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* Copyright 2018 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#include "SkRemoteGlyphCache.h"
#include <iterator>
#include <memory>
#include <new>
#include <string>
#include <tuple>
#include "SkDevice.h"
#include "SkDraw.h"
#include "SkGlyphRun.h"
#include "SkRemoteGlyphCacheImpl.h"
#include "SkStrike.h"
#include "SkStrikeCache.h"
#include "SkTLazy.h"
#include "SkTraceEvent.h"
#include "SkTypeface_remote.h"
#include "GrDrawOpAtlas.h"
#include "text/GrTextContext.h"
static SkDescriptor* auto_descriptor_from_desc(const SkDescriptor* source_desc,
SkFontID font_id,
SkAutoDescriptor* ad) {
auto* desc = ad->getDesc();
// Rec.
uint32_t size;
auto ptr = source_desc->findEntry(kRec_SkDescriptorTag, &size);
SkScalerContextRec rec;
std::memcpy(&rec, ptr, size);
rec.fFontID = font_id;
desc->addEntry(kRec_SkDescriptorTag, sizeof(rec), &rec);
// Effects.
uint32_t size;
auto ptr = source_desc->findEntry(kEffects_SkDescriptorTag, &size);
if (ptr) { desc->addEntry(kEffects_SkDescriptorTag, size, ptr); }
return desc;
static const SkDescriptor* create_descriptor(
const SkPaint& paint, const SkFont& font, const SkMatrix& m,
const SkSurfaceProps& props, SkScalerContextFlags flags,
SkAutoDescriptor* ad, SkScalerContextEffects* effects) {
SkScalerContextRec rec;
SkScalerContext::MakeRecAndEffects(font, paint, props, flags, m, &rec, effects);
return SkScalerContext::AutoDescriptorGivenRecAndEffects(rec, *effects, ad);
// -- Serializer ----------------------------------------------------------------------------------
size_t pad(size_t size, size_t alignment) { return (size + (alignment - 1)) & ~(alignment - 1); }
class Serializer {
Serializer(std::vector<uint8_t>* buffer) : fBuffer{buffer} { }
template <typename T, typename... Args>
T* emplace(Args&&... args) {
auto result = allocate(sizeof(T), alignof(T));
return new (result) T{std::forward<Args>(args)...};
template <typename T>
void write(const T& data) {
T* result = (T*)allocate(sizeof(T), alignof(T));
memcpy(result, &data, sizeof(T));
template <typename T>
T* allocate() {
T* result = (T*)allocate(sizeof(T), alignof(T));
return result;
void writeDescriptor(const SkDescriptor& desc) {
auto result = allocate(desc.getLength(), alignof(SkDescriptor));
memcpy(result, &desc, desc.getLength());
void* allocate(size_t size, size_t alignment) {
size_t aligned = pad(fBuffer->size(), alignment);
fBuffer->resize(aligned + size);
return &(*fBuffer)[aligned];
std::vector<uint8_t>* fBuffer;
// -- Deserializer -------------------------------------------------------------------------------
// Note that the Deserializer is reading untrusted data, we need to guard against invalid data.
class Deserializer {
Deserializer(const volatile char* memory, size_t memorySize)
: fMemory(memory), fMemorySize(memorySize) {}
template <typename T>
bool read(T* val) {
auto* result = this->ensureAtLeast(sizeof(T), alignof(T));
if (!result) return false;
memcpy(val, const_cast<const char*>(result), sizeof(T));
return true;
bool readDescriptor(SkAutoDescriptor* ad) {
uint32_t descLength = 0u;
if (!read<uint32_t>(&descLength)) return false;
if (descLength < sizeof(SkDescriptor)) return false;
if (descLength != SkAlign4(descLength)) return false;
auto* result = this->ensureAtLeast(descLength, alignof(SkDescriptor));
if (!result) return false;
memcpy(ad->getDesc(), const_cast<const char*>(result), descLength);
if (ad->getDesc()->getLength() > descLength) return false;
return ad->getDesc()->isValid();
const volatile void* read(size_t size, size_t alignment) {
return this->ensureAtLeast(size, alignment);
const volatile char* ensureAtLeast(size_t size, size_t alignment) {
size_t padded = pad(fBytesRead, alignment);
// Not enough data.
if (padded > fMemorySize) return nullptr;
if (size > fMemorySize - padded) return nullptr;
auto* result = fMemory + padded;
fBytesRead = padded + size;
return result;
// Note that we read each piece of memory only once to guard against TOCTOU violations.
const volatile char* fMemory;
size_t fMemorySize;
size_t fBytesRead = 0u;
// Paths use a SkWriter32 which requires 4 byte alignment.
static const size_t kPathAlignment = 4u;
bool read_path(Deserializer* deserializer, SkGlyph* glyph, SkStrike* cache) {
uint64_t pathSize = 0u;
if (!deserializer->read<uint64_t>(&pathSize)) return false;
if (pathSize == 0u) return true;
auto* path = deserializer->read(pathSize, kPathAlignment);
if (!path) return false;
// Don't overwrite the path if we already have one. We could have used a fallback if the
// glyph was missing earlier.
if (glyph->fPathData != nullptr) return true;
return cache->initializePath(glyph, path, pathSize);
size_t SkDescriptorMapOperators::operator()(const SkDescriptor* key) const {
return key->getChecksum();
bool SkDescriptorMapOperators::operator()(const SkDescriptor* lhs, const SkDescriptor* rhs) const {
return *lhs == *rhs;
struct StrikeSpec {
StrikeSpec() {}
StrikeSpec(SkFontID typefaceID_, SkDiscardableHandleId discardableHandleId_)
: typefaceID{typefaceID_}, discardableHandleId(discardableHandleId_) {}
SkFontID typefaceID = 0u;
SkDiscardableHandleId discardableHandleId = 0u;
/* desc */
/* n X (glyphs ids) */
// -- TrackLayerDevice -----------------------------------------------------------------------------
const SkIRect& bounds, const SkSurfaceProps& props, SkStrikeServer* server,
sk_sp<SkColorSpace> colorSpace, const SkTextBlobCacheDiffCanvas::Settings& settings)
: SkNoPixelsDevice(bounds, props, std::move(colorSpace))
, fStrikeServer(server)
, fSettings(settings)
, fPainter{props, kUnknown_SkColorType, imageInfo().colorSpace(), fStrikeServer} {
SkBaseDevice* SkTextBlobCacheDiffCanvas::TrackLayerDevice::onCreateDevice(
const CreateInfo& cinfo, const SkPaint*) {
const SkSurfaceProps surfaceProps(this->surfaceProps().flags(), cinfo.fPixelGeometry);
return new TrackLayerDevice(this->getGlobalBounds(), surfaceProps, fStrikeServer,
cinfo.fInfo.refColorSpace(), fSettings);
void SkTextBlobCacheDiffCanvas::TrackLayerDevice::drawGlyphRunList(
const SkGlyphRunList& glyphRunList) {
GrTextContext::Options options;
options.fMinDistanceFieldFontSize = fSettings.fMinDistanceFieldFontSize;
options.fMaxDistanceFieldFontSize = fSettings.fMaxDistanceFieldFontSize;
#endif // SK_SUPPORT_GPU
// -- SkTextBlobCacheDiffCanvas -------------------------------------------------------------------
SkTextBlobCacheDiffCanvas::Settings::Settings() = default;
int width, int height, const SkSurfaceProps& props,
SkStrikeServer* strikeServer, Settings settings)
: SkNoDrawCanvas{sk_make_sp<TrackLayerDevice>(
SkIRect::MakeWH(width, height), props, strikeServer, nullptr, settings)} {}
SkTextBlobCacheDiffCanvas::SkTextBlobCacheDiffCanvas(int width, int height,
const SkSurfaceProps& props,
SkStrikeServer* strikeServer,
sk_sp<SkColorSpace> colorSpace,
Settings settings)
: SkNoDrawCanvas{sk_make_sp<TrackLayerDevice>(SkIRect::MakeWH(width, height), props,
strikeServer, std::move(colorSpace), settings)} {}
SkTextBlobCacheDiffCanvas::~SkTextBlobCacheDiffCanvas() = default;
SkCanvas::SaveLayerStrategy SkTextBlobCacheDiffCanvas::getSaveLayerStrategy(
const SaveLayerRec& rec) {
return kFullLayer_SaveLayerStrategy;
bool SkTextBlobCacheDiffCanvas::onDoSaveBehind(const SkRect*) {
return false;
void SkTextBlobCacheDiffCanvas::onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
const SkPaint& paint) {
SkCanvas::onDrawTextBlob(blob, x, y, paint);
struct WireTypeface {
WireTypeface() = default;
WireTypeface(SkFontID typeface_id, int glyph_count, SkFontStyle style, bool is_fixed)
: typefaceID(typeface_id), glyphCount(glyph_count), style(style), isFixed(is_fixed) {}
SkFontID typefaceID;
int glyphCount;
SkFontStyle style;
bool isFixed;
// SkStrikeServer -----------------------------------------
SkStrikeServer::SkStrikeServer(DiscardableHandleManager* discardableHandleManager)
: fDiscardableHandleManager(discardableHandleManager) {
SkStrikeServer::~SkStrikeServer() = default;
sk_sp<SkData> SkStrikeServer::serializeTypeface(SkTypeface* tf) {
auto* data = fSerializedTypefaces.find(SkTypeface::UniqueID(tf));
if (data) {
return *data;
WireTypeface wire(SkTypeface::UniqueID(tf), tf->countGlyphs(), tf->fontStyle(),
data = fSerializedTypefaces.set(SkTypeface::UniqueID(tf),
SkData::MakeWithCopy(&wire, sizeof(wire)));
return *data;
void SkStrikeServer::writeStrikeData(std::vector<uint8_t>* memory) {
if (fLockedDescs.empty() && fTypefacesToSend.empty()) {
Serializer serializer(memory);
for (const auto& tf : fTypefacesToSend) serializer.write<WireTypeface>(tf);
for (const auto* desc : fLockedDescs) {
auto it = fRemoteGlyphStateMap.find(desc);
SkASSERT(it != fRemoteGlyphStateMap.end());
SkStrikeServer::SkGlyphCacheState* SkStrikeServer::getOrCreateCache(
const SkPaint& paint,
const SkFont& font,
const SkSurfaceProps& props,
const SkMatrix& matrix,
SkScalerContextFlags flags,
SkScalerContextEffects* effects) {
SkAutoDescriptor descStorage;
auto desc = create_descriptor(paint, font, matrix, props, flags, &descStorage, effects);
return this->getOrCreateCache(*desc, *font.getTypefaceOrDefault(), *effects);
SkScopedStrike SkStrikeServer::findOrCreateScopedStrike(const SkDescriptor& desc,
const SkScalerContextEffects& effects,
const SkTypeface& typeface) {
return SkScopedStrike{this->getOrCreateCache(desc, typeface, effects)};
void SkStrikeServer::checkForDeletedEntries() {
auto it = fRemoteGlyphStateMap.begin();
while (fRemoteGlyphStateMap.size() > fMaxEntriesInDescriptorMap &&
it != fRemoteGlyphStateMap.end()) {
if (fDiscardableHandleManager->isHandleDeleted(it->second->discardableHandleId())) {
it = fRemoteGlyphStateMap.erase(it);
} else {
SkStrikeServer::SkGlyphCacheState* SkStrikeServer::getOrCreateCache(
const SkDescriptor& desc, const SkTypeface& typeface, SkScalerContextEffects effects) {
// In cases where tracing is turned off, make sure not to get an unused function warning.
// Lambdaize the function.
TRACE_EVENT1("skia", "RecForDesc", "rec",
auto ptr = desc.findEntry(kRec_SkDescriptorTag, nullptr);
SkScalerContextRec rec;
std::memcpy(&rec, ptr, sizeof(rec));
return rec.dump();
// Already locked.
if (fLockedDescs.find(&desc) != fLockedDescs.end()) {
auto it = fRemoteGlyphStateMap.find(&desc);
SkASSERT(it != fRemoteGlyphStateMap.end());
SkGlyphCacheState* cache = it->second.get();
cache->setTypefaceAndEffects(&typeface, effects);
return cache;
// Try to lock.
auto it = fRemoteGlyphStateMap.find(&desc);
if (it != fRemoteGlyphStateMap.end()) {
SkGlyphCacheState* cache = it->second.get();
bool locked = fDiscardableHandleManager->lockHandle(it->second->discardableHandleId());
if (locked) {
cache->setTypefaceAndEffects(&typeface, effects);
return cache;
// If the lock failed, the entry was deleted on the client. Remove our
// tracking.
const SkFontID typefaceId = typeface.uniqueID();
if (!fCachedTypefaces.contains(typefaceId)) {
fTypefacesToSend.emplace_back(typefaceId, typeface.countGlyphs(),
auto context = typeface.createScalerContext(effects, &desc);
// Create a new cache state and insert it into the map.
auto newHandle = fDiscardableHandleManager->createHandle();
auto cacheState = skstd::make_unique<SkGlyphCacheState>(desc, std::move(context), newHandle);
auto* cacheStatePtr = cacheState.get();
fRemoteGlyphStateMap[&cacheStatePtr->getDescriptor()] = std::move(cacheState);
cacheStatePtr->setTypefaceAndEffects(&typeface, effects);
return cacheStatePtr;
// -- SkGlyphCacheState ----------------------------------------------------------------------------
const SkDescriptor& descriptor,
std::unique_ptr<SkScalerContext> context,
uint32_t discardableHandleId)
: fDescriptor{descriptor}
, fDiscardableHandleId(discardableHandleId)
, fIsSubpixel{context->isSubpixel()}
, fAxisAlignmentForHText{context->computeAxisAlignmentForHText()}
// N.B. context must come last because it is used above.
, fContext{std::move(context)} {
SkASSERT(fDescriptor.getDesc() != nullptr);
SkASSERT(fContext != nullptr);
SkStrikeServer::SkGlyphCacheState::~SkGlyphCacheState() = default;
void SkStrikeServer::SkGlyphCacheState::addGlyph(SkPackedGlyphID glyph, bool asPath) {
auto* cache = asPath ? &fCachedGlyphPaths : &fCachedGlyphImages;
auto* pending = asPath ? &fPendingGlyphPaths : &fPendingGlyphImages;
// Already cached.
if (cache->contains(glyph)) {
// A glyph is going to be sent. Make sure we have a scaler context to send it.
// Serialize and cache. Also create the scalar context to use when serializing
// this glyph.
static void writeGlyph(SkGlyph* glyph, Serializer* serializer) {
void SkStrikeServer::SkGlyphCacheState::writePendingGlyphs(Serializer* serializer) {
// TODO(khushalsagar): Write a strike only if it has any pending glyphs.
if (!this->hasPendingGlyphs()) {
// Write the desc.
serializer->emplace<StrikeSpec>(fContext->getTypeface()->uniqueID(), fDiscardableHandleId);
// Write FontMetrics.
// TODO(khushalsagar): Do we need to re-send each time?
SkFontMetrics fontMetrics;
// Write glyphs images.
for (const auto& glyphID : fPendingGlyphImages) {
SkGlyph glyph{glyphID};
writeGlyph(&glyph, serializer);
auto imageSize = glyph.computeImageSize();
if (imageSize == 0u) continue;
glyph.fImage = serializer->allocate(imageSize, glyph.formatAlignment());
// TODO: Generating the image can change the mask format, do we need to update it in the
// serialized glyph?
// Write glyphs paths.
for (const auto& glyphID : fPendingGlyphPaths) {
SkGlyph glyph{glyphID};
writeGlyph(&glyph, serializer);
writeGlyphPath(glyphID, serializer);
void SkStrikeServer::SkGlyphCacheState::ensureScalerContext() {
if (fContext == nullptr) {
fContext = fTypeface->createScalerContext(fEffects, fDescriptor.getDesc());
void SkStrikeServer::SkGlyphCacheState::resetScalerContext() {
fTypeface = nullptr;
void SkStrikeServer::SkGlyphCacheState::setTypefaceAndEffects(
const SkTypeface* typeface, SkScalerContextEffects effects) {
fTypeface = typeface;
fEffects = effects;
SkVector SkStrikeServer::SkGlyphCacheState::rounding() const {
return SkStrikeCommon::PixelRounding(fIsSubpixel, fAxisAlignmentForHText);
// Note: In the split Renderer/GPU architecture, if getGlyphMetrics is called in the Renderer
// process, then it will be called on the GPU process because they share the rendering code. Any
// data that is created in the Renderer process needs to be found in the GPU process. By
// implication, any cache-miss/glyph-creation data needs to be sent to the GPU.
const SkGlyph& SkStrikeServer::SkGlyphCacheState::getGlyphMetrics(
SkGlyphID glyphID, SkPoint position) {
SkIPoint lookupPoint = SkStrikeCommon::SubpixelLookup(fAxisAlignmentForHText, position);
SkPackedGlyphID packedGlyphID = fIsSubpixel ? SkPackedGlyphID{glyphID, lookupPoint}
: SkPackedGlyphID{glyphID};
// Check the cache for the glyph.
SkGlyph* glyphPtr = fGlyphMap.findOrNull(packedGlyphID);
// Has this glyph ever been seen before?
if (glyphPtr == nullptr) {
// Never seen before. Make a new glyph.
glyphPtr = fAlloc.make<SkGlyph>(packedGlyphID);
// Make sure to send the glyph to the GPU because we always send the image for a glyph.
return *glyphPtr;
// Because the strike calls between the Renderer and the GPU are mirror images of each other, the
// information needed to make the call in the Renderer needs to be sent to the GPU so it can also
// make the call. If there is a path then it should be sent, and the path is queued to be sent and
// true returned. Otherwise, false is returned signaling an empty glyph.
// A key reason for no path is the fact that the glyph is a color image or is a bitmap only
// font.
bool SkStrikeServer::SkGlyphCacheState::decideCouldDrawFromPath(const SkGlyph& glyph) {
// Check to see if we have processed this glyph for a path before.
if (glyph.fPathData == nullptr) {
// Never checked for a path before. Add the path now.
auto path = const_cast<SkGlyph&>(glyph).addPath(fContext.get(), &fAlloc);
if (path != nullptr) {
// A path was added make sure to send it to the GPU.
return true;
return glyph.path() != nullptr;
void SkStrikeServer::SkGlyphCacheState::writeGlyphPath(const SkPackedGlyphID& glyphID,
Serializer* serializer) const {
SkPath path;
if (!fContext->getPath(glyphID, &path)) {
size_t pathSize = path.writeToMemory(nullptr);
path.writeToMemory(serializer->allocate(pathSize, kPathAlignment));
// This version of glyphMetrics only adds entries to result if their data need to be sent to the
// GPU process. As a result, empty glyphs will be sent so that the GPU code can lookup the glyph
// and detect that it is empty.
SkSpan<const SkGlyphPos> SkStrikeServer::SkGlyphCacheState::prepareForDrawing(
const SkGlyphID glyphIDs[],
const SkPoint positions[],
size_t n,
int maxDimension,
SkGlyphPos results[]) {
size_t glyphsToSendCount = 0;
for (size_t i = 0; i < n; i++) {
SkPoint glyphPos = positions[i];
SkGlyphID glyphID = glyphIDs[i];
SkIPoint lookupPoint = SkStrikeCommon::SubpixelLookup(fAxisAlignmentForHText, glyphPos);
SkPackedGlyphID packedGlyphID = fIsSubpixel ? SkPackedGlyphID{glyphID, lookupPoint}
: SkPackedGlyphID{glyphID};
// Check the cache for the glyph.
SkGlyph* glyphPtr = fGlyphMap.findOrNull(packedGlyphID);
// Has this glyph ever been seen before?
if (glyphPtr == nullptr) {
// Never seen before. Make a new glyph.
glyphPtr = fAlloc.make<SkGlyph>(packedGlyphID);
if (glyphPtr->maxDimension() <= maxDimension) {
// The mask/SDF will fit in the cache.
// TODO: no need to do this once code base converted over to bulk.
results[glyphsToSendCount++] = {i, glyphPtr, glyphPos};
} else if (glyphPtr->fMaskFormat != SkMask::kARGB32_Format) {
// The glyph is too big for the atlas, but it is not color, so it is handled with a
// path.
if (glyphPtr->fPathData == nullptr) {
// Never checked for a path before. Add the path now.
auto path = const_cast<SkGlyph&>(*glyphPtr).addPath(fContext.get(), &fAlloc);
if (path != nullptr) {
// A path was added make sure to send it to the GPU.
} else {
// This will be handled by the fallback strike.
SkASSERT(glyphPtr->maxDimension() > maxDimension
&& glyphPtr->fMaskFormat == SkMask::kARGB32_Format);
// Make sure to send the glyph to the GPU because we always send the image for a glyph.
return SkSpan<const SkGlyphPos>(results, glyphsToSendCount);
// SkStrikeClient -----------------------------------------
class SkStrikeClient::DiscardableStrikePinner : public SkStrikePinner {
DiscardableStrikePinner(SkDiscardableHandleId discardableHandleId,
sk_sp<DiscardableHandleManager> manager)
: fDiscardableHandleId(discardableHandleId), fManager(std::move(manager)) {}
~DiscardableStrikePinner() override = default;
bool canDelete() override { return fManager->deleteHandle(fDiscardableHandleId); }
const SkDiscardableHandleId fDiscardableHandleId;
sk_sp<DiscardableHandleManager> fManager;
SkStrikeClient::SkStrikeClient(sk_sp<DiscardableHandleManager> discardableManager,
bool isLogging,
SkStrikeCache* strikeCache)
: fDiscardableHandleManager(std::move(discardableManager))
, fStrikeCache{strikeCache ? strikeCache : SkStrikeCache::GlobalStrikeCache()}
, fIsLogging{isLogging} {}
SkStrikeClient::~SkStrikeClient() = default;
#define READ_FAILURE \
{ \
SkDebugf("Bad font data serialization"); \
return false; \
static bool readGlyph(SkTLazy<SkGlyph>& glyph, Deserializer* deserializer) {
SkPackedGlyphID glyphID;
if (!deserializer->read<SkPackedGlyphID>(&glyphID)) return false;
if (!deserializer->read<float>(&glyph->fAdvanceX)) return false;
if (!deserializer->read<float>(&glyph->fAdvanceY)) return false;
if (!deserializer->read<uint16_t>(&glyph->fWidth)) return false;
if (!deserializer->read<uint16_t>(&glyph->fHeight)) return false;
if (!deserializer->read<int16_t>(&glyph->fTop)) return false;
if (!deserializer->read<int16_t>(&glyph->fLeft)) return false;
if (!deserializer->read<int8_t>(&glyph->fForceBW)) return false;
if (!deserializer->read<uint8_t>(&glyph->fMaskFormat)) return false;
if (!SkMask::IsValidFormat(glyph->fMaskFormat)) return false;
return true;
bool SkStrikeClient::readStrikeData(const volatile void* memory, size_t memorySize) {
SkASSERT(memorySize != 0u);
Deserializer deserializer(static_cast<const volatile char*>(memory), memorySize);
uint64_t typefaceSize = 0u;
if (!<uint64_t>(&typefaceSize)) READ_FAILURE
for (size_t i = 0; i < typefaceSize; ++i) {
WireTypeface wire;
if (!<WireTypeface>(&wire)) READ_FAILURE
// TODO(khushalsagar): The typeface no longer needs a reference to the
// SkStrikeClient, since all needed glyphs must have been pushed before
// raster.
uint64_t strikeCount = 0u;
if (!<uint64_t>(&strikeCount)) READ_FAILURE
for (size_t i = 0; i < strikeCount; ++i) {
bool has_glyphs = false;
if (!<bool>(&has_glyphs)) READ_FAILURE
if (!has_glyphs) continue;
StrikeSpec spec;
if (!<StrikeSpec>(&spec)) READ_FAILURE
SkAutoDescriptor sourceAd;
if (!deserializer.readDescriptor(&sourceAd)) READ_FAILURE
SkFontMetrics fontMetrics;
if (!<SkFontMetrics>(&fontMetrics)) READ_FAILURE
// Get the local typeface from remote fontID.
auto* tfPtr = fRemoteFontIdToTypeface.find(spec.typefaceID);
// Received strikes for a typeface which doesn't exist.
if (!tfPtr) READ_FAILURE
auto* tf = tfPtr->get();
// Replace the ContextRec in the desc from the server to create the client
// side descriptor.
// TODO: Can we do this in-place and re-compute checksum? Instead of a complete copy.
SkAutoDescriptor ad;
auto* client_desc = auto_descriptor_from_desc(sourceAd.getDesc(), tf->uniqueID(), &ad);
auto strike = fStrikeCache->findStrikeExclusive(*client_desc);
if (strike == nullptr) {
// Note that we don't need to deserialize the effects since we won't be generating any
// glyphs here anyway, and the desc is still correct since it includes the serialized
// effects.
SkScalerContextEffects effects;
auto scaler = SkStrikeCache::CreateScalerContext(*client_desc, effects, *tf);
strike = fStrikeCache->createStrikeExclusive(
*client_desc, std::move(scaler), &fontMetrics,
auto proxyContext = static_cast<SkScalerContextProxy*>(strike->getScalerContext());
proxyContext->initCache(strike.get(), fStrikeCache);
uint64_t glyphImagesCount = 0u;
if (!<uint64_t>(&glyphImagesCount)) READ_FAILURE
for (size_t j = 0; j < glyphImagesCount; j++) {
SkTLazy<SkGlyph> glyph;
if (!readGlyph(glyph, &deserializer)) READ_FAILURE
SkGlyph* allocatedGlyph = strike->getRawGlyphByID(glyph->getPackedID());
// Update the glyph unless it's already got an image (from fallback),
// preserving any path that might be present.
if (allocatedGlyph->fImage == nullptr) {
auto* glyphPath = allocatedGlyph->fPathData;
*allocatedGlyph = *glyph;
allocatedGlyph->fPathData = glyphPath;
auto imageSize = glyph->computeImageSize();
if (imageSize == 0u) continue;
auto* image =, glyph->formatAlignment());
if (!image) READ_FAILURE
// Don't overwrite the image if we already have one. We could have used a fallback if
// the glyph was missing earlier.
if (allocatedGlyph->fImage == nullptr) {
strike->initializeImage(image, imageSize, allocatedGlyph);
uint64_t glyphPathsCount = 0u;
if (!<uint64_t>(&glyphPathsCount)) READ_FAILURE
for (size_t j = 0; j < glyphPathsCount; j++) {
SkTLazy<SkGlyph> glyph;
if (!readGlyph(glyph, &deserializer)) READ_FAILURE
SkGlyph* allocatedGlyph = strike->getRawGlyphByID(glyph->getPackedID());
// Update the glyph unless it's already got a path (from fallback),
// preserving any image that might be present.
if (allocatedGlyph->fPathData == nullptr) {
auto* glyphImage = allocatedGlyph->fImage;
*allocatedGlyph = *glyph;
allocatedGlyph->fImage = glyphImage;
if (!read_path(&deserializer, allocatedGlyph, strike.get())) READ_FAILURE
return true;
sk_sp<SkTypeface> SkStrikeClient::deserializeTypeface(const void* buf, size_t len) {
WireTypeface wire;
if (len != sizeof(wire)) return nullptr;
memcpy(&wire, buf, sizeof(wire));
return this->addTypeface(wire);
sk_sp<SkTypeface> SkStrikeClient::addTypeface(const WireTypeface& wire) {
auto* typeface = fRemoteFontIdToTypeface.find(wire.typefaceID);
if (typeface) return *typeface;
auto newTypeface = sk_make_sp<SkTypefaceProxy>(
wire.typefaceID, wire.glyphCount,, wire.isFixed,
fDiscardableHandleManager, fIsLogging);
fRemoteFontIdToTypeface.set(wire.typefaceID, newTypeface);
return std::move(newTypeface);