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// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "third_party/blink/renderer/modules/font_access/font_metadata.h"
#include "base/big_endian.h"
#include "base/metrics/histogram_functions.h"
#include "base/sys_byteorder.h"
#include "build/build_config.h"
#include "third_party/blink/renderer/bindings/core/v8/script_promise_resolver.h"
#include "third_party/blink/renderer/core/fileapi/blob.h"
#include "third_party/blink/renderer/modules/font_access/font_table_map.h"
#include "third_party/blink/renderer/platform/bindings/script_state.h"
#include "third_party/blink/renderer/platform/fonts/font_cache.h"
#include "third_party/blink/renderer/platform/fonts/font_global_context.h"
#include "third_party/blink/renderer/platform/fonts/font_unique_name_lookup.h"
#include "third_party/blink/renderer/platform/scheduler/public/thread.h"
#include "third_party/skia/include/core/SkStream.h"
#include "third_party/skia/include/core/SkTypes.h"
namespace blink {
namespace {
// Sets up internal FontUniqueLookup metadata that will allow matching
// unique names, on platforms that apply.
void SetUpFontUniqueLookupIfNecessary() {
FontUniqueNameLookup* unique_name_lookup =
FontGlobalContext::Get()->GetFontUniqueNameLookup();
if (!unique_name_lookup)
return;
// Contrary to what the method name might imply, this is not an idempotent
// method. It also initializes the state in the FontUniqueNameLookup object
// to either retrieve from tables on Windows 7, or direct lookups on
// Windows 10.
unique_name_lookup->IsFontUniqueNameLookupReadyForSyncLookup();
}
} // namespace
FontMetadata::FontMetadata(const FontEnumerationEntry& entry)
: postscriptName_(entry.postscript_name),
fullName_(entry.full_name),
family_(entry.family),
style_(entry.style) {}
FontMetadata* FontMetadata::Create(const FontEnumerationEntry& entry) {
return MakeGarbageCollected<FontMetadata>(entry);
}
ScriptPromise FontMetadata::blob(ScriptState* script_state) {
ScriptPromiseResolver* resolver =
MakeGarbageCollected<ScriptPromiseResolver>(script_state);
ScriptPromise promise = resolver->Promise();
Thread::Current()->GetTaskRunner()->PostTask(
FROM_HERE, WTF::Bind(&FontMetadata::BlobImpl, WrapPersistent(resolver),
postscriptName_));
return promise;
}
void FontMetadata::Trace(blink::Visitor* visitor) const {
ScriptWrappable::Trace(visitor);
}
// static
void FontMetadata::BlobImpl(ScriptPromiseResolver* resolver,
const String& postscriptName) {
if (!resolver->GetScriptState()->ContextIsValid())
return;
SetUpFontUniqueLookupIfNecessary();
FontDescription description;
scoped_refptr<SimpleFontData> font_data =
FontCache::GetFontCache()->GetFontData(
description, AtomicString(postscriptName),
AlternateFontName::kLocalUniqueFace);
if (!font_data) {
auto message = String::Format("The font %s could not be accessed.",
postscriptName.Latin1().c_str());
ScriptState::Scope scope(resolver->GetScriptState());
resolver->Reject(V8ThrowException::CreateTypeError(
resolver->GetScriptState()->GetIsolate(), message));
return;
}
const SkTypeface* typeface = font_data->PlatformData().Typeface();
// On Mac, this will not be as efficient as on other platforms: data from
// tables will be copied and assembled into valid SNFT font data. This is
// because Mac system APIs only return per-table data.
int ttc_index = 0;
std::unique_ptr<SkStreamAsset> stream = typeface->openStream(&ttc_index);
if (!(stream && stream->getMemoryBase())) {
// TODO(https://crbug.com/1086840): openStream rarely fails, but it happens
// sometimes. A potential remediation is to synthesize a font from tables
// at the cost of memory and throughput.
// For reference, the UMA metric "Blink.Fonts.HarfBuzzFaceZeroCopyAccess"
// indicates that the success rate is close to 100% on all platforms where
// it applies, but failures do happen.
base::UmaHistogramBoolean("Blink.Fonts.DataAccess.StreamCreation", false);
auto message = String::Format("Font data for %s could not be accessed.",
postscriptName.Latin1().c_str());
ScriptState::Scope scope(resolver->GetScriptState());
resolver->Reject(V8ThrowException::CreateTypeError(
resolver->GetScriptState()->GetIsolate(), message));
return;
}
base::UmaHistogramBoolean("Blink.Fonts.DataAccess.StreamCreation", true);
wtf_size_t font_byte_size = SafeCast<wtf_size_t>(stream->getLength());
// TODO(https://crbug.com/1069900): This copies the font bytes. Lazy load and
// stream the data instead.
Vector<char> bytes(font_byte_size);
size_t returned_size = stream->read(bytes.data(), font_byte_size);
DCHECK_EQ(returned_size, font_byte_size);
scoped_refptr<RawData> raw_data = RawData::Create();
bytes.swap(*raw_data->MutableData());
auto blob_data = std::make_unique<BlobData>();
blob_data->AppendData(std::move(raw_data));
blob_data->SetContentType("application/octet-stream");
auto* blob = MakeGarbageCollected<Blob>(
BlobDataHandle::Create(std::move(blob_data), font_byte_size));
resolver->Resolve(blob);
}
} // namespace blink
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