1 /*
2  * Copyright 2008 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 "SkStream.h"
12 #include "SkTemplates.h"
13 #include "SkTypeface.h"
14 #include "SkTypefaceCache.h"
15 #include "SkResourceCache.h"
16 
17 ///////////////////////////////////////////////////////////////////////////////
18 ///////////////////////////////////////////////////////////////////////////////
19 
20 SK_DECLARE_STATIC_MUTEX(gFontConfigInterfaceMutex);
21 static SkFontConfigInterface* gFontConfigInterface;
22 
RefGlobal()23 SkFontConfigInterface* SkFontConfigInterface::RefGlobal() {
24     SkAutoMutexAcquire ac(gFontConfigInterfaceMutex);
25 
26     return SkSafeRef(gFontConfigInterface);
27 }
28 
SetGlobal(SkFontConfigInterface * fc)29 SkFontConfigInterface* SkFontConfigInterface::SetGlobal(SkFontConfigInterface* fc) {
30     SkAutoMutexAcquire ac(gFontConfigInterfaceMutex);
31 
32     SkRefCnt_SafeAssign(gFontConfigInterface, fc);
33     return fc;
34 }
35 
36 ///////////////////////////////////////////////////////////////////////////////
37 ///////////////////////////////////////////////////////////////////////////////
38 
39 // convenience function to create the direct interface if none is installed.
40 extern SkFontConfigInterface* SkCreateDirectFontConfigInterface();
41 
RefFCI()42 static SkFontConfigInterface* RefFCI() {
43     for (;;) {
44         SkFontConfigInterface* fci = SkFontConfigInterface::RefGlobal();
45         if (fci) {
46             return fci;
47         }
48         fci = SkFontConfigInterface::GetSingletonDirectInterface(&gFontConfigInterfaceMutex);
49         SkFontConfigInterface::SetGlobal(fci);
50     }
51 }
52 
53 // export this to SkFontMgr_fontconfig.cpp until this file just goes away.
54 SkFontConfigInterface* SkFontHost_fontconfig_ref_global();
SkFontHost_fontconfig_ref_global()55 SkFontConfigInterface* SkFontHost_fontconfig_ref_global() {
56     return RefFCI();
57 }
58 
59 ///////////////////////////////////////////////////////////////////////////////
60 
find_by_FontIdentity(SkTypeface * cachedTypeface,const SkFontStyle &,void * ctx)61 static bool find_by_FontIdentity(SkTypeface* cachedTypeface, const SkFontStyle&, void* ctx) {
62     typedef SkFontConfigInterface::FontIdentity FontIdentity;
63     FontConfigTypeface* cachedFCTypeface = static_cast<FontConfigTypeface*>(cachedTypeface);
64     FontIdentity* identity = static_cast<FontIdentity*>(ctx);
65 
66     return cachedFCTypeface->getIdentity() == *identity;
67 }
68 
69 SK_DECLARE_STATIC_MUTEX(gSkFontHostRequestCacheMutex);
70 class SkFontHostRequestCache {
71 
72     // The value of maxSize here is a compromise between cache hits and cache size.
73     static const size_t gMaxSize = 1 << 12;
74 
Get()75     static SkFontHostRequestCache& Get() {
76         gSkFontHostRequestCacheMutex.assertHeld();
77         static SkFontHostRequestCache gCache(gMaxSize);
78         return gCache;
79     }
80 
81 public:
82     struct Request : public SkResourceCache::Key {
83     private:
RequestSkFontHostRequestCache::Request84         Request(const char* name, size_t nameLen, const SkFontStyle& style) : fStyle(style) {
85             /** Pointer to just after the last field of this class. */
86             char* content = const_cast<char*>(SkTAfter<const char>(&this->fStyle));
87 
88             // No holes.
89             SkASSERT(SkTAddOffset<char>(this, sizeof(SkResourceCache::Key) + keySize) == content);
90 
91             // Has a size divisible by size of uint32_t.
92             SkASSERT((content - reinterpret_cast<char*>(this)) % sizeof(uint32_t) == 0);
93 
94             size_t contentLen = SkAlign4(nameLen);
95             sk_careful_memcpy(content, name, nameLen);
96             sk_bzero(content + nameLen, contentLen - nameLen);
97             this->init(&gSkFontHostRequestCacheMutex, 0, keySize + contentLen);
98         }
99         const SkFontStyle fStyle;
100         /** The sum of the sizes of the fields of this class. */
101         static const size_t keySize = sizeof(fStyle);
102 
103     public:
CreateSkFontHostRequestCache::Request104         static Request* Create(const char* name, const SkFontStyle& style) {
105             size_t nameLen = name ? strlen(name) : 0;
106             size_t contentLen = SkAlign4(nameLen);
107             char* storage = new char[sizeof(Request) + contentLen];
108             return new (storage) Request(name, nameLen, style);
109         }
operator deleteSkFontHostRequestCache::Request110         void operator delete(void* storage) {
111             delete[] reinterpret_cast<char*>(storage);
112         }
113     };
114 
115 
116 private:
117     struct Result : public SkResourceCache::Rec {
ResultSkFontHostRequestCache::Result118         Result(Request* request, SkTypeface* typeface)
119             : fRequest(request)
120             , fFace(SkSafeRef(typeface)) {}
121         Result(Result&&) = default;
122         Result& operator=(Result&&) = default;
123 
getKeySkFontHostRequestCache::Result124         const Key& getKey() const override { return *fRequest; }
bytesUsedSkFontHostRequestCache::Result125         size_t bytesUsed() const override { return fRequest->size() + sizeof(fFace); }
getCategorySkFontHostRequestCache::Result126         const char* getCategory() const override { return "request_cache"; }
diagnostic_only_getDiscardableSkFontHostRequestCache::Result127         SkDiscardableMemory* diagnostic_only_getDiscardable() const override { return nullptr; }
128 
129         SkAutoTDelete<Request> fRequest;
130         SkAutoTUnref<SkTypeface> fFace;
131     };
132 
133     SkResourceCache fCachedResults;
134 
135 public:
SkFontHostRequestCache(size_t maxSize)136     SkFontHostRequestCache(size_t maxSize) : fCachedResults(maxSize) {}
137 
138     /** Takes ownership of request. It will be deleted when no longer needed. */
add(SkTypeface * face,Request * request)139     void add(SkTypeface* face, Request* request) {
140         fCachedResults.add(new Result(request, face));
141     }
142     /** Does not take ownership of request. */
findAndRef(Request * request)143     SkTypeface* findAndRef(Request* request) {
144         SkTypeface* face = nullptr;
145         fCachedResults.find(*request, [](const SkResourceCache::Rec& rec, void* context) -> bool {
146             const Result& result = static_cast<const Result&>(rec);
147             SkTypeface** face = static_cast<SkTypeface**>(context);
148 
149             *face = result.fFace;
150             return true;
151         }, &face);
152         return SkSafeRef(face);
153     }
154 
155     /** Takes ownership of request. It will be deleted when no longer needed. */
Add(SkTypeface * face,Request * request)156     static void Add(SkTypeface* face, Request* request) {
157         SkAutoMutexAcquire ama(gSkFontHostRequestCacheMutex);
158         Get().add(face, request);
159     }
160 
161     /** Does not take ownership of request. */
FindAndRef(Request * request)162     static SkTypeface* FindAndRef(Request* request) {
163         SkAutoMutexAcquire ama(gSkFontHostRequestCacheMutex);
164         return Get().findAndRef(request);
165     }
166 };
167 
LegacyCreateTypeface(const char requestedFamilyName[],SkTypeface::Style requestedOldStyle)168 SkTypeface* FontConfigTypeface::LegacyCreateTypeface(const char requestedFamilyName[],
169                                                      SkTypeface::Style requestedOldStyle)
170 {
171     SkAutoTUnref<SkFontConfigInterface> fci(RefFCI());
172     if (nullptr == fci.get()) {
173         return nullptr;
174     }
175 
176     // Check if this request is already in the request cache.
177     using Request = SkFontHostRequestCache::Request;
178     SkFontStyle requestedStyle(requestedOldStyle);
179     SkAutoTDelete<Request> request(Request::Create(requestedFamilyName, requestedStyle));
180     SkTypeface* face = SkFontHostRequestCache::FindAndRef(request);
181     if (face) {
182         return face;
183     }
184 
185     SkFontConfigInterface::FontIdentity identity;
186     SkString outFamilyName;
187     SkTypeface::Style outOldStyle;
188     if (!fci->matchFamilyName(requestedFamilyName, requestedOldStyle,
189                               &identity, &outFamilyName, &outOldStyle))
190     {
191         return nullptr;
192     }
193 
194     // Check if a typeface with this FontIdentity is already in the FontIdentity cache.
195     face = SkTypefaceCache::FindByProcAndRef(find_by_FontIdentity, &identity);
196     if (!face) {
197         face = FontConfigTypeface::Create(SkFontStyle(outOldStyle), identity, outFamilyName);
198         // Add this FontIdentity to the FontIdentity cache.
199         SkTypefaceCache::Add(face, SkFontStyle(outOldStyle));
200     }
201     // Add this request to the request cache.
202     SkFontHostRequestCache::Add(face, request.release());
203 
204     return face;
205 }
206 
207 ///////////////////////////////////////////////////////////////////////////////
208 
onOpenStream(int * ttcIndex) const209 SkStreamAsset* FontConfigTypeface::onOpenStream(int* ttcIndex) const {
210     SkStreamAsset* stream = this->getLocalStream();
211     if (stream) {
212         // TODO: should have been provided by CreateFromStream()
213         *ttcIndex = 0;
214         return stream->duplicate();
215     }
216 
217     SkAutoTUnref<SkFontConfigInterface> fci(RefFCI());
218     if (nullptr == fci.get()) {
219         return nullptr;
220     }
221 
222     *ttcIndex = this->getIdentity().fTTCIndex;
223     return fci->openStream(this->getIdentity());
224 }
225 
onGetFamilyName(SkString * familyName) const226 void FontConfigTypeface::onGetFamilyName(SkString* familyName) const {
227     *familyName = fFamilyName;
228 }
229 
onGetFontDescriptor(SkFontDescriptor * desc,bool * isLocalStream) const230 void FontConfigTypeface::onGetFontDescriptor(SkFontDescriptor* desc,
231                                              bool* isLocalStream) const {
232     SkString name;
233     this->getFamilyName(&name);
234     desc->setFamilyName(name.c_str());
235     *isLocalStream = SkToBool(this->getLocalStream());
236 }
237