com.google.common.collect.Platform Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* 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 com.google.common.annotations.J2ktIncompatible;
import java.util.Arrays;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* Methods factored out so that they can be emulated differently in GWT.
*
* @author Hayward Chan
*/
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
final class Platform {
/** Returns the platform preferred implementation of a map based on a hash table. */
static
Map newHashMapWithExpectedSize(int expectedSize) {
return Maps.newHashMapWithExpectedSize(expectedSize);
}
/**
* Returns the platform preferred implementation of an insertion ordered map based on a hash
* table.
*/
static
Map newLinkedHashMapWithExpectedSize(int expectedSize) {
return Maps.newLinkedHashMapWithExpectedSize(expectedSize);
}
/** Returns the platform preferred implementation of a set based on a hash table. */
static Set newHashSetWithExpectedSize(int expectedSize) {
return Sets.newHashSetWithExpectedSize(expectedSize);
}
/** Returns the platform preferred implementation of a thread-safe hash set. */
static Set newConcurrentHashSet() {
return ConcurrentHashMap.newKeySet();
}
/**
* Returns the platform preferred implementation of an insertion ordered set based on a hash
* table.
*/
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 CompactHashSet.create();
}
/**
* 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
*/
/*
* The new array contains nulls, even if the old array did not. If we wanted to be accurate, we
* would declare a return type of `@Nullable T[]`. However, we've decided not to think too hard
* about arrays for now, as they're a mess. (We previously discussed this in the review of
* ObjectArrays, which is the main caller of this method.)
*/
static T[] newArray(T[] reference, int length) {
T[] empty = reference.length == 0 ? reference : Arrays.copyOf(reference, 0);
return Arrays.copyOf(empty, length);
}
/** Equivalent to Arrays.copyOfRange(source, from, to, arrayOfType.getClass()). */
/*
* Arrays are a mess from a nullness perspective, and Class instances for object-array types are
* even worse. For now, we just suppress and move on with our lives.
*
* - https://github.com/jspecify/jspecify/issues/65
*
* - https://github.com/jspecify/jdk/commit/71d826792b8c7ef95d492c50a274deab938f2552
*/
@SuppressWarnings("nullness")
static T[] copy(Object[] source, int from, int to, T[] arrayOfType) {
return Arrays.copyOfRange(source, from, to, (Class) arrayOfType.getClass());
}
/**
* 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.
*/
@J2ktIncompatible
static MapMaker tryWeakKeys(MapMaker mapMaker) {
return mapMaker.weakKeys();
}
static > Class getDeclaringClassOrObjectForJ2cl(E e) {
return e.getDeclaringClass();
}
static int reduceIterationsIfGwt(int iterations) {
return iterations;
}
static int reduceExponentIfGwt(int exponent) {
return exponent;
}
private Platform() {}
}