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1 /*
2  * Copyright 2013 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "SkFontConfigInterface.h"
9 #include "SkFontConfigTypeface.h"
10 #include "SkFontDescriptor.h"
11 #include "SkFontMgr.h"
12 #include "SkFontMgr_FontConfigInterface.h"
13 #include "SkFontStyle.h"
14 #include "SkMakeUnique.h"
15 #include "SkMutex.h"
16 #include "SkString.h"
17 #include "SkTypeface.h"
18 #include "SkTypefaceCache.h"
19 #include "SkResourceCache.h"
20 
onOpenStream(int * ttcIndex) const21 SkStreamAsset* SkTypeface_FCI::onOpenStream(int* ttcIndex) const {
22     *ttcIndex =  this->getIdentity().fTTCIndex;
23 
24     if (fFontData) {
25         SkStreamAsset* stream = fFontData->getStream();
26         if (!stream) {
27             return nullptr;
28         }
29         return stream->duplicate();
30     }
31 
32     return fFCI->openStream(this->getIdentity());
33 }
34 
onMakeFontData() const35 std::unique_ptr<SkFontData> SkTypeface_FCI::onMakeFontData() const {
36     if (fFontData) {
37         return skstd::make_unique<SkFontData>(*fFontData);
38     }
39 
40     const SkFontConfigInterface::FontIdentity& id = this->getIdentity();
41     return skstd::make_unique<SkFontData>(std::unique_ptr<SkStreamAsset>(fFCI->openStream(id)),
42                                           id.fTTCIndex, nullptr, 0);
43 }
44 
onGetFontDescriptor(SkFontDescriptor * desc,bool * isLocalStream) const45 void SkTypeface_FCI::onGetFontDescriptor(SkFontDescriptor* desc, bool* isLocalStream) const {
46     SkString name;
47     this->getFamilyName(&name);
48     desc->setFamilyName(name.c_str());
49     desc->setStyle(this->fontStyle());
50     *isLocalStream = SkToBool(fFontData);
51 }
52 
53 ///////////////////////////////////////////////////////////////////////////////
54 
55 class SkFontStyleSet_FCI : public SkFontStyleSet {
56 public:
SkFontStyleSet_FCI()57     SkFontStyleSet_FCI() {}
58 
count()59     int count() override { return 0; }
getStyle(int index,SkFontStyle *,SkString * style)60     void getStyle(int index, SkFontStyle*, SkString* style) override { SkASSERT(false); }
createTypeface(int index)61     SkTypeface* createTypeface(int index) override { SkASSERT(false); return nullptr; }
matchStyle(const SkFontStyle & pattern)62     SkTypeface* matchStyle(const SkFontStyle& pattern) override { return nullptr; }
63 };
64 
65 ///////////////////////////////////////////////////////////////////////////////
66 
67 class SkFontRequestCache {
68 public:
69     struct Request : public SkResourceCache::Key {
70     private:
RequestSkFontRequestCache::Request71         Request(const char* name, size_t nameLen, const SkFontStyle& style) : fStyle(style) {
72             /** Pointer to just after the last field of this class. */
73             char* content = const_cast<char*>(SkTAfter<const char>(&this->fStyle));
74 
75             // No holes.
76             SkASSERT(SkTAddOffset<char>(this, sizeof(SkResourceCache::Key) + keySize) == content);
77 
78             // Has a size divisible by size of uint32_t.
79             SkASSERT((content - reinterpret_cast<char*>(this)) % sizeof(uint32_t) == 0);
80 
81             size_t contentLen = SkAlign4(nameLen);
82             sk_careful_memcpy(content, name, nameLen);
83             sk_bzero(content + nameLen, contentLen - nameLen);
84             this->init(nullptr, 0, keySize + contentLen);
85         }
86         const SkFontStyle fStyle;
87         /** The sum of the sizes of the fields of this class. */
88         static const size_t keySize = sizeof(fStyle);
89 
90     public:
CreateSkFontRequestCache::Request91         static Request* Create(const char* name, const SkFontStyle& style) {
92             size_t nameLen = name ? strlen(name) : 0;
93             size_t contentLen = SkAlign4(nameLen);
94             char* storage = new char[sizeof(Request) + contentLen];
95             return new (storage) Request(name, nameLen, style);
96         }
operator deleteSkFontRequestCache::Request97         void operator delete(void* storage) {
98             delete[] reinterpret_cast<char*>(storage);
99         }
100     };
101 
102 
103 private:
104     struct Result : public SkResourceCache::Rec {
ResultSkFontRequestCache::Result105         Result(Request* request, SkTypeface* typeface)
106             : fRequest(request)
107             , fFace(SkSafeRef(typeface)) {}
108         Result(Result&&) = default;
109         Result& operator=(Result&&) = default;
110 
getKeySkFontRequestCache::Result111         const Key& getKey() const override { return *fRequest; }
bytesUsedSkFontRequestCache::Result112         size_t bytesUsed() const override { return fRequest->size() + sizeof(fFace); }
getCategorySkFontRequestCache::Result113         const char* getCategory() const override { return "request_cache"; }
diagnostic_only_getDiscardableSkFontRequestCache::Result114         SkDiscardableMemory* diagnostic_only_getDiscardable() const override { return nullptr; }
115 
116         std::unique_ptr<Request> fRequest;
117         sk_sp<SkTypeface> fFace;
118     };
119 
120     SkResourceCache fCachedResults;
121 
122 public:
SkFontRequestCache(size_t maxSize)123     SkFontRequestCache(size_t maxSize) : fCachedResults(maxSize) {}
124 
125     /** Takes ownership of request. It will be deleted when no longer needed. */
add(SkTypeface * face,Request * request)126     void add(SkTypeface* face, Request* request) {
127         fCachedResults.add(new Result(request, face));
128     }
129     /** Does not take ownership of request. */
findAndRef(Request * request)130     SkTypeface* findAndRef(Request* request) {
131         SkTypeface* face = nullptr;
132         fCachedResults.find(*request, [](const SkResourceCache::Rec& rec, void* context) -> bool {
133             const Result& result = static_cast<const Result&>(rec);
134             SkTypeface** face = static_cast<SkTypeface**>(context);
135 
136             *face = result.fFace.get();
137             return true;
138         }, &face);
139         return SkSafeRef(face);
140     }
141 };
142 
143 ///////////////////////////////////////////////////////////////////////////////
144 
find_by_FontIdentity(SkTypeface * cachedTypeface,void * ctx)145 static bool find_by_FontIdentity(SkTypeface* cachedTypeface, void* ctx) {
146     typedef SkFontConfigInterface::FontIdentity FontIdentity;
147     SkTypeface_FCI* cachedFCTypeface = static_cast<SkTypeface_FCI*>(cachedTypeface);
148     FontIdentity* identity = static_cast<FontIdentity*>(ctx);
149 
150     return cachedFCTypeface->getIdentity() == *identity;
151 }
152 
153 ///////////////////////////////////////////////////////////////////////////////
154 
155 class SkFontMgr_FCI : public SkFontMgr {
156     sk_sp<SkFontConfigInterface> fFCI;
157     SkTypeface_FreeType::Scanner fScanner;
158 
159     mutable SkMutex fMutex;
160     mutable SkTypefaceCache fTFCache;
161 
162     // The value of maxSize here is a compromise between cache hits and cache size.
163     // See https://crbug.com/424082#63 for reason for current size.
164     static const size_t kMaxSize = 1 << 15;
165     mutable SkFontRequestCache fCache;
166 
167 public:
SkFontMgr_FCI(sk_sp<SkFontConfigInterface> fci)168     SkFontMgr_FCI(sk_sp<SkFontConfigInterface> fci)
169         : fFCI(std::move(fci))
170         , fCache(kMaxSize)
171     {}
172 
173 protected:
onCountFamilies() const174     int onCountFamilies() const override {
175         return 0;
176     }
177 
onGetFamilyName(int index,SkString * familyName) const178     void onGetFamilyName(int index, SkString* familyName) const override {
179         SkFAIL("Not implemented.");
180     }
181 
onCreateStyleSet(int index) const182     SkFontStyleSet* onCreateStyleSet(int index) const override {
183         SkFAIL("Not implemented.");
184         return nullptr;
185     }
186 
onMatchFamily(const char familyName[]) const187     SkFontStyleSet* onMatchFamily(const char familyName[]) const override {
188         return new SkFontStyleSet_FCI();
189     }
190 
onMatchFamilyStyle(const char familyName[],const SkFontStyle &) const191     SkTypeface* onMatchFamilyStyle(const char familyName[],
192                                    const SkFontStyle&) const override { return nullptr; }
onMatchFamilyStyleCharacter(const char familyName[],const SkFontStyle &,const char * bcp47[],int bcp47Count,SkUnichar character) const193     SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
194                                             const char* bcp47[], int bcp47Count,
195                                             SkUnichar character) const override {
196         return nullptr;
197     }
onMatchFaceStyle(const SkTypeface *,const SkFontStyle &) const198     SkTypeface* onMatchFaceStyle(const SkTypeface*,
199                                  const SkFontStyle&) const override { return nullptr; }
200 
onCreateFromData(SkData *,int ttcIndex) const201     SkTypeface* onCreateFromData(SkData*, int ttcIndex) const override { return nullptr; }
202 
onCreateFromStream(SkStreamAsset * bareStream,int ttcIndex) const203     SkTypeface* onCreateFromStream(SkStreamAsset* bareStream, int ttcIndex) const override {
204         std::unique_ptr<SkStreamAsset> stream(bareStream);
205         const size_t length = stream->getLength();
206         if (!length) {
207             return nullptr;
208         }
209         if (length >= 1024 * 1024 * 1024) {
210             return nullptr;  // don't accept too large fonts (>= 1GB) for safety.
211         }
212 
213         // TODO should the caller give us the style or should we get it from freetype?
214         SkString name;
215         SkFontStyle style;
216         bool isFixedPitch = false;
217         if (!fScanner.scanFont(stream.get(), 0, &name, &style, &isFixedPitch, nullptr)) {
218             return nullptr;
219         }
220 
221         auto fontData = skstd::make_unique<SkFontData>(std::move(stream), ttcIndex, nullptr, 0);
222         return SkTypeface_FCI::Create(std::move(fontData), std::move(name), style, isFixedPitch);
223     }
224 
onCreateFromStream(SkStreamAsset * s,const SkFontArguments & args) const225     SkTypeface* onCreateFromStream(SkStreamAsset* s, const SkFontArguments& args) const override {
226         using Scanner = SkTypeface_FreeType::Scanner;
227         std::unique_ptr<SkStreamAsset> stream(s);
228         const size_t length = stream->getLength();
229         if (!length) {
230             return nullptr;
231         }
232         if (length >= 1024 * 1024 * 1024) {
233             return nullptr;  // don't accept too large fonts (>= 1GB) for safety.
234         }
235 
236         bool isFixedPitch;
237         SkFontStyle style;
238         SkString name;
239         Scanner::AxisDefinitions axisDefinitions;
240         if (!fScanner.scanFont(stream.get(), args.getCollectionIndex(),
241                                &name, &style, &isFixedPitch, &axisDefinitions))
242         {
243             return nullptr;
244         }
245 
246         SkAutoSTMalloc<4, SkFixed> axisValues(axisDefinitions.count());
247         Scanner::computeAxisValues(axisDefinitions, args.getVariationDesignPosition(),
248                                    axisValues, name);
249 
250         auto fontData = skstd::make_unique<SkFontData>(std::move(stream),
251                                                        args.getCollectionIndex(),
252                                                        axisValues.get(),
253                                                        axisDefinitions.count());
254         return SkTypeface_FCI::Create(std::move(fontData), std::move(name), style, isFixedPitch);
255     }
256 
onCreateFromFile(const char path[],int ttcIndex) const257     SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const override {
258         std::unique_ptr<SkStreamAsset> stream = SkStream::MakeFromFile(path);
259         return stream.get() ? this->createFromStream(stream.release(), ttcIndex) : nullptr;
260     }
261 
onLegacyCreateTypeface(const char requestedFamilyName[],SkFontStyle requestedStyle) const262     SkTypeface* onLegacyCreateTypeface(const char requestedFamilyName[],
263                                        SkFontStyle requestedStyle) const override
264     {
265         SkAutoMutexAcquire ama(fMutex);
266 
267         // Check if this request is already in the request cache.
268         using Request = SkFontRequestCache::Request;
269         std::unique_ptr<Request> request(Request::Create(requestedFamilyName, requestedStyle));
270         SkTypeface* face = fCache.findAndRef(request.get());
271         if (face) {
272             return face;
273         }
274 
275         SkFontConfigInterface::FontIdentity identity;
276         SkString outFamilyName;
277         SkFontStyle outStyle;
278         if (!fFCI->matchFamilyName(requestedFamilyName, requestedStyle,
279                                    &identity, &outFamilyName, &outStyle))
280         {
281             return nullptr;
282         }
283 
284         // Check if a typeface with this FontIdentity is already in the FontIdentity cache.
285         face = fTFCache.findByProcAndRef(find_by_FontIdentity, &identity);
286         if (!face) {
287             face = SkTypeface_FCI::Create(fFCI, identity, std::move(outFamilyName), outStyle);
288             // Add this FontIdentity to the FontIdentity cache.
289             fTFCache.add(face);
290         }
291         // Add this request to the request cache.
292         fCache.add(face, request.release());
293 
294         return face;
295     }
296 };
297 
SkFontMgr_New_FCI(sk_sp<SkFontConfigInterface> fci)298 SK_API sk_sp<SkFontMgr> SkFontMgr_New_FCI(sk_sp<SkFontConfigInterface> fci) {
299     SkASSERT(fci);
300     return sk_make_sp<SkFontMgr_FCI>(std::move(fci));
301 }
302