Pass the whole locale list down to Minikin.

Also, compute LocaleList's string representation at construction.
This is to further push the cost of doing costly operations related
to LocaleLists to construction time.

Change-Id: Ia55b8ce66b1088ff54cb42eb1e11149b5bd10f17
diff --git a/core/jni/android/graphics/Paint.cpp b/core/jni/android/graphics/Paint.cpp
index 314e4b6..6b09450 100644
--- a/core/jni/android/graphics/Paint.cpp
+++ b/core/jni/android/graphics/Paint.cpp
@@ -43,12 +43,10 @@
 #include "Paint.h"
 #include "TypefaceImpl.h"
 
-#include <vector>
+#include <cassert>
+#include <cstring>
 #include <memory>
-
-// temporary for debugging
-#include <Caches.h>
-#include <utils/Log.h>
+#include <vector>
 
 namespace android {
 
@@ -71,12 +69,12 @@
     paint->setTextEncoding(Paint::kGlyphID_TextEncoding);
 }
 
-struct LocaleCacheEntry {
-    std::string javaLocale;
-    std::string languageTag;
+struct LocalesCacheEntry {
+    std::string javaLocales;
+    std::string languageTags;
 };
 
-static thread_local LocaleCacheEntry sSingleEntryLocaleCache;
+static thread_local LocalesCacheEntry sSingleEntryLocalesCache;
 
 namespace PaintGlue {
     enum MoveOpt {
@@ -360,17 +358,57 @@
         output[0] = '\0';
     }
 
-    static void setTextLocale(JNIEnv* env, jobject clazz, jlong objHandle, jstring locale) {
-        Paint* obj = reinterpret_cast<Paint*>(objHandle);
-        ScopedUtfChars localeChars(env, locale);
-        if (sSingleEntryLocaleCache.javaLocale != localeChars.c_str()) {
-            sSingleEntryLocaleCache.javaLocale = localeChars.c_str();
-            char langTag[ULOC_FULLNAME_CAPACITY];
-            toLanguageTag(langTag, ULOC_FULLNAME_CAPACITY, localeChars.c_str());
-            sSingleEntryLocaleCache.languageTag = langTag;
+    static void toLanguageTags(std::string* output, const char* locales) {
+        if (output == NULL) {
+            return;
+        }
+        if (locales == NULL) {
+            output->clear();
+            return;
         }
 
-        obj->setTextLocale(sSingleEntryLocaleCache.languageTag);
+        char langTag[ULOC_FULLNAME_CAPACITY];
+        const char* commaLoc = strchr(locales, ',');
+        if (commaLoc == NULL) {
+            assert(locales[0] != '\0');  // the string should not be empty
+            toLanguageTag(langTag, ULOC_FULLNAME_CAPACITY, locales);
+            *output = langTag;
+            return;
+        }
+
+        size_t len = strlen(locales);
+        char locale[len];
+        output->clear();
+        output->reserve(len);
+        const char* lastStart = locales;
+        do {
+            assert(lastStart > commaLoc);  // the substring should not be empty
+            strncpy(locale, lastStart, commaLoc - lastStart);
+            locale[commaLoc - lastStart] = '\0';
+            toLanguageTag(langTag, ULOC_FULLNAME_CAPACITY, locale);
+            if (langTag[0] != '\0') {
+                output->append(langTag);
+                output->push_back(',');
+            }
+            lastStart = commaLoc + 1;
+            commaLoc = strchr(lastStart, ',');
+        } while (commaLoc != NULL);
+        assert(lastStart[0] != '\0');  // the final substring should not be empty
+        toLanguageTag(langTag, ULOC_FULLNAME_CAPACITY, lastStart);
+        if (langTag[0] != '\0') {
+            output->append(langTag);
+        }
+    }
+
+    static void setTextLocales(JNIEnv* env, jobject clazz, jlong objHandle, jstring locales) {
+        Paint* obj = reinterpret_cast<Paint*>(objHandle);
+        ScopedUtfChars localesChars(env, locales);
+        if (sSingleEntryLocalesCache.javaLocales != localesChars.c_str()) {
+            sSingleEntryLocalesCache.javaLocales = localesChars.c_str();
+            toLanguageTags(&sSingleEntryLocalesCache.languageTags, localesChars.c_str());
+        }
+
+        obj->setTextLocales(sSingleEntryLocalesCache.languageTags);
     }
 
     static jboolean isElegantTextHeight(JNIEnv* env, jobject, jlong paintHandle) {
@@ -952,7 +990,7 @@
     {"nSetRasterizer","!(JJ)J", (void*) PaintGlue::setRasterizer},
     {"nGetTextAlign","!(J)I", (void*) PaintGlue::getTextAlign},
     {"nSetTextAlign","!(JI)V", (void*) PaintGlue::setTextAlign},
-    {"nSetTextLocale","!(JLjava/lang/String;)V", (void*) PaintGlue::setTextLocale},
+    {"nSetTextLocales","!(JLjava/lang/String;)V", (void*) PaintGlue::setTextLocales},
     {"nIsElegantTextHeight","!(J)Z", (void*) PaintGlue::isElegantTextHeight},
     {"nSetElegantTextHeight","!(JZ)V", (void*) PaintGlue::setElegantTextHeight},
     {"nGetTextSize","!(J)F", (void*) PaintGlue::getTextSize},