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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 */
#include "mozilla/layers/WebRenderMessages.h"
#include "mozilla/layers/RefCountedShmem.h"
#include "mozilla/layers/TextureClient.h"
#include "mozilla/webrender/WebRenderTypes.h"
namespace mozilla {
namespace ipc {
class IShmemAllocator;
namespace layers {
class TextureClient;
class WebRenderBridgeChild;
} // namespace layers
namespace wr {
/// ShmSegmentsWriter pushes bytes in a sequence of fixed size shmems for small
/// allocations and creates dedicated shmems for large allocations.
class ShmSegmentsWriter {
ShmSegmentsWriter(layers::WebRenderBridgeChild* aAllocator,
size_t aChunkSize);
ShmSegmentsWriter(ShmSegmentsWriter&& aOther) noexcept;
ShmSegmentsWriter& operator=(ShmSegmentsWriter&& aOther) noexcept;
ShmSegmentsWriter(const ShmSegmentsWriter& aOther) = delete;
ShmSegmentsWriter& operator=(const ShmSegmentsWriter& aOther) = delete;
layers::OffsetRange Write(Range<uint8_t> aBytes);
template <typename T>
layers::OffsetRange WriteAsBytes(Range<T> aValues) {
return Write(Range<uint8_t>((uint8_t*)aValues.begin().get(),
aValues.length() * sizeof(T)));
void Flush(nsTArray<layers::RefCountedShmem>& aSmallAllocs,
nsTArray<mozilla::ipc::Shmem>& aLargeAllocs);
void Clear();
bool IsEmpty() const;
layers::WebRenderBridgeChild* WrBridge() const { return mShmAllocator; }
size_t ChunkSize() const { return mChunkSize; }
bool AllocChunk();
layers::OffsetRange AllocLargeChunk(size_t aSize);
nsTArray<layers::RefCountedShmem> mSmallAllocs;
nsTArray<mozilla::ipc::Shmem> mLargeAllocs;
layers::WebRenderBridgeChild* mShmAllocator;
size_t mCursor;
size_t mChunkSize;
class ShmSegmentsReader {
ShmSegmentsReader(const nsTArray<layers::RefCountedShmem>& aSmallShmems,
const nsTArray<mozilla::ipc::Shmem>& aLargeShmems);
bool Read(const layers::OffsetRange& aRange, wr::Vec<uint8_t>& aInto);
// Get a read pointer, if possible, directly into the shm. If the range has
// been broken up into multiple chunks that can't be represented by a single
// range, nothing will be returned to indicate failure.
Maybe<Range<uint8_t>> GetReadPointer(const layers::OffsetRange& aRange);
// Get a read pointer, if possible, directly into the shm. Otherwise, copy
// it into the Vec and return a pointer to that contiguous memory instead.
// If all fails, return nothing.
Maybe<Range<uint8_t>> GetReadPointerOrCopy(const layers::OffsetRange& aRange,
wr::Vec<uint8_t>& aInto) {
if (Maybe<Range<uint8_t>> ptr = GetReadPointer(aRange)) {
return ptr;
} else {
size_t initialLength = aInto.Length();
if (Read(aRange, aInto)) {
return Some(Range<uint8_t>(aInto.Data() + initialLength,
aInto.Length() - initialLength));
} else {
return Nothing();
bool ReadLarge(const layers::OffsetRange& aRange, wr::Vec<uint8_t>& aInto);
Maybe<Range<uint8_t>> GetReadPointerLarge(const layers::OffsetRange& aRange);
const nsTArray<layers::RefCountedShmem>& mSmallAllocs;
const nsTArray<mozilla::ipc::Shmem>& mLargeAllocs;
size_t mChunkSize;
class IpcResourceUpdateQueue {
// Because we are using shmems, the size should be a multiple of the page
// size. Each shmem has two guard pages, and the minimum shmem size (at least
// one Windows) is 64k which is already quite large for a lot of the resources
// we use here. The RefCountedShmem type used to allocate the chunks keeps a
// 16 bytes header in the buffer which we account for here as well. So we pick
// 64k - 2 * 4k - 16 = 57328 bytes as the default alloc size.
explicit IpcResourceUpdateQueue(layers::WebRenderBridgeChild* aAllocator,
size_t aChunkSize = 57328);
IpcResourceUpdateQueue(IpcResourceUpdateQueue&& aOther) noexcept;
IpcResourceUpdateQueue& operator=(IpcResourceUpdateQueue&& aOther) noexcept;
IpcResourceUpdateQueue(const IpcResourceUpdateQueue& aOther) = delete;
IpcResourceUpdateQueue& operator=(const IpcResourceUpdateQueue& aOther) =
// Moves over everything but the subqueues
void ReplaceResources(IpcResourceUpdateQueue&& aOther);
bool AddImage(wr::ImageKey aKey, const ImageDescriptor& aDescriptor,
Range<uint8_t> aBytes);
bool AddBlobImage(wr::BlobImageKey aKey, const ImageDescriptor& aDescriptor,
Range<uint8_t> aBytes, ImageIntRect aVisibleRect);
void AddSharedExternalImage(wr::ExternalImageId aExtId, wr::ImageKey aKey);
void PushExternalImageForTexture(wr::ExternalImageId aExtId,
wr::ImageKey aKey,
layers::TextureClient* aTexture,
bool aIsUpdate);
bool UpdateImageBuffer(wr::ImageKey aKey, const ImageDescriptor& aDescriptor,
Range<uint8_t> aBytes);
bool UpdateBlobImage(wr::BlobImageKey aKey,
const ImageDescriptor& aDescriptor,
Range<uint8_t> aBytes, ImageIntRect aVisibleRect,
ImageIntRect aDirtyRect);
void UpdateSharedExternalImage(ExternalImageId aExtID, ImageKey aKey,
ImageIntRect aDirtyRect);
void SetBlobImageVisibleArea(BlobImageKey aKey, const ImageIntRect& aArea);
void DeleteImage(wr::ImageKey aKey);
void DeleteBlobImage(wr::BlobImageKey aKey);
bool AddRawFont(wr::FontKey aKey, Range<uint8_t> aBytes, uint32_t aIndex);
bool AddFontDescriptor(wr::FontKey aKey, Range<uint8_t> aBytes,
uint32_t aIndex);
void DeleteFont(wr::FontKey aKey);
void AddFontInstance(wr::FontInstanceKey aKey, wr::FontKey aFontKey,
float aGlyphSize,
const wr::FontInstanceOptions* aOptions,
const wr::FontInstancePlatformOptions* aPlatformOptions,
Range<const gfx::FontVariation> aVariations);
void DeleteFontInstance(wr::FontInstanceKey aKey);
void Clear();
void Flush(nsTArray<layers::OpUpdateResource>& aUpdates,
nsTArray<layers::RefCountedShmem>& aSmallAllocs,
nsTArray<mozilla::ipc::Shmem>& aLargeAllocs);
bool IsEmpty() const;
static void ReleaseShmems(mozilla::ipc::IProtocol*,
nsTArray<layers::RefCountedShmem>& aShms);
static void ReleaseShmems(mozilla::ipc::IProtocol*,
nsTArray<mozilla::ipc::Shmem>& aShms);
ShmSegmentsWriter mWriter;
nsTArray<layers::OpUpdateResource> mUpdates;
} // namespace wr
} // namespace mozilla