org.pushingpixels.substance.internal.utils.LazyResettableHashMap Maven / Gradle / Ivy
/*
* Copyright (c) 2005-2020 Radiance Kirill Grouchnikov. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* o Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* o Neither the name of the copyright holder nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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*/
package org.pushingpixels.substance.internal.utils;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
/**
* Lazily initialized hash map for caching images.
*
* @author Kirill Grouchnikov
* @param
* Class for the stored values.
*/
public class LazyResettableHashMap {
/**
* List of all existing maps.
*/
private static List> all;
/**
* The delegate cache.
*/
private Map cache;
/**
* Display name of this hash map. Is used for tracking the statistics.
*/
private String displayName;
/**
* Creates a new hash map.
*
* @param displayName
* Display name of the new hash map.
*/
public LazyResettableHashMap(String displayName) {
this.displayName = displayName;
if (all == null) {
all = new LinkedList<>();
}
all.add(this);
}
/**
* Creates the delegate cache if necessary.
*/
private void createIfNecessary() {
if (this.cache == null)
this.cache = new SoftHashMap<>();
}
/**
* Puts a new key-value pair in the map.
*
* @param key
* Pair key.
* @param entry
* Pair value.
*/
public synchronized void put(HashMapKey key, T entry) {
this.createIfNecessary();
this.cache.put(key, entry);
}
/**
* Returns the value registered for the specified key.
*
* @param key
* Key.
* @return Registered value or null if none.
*/
public synchronized T get(HashMapKey key) {
if (this.cache == null)
return null;
return this.cache.get(key);
}
/**
* Checks whether there is a value associated with the specified key.
*
* @param key
* Key.
* @return true if there is an associated value,
* false otherwise.
*/
public boolean containsKey(HashMapKey key) {
if (this.cache == null) {
return false;
}
return this.cache.containsKey(key);
}
/**
* Returns the number of key-value pairs of this hash map.
*
* @return The number of key-value pairs of this hash map.
*/
public int size() {
if (this.cache == null) {
return 0;
}
return this.cache.size();
}
/**
* Resets all existing hash maps.
*/
public static void reset() {
if (all != null) {
for (LazyResettableHashMap map : all) {
if (map.cache != null) {
map.cache.clear();
}
}
}
}
/**
* Returns statistical information of the existing hash maps.
*
* @return Statistical information of the existing hash maps.
*/
public static List getStats() {
if (all != null) {
List result = new LinkedList<>();
Map mapCounter = new TreeMap<>();
Map entryCounter = new TreeMap<>();
for (LazyResettableHashMap map : all) {
String key = map.displayName;
if (!mapCounter.containsKey(key)) {
mapCounter.put(key, 0);
entryCounter.put(key, 0);
}
mapCounter.put(key, mapCounter.get(key) + 1);
entryCounter.put(key, entryCounter.get(key) + map.size());
}
for (Map.Entry entry : mapCounter.entrySet()) {
String key = entry.getKey();
result.add(entry.getValue() + " " + key + " with "
+ entryCounter.get(key) + " entries total");
}
return result;
}
return null;
}
}