com.swirlds.fchashmap.internal.FCOneToManyRelationIterator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of swirlds-fchashmap Show documentation
Show all versions of swirlds-fchashmap Show documentation
Swirlds is a software platform designed to build fully-distributed applications that harness the power of the cloud without servers. Now you can develop applications with fairness in decision making, speed, trust and reliability, at a fraction of the cost of traditional server-based platforms.
/*
* Copyright (C) 2018-2024 Hedera Hashgraph, LLC
*
* 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.swirlds.fchashmap.internal;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
/**
* This object is capable of iterating over all keys that map to a given value
*
* @param
* the type of the key
* @param
* the type of the value
*/
public class FCOneToManyRelationIterator implements Iterator {
private final Map, V> associationMap;
private final K key;
private final int endIndex;
private int nextIndex;
/**
* Create a new iterator.
*
* @param associationMap
* the map containing all associations
* @param key
* the key whose values will be iterated
* @param startIndex
* the index where iteration starts (inclusive)
* @param endIndex
* the index where iteration ends (exclusive)
*/
public FCOneToManyRelationIterator(
final Map, V> associationMap, final K key, final int startIndex, final int endIndex) {
this.associationMap = associationMap;
this.key = key;
this.endIndex = endIndex;
this.nextIndex = startIndex;
}
/**
* {@inheritDoc}
*/
@Override
public boolean hasNext() {
return nextIndex < endIndex;
}
/**
* {@inheritDoc}
*/
@Override
public V next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
final int index = nextIndex;
nextIndex++;
final V next = associationMap.get(new KeyIndexPair<>(key, index));
if (next == null) {
throw new IllegalStateException("end index exceeds number of available values");
}
return next;
}
}