src/fonts/SkFontMgr_fontconfig.cpp - platform/external/skia - Gitiles

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "SkFontConfigInterface.h"
 #include "SkFontConfigTypeface.h"
 #include "SkFontDescriptor.h"
 #include "SkFontMgr.h"
 #include "SkFontStyle.h"
 #include "SkMutex.h"
 #include "SkString.h"
 #include "SkTypeface.h"
 #include "SkTypefaceCache.h"
 #include "SkResourceCache.h"

 SkStreamAsset* SkTypeface_FCI::onOpenStream(int* ttcIndex) const {
     *ttcIndex =  this->getIdentity().fTTCIndex;

     SkStreamAsset* stream = this->getLocalStream();
     if (stream) {
         return stream->duplicate();
     }

     return fFCI->openStream(this->getIdentity());
 }

 void SkTypeface_FCI::onGetFontDescriptor(SkFontDescriptor* desc, bool* isLocalStream) const {
     SkString name;
     this->getFamilyName(&name);
     desc->setFamilyName(name.c_str());
     *isLocalStream = SkToBool(this->getLocalStream());
 }

 ///////////////////////////////////////////////////////////////////////////////

 class SkFontStyleSet_FCI : public SkFontStyleSet {
 public:
     SkFontStyleSet_FCI() {}

     int count() override { return 0; }
     void getStyle(int index, SkFontStyle*, SkString* style) override { SkASSERT(false); }
     SkTypeface* createTypeface(int index) override { SkASSERT(false); return nullptr; }
     SkTypeface* matchStyle(const SkFontStyle& pattern) override { return nullptr; }
 };

 ///////////////////////////////////////////////////////////////////////////////

 class SkFontRequestCache {
 public:
     struct Request : public SkResourceCache::Key {
     private:
         Request(const char* name, size_t nameLen, const SkFontStyle& style) : fStyle(style) {
             /** Pointer to just after the last field of this class. */
             char* content = const_cast<char*>(SkTAfter<const char>(&this->fStyle));

             // No holes.
             SkASSERT(SkTAddOffset<char>(this, sizeof(SkResourceCache::Key) + keySize) == content);

             // Has a size divisible by size of uint32_t.
             SkASSERT((content - reinterpret_cast<char*>(this)) % sizeof(uint32_t) == 0);

             size_t contentLen = SkAlign4(nameLen);
             sk_careful_memcpy(content, name, nameLen);
             sk_bzero(content + nameLen, contentLen - nameLen);
             this->init(nullptr, 0, keySize + contentLen);
         }
         const SkFontStyle fStyle;
         /** The sum of the sizes of the fields of this class. */
         static const size_t keySize = sizeof(fStyle);

     public:
         static Request* Create(const char* name, const SkFontStyle& style) {
             size_t nameLen = name ? strlen(name) : 0;
             size_t contentLen = SkAlign4(nameLen);
             char* storage = new char[sizeof(Request) + contentLen];
             return new (storage) Request(name, nameLen, style);
         }
         void operator delete(void* storage) {
             delete[] reinterpret_cast<char*>(storage);
         }
     };


 private:
     struct Result : public SkResourceCache::Rec {
         Result(Request* request, SkTypeface* typeface)
             : fRequest(request)
             , fFace(SkSafeRef(typeface)) {}
         Result(Result&&) = default;
         Result& operator=(Result&&) = default;

         const Key& getKey() const override { return *fRequest; }
         size_t bytesUsed() const override { return fRequest->size() + sizeof(fFace); }
         const char* getCategory() const override { return "request_cache"; }
         SkDiscardableMemory* diagnostic_only_getDiscardable() const override { return nullptr; }

         SkAutoTDelete<Request> fRequest;
         SkAutoTUnref<SkTypeface> fFace;
     };

     SkResourceCache fCachedResults;

 public:
     SkFontRequestCache(size_t maxSize) : fCachedResults(maxSize) {}

     /** Takes ownership of request. It will be deleted when no longer needed. */
     void add(SkTypeface* face, Request* request) {
         fCachedResults.add(new Result(request, face));
     }
     /** Does not take ownership of request. */
     SkTypeface* findAndRef(Request* request) {
         SkTypeface* face = nullptr;
         fCachedResults.find(*request, [](const SkResourceCache::Rec& rec, void* context) -> bool {
             const Result& result = static_cast<const Result&>(rec);
             SkTypeface** face = static_cast<SkTypeface**>(context);

             *face = result.fFace;
             return true;
         }, &face);
         return SkSafeRef(face);
     }
 };

 ///////////////////////////////////////////////////////////////////////////////

 static bool find_by_FontIdentity(SkTypeface* cachedTypeface, void* ctx) {
     typedef SkFontConfigInterface::FontIdentity FontIdentity;
     SkTypeface_FCI* cachedFCTypeface = static_cast<SkTypeface_FCI*>(cachedTypeface);
     FontIdentity* identity = static_cast<FontIdentity*>(ctx);

     return cachedFCTypeface->getIdentity() == *identity;
 }

 ///////////////////////////////////////////////////////////////////////////////

 class SkFontMgr_FCI : public SkFontMgr {
     SkAutoTUnref<SkFontConfigInterface> fFCI;
     SkAutoTUnref<SkDataTable> fFamilyNames;
     SkTypeface_FreeType::Scanner fScanner;

     mutable SkMutex fMutex;
     mutable SkTypefaceCache fTFCache;

     // The value of maxSize here is a compromise between cache hits and cache size.
     // See https://crbug.com/424082#63 for reason for current size.
     static const size_t kMaxSize = 1 << 15;
     mutable SkFontRequestCache fCache;

 public:
     SkFontMgr_FCI(SkFontConfigInterface* fci)
         : fFCI(fci)
         , fFamilyNames(fFCI->getFamilyNames())
         , fCache(kMaxSize)
     {}

 protected:
     int onCountFamilies() const override {
         return fFamilyNames->count();
     }

     void onGetFamilyName(int index, SkString* familyName) const override {
         familyName->set(fFamilyNames->atStr(index));
     }

     SkFontStyleSet* onCreateStyleSet(int index) const override {
         return this->onMatchFamily(fFamilyNames->atStr(index));
     }

     SkFontStyleSet* onMatchFamily(const char familyName[]) const override {
         return new SkFontStyleSet_FCI();
     }

     SkTypeface* onMatchFamilyStyle(const char familyName[],
                                    const SkFontStyle&) const override { return nullptr; }
     SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
                                             const char* bcp47[], int bcp47Count,
                                             SkUnichar character) const override {
         return nullptr;
     }
     SkTypeface* onMatchFaceStyle(const SkTypeface*,
                                  const SkFontStyle&) const override { return nullptr; }

     SkTypeface* onCreateFromData(SkData*, int ttcIndex) const override { return nullptr; }

     SkTypeface* onCreateFromStream(SkStreamAsset* bareStream, int ttcIndex) const override {
         SkAutoTDelete<SkStreamAsset> stream(bareStream);
         const size_t length = stream->getLength();
         if (!length) {
             return nullptr;
         }
         if (length >= 1024 * 1024 * 1024) {
             return nullptr;  // don't accept too large fonts (>= 1GB) for safety.
         }

         // TODO should the caller give us the style or should we get it from freetype?
         SkFontStyle style;
         bool isFixedWidth = false;
         if (!fScanner.scanFont(stream, 0, nullptr, &style, &isFixedWidth, nullptr)) {
             return nullptr;
         }

         return SkTypeface_FCI::Create(style, isFixedWidth, stream.release(), ttcIndex);
     }

     SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const override {
         SkAutoTDelete<SkStreamAsset> stream(SkStream::NewFromFile(path));
         return stream.get() ? this->createFromStream(stream.release(), ttcIndex) : nullptr;
     }

     SkTypeface* onLegacyCreateTypeface(const char requestedFamilyName[],
                                        SkFontStyle requestedStyle) const override
     {
         SkAutoMutexAcquire ama(fMutex);

         // Check if this request is already in the request cache.
         using Request = SkFontRequestCache::Request;
         SkAutoTDelete<Request> request(Request::Create(requestedFamilyName, requestedStyle));
         SkTypeface* face = fCache.findAndRef(request);
         if (face) {
             return face;
         }

         SkFontConfigInterface::FontIdentity identity;
         SkString outFamilyName;
         SkFontStyle outStyle;
         if (!fFCI->matchFamilyName(requestedFamilyName, requestedStyle,
                                    &identity, &outFamilyName, &outStyle))
         {
             return nullptr;
         }

         // Check if a typeface with this FontIdentity is already in the FontIdentity cache.
         face = fTFCache.findByProcAndRef(find_by_FontIdentity, &identity);
         if (!face) {
             face = SkTypeface_FCI::Create(fFCI, identity, outFamilyName, outStyle);
             // Add this FontIdentity to the FontIdentity cache.
             fTFCache.add(face);
         }
         // Add this request to the request cache.
         fCache.add(face, request.release());

         return face;
     }
 };

 SK_API SkFontMgr* SkFontMgr_New_FCI(SkFontConfigInterface* fci) {
     SkASSERT(fci);
     return new SkFontMgr_FCI(fci);
 }
	/*
	* Copyright 2013 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "SkFontConfigInterface.h"
	#include "SkFontConfigTypeface.h"
	#include "SkFontDescriptor.h"
	#include "SkFontMgr.h"
	#include "SkFontStyle.h"
	#include "SkMutex.h"
	#include "SkString.h"
	#include "SkTypeface.h"
	#include "SkTypefaceCache.h"
	#include "SkResourceCache.h"

	SkStreamAsset* SkTypeface_FCI::onOpenStream(int* ttcIndex) const {
	*ttcIndex = this->getIdentity().fTTCIndex;

	SkStreamAsset* stream = this->getLocalStream();
	if (stream) {
	return stream->duplicate();
	}

	return fFCI->openStream(this->getIdentity());
	}

	void SkTypeface_FCI::onGetFontDescriptor(SkFontDescriptor* desc, bool* isLocalStream) const {
	SkString name;
	this->getFamilyName(&name);
	desc->setFamilyName(name.c_str());
	*isLocalStream = SkToBool(this->getLocalStream());
	}

	///////////////////////////////////////////////////////////////////////////////

	class SkFontStyleSet_FCI : public SkFontStyleSet {
	public:
	SkFontStyleSet_FCI() {}

	int count() override { return 0; }
	void getStyle(int index, SkFontStyle, SkString style) override { SkASSERT(false); }
	SkTypeface* createTypeface(int index) override { SkASSERT(false); return nullptr; }
	SkTypeface* matchStyle(const SkFontStyle& pattern) override { return nullptr; }
	};

	///////////////////////////////////////////////////////////////////////////////

	class SkFontRequestCache {
	public:
	struct Request : public SkResourceCache::Key {
	private:
	Request(const char* name, size_t nameLen, const SkFontStyle& style) : fStyle(style) {
	/** Pointer to just after the last field of this class. */
	char* content = const_cast<char*>(SkTAfter<const char>(&this->fStyle));

	// No holes.
	SkASSERT(SkTAddOffset<char>(this, sizeof(SkResourceCache::Key) + keySize) == content);

	// Has a size divisible by size of uint32_t.
	SkASSERT((content - reinterpret_cast<char*>(this)) % sizeof(uint32_t) == 0);

	size_t contentLen = SkAlign4(nameLen);
	sk_careful_memcpy(content, name, nameLen);
	sk_bzero(content + nameLen, contentLen - nameLen);
	this->init(nullptr, 0, keySize + contentLen);
	}
	const SkFontStyle fStyle;
	/** The sum of the sizes of the fields of this class. */
	static const size_t keySize = sizeof(fStyle);

	public:
	static Request* Create(const char* name, const SkFontStyle& style) {
	size_t nameLen = name ? strlen(name) : 0;
	size_t contentLen = SkAlign4(nameLen);
	char* storage = new char[sizeof(Request) + contentLen];
	return new (storage) Request(name, nameLen, style);
	}
	void operator delete(void* storage) {
	delete[] reinterpret_cast<char*>(storage);
	}
	};


	private:
	struct Result : public SkResourceCache::Rec {
	Result(Request* request, SkTypeface* typeface)
	: fRequest(request)
	, fFace(SkSafeRef(typeface)) {}
	Result(Result&&) = default;
	Result& operator=(Result&&) = default;

	const Key& getKey() const override { return *fRequest; }
	size_t bytesUsed() const override { return fRequest->size() + sizeof(fFace); }
	const char* getCategory() const override { return "request_cache"; }
	SkDiscardableMemory* diagnostic_only_getDiscardable() const override { return nullptr; }

	SkAutoTDelete<Request> fRequest;
	SkAutoTUnref<SkTypeface> fFace;
	};

	SkResourceCache fCachedResults;

	public:
	SkFontRequestCache(size_t maxSize) : fCachedResults(maxSize) {}

	/** Takes ownership of request. It will be deleted when no longer needed. */
	void add(SkTypeface* face, Request* request) {
	fCachedResults.add(new Result(request, face));
	}
	/** Does not take ownership of request. */
	SkTypeface* findAndRef(Request* request) {
	SkTypeface* face = nullptr;
	fCachedResults.find(request, [](const SkResourceCache::Rec& rec, void context) -> bool {
	const Result& result = static_cast<const Result&>(rec);
	SkTypeface face = static_cast<SkTypeface>(context);

	*face = result.fFace;
	return true;
	}, &face);
	return SkSafeRef(face);
	}
	};

	///////////////////////////////////////////////////////////////////////////////

	static bool find_by_FontIdentity(SkTypeface* cachedTypeface, void* ctx) {
	typedef SkFontConfigInterface::FontIdentity FontIdentity;
	SkTypeface_FCI* cachedFCTypeface = static_cast<SkTypeface_FCI*>(cachedTypeface);
	FontIdentity* identity = static_cast<FontIdentity*>(ctx);

	return cachedFCTypeface->getIdentity() == *identity;
	}

	///////////////////////////////////////////////////////////////////////////////

	class SkFontMgr_FCI : public SkFontMgr {
	SkAutoTUnref<SkFontConfigInterface> fFCI;
	SkAutoTUnref<SkDataTable> fFamilyNames;
	SkTypeface_FreeType::Scanner fScanner;

	mutable SkMutex fMutex;
	mutable SkTypefaceCache fTFCache;

	// The value of maxSize here is a compromise between cache hits and cache size.
	// See https://crbug.com/424082#63 for reason for current size.
	static const size_t kMaxSize = 1 << 15;
	mutable SkFontRequestCache fCache;

	public:
	SkFontMgr_FCI(SkFontConfigInterface* fci)
	: fFCI(fci)
	, fFamilyNames(fFCI->getFamilyNames())
	, fCache(kMaxSize)
	{}

	protected:
	int onCountFamilies() const override {
	return fFamilyNames->count();
	}

	void onGetFamilyName(int index, SkString* familyName) const override {
	familyName->set(fFamilyNames->atStr(index));
	}

	SkFontStyleSet* onCreateStyleSet(int index) const override {
	return this->onMatchFamily(fFamilyNames->atStr(index));
	}

	SkFontStyleSet* onMatchFamily(const char familyName[]) const override {
	return new SkFontStyleSet_FCI();
	}

	SkTypeface* onMatchFamilyStyle(const char familyName[],
	const SkFontStyle&) const override { return nullptr; }
	SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
	const char* bcp47[], int bcp47Count,
	SkUnichar character) const override {
	return nullptr;
	}
	SkTypeface* onMatchFaceStyle(const SkTypeface*,
	const SkFontStyle&) const override { return nullptr; }

	SkTypeface* onCreateFromData(SkData*, int ttcIndex) const override { return nullptr; }

	SkTypeface* onCreateFromStream(SkStreamAsset* bareStream, int ttcIndex) const override {
	SkAutoTDelete<SkStreamAsset> stream(bareStream);
	const size_t length = stream->getLength();
	if (!length) {
	return nullptr;
	}
	if (length >= 1024 * 1024 * 1024) {
	return nullptr; // don't accept too large fonts (>= 1GB) for safety.
	}

	// TODO should the caller give us the style or should we get it from freetype?
	SkFontStyle style;
	bool isFixedWidth = false;
	if (!fScanner.scanFont(stream, 0, nullptr, &style, &isFixedWidth, nullptr)) {
	return nullptr;
	}

	return SkTypeface_FCI::Create(style, isFixedWidth, stream.release(), ttcIndex);
	}

	SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const override {
	SkAutoTDelete<SkStreamAsset> stream(SkStream::NewFromFile(path));
	return stream.get() ? this->createFromStream(stream.release(), ttcIndex) : nullptr;
	}

	SkTypeface* onLegacyCreateTypeface(const char requestedFamilyName[],
	SkFontStyle requestedStyle) const override
	{
	SkAutoMutexAcquire ama(fMutex);

	// Check if this request is already in the request cache.
	using Request = SkFontRequestCache::Request;
	SkAutoTDelete<Request> request(Request::Create(requestedFamilyName, requestedStyle));
	SkTypeface* face = fCache.findAndRef(request);
	if (face) {
	return face;
	}

	SkFontConfigInterface::FontIdentity identity;
	SkString outFamilyName;
	SkFontStyle outStyle;
	if (!fFCI->matchFamilyName(requestedFamilyName, requestedStyle,
	&identity, &outFamilyName, &outStyle))
	{
	return nullptr;
	}

	// Check if a typeface with this FontIdentity is already in the FontIdentity cache.
	face = fTFCache.findByProcAndRef(find_by_FontIdentity, &identity);
	if (!face) {
	face = SkTypeface_FCI::Create(fFCI, identity, outFamilyName, outStyle);
	// Add this FontIdentity to the FontIdentity cache.
	fTFCache.add(face);
	}
	// Add this request to the request cache.
	fCache.add(face, request.release());

	return face;
	}
	};

	SK_API SkFontMgr* SkFontMgr_New_FCI(SkFontConfigInterface* fci) {
	SkASSERT(fci);
	return new SkFontMgr_FCI(fci);
	}