Preload Roboto-Regualr.ttf

Bug: 179026427
Test: N/A
Change-Id: I47cf1f0d86ca93cfef429ed2f3af8e60d68d385b

graphics/java/android/graphics/Typeface.java

@@ -1346,6 +1346,19 @@ public class Typeface {
         }
     }
 
+    static {
+        // Preload Roboto-Regular.ttf in Zygote for improving app launch performance.
+        // TODO: add new attribute to fonts.xml to preload fonts in Zygote.
+        preloadFontFile("/system/fonts/Roboto-Regular.ttf");
+    }
+
+    private static void preloadFontFile(String filePath) {
+        File file = new File(filePath);
+        if (file.exists()) {
+            nativeWarmUpCache(filePath);
+        }
+    }
+
     /** @hide */
     @VisibleForTesting
     public static void destroySystemFontMap() {
@@ -1464,4 +1477,6 @@ public class Typeface {
     private static native @Nullable long[] nativeReadTypefaces(@NonNull ByteBuffer buffer);
 
     private static native void nativeForceSetStaticFinalField(String fieldName, Typeface typeface);
+
+    private static native void nativeWarmUpCache(String fileName);
 }

libs/hwui/jni/Typeface.cpp

@@ -367,6 +367,12 @@ static jlong Typeface_getFamily(CRITICAL_JNI_PARAMS_COMMA jlong faceHandle, jint
     return reinterpret_cast<jlong>(new FontFamilyWrapper(std::move(family)));
 }
 
+// Regular JNI
+static void Typeface_warmUpCache(JNIEnv* env, jobject, jstring jFilePath) {
+    ScopedUtfChars filePath(env, jFilePath);
+    makeSkDataCached(filePath.c_str(), false /* fs verity */);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 static const JNINativeMethod gTypefaceMethods[] = {
@@ -390,6 +396,7 @@ static const JNINativeMethod gTypefaceMethods[] = {
          (void*)Typeface_forceSetStaticFinalField},
         {"nativeGetFamilySize", "(J)I", (void*)Typeface_getFamilySize},
         {"nativeGetFamily", "(JI)J", (void*)Typeface_getFamily},
+        {"nativeWarmUpCache", "(Ljava/lang/String;)V", (void*)Typeface_warmUpCache},
 };
 
 int register_android_graphics_Typeface(JNIEnv* env)