Bug 1798036 - Attach a SharedFTFaceData (recording the filename) when instantiating SharedFTFace for an installed variation font. r=lsalzman

This is needed so that UnscaledFontFreeType::CreateScaledFont can later call CloneFace
if it needs to apply variation settings.

Tested locally with an emulator running Android 13; not testable in CI as the older Android
versions we have there don't use the new variable-font version of Roboto.

Differential Revision: https://phabricator.services.mozilla.com/D161762

gfx/2d/2D.h

@@ -1067,6 +1067,40 @@ class SharedFTFaceRefCountedData : public SharedFTFaceData {
   void ReleaseData() { static_cast<T*>(this)->Release(); }
 };
 
+// Helper class used for clearing out user font data when FT font
+// face is destroyed. Since multiple faces may use the same data, be
+// careful to assure that the data is only cleared out when all uses
+// expire. The font entry object contains a refptr to FTUserFontData and
+// each FT face created from that font entry contains a refptr to that
+// same FTUserFontData object.
+// This is also attached to FT faces for installed fonts (recording the
+// filename, rather than storing the font data) if variations are present.
+class FTUserFontData final
+    : public mozilla::gfx::SharedFTFaceRefCountedData<FTUserFontData> {
+ public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(FTUserFontData)
+
+  FTUserFontData(const uint8_t* aData, uint32_t aLength)
+      : mFontData(aData), mLength(aLength) {}
+  explicit FTUserFontData(const char* aFilename) : mFilename(aFilename) {}
+
+  const uint8_t* FontData() const { return mFontData; }
+
+  already_AddRefed<mozilla::gfx::SharedFTFace> CloneFace(
+      int aFaceIndex = 0) override;
+
+ private:
+  ~FTUserFontData() {
+    if (mFontData) {
+      free((void*)mFontData);
+    }
+  }
+
+  std::string mFilename;
+  const uint8_t* mFontData = nullptr;
+  uint32_t mLength = 0;
+};
+
 /** SharedFTFace is a shared wrapper around an FT_Face. It is ref-counted,
  * unlike FT_Face itself, so that it may be shared among many users with
  * RefPtr. Users should take care to lock SharedFTFace before accessing any
@@ -1078,7 +1112,7 @@ class SharedFTFace : public external::AtomicRefCounted<SharedFTFace> {
  public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(SharedFTFace)
 
-  explicit SharedFTFace(FT_Face aFace, SharedFTFaceData* aData = nullptr);
+  explicit SharedFTFace(FT_Face aFace, SharedFTFaceData* aData);
   virtual ~SharedFTFace();
 
   FT_Face GetFace() const { return mFace; }

gfx/2d/Factory.cpp

@@ -200,6 +200,25 @@ namespace mozilla::gfx {
 #ifdef MOZ_ENABLE_FREETYPE
 FT_Library Factory::mFTLibrary = nullptr;
 StaticMutex Factory::mFTLock;
+
+already_AddRefed<SharedFTFace> FTUserFontData::CloneFace(int aFaceIndex) {
+  if (mFontData) {
+    RefPtr<SharedFTFace> face = Factory::NewSharedFTFaceFromData(
+        nullptr, mFontData, mLength, aFaceIndex, this);
+    if (!face ||
+        (FT_Select_Charmap(face->GetFace(), FT_ENCODING_UNICODE) != FT_Err_Ok &&
+         FT_Select_Charmap(face->GetFace(), FT_ENCODING_MS_SYMBOL) !=
+             FT_Err_Ok)) {
+      return nullptr;
+    }
+    return face.forget();
+  }
+  FT_Face face = Factory::NewFTFace(nullptr, mFilename.c_str(), aFaceIndex);
+  if (face) {
+    return MakeAndAddRef<SharedFTFace>(face, this);
+  }
+  return nullptr;
+}
 #endif
 
 #ifdef WIN32
@@ -649,11 +668,19 @@ FT_Face Factory::NewFTFace(FT_Library aFTLibrary, const char* aFileName,
 already_AddRefed<SharedFTFace> Factory::NewSharedFTFace(FT_Library aFTLibrary,
                                                         const char* aFilename,
                                                         int aFaceIndex) {
-  if (FT_Face face = NewFTFace(aFTLibrary, aFilename, aFaceIndex)) {
-    return MakeAndAddRef<SharedFTFace>(face);
-  } else {
+  FT_Face face = NewFTFace(aFTLibrary, aFilename, aFaceIndex);
+  if (!face) {
     return nullptr;
   }
+
+  // If the font has variations, we may later need to "clone" it in
+  // UnscaledFontFreeType::CreateScaledFont. To support this, we attach an
+  // FTUserFontData that records the filename used to instantiate the face.
+  RefPtr<FTUserFontData> data;
+  if (face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS) {
+    data = new FTUserFontData(aFilename);
+  }
+  return MakeAndAddRef<SharedFTFace>(face, data);
 }
 
 FT_Face Factory::NewFTFaceFromData(FT_Library aFTLibrary, const uint8_t* aData,

gfx/2d/ScaledFontFreeType.cpp

@@ -127,50 +127,6 @@ ScaledFontFreeType::InstanceData::InstanceData(
   }
 }
 
-already_AddRefed<ScaledFont> UnscaledFontFreeType::CreateScaledFont(
-    Float aGlyphSize, const uint8_t* aInstanceData,
-    uint32_t aInstanceDataLength, const FontVariation* aVariations,
-    uint32_t aNumVariations) {
-  if (aInstanceDataLength < sizeof(ScaledFontFreeType::InstanceData)) {
-    gfxWarning() << "FreeType scaled font instance data is truncated.";
-    return nullptr;
-  }
-  const ScaledFontFreeType::InstanceData& instanceData =
-      *reinterpret_cast<const ScaledFontFreeType::InstanceData*>(aInstanceData);
-
-  RefPtr<SharedFTFace> face(InitFace());
-  if (!face) {
-    gfxWarning() << "Attempted to deserialize FreeType scaled font without "
-                    "FreeType face";
-    return nullptr;
-  }
-
-  if (aNumVariations > 0 && face->GetData()) {
-    if (RefPtr<SharedFTFace> varFace = face->GetData()->CloneFace()) {
-      face = varFace;
-    }
-  }
-
-  // Only apply variations if we have an explicitly cloned face.
-  if (aNumVariations > 0 && face != GetFace()) {
-    ApplyVariationsToFace(aVariations, aNumVariations, face->GetFace());
-  }
-
-  RefPtr<ScaledFontFreeType> scaledFont = new ScaledFontFreeType(
-      std::move(face), this, aGlyphSize, instanceData.mApplySyntheticBold);
-
-  return scaledFont.forget();
-}
-
-already_AddRefed<ScaledFont> UnscaledFontFreeType::CreateScaledFontFromWRFont(
-    Float aGlyphSize, const wr::FontInstanceOptions* aOptions,
-    const wr::FontInstancePlatformOptions* aPlatformOptions,
-    const FontVariation* aVariations, uint32_t aNumVariations) {
-  ScaledFontFreeType::InstanceData instanceData(aOptions, aPlatformOptions);
-  return CreateScaledFont(aGlyphSize, reinterpret_cast<uint8_t*>(&instanceData),
-                          sizeof(instanceData), aVariations, aNumVariations);
-}
-
 bool ScaledFontFreeType::HasVariationSettings() {
   // Check if the FT face has been cloned.
   return mFace &&
@@ -179,17 +135,5 @@ bool ScaledFontFreeType::HasVariationSettings() {
              static_cast<UnscaledFontFreeType*>(mUnscaledFont.get())->GetFace();
 }
 
-already_AddRefed<UnscaledFont> UnscaledFontFreeType::CreateFromFontDescriptor(
-    const uint8_t* aData, uint32_t aDataLength, uint32_t aIndex) {
-  if (aDataLength == 0) {
-    gfxWarning() << "FreeType font descriptor is truncated.";
-    return nullptr;
-  }
-  const char* path = reinterpret_cast<const char*>(aData);
-  RefPtr<UnscaledFont> unscaledFont =
-      new UnscaledFontFreeType(std::string(path, aDataLength), aIndex);
-  return unscaledFont.forget();
-}
-
 }  // namespace gfx
 }  // namespace mozilla

gfx/2d/UnscaledFontFreeType.cpp

@@ -179,4 +179,64 @@ void UnscaledFontFreeType::ApplyVariationsToFace(
   }
 }
 
+#ifdef MOZ_WIDGET_ANDROID
+
+already_AddRefed<ScaledFont> UnscaledFontFreeType::CreateScaledFont(
+    Float aGlyphSize, const uint8_t* aInstanceData,
+    uint32_t aInstanceDataLength, const FontVariation* aVariations,
+    uint32_t aNumVariations) {
+  if (aInstanceDataLength < sizeof(ScaledFontFreeType::InstanceData)) {
+    gfxWarning() << "FreeType scaled font instance data is truncated.";
+    return nullptr;
+  }
+  const ScaledFontFreeType::InstanceData& instanceData =
+      *reinterpret_cast<const ScaledFontFreeType::InstanceData*>(aInstanceData);
+
+  RefPtr<SharedFTFace> face(InitFace());
+  if (!face) {
+    gfxWarning() << "Attempted to deserialize FreeType scaled font without "
+                    "FreeType face";
+    return nullptr;
+  }
+
+  if (aNumVariations > 0 && face->GetData()) {
+    if (RefPtr<SharedFTFace> varFace = face->GetData()->CloneFace()) {
+      face = varFace;
+    }
+  }
+
+  // Only apply variations if we have an explicitly cloned face.
+  if (aNumVariations > 0 && face != GetFace()) {
+    ApplyVariationsToFace(aVariations, aNumVariations, face->GetFace());
+  }
+
+  RefPtr<ScaledFontFreeType> scaledFont = new ScaledFontFreeType(
+      std::move(face), this, aGlyphSize, instanceData.mApplySyntheticBold);
+
+  return scaledFont.forget();
+}
+
+already_AddRefed<ScaledFont> UnscaledFontFreeType::CreateScaledFontFromWRFont(
+    Float aGlyphSize, const wr::FontInstanceOptions* aOptions,
+    const wr::FontInstancePlatformOptions* aPlatformOptions,
+    const FontVariation* aVariations, uint32_t aNumVariations) {
+  ScaledFontFreeType::InstanceData instanceData(aOptions, aPlatformOptions);
+  return CreateScaledFont(aGlyphSize, reinterpret_cast<uint8_t*>(&instanceData),
+                          sizeof(instanceData), aVariations, aNumVariations);
+}
+
+already_AddRefed<UnscaledFont> UnscaledFontFreeType::CreateFromFontDescriptor(
+    const uint8_t* aData, uint32_t aDataLength, uint32_t aIndex) {
+  if (aDataLength == 0) {
+    gfxWarning() << "FreeType font descriptor is truncated.";
+    return nullptr;
+  }
+  const char* path = reinterpret_cast<const char*>(aData);
+  RefPtr<UnscaledFont> unscaledFont =
+      new UnscaledFontFreeType(std::string(path, aDataLength), aIndex);
+  return unscaledFont.forget();
+}
+
+#endif  // MOZ_WIDGET_ANDROID
+
 }  // namespace mozilla::gfx

gfx/thebes/gfxFT2FontBase.cpp

@@ -822,15 +822,3 @@ void gfxFT2FontBase::SetupVarCoords(
 #endif
   }
 }
-
-already_AddRefed<SharedFTFace> FTUserFontData::CloneFace(int aFaceIndex) {
-  RefPtr<SharedFTFace> face = Factory::NewSharedFTFaceFromData(
-      nullptr, mFontData, mLength, aFaceIndex, this);
-  if (!face ||
-      (FT_Select_Charmap(face->GetFace(), FT_ENCODING_UNICODE) != FT_Err_Ok &&
-       FT_Select_Charmap(face->GetFace(), FT_ENCODING_MS_SYMBOL) !=
-           FT_Err_Ok)) {
-    return nullptr;
-  }
-  return face.forget();
-}

gfx/thebes/gfxFT2FontBase.h

@@ -150,35 +150,4 @@ class gfxFT2FontBase : public gfxFont {
       mGlyphMetrics MOZ_GUARDED_BY(mLock);
 };
 
-// Helper classes used for clearing out user font data when FT font
-// face is destroyed. Since multiple faces may use the same data, be
-// careful to assure that the data is only cleared out when all uses
-// expire. The font entry object contains a refptr to FTUserFontData and
-// each FT face created from that font entry contains a refptr to that
-// same FTUserFontData object.
-
-class FTUserFontData final
-    : public mozilla::gfx::SharedFTFaceRefCountedData<FTUserFontData> {
- public:
-  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(FTUserFontData)
-
-  FTUserFontData(const uint8_t* aData, uint32_t aLength)
-      : mFontData(aData), mLength(aLength) {}
-
-  const uint8_t* FontData() const { return mFontData; }
-
-  already_AddRefed<mozilla::gfx::SharedFTFace> CloneFace(
-      int aFaceIndex = 0) override;
-
- private:
-  ~FTUserFontData() {
-    if (mFontData) {
-      free((void*)mFontData);
-    }
-  }
-
-  const uint8_t* mFontData;
-  uint32_t mLength;
-};
-
 #endif /* GFX_FT2FONTBASE_H */

gfx/thebes/gfxFT2FontList.cpp

@@ -114,7 +114,8 @@ already_AddRefed<SharedFTFace> FT2FontEntry::GetFTFace(bool aCommit) {
       }
     }
   } else {
-    face = Factory::NewSharedFTFace(nullptr, mFilename.get(), mFTFontIndex);
+    RefPtr<FTUserFontData> fd = new FTUserFontData(mFilename.get());
+    face = fd->CloneFace(mFTFontIndex);
     if (!face) {
       NS_WARNING("failed to create freetype face");
       return nullptr;

gfx/thebes/gfxFT2FontList.h

@@ -15,18 +15,21 @@ namespace mozilla {
 namespace dom {
 class SystemFontListEntry;
 };
+namespace gfx {
+class FTUserFontData;
+};
 };  // namespace mozilla
 
 class FontNameCache;
 typedef struct FT_FaceRec_* FT_Face;
 class nsZipArchive;
 class WillShutdownObserver;
-class FTUserFontData;
 
 class FT2FontEntry final : public gfxFT2FontEntryBase {
   friend class gfxFT2FontList;
 
   using FontListEntry = mozilla::dom::SystemFontListEntry;
+  using FTUserFontData = mozilla::gfx::FTUserFontData;
 
  public:
   explicit FT2FontEntry(const nsACString& aFaceName)

gfx/thebes/gfxFcPlatformFontList.cpp

@@ -503,7 +503,9 @@ bool gfxFontconfigFontEntry::TestCharacterMap(uint32_t aCh) {
 
 bool gfxFontconfigFontEntry::HasFontTable(uint32_t aTableTag) {
   if (FTUserFontData* ufd = GetUserFontData()) {
-    return !!gfxFontUtils::FindTableDirEntry(ufd->FontData(), aTableTag);
+    if (ufd->FontData()) {
+      return !!gfxFontUtils::FindTableDirEntry(ufd->FontData(), aTableTag);
+    }
   }
   return gfxFT2FontEntryBase::FaceHasTable(GetFTFace(), aTableTag);
 }
@@ -511,7 +513,9 @@ bool gfxFontconfigFontEntry::HasFontTable(uint32_t aTableTag) {
 hb_blob_t* gfxFontconfigFontEntry::GetFontTable(uint32_t aTableTag) {
   // for data fonts, read directly from the font data
   if (FTUserFontData* ufd = GetUserFontData()) {
-    return gfxFontUtils::GetTableFromFontData(ufd->FontData(), aTableTag);
+    if (ufd->FontData()) {
+      return gfxFontUtils::GetTableFromFontData(ufd->FontData(), aTableTag);
+    }
   }
 
   return gfxFontEntry::GetFontTable(aTableTag);

gfx/thebes/gfxFcPlatformFontList.h

@@ -66,6 +66,7 @@ class DefaultDelete<FcObjectSet> {
 
 class gfxFontconfigFontEntry final : public gfxFT2FontEntryBase {
   friend class gfxFcPlatformFontList;
+  using FTUserFontData = mozilla::gfx::FTUserFontData;
 
  public:
   // used for system fonts with explicit patterns