Merge \"Quick workaround for a performance regression in IME APIs.\" into nyc-dev (bb587122) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/inputmethod/InputMethodUtils.java

+38 −0

Original line number	Diff line number	Diff line
		@@ -41,6 +41,7 @@ import android.view.inputmethod.InputMethodSubtype;
		import android.view.textservice.SpellCheckerInfo;
		import android.view.textservice.TextServicesManager;

		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.annotations.VisibleForTesting;

		import java.util.ArrayList;
		@@ -83,6 +84,17 @@ public class InputMethodUtils {
		Locale.UK, // "en_GB"
		};

		// A temporary workaround for the performance concerns in
		// #getImplicitlyApplicableSubtypesLocked(Resources, InputMethodInfo).
		// TODO: Optimize all the critical paths including this one.
		private static final Object sCacheLock = new Object();
		@GuardedBy("sCacheLock")
		private static LocaleList sCachedSystemLocales;
		@GuardedBy("sCacheLock")
		private static InputMethodInfo sCachedInputMethodInfo;
		@GuardedBy("sCacheLock")
		private static ArrayList<InputMethodSubtype> sCachedResult;

		private InputMethodUtils() {
		// This utility class is not publicly instantiable.
		}
		@@ -498,6 +510,32 @@ public class InputMethodUtils {
		@VisibleForTesting
		public static ArrayList<InputMethodSubtype> getImplicitlyApplicableSubtypesLocked(
		Resources res, InputMethodInfo imi) {
		final LocaleList systemLocales = res.getConfiguration().getLocales();

		synchronized (sCacheLock) {
		// We intentionally do not use InputMethodInfo#equals(InputMethodInfo) here because
		// it does not check if subtypes are also identical.
		if (systemLocales.equals(sCachedSystemLocales) && sCachedInputMethodInfo == imi) {
		return new ArrayList<>(sCachedResult);
		}
		}

		// Note: Only resource info in "res" is used in getImplicitlyApplicableSubtypesLockedImpl().
		// TODO: Refactor getImplicitlyApplicableSubtypesLockedImpl() so that it can receive
		// LocaleList rather than Resource.
		final ArrayList<InputMethodSubtype> result =
		getImplicitlyApplicableSubtypesLockedImpl(res, imi);
		synchronized (sCacheLock) {
		// Both LocaleList and InputMethodInfo are immutable. No need to copy them here.
		sCachedSystemLocales = systemLocales;
		sCachedInputMethodInfo = imi;
		sCachedResult = new ArrayList<>(result);
		}
		return result;
		}

		private static ArrayList<InputMethodSubtype> getImplicitlyApplicableSubtypesLockedImpl(
		Resources res, InputMethodInfo imi) {
		final List<InputMethodSubtype> subtypes = InputMethodUtils.getSubtypes(imi);
		final LocaleList systemLocales = res.getConfiguration().getLocales();
		final String systemLocale = systemLocales.get(0).toString();