/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import java.lang.reflect.Array;
import java.util.Map;
import java.util.Set;

Methods factored out so that they can be emulated differently in GWT.
Author:Hayward Chan
/** * Methods factored out so that they can be emulated differently in GWT. * * @author Hayward Chan */
@GwtCompatible(emulated = true) final class Platform {
Returns the platform preferred implementation of a map based on a hash table.
/** Returns the platform preferred implementation of a map based on a hash table. */
static <K, V> Map<K, V> newHashMapWithExpectedSize(int expectedSize) { return Maps.newHashMapWithExpectedSize(expectedSize); }
Returns the platform preferred implementation of an insertion ordered map based on a hash table.
/** * Returns the platform preferred implementation of an insertion ordered map based on a hash * table. */
static <K, V> Map<K, V> newLinkedHashMapWithExpectedSize(int expectedSize) { return Maps.newLinkedHashMapWithExpectedSize(expectedSize); }
Returns the platform preferred implementation of a set based on a hash table.
/** Returns the platform preferred implementation of a set based on a hash table. */
static <E> Set<E> newHashSetWithExpectedSize(int expectedSize) { return Sets.newHashSetWithExpectedSize(expectedSize); }
Returns the platform preferred implementation of an insertion ordered set based on a hash table.
/** * Returns the platform preferred implementation of an insertion ordered set based on a hash * table. */
static <E> Set<E> newLinkedHashSetWithExpectedSize(int expectedSize) { return Sets.newLinkedHashSetWithExpectedSize(expectedSize); }
Returns the platform preferred map implementation that preserves insertion order when used only for insertions.
/** * Returns the platform preferred map implementation that preserves insertion order when used only * for insertions. */
static <K, V> Map<K, V> preservesInsertionOrderOnPutsMap() { return Maps.newLinkedHashMap(); }
Returns the platform preferred set implementation that preserves insertion order when used only for insertions.
/** * Returns the platform preferred set implementation that preserves insertion order when used only * for insertions. */
static <E> Set<E> preservesInsertionOrderOnAddsSet() { return Sets.newLinkedHashSet(); }
Returns a new array of the given length with the same type as a reference array.
Params:
  • reference – any array of the desired type
  • length – the length of the new array
/** * Returns a new array of the given length with the same type as a reference array. * * @param reference any array of the desired type * @param length the length of the new array */
static <T> T[] newArray(T[] reference, int length) { Class<?> type = reference.getClass().getComponentType(); // the cast is safe because // result.getClass() == reference.getClass().getComponentType() @SuppressWarnings("unchecked") T[] result = (T[]) Array.newInstance(type, length); return result; }
Configures the given map maker to use weak keys, if possible; does nothing otherwise (i.e., in GWT). This is sometimes acceptable, when only server-side code could generate enough volume that reclamation becomes important.
/** * Configures the given map maker to use weak keys, if possible; does nothing otherwise (i.e., in * GWT). This is sometimes acceptable, when only server-side code could generate enough volume * that reclamation becomes important. */
static MapMaker tryWeakKeys(MapMaker mapMaker) { return mapMaker.weakKeys(); } static int reduceIterationsIfGwt(int iterations) { return iterations; } static int reduceExponentIfGwt(int exponent) { return exponent; } private Platform() {} }