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Guava is a suite of core and expanded libraries that include utility classes, google's collections, io classes, and much much more. This project includes GWT-friendly sources.

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/*
 * 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 java.util.Arrays;
import java.util.Map;
import java.util.Set;
import jsinterop.annotations.JsPackage;
import jsinterop.annotations.JsProperty;
import jsinterop.annotations.JsType;

/**
 * Minimal GWT emulation of {@code com.google.common.collect.Platform}.
 *
 * This .java file should never be consumed by javac.
 *
 * @author Hayward Chan
 */
final class Platform {
  static  Map newHashMapWithExpectedSize(int expectedSize) {
    return Maps.newHashMapWithExpectedSize(expectedSize);
  }

  static  Map newLinkedHashMapWithExpectedSize(int expectedSize) {
    return Maps.newLinkedHashMapWithExpectedSize(expectedSize);
  }

  static  Set newHashSetWithExpectedSize(int expectedSize) {
    return Sets.newHashSetWithExpectedSize(expectedSize);
  }

  static  Set newLinkedHashSetWithExpectedSize(int expectedSize) {
    return Sets.newLinkedHashSetWithExpectedSize(expectedSize);
  }

  /**
   * Returns the platform preferred map implementation that preserves insertion order when used only
   * for insertions.
   */
  static  Map preservesInsertionOrderOnPutsMap() {
    return Maps.newLinkedHashMap();
  }

  /**
   * Returns the platform preferred set implementation that preserves insertion order when used only
   * for insertions.
   */
  static  Set preservesInsertionOrderOnAddsSet() {
    return Sets.newLinkedHashSet();
  }

  static  T[] newArray(T[] reference, int length) {
    T[] clone = Arrays.copyOf(reference, 0);
    resizeArray(clone, length);
    return clone;
  }

  private static void resizeArray(Object array, int newSize) {
    ((NativeArray) array).setLength(newSize);
  }

  /** Equivalent to Arrays.copyOfRange(source, from, to, arrayOfType.getClass()). */
  static  T[] copy(Object[] source, int from, int to, T[] arrayOfType) {
    T[] result = newArray(arrayOfType, to - from);
    System.arraycopy(source, from, result, 0, to - from);
    return result;
  }

  // TODO(user): Move this logic to a utility class.
  @JsType(isNative = true, name = "Array", namespace = JsPackage.GLOBAL)
  private interface NativeArray {
    @JsProperty
    void setLength(int length);
  }

  static MapMaker tryWeakKeys(MapMaker mapMaker) {
    return mapMaker;
  }

  static int reduceIterationsIfGwt(int iterations) {
    return iterations / 10;
  }

  static int reduceExponentIfGwt(int exponent) {
    return exponent / 2;
  }

  private Platform() {}
}