Optimize ResTable::getLocales() to improve bindApplication performance

Change from linear searching for uniqueness to binary search.

Bug:27198799
Change-Id: I1ccb6e93cc213810848f07d631d9d8de7c719803
diff --git a/libs/androidfw/tests/ResTable_test.cpp b/libs/androidfw/tests/ResTable_test.cpp
index 7cd7fb5..b8b4625 100644
--- a/libs/androidfw/tests/ResTable_test.cpp
+++ b/libs/androidfw/tests/ResTable_test.cpp
@@ -39,8 +39,20 @@
  */
 #include "data/basic/basic_arsc.h"
 
+/**
+ * Include a binary library resource table.
+ *
+ * Package: com.android.test.basic
+ */
 #include "data/lib/lib_arsc.h"
 
+/**
+ * Include a system resource table.
+ *
+ * Package: android
+ */
+#include "data/system/system_arsc.h"
+
 TEST(ResTableTest, shouldLoadSuccessfully) {
     ResTable table;
     ASSERT_EQ(NO_ERROR, table.add(basic_arsc, basic_arsc_len));
@@ -324,4 +336,25 @@
     ASSERT_EQ(uint32_t(600), val.data);
 }
 
+TEST(ResTableTest, GetConfigurationsReturnsUniqueList) {
+    ResTable table;
+    ASSERT_EQ(NO_ERROR, table.add(system_arsc, system_arsc_len));
+    ASSERT_EQ(NO_ERROR, table.add(basic_arsc, basic_arsc_len));
+
+    ResTable_config configSv;
+    memset(&configSv, 0, sizeof(configSv));
+    configSv.language[0] = 's';
+    configSv.language[1] = 'v';
+
+    Vector<ResTable_config> configs;
+    table.getConfigurations(&configs);
+
+    EXPECT_EQ(1, std::count(configs.begin(), configs.end(), configSv));
+
+    Vector<String8> locales;
+    table.getLocales(&locales);
+
+    EXPECT_EQ(1, std::count(locales.begin(), locales.end(), String8("sv")));
+}
+
 } // namespace