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/*
* Copyright 2007 Kasper B. Graversen
*
* 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 org.supercsv.util;
import java.util.HashMap;
import java.util.Set;
/**
* A 3-dimensional HashMap is a HashMap that enables you to refer to values via three keys rather than one. The
* underlying implementation is simply a HashMap containing HashMap containing a HashMap, each of which maps to values.
*
* @param
* the first key type
* @param
* the second key type
* @param
* the third key type
* @param
* the value type
* @author Kasper B. Graversen
* @since 2.0.0 (migrated from Spiffy 0.5)
*/
public class ThreeDHashMap {
private final HashMap>> map = new HashMap>>();
/**
* Existence check of a value (or null) mapped to the keys.
*
* @param firstKey
* first key
* @param secondKey
* second key
* @return true when an element (or null) has been stored with the keys
*/
public boolean containsKey(final K1 firstKey, final K2 secondKey) {
// existence check on inner map
final HashMap> innerMap1 = map.get(firstKey);
if( innerMap1 == null ) {
return false;
}
return innerMap1.containsKey(secondKey);
}
/**
* Existence check of a value (or null) mapped to the keys.
*
* @param firstKey
* first key
* @param secondKey
* second key
* @param thirdKey
* third key
* @return true when an element (or null) has been stored with the keys
*/
public boolean containsKey(final K1 firstKey, final K2 secondKey, final K3 thirdKey) {
// existence check on inner map
final HashMap> innerMap1 = map.get(firstKey);
if( innerMap1 == null ) {
return false;
}
// existence check on inner map1
final HashMap innerMap2 = innerMap1.get(secondKey);
if( innerMap2 == null ) {
return false;
}
return innerMap2.containsKey(thirdKey);
}
/**
* Fetch the outermost Hashmap.
*
* @param firstKey
* first key
* @return the the innermost hashmap
*/
public HashMap> get(final K1 firstKey) {
return map.get(firstKey);
}
/**
* Fetch the outermost Hashmap as a TwoDHashMap.
*
* @param firstKey
* first key
* @return the the innermost hashmap
*/
public TwoDHashMap getAs2d(final K1 firstKey) {
final HashMap> innerMap1 = map.get(firstKey);
if( innerMap1 != null ) {
return new TwoDHashMap(innerMap1);
} else {
return new TwoDHashMap();
}
}
/**
* Fetch the innermost Hashmap.
*
* @param firstKey
* first key
* @param secondKey
* second key
* @return the the innermost hashmap
*/
public HashMap get(final K1 firstKey, final K2 secondKey) {
// existence check on inner map
final HashMap> innerMap1 = map.get(firstKey);
if( innerMap1 == null ) {
return null;
}
return innerMap1.get(secondKey);
}
/**
* Fetch a value from the Hashmap.
*
* @param firstKey
* first key
* @param secondKey
* second key
* @param thirdKey
* third key
* @return the element or null.
*/
public V get(final K1 firstKey, final K2 secondKey, final K3 thirdKey) {
// existence check on inner map
final HashMap> innerMap1 = map.get(firstKey);
if( innerMap1 == null ) {
return null;
}
// existence check on inner map1
final HashMap innerMap2 = innerMap1.get(secondKey);
if( innerMap2 == null ) {
return null;
}
return innerMap2.get(thirdKey);
}
/**
* Insert a value
*
* @param firstKey
* first key
* @param secondKey
* second key
* @param thirdKey
* third key
* @param value
* the value to be inserted. null may be inserted as well.
* @return null or the value the insert is replacing.
*/
public Object set(final K1 firstKey, final K2 secondKey, final K3 thirdKey, final V value) {
// existence check on inner map1
HashMap> innerMap1 = map.get(firstKey);
if( innerMap1 == null ) {
// no inner map, create it
innerMap1 = new HashMap>();
map.put(firstKey, innerMap1);
}
// existence check on inner map1
HashMap innerMap2 = innerMap1.get(secondKey);
if( innerMap2 == null ) {
// no inner map, create it
innerMap2 = new HashMap();
innerMap1.put(secondKey, innerMap2);
}
return innerMap2.put(thirdKey, value);
}
/**
* Returns the number of key-value mappings in this map for the first key.
*
* @return Returns the number of key-value mappings in this map for the first key.
*/
public int size() {
return map.size();
}
/**
* Returns the number of key-value mappings in this map for the second key.
*
* @param firstKey
* the first key
* @return Returns the number of key-value mappings in this map for the second key.
*/
public int size(final K1 firstKey) {
// existence check on inner map
final HashMap> innerMap = map.get(firstKey);
if( innerMap == null ) {
return 0;
}
return innerMap.size();
}
/**
* Returns the number of key-value mappings in this map for the third key.
*
* @param firstKey
* the first key
* @param secondKey
* the second key
* @return Returns the number of key-value mappings in this map for the third key.
*/
public int size(final K1 firstKey, final K2 secondKey) {
// existence check on inner map
final HashMap> innerMap1 = map.get(firstKey);
if( innerMap1 == null ) {
return 0;
}
// existence check on inner map1
final HashMap innerMap2 = innerMap1.get(secondKey);
if( innerMap2 == null ) {
return 0;
}
return innerMap2.size();
}
/**
* Returns a set of the keys of the outermost map.
*
* @return the key set for the outermost map
*/
public Set keySet() {
return map.keySet();
}
}