Add support for caching font files in the Android SkFontMgr.

src/ports/SkFontMgr_android.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTypes.h"
 
+#include "SkData.h"
 #include "SkFixed.h"
 #include "SkFontDescriptor.h"
 #include "SkFontHost_FreeType_common.h"
 #include "SkFontMgr.h"
 #include "SkFontMgr_android.h"
 #include "SkFontMgr_android_parser.h"
 #include "SkFontStyle.h"
+#include "SkOSFile.h"
 #include "SkPaint.h"
 #include "SkRefCnt.h"
 #include "SkString.h"
 #include "SkStream.h"
 #include "SkTArray.h"
 #include "SkTDArray.h"
 #include "SkTSearch.h"
 #include "SkTemplates.h"
 #include "SkTypefaceCache.h"
 
@@ skipping 17 matching lines @@
 
     SkString fFamilyName;
 
 private:
     typedef SkTypeface_FreeType INHERITED;
 };
 
 class SkTypeface_AndroidSystem : public SkTypeface_Android {
 public:
     SkTypeface_AndroidSystem(const SkString& pathName,
+                             const bool cacheFontFiles,
                              int index,
                              const SkFixed* axes, int axesCount,
                              const SkFontStyle& style,
                              bool isFixedPitch,
                              const SkString& familyName,
                              const SkLanguage& lang,
                              FontVariant variantStyle)
         : INHERITED(style, isFixedPitch, familyName)
         , fPathName(pathName)
         , fIndex(index)
         , fAxes(axes, axesCount)
         , fLang(lang)
-        , fVariantStyle(variantStyle) { }
+        , fVariantStyle(variantStyle)
+        , fFile(

[bungeman-skia, 2016/02/11 20:06:09]

Skia allows up to 100 character lines, can probably pull up the next line.

[Khushal, 2016/02/12 04:54:07]

Done.

+            cacheFontFiles ? sk_fopen(fPathName.c_str(), kRead_SkFILE_Flag)
+                           : nullptr)
+        , closeOnDestroy(fFile) {
+        if(cacheFontFiles)

[bungeman-skia, 2016/02/11 20:06:09]

space between 'if' and '('.

[Khushal, 2016/02/12 04:54:07]

Done.

+          SkASSERT(fFile);

[bungeman-skia, 2016/02/11 20:06:09]

four space indents, here and below

[Khushal, 2016/02/12 04:54:07]

Done.

+    }
+
+    SkStreamAsset* createStream() const {
+      if (fFile) {
+        SkData* data = SkData::NewFromFILE(fFile);
+        return data ? new SkMemoryStream(data) : nullptr;
+      }
+      return SkStream::NewFromFile(fPathName.c_str());
+    }
 
     virtual void onGetFontDescriptor(SkFontDescriptor* desc, bool* serialize) const override {
         SkASSERT(desc);
         SkASSERT(serialize);
         desc->setFamilyName(fFamilyName.c_str());
         *serialize = false;
     }
     SkStreamAsset* onOpenStream(int* ttcIndex) const override {
         *ttcIndex = fIndex;
-        return SkStream::NewFromFile(fPathName.c_str());
+        return this->createStream();
     }
     SkFontData* onCreateFontData() const override {
-        return new SkFontData(SkStream::NewFromFile(fPathName.c_str()), fIndex,
+        return new SkFontData(this->createStream(), fIndex,
                               fAxes.begin(), fAxes.count());
     }
 
     const SkString fPathName;
     int fIndex;
     const SkSTArray<4, SkFixed, true> fAxes;
     const SkLanguage fLang;
     const FontVariant fVariantStyle;
+    FILE* fFile;
+    SkAutoTCallVProc<FILE, sk_fclose> closeOnDestroy;

[bungeman-skia, 2016/02/11 20:06:09]

This extra field isn't needed, SkAUtoTCallVProc is actually just a wrapper for
unique_ptr with a deleter with calls the given proc. In other words, these two
lines can just be:

SkAutoTCallVProc<FILE, sk_fclose> fFile;

[Khushal, 2016/02/12 04:54:07]

Oh. Done. Thanks!

 
     typedef SkTypeface_Android INHERITED;
 };
 
 class SkTypeface_AndroidStream : public SkTypeface_Android {
 public:
     SkTypeface_AndroidStream(SkFontData* data,
                              const SkFontStyle& style,
                              bool isFixedPitch,
                              const SkString& familyName)
@@ skipping 20 matching lines @@
 
 private:
     const SkAutoTDelete<const SkFontData> fData;
     typedef SkTypeface_Android INHERITED;
 };
 
 class SkFontStyleSet_Android : public SkFontStyleSet {
     typedef SkTypeface_FreeType::Scanner Scanner;
 
 public:
-    explicit SkFontStyleSet_Android(const FontFamily& family, const Scanner& scanner) {
+    explicit SkFontStyleSet_Android(const FontFamily& family, const Scanner& scanner,
+                                    const bool cacheFontFiles) {
         const SkString* cannonicalFamilyName = nullptr;
         if (family.fNames.count() > 0) {
             cannonicalFamilyName = &family.fNames[0];
         }
         // TODO? make this lazy
         for (int i = 0; i < family.fFonts.count(); ++i) {
             const FontFileInfo& fontFile = family.fFonts[i];
 
             SkString pathName(family.fBasePath);
             pathName.append(fontFile.fFileName);
@@ skipping 80 matching lines @@
                     }
                     if (!found) {
                         SkDEBUGF(("Requested font axis not found: %s '%c%c%c%c'\n",
                                     familyName.c_str(), (skTag >> 24) & 0xFF,
                                     (skTag >> 16) & 0xFF, (skTag >> 8) & 0xFF, (skTag)&0xFF));
                     }
                 }
             )
 
             fStyles.push_back().reset(new SkTypeface_AndroidSystem(
-                    pathName, ttcIndex, axisValues.get(), axisDefinitions.count(), style,
+                    pathName, cacheFontFiles, ttcIndex, axisValues.get(), axisDefinitions.count(), style,

[bungeman-skia, 2016/02/11 20:06:09]

This line is a bit long (more than 100 characters)

[Khushal, 2016/02/12 04:54:07]

Done.

                     isFixedWidth, familyName, lang, variant));
         }
     }
 
     int count() override {
         return fStyles.count();
     }
     void getStyle(int index, SkFontStyle* style, SkString* name) override {
         if (index < 0 || fStyles.count() <= index) {
             return;
@@ skipping 58 matching lines @@
  *  (non-replicated) set of typefaces.
  *  SkTDict<> doesn't let us do index-based lookup, so we write our own mapping.
  */
 struct NameToFamily {
     SkString name;
     SkFontStyleSet_Android* styleSet;
 };
 
 class SkFontMgr_Android : public SkFontMgr {
 public:
-    SkFontMgr_Android(const SkFontMgr_Android_CustomFonts* custom) {
+    SkFontMgr_Android(const SkFontMgr_Android_CustomFonts* custom)
+        : fIsolated(custom ? custom->fIsolated : false)
+    {
         SkTDArray<FontFamily*> families;
         if (custom && SkFontMgr_Android_CustomFonts::kPreferSystem != custom->fSystemFontUse) {
             SkString base(custom->fBasePath);
             SkFontMgr_Android_Parser::GetCustomFontFamilies(
                 families, base, custom->fFontsXml, custom->fFallbackFontsXml);
         }
         if (!custom ||
             (custom && SkFontMgr_Android_CustomFonts::kOnlyCustom != custom->fSystemFontUse))
         {
             SkFontMgr_Android_Parser::GetSystemFontFamilies(families);
@@ skipping 194 matching lines @@
 
     virtual SkTypeface* onLegacyCreateTypeface(const char familyName[],
                                                unsigned styleBits) const override {
         SkFontStyle style = SkFontStyle(styleBits);
 
         if (familyName) {
             // On Android, we must return nullptr when we can't find the requested
             // named typeface so that the system/app can provide their own recovery
             // mechanism. On other platforms we'd provide a typeface from the
             // default family instead.
-            return this->onMatchFamilyStyle(familyName, style);
+            // We only return the default family when the font manager is running
+            // as isolated since we don't expect the app to have a recovery mechanism.
+            SkTypeface* typeface = this->onMatchFamilyStyle(familyName, style);
+            if (typeface || !fIsolated)

[bungeman-skia, 2016/02/11 20:06:09]

I'm going to have to take quite a look into this. 

[Khushal, 2016/02/12 04:54:07]

I tried reproducing this to trace back the calls. I think I might have made an
error with how I was testing this change with the corresponding change in blink.
I'm not seeing it with the final patch,
https://codereview.chromium.org/1685053002/.
Sorry about the confusion. Removed it.

[bungeman-skia, 2016/02/12 15:13:47]

That is awesome, I was just building Chromium to take a look at this. Saves me a
day of investigating.

+              return typeface;
         }
         return fDefaultFamily->matchStyle(style);
     }
 
 
 private:
 
     SkTypeface_FreeType::Scanner fScanner;
 
     SkTArray<SkAutoTUnref<SkFontStyleSet_Android>, true> fFontStyleSets;
     SkFontStyleSet* fDefaultFamily;
     SkTypeface* fDefaultTypeface;
 
     SkTDArray<NameToFamily> fNameToFamilyMap;
     SkTDArray<NameToFamily> fFallbackNameToFamilyMap;
 
+    const bool fIsolated;
+
     void buildNameToFamilyMap(SkTDArray<FontFamily*> families) {
         for (int i = 0; i < families.count(); i++) {
             FontFamily& family = *families[i];
 
             SkTDArray<NameToFamily>* nameToFamily = &fNameToFamilyMap;
             if (family.fIsFallbackFont) {
                 nameToFamily = &fFallbackNameToFamilyMap;
 
                 if (0 == family.fNames.count()) {
                     SkString& fallbackName = family.fNames.push_back();
                     fallbackName.printf("%.2x##fallback", i);
                 }
             }
 
-            SkFontStyleSet_Android* newSet = new SkFontStyleSet_Android(family, fScanner);
+            SkFontStyleSet_Android* newSet = new SkFontStyleSet_Android(family, fScanner, fIsolated);

[bungeman-skia, 2016/02/11 20:06:09]

this line ran a bit long too.

[Khushal, 2016/02/12 04:54:07]

Done.

             if (0 == newSet->count()) {
                 delete newSet;
                 continue;
             }
             fFontStyleSets.push_back().reset(newSet);
 
             for (int j = 0; j < family.fNames.count(); j++) {
                 NameToFamily* nextEntry = nameToFamily->append();
                 new (&nextEntry->name) SkString(family.fNames[j]);
                 nextEntry->styleSet = newSet;
@@ skipping 40 matching lines @@
         SkASSERT(custom->fSystemFontUse < SK_ARRAY_COUNT(gSystemFontUseStrings));
         SkDEBUGF(("SystemFontUse: %s BasePath: %s Fonts: %s FallbackFonts: %s\n",
                   gSystemFontUseStrings[custom->fSystemFontUse],
                   custom->fBasePath,
                   custom->fFontsXml,
                   custom->fFallbackFontsXml));
     }
 
     return new SkFontMgr_Android(custom);
 }