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 #include <new>
21 
22 SkStreamAsset* SkTypeface_FCI::onOpenStream(int* ttcIndex) const {
23     *ttcIndex =  this->getIdentity().fTTCIndex;
24 
25     if (fFontData) {
26         SkStreamAsset* stream = fFontData->getStream();
27         if (!stream) {
28             return nullptr;
29         }
30         return stream->duplicate().release();
31     }
32 
33     return fFCI->openStream(this->getIdentity());
34 }
35 
36 std::unique_ptr<SkFontData> SkTypeface_FCI::onMakeFontData() const {
37     if (fFontData) {
38         return skstd::make_unique<SkFontData>(*fFontData);
39     }
40 
41     const SkFontConfigInterface::FontIdentity& id = this->getIdentity();
42     return skstd::make_unique<SkFontData>(std::unique_ptr<SkStreamAsset>(fFCI->openStream(id)),
43                                           id.fTTCIndex, nullptr, 0);
44 }
45 
46 void SkTypeface_FCI::onGetFontDescriptor(SkFontDescriptor* desc, bool* isLocalStream) const {
47     SkString name;
48     this->getFamilyName(&name);
49     desc->setFamilyName(name.c_str());
50     desc->setStyle(this->fontStyle());
51     *isLocalStream = SkToBool(fFontData);
52 }
53 
54 ///////////////////////////////////////////////////////////////////////////////
55 
56 class SkFontStyleSet_FCI : public SkFontStyleSet {
57 public:
58     SkFontStyleSet_FCI() {}
59 
60     int count() override { return 0; }
61     void getStyle(int index, SkFontStyle*, SkString* style) override { SkASSERT(false); }
62     SkTypeface* createTypeface(int index) override { SkASSERT(false); return nullptr; }
63     SkTypeface* matchStyle(const SkFontStyle& pattern) override { return nullptr; }
64 };
65 
66 ///////////////////////////////////////////////////////////////////////////////
67 
68 class SkFontRequestCache {
69 public:
70     struct Request : public SkResourceCache::Key {
71     private:
72         Request(const char* name, size_t nameLen, const SkFontStyle& style) : fStyle(style) {
73             /** Pointer to just after the last field of this class. */
74             char* content = const_cast<char*>(SkTAfter<const char>(&this->fStyle));
75 
76             // No holes.
77             SkASSERT(SkTAddOffset<char>(this, sizeof(SkResourceCache::Key) + keySize) == content);
78 
79             // Has a size divisible by size of uint32_t.
80             SkASSERT((content - reinterpret_cast<char*>(this)) % sizeof(uint32_t) == 0);
81 
82             size_t contentLen = SkAlign4(nameLen);
83             sk_careful_memcpy(content, name, nameLen);
84             sk_bzero(content + nameLen, contentLen - nameLen);
85             this->init(nullptr, 0, keySize + contentLen);
86         }
87         const SkFontStyle fStyle;
88         /** The sum of the sizes of the fields of this class. */
89         static const size_t keySize = sizeof(fStyle);
90 
91     public:
92         static Request* Create(const char* name, const SkFontStyle& style) {
93             size_t nameLen = name ? strlen(name) : 0;
94             size_t contentLen = SkAlign4(nameLen);
95             char* storage = new char[sizeof(Request) + contentLen];
96             return new (storage) Request(name, nameLen, style);
97         }
98         void operator delete(void* storage) {
99             delete[] reinterpret_cast<char*>(storage);
100         }
101     };
102 
103 
104 private:
105     struct Result : public SkResourceCache::Rec {
106         Result(Request* request, SkTypeface* typeface)
107             : fRequest(request)
108             , fFace(SkSafeRef(typeface)) {}
109         Result(Result&&) = default;
110         Result& operator=(Result&&) = default;
111 
112         const Key& getKey() const override { return *fRequest; }
113         size_t bytesUsed() const override { return fRequest->size() + sizeof(fFace); }
114         const char* getCategory() const override { return "request_cache"; }
115         SkDiscardableMemory* diagnostic_only_getDiscardable() const override { return nullptr; }
116 
117         std::unique_ptr<Request> fRequest;
118         sk_sp<SkTypeface> fFace;
119     };
120 
121     SkResourceCache fCachedResults;
122 
123 public:
124     SkFontRequestCache(size_t maxSize) : fCachedResults(maxSize) {}
125 
126     /** Takes ownership of request. It will be deleted when no longer needed. */
127     void add(SkTypeface* face, Request* request) {
128         fCachedResults.add(new Result(request, face));
129     }
130     /** Does not take ownership of request. */
131     SkTypeface* findAndRef(Request* request) {
132         SkTypeface* face = nullptr;
133         fCachedResults.find(*request, [](const SkResourceCache::Rec& rec, void* context) -> bool {
134             const Result& result = static_cast<const Result&>(rec);
135             SkTypeface** face = static_cast<SkTypeface**>(context);
136 
137             *face = result.fFace.get();
138             return true;
139         }, &face);
140         return SkSafeRef(face);
141     }
142 };
143 
144 ///////////////////////////////////////////////////////////////////////////////
145 
146 static bool find_by_FontIdentity(SkTypeface* cachedTypeface, void* ctx) {
147     typedef SkFontConfigInterface::FontIdentity FontIdentity;
148     SkTypeface_FCI* cachedFCTypeface = static_cast<SkTypeface_FCI*>(cachedTypeface);
149     FontIdentity* identity = static_cast<FontIdentity*>(ctx);
150 
151     return cachedFCTypeface->getIdentity() == *identity;
152 }
153 
154 ///////////////////////////////////////////////////////////////////////////////
155 
156 class SkFontMgr_FCI : public SkFontMgr {
157     sk_sp<SkFontConfigInterface> fFCI;
158     SkTypeface_FreeType::Scanner fScanner;
159 
160     mutable SkMutex fMutex;
161     mutable SkTypefaceCache fTFCache;
162 
163     // The value of maxSize here is a compromise between cache hits and cache size.
164     // See https://crbug.com/424082#63 for reason for current size.
165     static const size_t kMaxSize = 1 << 15;
166     mutable SkFontRequestCache fCache;
167 
168 public:
169     SkFontMgr_FCI(sk_sp<SkFontConfigInterface> fci)
170         : fFCI(std::move(fci))
171         , fCache(kMaxSize)
172     {}
173 
174 protected:
175     int onCountFamilies() const override {
176         SK_ABORT("Not implemented.");
177         return 0;
178     }
179 
180     void onGetFamilyName(int index, SkString* familyName) const override {
181         SK_ABORT("Not implemented.");
182     }
183 
184     SkFontStyleSet* onCreateStyleSet(int index) const override {
185         SK_ABORT("Not implemented.");
186         return nullptr;
187     }
188 
189     SkFontStyleSet* onMatchFamily(const char familyName[]) const override {
190         SK_ABORT("Not implemented.");
191         return new SkFontStyleSet_FCI();
192     }
193 
194     SkTypeface* onMatchFamilyStyle(const char requestedFamilyName[],
195                                    const SkFontStyle& requestedStyle) const override
196     {
197         SkAutoMutexAcquire ama(fMutex);
198 
199         SkFontConfigInterface::FontIdentity identity;
200         SkString outFamilyName;
201         SkFontStyle outStyle;
202         if (!fFCI->matchFamilyName(requestedFamilyName, requestedStyle,
203                                    &identity, &outFamilyName, &outStyle))
204         {
205             return nullptr;
206         }
207 
208         // Check if a typeface with this FontIdentity is already in the FontIdentity cache.
209         SkTypeface* face = fTFCache.findByProcAndRef(find_by_FontIdentity, &identity);
210         if (!face) {
211             face = SkTypeface_FCI::Create(fFCI, identity, std::move(outFamilyName), outStyle);
212             // Add this FontIdentity to the FontIdentity cache.
213             fTFCache.add(face);
214         }
215         return face;
216     }
217 
218     SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
219                                             const char* bcp47[], int bcp47Count,
220                                             SkUnichar character) const override {
221         SK_ABORT("Not implemented.");
222         return nullptr;
223     }
224 
225     SkTypeface* onMatchFaceStyle(const SkTypeface*, const SkFontStyle&) const override {
226         SK_ABORT("Not implemented.");
227         return nullptr;
228     }
229 
230     sk_sp<SkTypeface> onMakeFromData(sk_sp<SkData> data, int ttcIndex) const override {
231         return this->onMakeFromStreamIndex(SkMemoryStream::Make(std::move(data)), ttcIndex);
232     }
233 
234     sk_sp<SkTypeface> onMakeFromStreamIndex(std::unique_ptr<SkStreamAsset> stream,
235                                             int ttcIndex) const override {
236         const size_t length = stream->getLength();
237         if (!length) {
238             return nullptr;
239         }
240         if (length >= 1024 * 1024 * 1024) {
241             return nullptr;  // don't accept too large fonts (>= 1GB) for safety.
242         }
243 
244         // TODO should the caller give us the style or should we get it from freetype?
245         SkString name;
246         SkFontStyle style;
247         bool isFixedPitch = false;
248         if (!fScanner.scanFont(stream.get(), 0, &name, &style, &isFixedPitch, nullptr)) {
249             return nullptr;
250         }
251 
252         auto fontData = skstd::make_unique<SkFontData>(std::move(stream), ttcIndex, nullptr, 0);
253         return sk_sp<SkTypeface>(SkTypeface_FCI::Create(std::move(fontData), std::move(name),
254                                                         style, isFixedPitch));
255     }
256 
257     sk_sp<SkTypeface> onMakeFromStreamArgs(std::unique_ptr<SkStreamAsset> stream,
258                                            const SkFontArguments& args) const override {
259         using Scanner = SkTypeface_FreeType::Scanner;
260         const size_t length = stream->getLength();
261         if (!length) {
262             return nullptr;
263         }
264         if (length >= 1024 * 1024 * 1024) {
265             return nullptr;  // don't accept too large fonts (>= 1GB) for safety.
266         }
267 
268         bool isFixedPitch;
269         SkFontStyle style;
270         SkString name;
271         Scanner::AxisDefinitions axisDefinitions;
272         if (!fScanner.scanFont(stream.get(), args.getCollectionIndex(),
273                                &name, &style, &isFixedPitch, &axisDefinitions))
274         {
275             return nullptr;
276         }
277 
278         SkAutoSTMalloc<4, SkFixed> axisValues(axisDefinitions.count());
279         Scanner::computeAxisValues(axisDefinitions, args.getVariationDesignPosition(),
280                                    axisValues, name);
281 
282         auto fontData = skstd::make_unique<SkFontData>(std::move(stream),
283                                                        args.getCollectionIndex(),
284                                                        axisValues.get(),
285                                                        axisDefinitions.count());
286         return sk_sp<SkTypeface>(SkTypeface_FCI::Create(std::move(fontData), std::move(name),
287                                                         style, isFixedPitch));
288     }
289 
290     sk_sp<SkTypeface> onMakeFromFile(const char path[], int ttcIndex) const override {
291         std::unique_ptr<SkStreamAsset> stream = SkStream::MakeFromFile(path);
292         return stream ? this->makeFromStream(std::move(stream), ttcIndex) : nullptr;
293     }
294 
295     sk_sp<SkTypeface> onLegacyMakeTypeface(const char requestedFamilyName[],
296                                            SkFontStyle requestedStyle) const override
297     {
298         SkAutoMutexAcquire ama(fMutex);
299 
300         // Check if this request is already in the request cache.
301         using Request = SkFontRequestCache::Request;
302         std::unique_ptr<Request> request(Request::Create(requestedFamilyName, requestedStyle));
303         SkTypeface* face = fCache.findAndRef(request.get());
304         if (face) {
305             return sk_sp<SkTypeface>(face);
306         }
307 
308         SkFontConfigInterface::FontIdentity identity;
309         SkString outFamilyName;
310         SkFontStyle outStyle;
311         if (!fFCI->matchFamilyName(requestedFamilyName, requestedStyle,
312                                    &identity, &outFamilyName, &outStyle))
313         {
314             return nullptr;
315         }
316 
317         // Check if a typeface with this FontIdentity is already in the FontIdentity cache.
318         face = fTFCache.findByProcAndRef(find_by_FontIdentity, &identity);
319         if (!face) {
320             face = SkTypeface_FCI::Create(fFCI, identity, std::move(outFamilyName), outStyle);
321             // Add this FontIdentity to the FontIdentity cache.
322             fTFCache.add(face);
323         }
324         // Add this request to the request cache.
325         fCache.add(face, request.release());
326 
327         return sk_sp<SkTypeface>(face);
328     }
329 };
330 
331 SK_API sk_sp<SkFontMgr> SkFontMgr_New_FCI(sk_sp<SkFontConfigInterface> fci) {
332     SkASSERT(fci);
333     return sk_make_sp<SkFontMgr_FCI>(std::move(fci));
334 }
335