it.unimi.dsi.fastutil.Size64 Maven / Gradle / Ivy
Show all versions of fastutil Show documentation
/*
* Copyright (C) 2010-2023 Sebastiano Vigna
*
* 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 it.unimi.dsi.fastutil;
import java.util.Collection;
/** An interface for data structures whose size can exceed {@link Integer#MAX_VALUE}.
*
* The only methods specified by this interfaces are {@link #size64()}, and
* a deprecated {@link #size()} identical to {@link Collection#size()},
* but with a default implementation. Implementations
* can work around the type problem of {@link java.util.Collection#size()}
* (e.g., not being able to return more than {@link Integer#MAX_VALUE}) by implementing this
* interface. Callers interested in large structures
* can use a reflective call to {@code instanceof} to check for the presence of {@link #size64()}.
*/
public interface Size64 {
/** Returns the size of this data structure as a long.
*
* @return the size of this data structure.
*/
long size64();
/** Returns the size of this data structure, minimized with {@link Integer#MAX_VALUE}.
*
*
This default implementation follows the definition above, which is compatible
* with {@link Collection#size()}.
*
* @return the size of this data structure, minimized with {@link Integer#MAX_VALUE}.
* @see java.util.Collection#size()
* @deprecated Use {@link #size64()} instead.
*/
@Deprecated
default int size() {
return (int)Math.min(Integer.MAX_VALUE, size64());
}
// This is here instead of in one of the Collection classes because this method does
// not change per type-specific, so there is no need to generate type-specific implementations
// of these methods that the JVM has to separately compile.
/** Returns the size for a given {@link Collection} as a {@code long}, using {@link #size64()}
* if applicable, else using {@link Collection#size()}.
*
* @param c the collection whose size to get
* @return the size
*/
public static long sizeOf(final Collection c) {
return c instanceof Size64 ? ((Size64)c).size64() : c.size();
}
/** Returns the size for a given {@link java.util.Map} as a {@code long}, using {@link #size64()}
* if applicable, else using {@link java.util.Map#size()}.
*
* @param m the map whose size to get
* @return the size
*/
public static long sizeOf(final java.util.Map m) {
return m instanceof Size64 ? ((Size64)m).size64() : m.size();
}
}