mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-24 05:11:16 +00:00
ebbc7ae838
Differential Revision: https://phabricator.services.mozilla.com/D78049
707 lines
22 KiB
C++
707 lines
22 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "SourceBuffer.h"
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#include <algorithm>
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#include <cmath>
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#include <cstring>
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#include "mozilla/Likely.h"
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#include "nsIInputStream.h"
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#include "MainThreadUtils.h"
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#include "SurfaceCache.h"
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using std::max;
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using std::min;
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namespace mozilla {
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namespace image {
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//////////////////////////////////////////////////////////////////////////////
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// SourceBufferIterator implementation.
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//////////////////////////////////////////////////////////////////////////////
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SourceBufferIterator::~SourceBufferIterator() {
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if (mOwner) {
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mOwner->OnIteratorRelease();
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}
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}
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SourceBufferIterator& SourceBufferIterator::operator=(
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SourceBufferIterator&& aOther) {
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if (mOwner) {
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mOwner->OnIteratorRelease();
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}
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mOwner = std::move(aOther.mOwner);
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mState = aOther.mState;
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mData = aOther.mData;
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mChunkCount = aOther.mChunkCount;
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mByteCount = aOther.mByteCount;
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mRemainderToRead = aOther.mRemainderToRead;
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return *this;
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}
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SourceBufferIterator::State SourceBufferIterator::AdvanceOrScheduleResume(
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size_t aRequestedBytes, IResumable* aConsumer) {
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MOZ_ASSERT(mOwner);
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if (MOZ_UNLIKELY(!HasMore())) {
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MOZ_ASSERT_UNREACHABLE("Should not advance a completed iterator");
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return COMPLETE;
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}
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// The range of data [mOffset, mOffset + mNextReadLength) has just been read
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// by the caller (or at least they don't have any interest in it), so consume
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// that data.
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MOZ_ASSERT(mData.mIterating.mNextReadLength <=
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mData.mIterating.mAvailableLength);
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mData.mIterating.mOffset += mData.mIterating.mNextReadLength;
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mData.mIterating.mAvailableLength -= mData.mIterating.mNextReadLength;
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// An iterator can have a limit imposed on it to read only a subset of a
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// source buffer. If it is present, we need to mimic the same behaviour as
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// the owning SourceBuffer.
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if (MOZ_UNLIKELY(mRemainderToRead != SIZE_MAX)) {
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MOZ_ASSERT(mData.mIterating.mNextReadLength <= mRemainderToRead);
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mRemainderToRead -= mData.mIterating.mNextReadLength;
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if (MOZ_UNLIKELY(mRemainderToRead == 0)) {
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mData.mIterating.mNextReadLength = 0;
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SetComplete(NS_OK);
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return COMPLETE;
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}
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if (MOZ_UNLIKELY(aRequestedBytes > mRemainderToRead)) {
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aRequestedBytes = mRemainderToRead;
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}
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}
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mData.mIterating.mNextReadLength = 0;
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if (MOZ_LIKELY(mState == READY)) {
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// If the caller wants zero bytes of data, that's easy enough; we just
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// configured ourselves for a zero-byte read above! In theory we could do
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// this even in the START state, but it's not important for performance and
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// breaking the ability of callers to assert that the pointer returned by
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// Data() is non-null doesn't seem worth it.
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if (aRequestedBytes == 0) {
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MOZ_ASSERT(mData.mIterating.mNextReadLength == 0);
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return READY;
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}
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// Try to satisfy the request out of our local buffer. This is potentially
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// much faster than requesting data from our owning SourceBuffer because we
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// don't have to take the lock. Note that if we have anything at all in our
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// local buffer, we use it to satisfy the request; @aRequestedBytes is just
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// the *maximum* number of bytes we can return.
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if (mData.mIterating.mAvailableLength > 0) {
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return AdvanceFromLocalBuffer(aRequestedBytes);
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}
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}
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// Our local buffer is empty, so we'll have to request data from our owning
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// SourceBuffer.
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return mOwner->AdvanceIteratorOrScheduleResume(*this, aRequestedBytes,
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aConsumer);
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}
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bool SourceBufferIterator::RemainingBytesIsNoMoreThan(size_t aBytes) const {
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MOZ_ASSERT(mOwner);
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return mOwner->RemainingBytesIsNoMoreThan(*this, aBytes);
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}
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//////////////////////////////////////////////////////////////////////////////
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// SourceBuffer implementation.
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//////////////////////////////////////////////////////////////////////////////
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const size_t SourceBuffer::MIN_CHUNK_CAPACITY;
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const size_t SourceBuffer::MAX_CHUNK_CAPACITY;
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SourceBuffer::SourceBuffer()
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: mMutex("image::SourceBuffer"), mConsumerCount(0), mCompacted(false) {}
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SourceBuffer::~SourceBuffer() {
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MOZ_ASSERT(mConsumerCount == 0,
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"SourceBuffer destroyed with active consumers");
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}
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nsresult SourceBuffer::AppendChunk(Maybe<Chunk>&& aChunk) {
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mMutex.AssertCurrentThreadOwns();
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#ifdef DEBUG
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if (mChunks.Length() > 0) {
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NS_WARNING("Appending an extra chunk for SourceBuffer");
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}
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#endif
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if (MOZ_UNLIKELY(!aChunk)) {
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return NS_ERROR_OUT_OF_MEMORY;
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}
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if (MOZ_UNLIKELY(aChunk->AllocationFailed())) {
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return NS_ERROR_OUT_OF_MEMORY;
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}
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if (MOZ_UNLIKELY(!mChunks.AppendElement(std::move(*aChunk), fallible))) {
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return NS_ERROR_OUT_OF_MEMORY;
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}
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return NS_OK;
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}
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Maybe<SourceBuffer::Chunk> SourceBuffer::CreateChunk(
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size_t aCapacity, size_t aExistingCapacity /* = 0 */,
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bool aRoundUp /* = true */) {
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if (MOZ_UNLIKELY(aCapacity == 0)) {
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MOZ_ASSERT_UNREACHABLE("Appending a chunk of zero size?");
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return Nothing();
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}
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// Round up if requested.
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size_t finalCapacity = aRoundUp ? RoundedUpCapacity(aCapacity) : aCapacity;
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// Use the size of the SurfaceCache as an additional heuristic to avoid
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// allocating huge buffers. Generally images do not get smaller when decoded,
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// so if we could store the source data in the SurfaceCache, we assume that
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// there's no way we'll be able to store the decoded version.
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if (MOZ_UNLIKELY(!SurfaceCache::CanHold(finalCapacity + aExistingCapacity))) {
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NS_WARNING(
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"SourceBuffer refused to create chunk too large for SurfaceCache");
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return Nothing();
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}
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return Some(Chunk(finalCapacity));
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}
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nsresult SourceBuffer::Compact() {
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mMutex.AssertCurrentThreadOwns();
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MOZ_ASSERT(mConsumerCount == 0, "Should have no consumers here");
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MOZ_ASSERT(mWaitingConsumers.Length() == 0, "Shouldn't have waiters");
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MOZ_ASSERT(mStatus, "Should be complete here");
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// If we've tried to compact once, don't attempt again.
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if (mCompacted) {
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return NS_OK;
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}
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mCompacted = true;
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// Compact our waiting consumers list, since we're complete and no future
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// consumer will ever have to wait.
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mWaitingConsumers.Compact();
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// If we have no chunks, then there's nothing to compact.
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if (mChunks.Length() < 1) {
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return NS_OK;
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}
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// If we have one chunk, then we can compact if it has excess capacity.
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if (mChunks.Length() == 1 && mChunks[0].Length() == mChunks[0].Capacity()) {
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return NS_OK;
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}
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// If the last chunk has the maximum capacity, then we know the total size
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// will be quite large and not worth consolidating. We can likely/cheapily
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// trim the last chunk if it is too big however.
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size_t capacity = mChunks.LastElement().Capacity();
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if (capacity == MAX_CHUNK_CAPACITY) {
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size_t lastLength = mChunks.LastElement().Length();
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if (lastLength != capacity) {
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mChunks.LastElement().SetCapacity(lastLength);
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}
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return NS_OK;
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}
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// We can compact our buffer. Determine the total length.
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size_t length = 0;
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for (uint32_t i = 0; i < mChunks.Length(); ++i) {
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length += mChunks[i].Length();
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}
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// If our total length is zero (which means ExpectLength() got called, but no
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// data ever actually got written) then just empty our chunk list.
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if (MOZ_UNLIKELY(length == 0)) {
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mChunks.Clear();
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return NS_OK;
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}
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Chunk& mergeChunk = mChunks[0];
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if (MOZ_UNLIKELY(!mergeChunk.SetCapacity(length))) {
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NS_WARNING("Failed to reallocate chunk for SourceBuffer compacting - OOM?");
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return NS_OK;
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}
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// Copy our old chunks into the newly reallocated first chunk.
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for (uint32_t i = 1; i < mChunks.Length(); ++i) {
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size_t offset = mergeChunk.Length();
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MOZ_ASSERT(offset < mergeChunk.Capacity());
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MOZ_ASSERT(offset + mChunks[i].Length() <= mergeChunk.Capacity());
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memcpy(mergeChunk.Data() + offset, mChunks[i].Data(), mChunks[i].Length());
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mergeChunk.AddLength(mChunks[i].Length());
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}
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MOZ_ASSERT(mergeChunk.Length() == mergeChunk.Capacity(),
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"Compacted chunk has slack space");
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// Remove the redundant chunks.
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mChunks.RemoveLastElements(mChunks.Length() - 1);
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mChunks.Compact();
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return NS_OK;
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}
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/* static */
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size_t SourceBuffer::RoundedUpCapacity(size_t aCapacity) {
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// Protect against overflow.
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if (MOZ_UNLIKELY(SIZE_MAX - aCapacity < MIN_CHUNK_CAPACITY)) {
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return aCapacity;
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}
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// Round up to the next multiple of MIN_CHUNK_CAPACITY (which should be the
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// size of a page).
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size_t roundedCapacity =
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(aCapacity + MIN_CHUNK_CAPACITY - 1) & ~(MIN_CHUNK_CAPACITY - 1);
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MOZ_ASSERT(roundedCapacity >= aCapacity, "Bad math?");
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MOZ_ASSERT(roundedCapacity - aCapacity < MIN_CHUNK_CAPACITY, "Bad math?");
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return roundedCapacity;
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}
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size_t SourceBuffer::FibonacciCapacityWithMinimum(size_t aMinCapacity) {
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mMutex.AssertCurrentThreadOwns();
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// We grow the source buffer using a Fibonacci growth rate. It will be capped
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// at MAX_CHUNK_CAPACITY, unless the available data exceeds that.
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size_t length = mChunks.Length();
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if (length == 0 || aMinCapacity > MAX_CHUNK_CAPACITY) {
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return aMinCapacity;
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}
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if (length == 1) {
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return min(max(2 * mChunks[0].Capacity(), aMinCapacity),
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MAX_CHUNK_CAPACITY);
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}
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return min(
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max(mChunks[length - 1].Capacity() + mChunks[length - 2].Capacity(),
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aMinCapacity),
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MAX_CHUNK_CAPACITY);
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}
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void SourceBuffer::AddWaitingConsumer(IResumable* aConsumer) {
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mMutex.AssertCurrentThreadOwns();
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MOZ_ASSERT(!mStatus, "Waiting when we're complete?");
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if (aConsumer) {
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mWaitingConsumers.AppendElement(aConsumer);
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}
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}
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void SourceBuffer::ResumeWaitingConsumers() {
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mMutex.AssertCurrentThreadOwns();
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if (mWaitingConsumers.Length() == 0) {
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return;
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}
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for (uint32_t i = 0; i < mWaitingConsumers.Length(); ++i) {
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mWaitingConsumers[i]->Resume();
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}
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mWaitingConsumers.Clear();
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}
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nsresult SourceBuffer::ExpectLength(size_t aExpectedLength) {
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MOZ_ASSERT(aExpectedLength > 0, "Zero expected size?");
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MutexAutoLock lock(mMutex);
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if (MOZ_UNLIKELY(mStatus)) {
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MOZ_ASSERT_UNREACHABLE("ExpectLength after SourceBuffer is complete");
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return NS_OK;
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}
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if (MOZ_UNLIKELY(mChunks.Length() > 0)) {
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MOZ_ASSERT_UNREACHABLE("Duplicate or post-Append call to ExpectLength");
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return NS_OK;
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}
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if (MOZ_UNLIKELY(!SurfaceCache::CanHold(aExpectedLength))) {
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NS_WARNING("SourceBuffer refused to store too large buffer");
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return HandleError(NS_ERROR_INVALID_ARG);
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}
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size_t length = min(aExpectedLength, MAX_CHUNK_CAPACITY);
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if (MOZ_UNLIKELY(NS_FAILED(AppendChunk(CreateChunk(length,
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/* aExistingCapacity */ 0,
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/* aRoundUp */ false))))) {
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return HandleError(NS_ERROR_OUT_OF_MEMORY);
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}
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return NS_OK;
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}
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nsresult SourceBuffer::Append(const char* aData, size_t aLength) {
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MOZ_ASSERT(aData, "Should have a buffer");
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MOZ_ASSERT(aLength > 0, "Writing a zero-sized chunk");
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size_t currentChunkCapacity = 0;
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size_t currentChunkLength = 0;
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char* currentChunkData = nullptr;
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size_t currentChunkRemaining = 0;
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size_t forCurrentChunk = 0;
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size_t forNextChunk = 0;
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size_t nextChunkCapacity = 0;
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size_t totalCapacity = 0;
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{
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MutexAutoLock lock(mMutex);
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if (MOZ_UNLIKELY(mStatus)) {
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// This SourceBuffer is already complete; ignore further data.
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return NS_ERROR_FAILURE;
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}
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if (MOZ_UNLIKELY(mChunks.Length() == 0)) {
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if (MOZ_UNLIKELY(NS_FAILED(AppendChunk(CreateChunk(aLength))))) {
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return HandleError(NS_ERROR_OUT_OF_MEMORY);
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}
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}
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// Copy out the current chunk's information so we can release the lock.
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// Note that this wouldn't be safe if multiple producers were allowed!
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Chunk& currentChunk = mChunks.LastElement();
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currentChunkCapacity = currentChunk.Capacity();
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currentChunkLength = currentChunk.Length();
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currentChunkData = currentChunk.Data();
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// Partition this data between the current chunk and the next chunk.
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// (Because we always allocate a chunk big enough to fit everything passed
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// to Append, we'll never need more than those two chunks to store
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// everything.)
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currentChunkRemaining = currentChunkCapacity - currentChunkLength;
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forCurrentChunk = min(aLength, currentChunkRemaining);
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forNextChunk = aLength - forCurrentChunk;
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// If we'll need another chunk, determine what its capacity should be while
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// we still hold the lock.
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nextChunkCapacity =
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forNextChunk > 0 ? FibonacciCapacityWithMinimum(forNextChunk) : 0;
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for (uint32_t i = 0; i < mChunks.Length(); ++i) {
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totalCapacity += mChunks[i].Capacity();
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}
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}
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// Write everything we can fit into the current chunk.
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MOZ_ASSERT(currentChunkLength + forCurrentChunk <= currentChunkCapacity);
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memcpy(currentChunkData + currentChunkLength, aData, forCurrentChunk);
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// If there's something left, create a new chunk and write it there.
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Maybe<Chunk> nextChunk;
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if (forNextChunk > 0) {
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MOZ_ASSERT(nextChunkCapacity >= forNextChunk, "Next chunk too small?");
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nextChunk = CreateChunk(nextChunkCapacity, totalCapacity);
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if (MOZ_LIKELY(nextChunk && !nextChunk->AllocationFailed())) {
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memcpy(nextChunk->Data(), aData + forCurrentChunk, forNextChunk);
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nextChunk->AddLength(forNextChunk);
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}
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}
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// Update shared data structures.
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{
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MutexAutoLock lock(mMutex);
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// Update the length of the current chunk.
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Chunk& currentChunk = mChunks.LastElement();
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MOZ_ASSERT(currentChunk.Data() == currentChunkData, "Multiple producers?");
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MOZ_ASSERT(currentChunk.Length() == currentChunkLength,
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"Multiple producers?");
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currentChunk.AddLength(forCurrentChunk);
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// If we created a new chunk, add it to the series.
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if (forNextChunk > 0) {
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if (MOZ_UNLIKELY(!nextChunk)) {
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return HandleError(NS_ERROR_OUT_OF_MEMORY);
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}
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if (MOZ_UNLIKELY(NS_FAILED(AppendChunk(std::move(nextChunk))))) {
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return HandleError(NS_ERROR_OUT_OF_MEMORY);
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}
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}
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// Resume any waiting readers now that there's new data.
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ResumeWaitingConsumers();
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}
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return NS_OK;
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}
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static nsresult AppendToSourceBuffer(nsIInputStream*, void* aClosure,
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const char* aFromRawSegment, uint32_t,
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uint32_t aCount, uint32_t* aWriteCount) {
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SourceBuffer* sourceBuffer = static_cast<SourceBuffer*>(aClosure);
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// Copy the source data. Unless we hit OOM, we squelch the return value here,
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// because returning an error means that ReadSegments stops reading data, and
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// we want to ensure that we read everything we get. If we hit OOM then we
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// return a failed status to the caller.
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nsresult rv = sourceBuffer->Append(aFromRawSegment, aCount);
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if (rv == NS_ERROR_OUT_OF_MEMORY) {
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return rv;
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}
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// Report that we wrote everything we got.
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*aWriteCount = aCount;
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return NS_OK;
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}
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nsresult SourceBuffer::AppendFromInputStream(nsIInputStream* aInputStream,
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uint32_t aCount) {
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uint32_t bytesRead;
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nsresult rv = aInputStream->ReadSegments(AppendToSourceBuffer, this, aCount,
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&bytesRead);
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if (NS_WARN_IF(NS_FAILED(rv))) {
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return rv;
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}
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if (bytesRead == 0) {
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// The loading of the image has been canceled.
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return NS_ERROR_FAILURE;
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}
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if (bytesRead != aCount) {
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// Only some of the given data was read. We may have failed in
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// SourceBuffer::Append but ReadSegments swallowed the error. Otherwise the
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// stream itself failed to yield the data.
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MutexAutoLock lock(mMutex);
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if (mStatus) {
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MOZ_ASSERT(NS_FAILED(*mStatus));
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return *mStatus;
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}
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MOZ_ASSERT_UNREACHABLE("AppendToSourceBuffer should consume everything");
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}
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return rv;
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}
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void SourceBuffer::Complete(nsresult aStatus) {
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MutexAutoLock lock(mMutex);
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// When an error occurs internally (e.g. due to an OOM), we save the status.
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// This will indirectly trigger a failure higher up and that will call
|
|
// SourceBuffer::Complete. Since it doesn't necessarily know we are already
|
|
// complete, it is safe to ignore.
|
|
if (mStatus && (MOZ_UNLIKELY(NS_SUCCEEDED(*mStatus) ||
|
|
aStatus != NS_IMAGELIB_ERROR_FAILURE))) {
|
|
MOZ_ASSERT_UNREACHABLE("Called Complete more than once");
|
|
return;
|
|
}
|
|
|
|
if (MOZ_UNLIKELY(NS_SUCCEEDED(aStatus) && IsEmpty())) {
|
|
// It's illegal to succeed without writing anything.
|
|
aStatus = NS_ERROR_FAILURE;
|
|
}
|
|
|
|
mStatus = Some(aStatus);
|
|
|
|
// Resume any waiting consumers now that we're complete.
|
|
ResumeWaitingConsumers();
|
|
|
|
// If we still have active consumers, just return.
|
|
if (mConsumerCount > 0) {
|
|
return;
|
|
}
|
|
|
|
// Attempt to compact our buffer down to a single chunk.
|
|
Compact();
|
|
}
|
|
|
|
bool SourceBuffer::IsComplete() {
|
|
MutexAutoLock lock(mMutex);
|
|
return bool(mStatus);
|
|
}
|
|
|
|
size_t SourceBuffer::SizeOfIncludingThisWithComputedFallback(
|
|
MallocSizeOf aMallocSizeOf) const {
|
|
MutexAutoLock lock(mMutex);
|
|
|
|
size_t n = aMallocSizeOf(this);
|
|
n += mChunks.ShallowSizeOfExcludingThis(aMallocSizeOf);
|
|
|
|
for (uint32_t i = 0; i < mChunks.Length(); ++i) {
|
|
size_t chunkSize = aMallocSizeOf(mChunks[i].Data());
|
|
|
|
if (chunkSize == 0) {
|
|
// We're on a platform where moz_malloc_size_of always returns 0.
|
|
chunkSize = mChunks[i].Capacity();
|
|
}
|
|
|
|
n += chunkSize;
|
|
}
|
|
|
|
return n;
|
|
}
|
|
|
|
SourceBufferIterator SourceBuffer::Iterator(size_t aReadLength) {
|
|
{
|
|
MutexAutoLock lock(mMutex);
|
|
mConsumerCount++;
|
|
}
|
|
|
|
return SourceBufferIterator(this, aReadLength);
|
|
}
|
|
|
|
void SourceBuffer::OnIteratorRelease() {
|
|
MutexAutoLock lock(mMutex);
|
|
|
|
MOZ_ASSERT(mConsumerCount > 0, "Consumer count doesn't add up");
|
|
mConsumerCount--;
|
|
|
|
// If we still have active consumers, or we're not complete yet, then return.
|
|
if (mConsumerCount > 0 || !mStatus) {
|
|
return;
|
|
}
|
|
|
|
// Attempt to compact our buffer down to a single chunk.
|
|
Compact();
|
|
}
|
|
|
|
bool SourceBuffer::RemainingBytesIsNoMoreThan(
|
|
const SourceBufferIterator& aIterator, size_t aBytes) const {
|
|
MutexAutoLock lock(mMutex);
|
|
|
|
// If we're not complete, we always say no.
|
|
if (!mStatus) {
|
|
return false;
|
|
}
|
|
|
|
// If the iterator's at the end, the answer is trivial.
|
|
if (!aIterator.HasMore()) {
|
|
return true;
|
|
}
|
|
|
|
uint32_t iteratorChunk = aIterator.mData.mIterating.mChunk;
|
|
size_t iteratorOffset = aIterator.mData.mIterating.mOffset;
|
|
size_t iteratorLength = aIterator.mData.mIterating.mAvailableLength;
|
|
|
|
// Include the bytes the iterator is currently pointing to in the limit, so
|
|
// that the current chunk doesn't have to be a special case.
|
|
size_t bytes = aBytes + iteratorOffset + iteratorLength;
|
|
|
|
// Count the length over all of our chunks, starting with the one that the
|
|
// iterator is currently pointing to. (This is O(N), but N is expected to be
|
|
// ~1, so it doesn't seem worth caching the length separately.)
|
|
size_t lengthSoFar = 0;
|
|
for (uint32_t i = iteratorChunk; i < mChunks.Length(); ++i) {
|
|
lengthSoFar += mChunks[i].Length();
|
|
if (lengthSoFar > bytes) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
SourceBufferIterator::State SourceBuffer::AdvanceIteratorOrScheduleResume(
|
|
SourceBufferIterator& aIterator, size_t aRequestedBytes,
|
|
IResumable* aConsumer) {
|
|
MutexAutoLock lock(mMutex);
|
|
|
|
MOZ_ASSERT(aIterator.HasMore(),
|
|
"Advancing a completed iterator and "
|
|
"AdvanceOrScheduleResume didn't catch it");
|
|
|
|
if (MOZ_UNLIKELY(mStatus && NS_FAILED(*mStatus))) {
|
|
// This SourceBuffer is complete due to an error; all reads fail.
|
|
return aIterator.SetComplete(*mStatus);
|
|
}
|
|
|
|
if (MOZ_UNLIKELY(mChunks.Length() == 0)) {
|
|
// We haven't gotten an initial chunk yet.
|
|
AddWaitingConsumer(aConsumer);
|
|
return aIterator.SetWaiting(!!aConsumer);
|
|
}
|
|
|
|
uint32_t iteratorChunkIdx = aIterator.mData.mIterating.mChunk;
|
|
MOZ_ASSERT(iteratorChunkIdx < mChunks.Length());
|
|
|
|
const Chunk& currentChunk = mChunks[iteratorChunkIdx];
|
|
size_t iteratorEnd = aIterator.mData.mIterating.mOffset +
|
|
aIterator.mData.mIterating.mAvailableLength;
|
|
MOZ_ASSERT(iteratorEnd <= currentChunk.Length());
|
|
MOZ_ASSERT(iteratorEnd <= currentChunk.Capacity());
|
|
|
|
if (iteratorEnd < currentChunk.Length()) {
|
|
// There's more data in the current chunk.
|
|
return aIterator.SetReady(iteratorChunkIdx, currentChunk.Data(),
|
|
iteratorEnd, currentChunk.Length() - iteratorEnd,
|
|
aRequestedBytes);
|
|
}
|
|
|
|
if (iteratorEnd == currentChunk.Capacity() &&
|
|
!IsLastChunk(iteratorChunkIdx)) {
|
|
// Advance to the next chunk.
|
|
const Chunk& nextChunk = mChunks[iteratorChunkIdx + 1];
|
|
return aIterator.SetReady(iteratorChunkIdx + 1, nextChunk.Data(), 0,
|
|
nextChunk.Length(), aRequestedBytes);
|
|
}
|
|
|
|
MOZ_ASSERT(IsLastChunk(iteratorChunkIdx), "Should've advanced");
|
|
|
|
if (mStatus) {
|
|
// There's no more data and this SourceBuffer completed successfully.
|
|
MOZ_ASSERT(NS_SUCCEEDED(*mStatus), "Handled failures earlier");
|
|
return aIterator.SetComplete(*mStatus);
|
|
}
|
|
|
|
// We're not complete, but there's no more data right now. Arrange to wake up
|
|
// the consumer when we get more data.
|
|
AddWaitingConsumer(aConsumer);
|
|
return aIterator.SetWaiting(!!aConsumer);
|
|
}
|
|
|
|
nsresult SourceBuffer::HandleError(nsresult aError) {
|
|
MOZ_ASSERT(NS_FAILED(aError), "Should have an error here");
|
|
MOZ_ASSERT(aError == NS_ERROR_OUT_OF_MEMORY || aError == NS_ERROR_INVALID_ARG,
|
|
"Unexpected error; may want to notify waiting readers, which "
|
|
"HandleError currently doesn't do");
|
|
|
|
mMutex.AssertCurrentThreadOwns();
|
|
|
|
NS_WARNING("SourceBuffer encountered an unrecoverable error");
|
|
|
|
// Record the error.
|
|
mStatus = Some(aError);
|
|
|
|
// Drop our references to waiting readers.
|
|
mWaitingConsumers.Clear();
|
|
|
|
return *mStatus;
|
|
}
|
|
|
|
bool SourceBuffer::IsEmpty() {
|
|
mMutex.AssertCurrentThreadOwns();
|
|
return mChunks.Length() == 0 || mChunks[0].Length() == 0;
|
|
}
|
|
|
|
bool SourceBuffer::IsLastChunk(uint32_t aChunk) {
|
|
mMutex.AssertCurrentThreadOwns();
|
|
return aChunk + 1 == mChunks.Length();
|
|
}
|
|
|
|
} // namespace image
|
|
} // namespace mozilla
|