1 /* 2 * Copyright (C) 2009 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.base; 18 19 import com.google.common.annotations.GwtCompatible; 20 21 import java.lang.ref.WeakReference; 22 23 /** 24 * Methods factored out so that they can be emulated differently in GWT. 25 * 26 * @author Jesse Wilson 27 */ 28 @GwtCompatible(emulated = true) 29 final class Platform { 30 private Platform() {} 31 32 /** Calls {@link System#nanoTime()}. */ 33 static long systemNanoTime() { 34 return System.nanoTime(); 35 } 36 37 static CharMatcher precomputeCharMatcher(CharMatcher matcher) { 38 return matcher.precomputedInternal(); 39 } 40 41 static <T extends Enum<T>> Optional<T> getEnumIfPresent(Class<T> enumClass, String value) { 42 WeakReference<? extends Enum<?>> ref = Enums.getEnumConstants(enumClass).get(value); 43 return ref == null 44 ? Optional.<T>absent() 45 : Optional.of(enumClass.cast(ref.get())); 46 } 47 } 48
