Don't read unecessary font files on Android.

src/ports/SkFontConfigParser_android.cpp

Index: src/ports/SkFontConfigParser_android.cpp
diff --git a/src/ports/SkFontConfigParser_android.cpp b/src/ports/SkFontConfigParser_android.cpp
index 2e9054d36d62527eab17a5497f0b1a7c9b48eb0f..e5483c8000a518a85eefed963b80cc4f3e4bf91a 100644
--- a/src/ports/SkFontConfigParser_android.cpp
+++ b/src/ports/SkFontConfigParser_android.cpp
@@ -57,13 +57,15 @@ struct FamilyData {
         , fCurrentFamily(NULL)
         , fCurrentFontInfo(NULL)
         , fCurrentTag(NO_TAG)
-    { };
+        , fVersion(0)
+    { }
 
     XML_Parser fParser;                       // The expat parser doing the work, owned by caller
     SkTDArray<FontFamily*>& fFamilies;        // The array to append families, owned by caller
     SkAutoTDelete<FontFamily> fCurrentFamily; // The family being created, owned by this
     FontFileInfo* fCurrentFontInfo;           // The fontInfo being created, owned by currentFamily
     int fCurrentTag;                          // Flag to indicate when we're in nameset/fileset tags
+    int fVersion;                             // The version of the file parsed.
 };
 
 /** http://www.w3.org/TR/html-markup/datatypes.html#common.data.integer.non-negative-def */
@@ -331,6 +333,7 @@ static void startElementHandler(void* data, const char* tag, const char** atts)
                 XML_SetElementHandler(familyData->fParser,
                                       lmpParser::startElementHandler,
                                       lmpParser::endElementHandler);
+                familyData->fVersion = version;
             }
         }
     } else if (len == 6 && strncmp(tag, "family", len) == 0) {
@@ -387,16 +390,16 @@ static void endElementHandler(void* data, const char* tag) {
 
 /**
  * This function parses the given filename and stores the results in the given
- * families array.
+ * families array. Returns the version of the file, negative if the file does not exist.
  */
-static void parseConfigFile(const char* filename, SkTDArray<FontFamily*> &families) {
+static int parseConfigFile(const char* filename, SkTDArray<FontFamily*> &families) {
 
     FILE* file = fopen(filename, "r");
 
     // Some of the files we attempt to parse (in particular, /vendor/etc/fallback_fonts.xml)
     // are optional - failure here is okay because one of these optional files may not exist.
     if (NULL == file) {
-        return;
+        return -1;
     }
 
     XML_Parser parser = XML_ParserCreate(NULL);
@@ -417,15 +420,17 @@ static void parseConfigFile(const char* filename, SkTDArray<FontFamily*> &famili
     }
     XML_ParserFree(parser);
     fclose(file);
+    return familyData.fVersion;
 }
 
-static void getSystemFontFamilies(SkTDArray<FontFamily*> &fontFamilies) {
+/** Returns the version of the system font file actually found, negative if none. */
+static int appendSystemFontFamilies(SkTDArray<FontFamily*> &fontFamilies) {

[mtklein, 2015/02/02 16:55:49]

Let's update to static_function_name_style and T& foo while we're here?

[bungeman-skia, 2015/02/02 18:36:37]

Done.

     int initialCount = fontFamilies.count();
-    parseConfigFile(LMP_SYSTEM_FONTS_FILE, fontFamilies);
-
-    if (initialCount == fontFamilies.count()) {
-        parseConfigFile(OLD_SYSTEM_FONTS_FILE, fontFamilies);
+    int version = parseConfigFile(LMP_SYSTEM_FONTS_FILE, fontFamilies);
+    if (version < 0 || fontFamilies.count() == initialCount) {
+        version = parseConfigFile(OLD_SYSTEM_FONTS_FILE, fontFamilies);
     }
+    return version;
 }
 
 /**
@@ -435,7 +440,9 @@ static void getSystemFontFamilies(SkTDArray<FontFamily*> &fontFamilies) {
  * directory for those files,add all of their entries to the fallback chain, and
  * include the locale as part of each entry.
  */
-static void getFallbackFontFamiliesForLocale(SkTDArray<FontFamily*> &fallbackFonts, const char* dir) {
+static void appendFallbackFontFamiliesForLocale(SkTDArray<FontFamily*> &fallbackFonts,
+                                                const char* dir)
+{
 #if defined(SK_BUILD_FOR_ANDROID_FRAMEWORK)
     // The framework is beyond Android 4.2 and can therefore skip this function
     return;
@@ -482,13 +489,15 @@ static void getFallbackFontFamiliesForLocale(SkTDArray<FontFamily*> &fallbackFon
     }
 }
 
-static void getFallbackFontFamilies(SkTDArray<FontFamily*> &fallbackFonts) {
-    SkTDArray<FontFamily*> vendorFonts;
+static void appendSystemFallbackFontFamilies(SkTDArray<FontFamily*> &fallbackFonts) {
     parseConfigFile(FALLBACK_FONTS_FILE, fallbackFonts);
-    parseConfigFile(VENDOR_FONTS_FILE, vendorFonts);
+    appendFallbackFontFamiliesForLocale(fallbackFonts, LOCALE_FALLBACK_FONTS_SYSTEM_DIR);
+}
 
-    getFallbackFontFamiliesForLocale(fallbackFonts, LOCALE_FALLBACK_FONTS_SYSTEM_DIR);
-    getFallbackFontFamiliesForLocale(vendorFonts, LOCALE_FALLBACK_FONTS_VENDOR_DIR);
+static void mixinVendorFallbackFontFamilies(SkTDArray<FontFamily*> &fallbackFonts) {
+    SkTDArray<FontFamily*> vendorFonts;
+    parseConfigFile(VENDOR_FONTS_FILE, vendorFonts);
+    appendFallbackFontFamiliesForLocale(vendorFonts, LOCALE_FALLBACK_FONTS_VENDOR_DIR);
 
     // This loop inserts the vendor fallback fonts in the correct order in the
     // overall fallbacks list.
@@ -519,12 +528,15 @@ static void getFallbackFontFamilies(SkTDArray<FontFamily*> &fallbackFonts) {
  * resulting data is returned in the given fontFamilies array.
  */
 void SkFontConfigParser::GetFontFamilies(SkTDArray<FontFamily*> &fontFamilies) {
-
-    getSystemFontFamilies(fontFamilies);
+    // Version 21 of the system font configuration does not need any fallback configuration files.
+    if (appendSystemFontFamilies(fontFamilies) >= 21) {
+        return;
+    }
 
     // Append all the fallback fonts to system fonts
     SkTDArray<FontFamily*> fallbackFonts;
-    getFallbackFontFamilies(fallbackFonts);
+    appendSystemFallbackFontFamilies(fallbackFonts);
+    mixinVendorFallbackFontFamilies(fallbackFonts);
     for (int i = 0; i < fallbackFonts.count(); ++i) {
         fallbackFonts[i]->fIsFallbackFont = true;
         *fontFamilies.append() = fallbackFonts[i];