDisplay.size() <= 1 || mPending > 0)) {
+ // If we already have pending frames, then the decoder is active and we
+ // cannot go below one. If we are displaying the only frame we have, and
+ // there are none pending, then we must request at least one more frame to
+ // continue to animation, because we won't advance again without a new
+ // frame. This may cause us to skip recycling because the previous frame
+ // is still in use.
+ newPending = 1;
+ }
+ mPending = newPending;
+ }
+}
+
+bool AnimationFrameRecyclingQueue::ResetInternal() {
+ // We should save any display frames that we can to save on at least the
+ // allocation. The first frame refresh area is guaranteed to be the aggregate
+ // dirty rect or the entire frame, and so the bare minimum area we can
+ // recycle. We don't need to worry about updating the dirty rect for the
+ // existing mRecycle entries, because that will happen in RecycleFrame when
+ // we try to pull out a frame to redecode the first frame.
+ for (RefPtr<imgFrame>& frame : mDisplay) {
+ RecycleEntry newEntry(mFirstFrameRefreshArea);
+ newEntry.mFrame = std::move(frame);
+ mRecycle.push_back(std::move(newEntry));
+ }
+
+ return AnimationFrameDiscardingQueue::ResetInternal();
+}
+
+RawAccessFrameRef AnimationFrameRecyclingQueue::RecycleFrame(
+ gfx::IntRect& aRecycleRect) {
+ if (mInsertIndex == 0) {
+ // If we are recreating the first frame, then we actually have already
+ // precomputed aggregate of the dirty rects as the first frame refresh
+ // area. We know that all of the frames still in the recycling queue
+ // need to take into account the same dirty rect because they are also
+ // frames which cross the boundary.
+ //
+ // Note that this may actually shrink the dirty rect if we estimated it
+ // earlier with the full frame size and now we have the actual, more
+ // conservative aggregate for the animation.
+ for (RecycleEntry& entry : mRecycle) {
+ entry.mDirtyRect = mFirstFrameRefreshArea;
+ }
+ // Until we advance to the first frame again, any subsequent recycled
+ // frames should also use the first frame refresh area.
+ mForceUseFirstFrameRefreshArea = true;
+ }
+
+ if (mRecycle.empty()) {
+ return RawAccessFrameRef();
+ }
+
+ RawAccessFrameRef recycledFrame;
+ if (mRecycle.front().mFrame) {
+ recycledFrame = mRecycle.front().mFrame->RawAccessRef();
+ MOZ_ASSERT(recycledFrame);
+ mRecycle.pop_front();
+
+ if (mForceUseFirstFrameRefreshArea) {
+ // We are still crossing the loop boundary and cannot rely upon the dirty
+ // rects of entries in mDisplay to be representative. E.g. The first frame
+ // is probably has a full frame dirty rect.
+ aRecycleRect = mFirstFrameRefreshArea;
+ } else {
+ // Calculate the recycle rect for the recycled frame. This is the
+ // cumulative dirty rect of all of the frames ahead of us to be displayed,
+ // and to be used for recycling. Or in other words, the dirty rect between
+ // the recycled frame and the decoded frame which reuses the buffer.
+ //
+ // We know at this point that mRecycle contains either frames from the end
+ // of the animation with the first frame refresh area as the dirty rect
+ // (plus the first frame likewise) and frames with their actual dirty rect
+ // from the start. mDisplay should also only contain frames from the start
+ // of the animation onwards.
+ aRecycleRect.SetRect(0, 0, 0, 0);
+ for (const RefPtr<imgFrame>& frame : mDisplay) {
+ aRecycleRect = aRecycleRect.Union(frame->GetDirtyRect());
+ }
+ for (const RecycleEntry& entry : mRecycle) {
+ aRecycleRect = aRecycleRect.Union(entry.mDirtyRect);
+ }
+ }
+ } else {
+ mRecycle.pop_front();
+ }
+
+ return recycledFrame;
+}
+
+} // namespace image
+} // namespace mozilla