scouter.util.IntSet Maven / Gradle / Ivy
/*
* Copyright 2015 the original author or authors.
* @https://github.com/scouter-project/scouter
*
* 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.
*
* The initial idea for this class is from "org.apache.commons.lang.IntHashMap";
* http://commons.apache.org/commons-lang-2.6-src.zip
*
*/
package scouter.util;
import java.util.NoSuchElementException;
/**
* @author Paul Kim ([email protected])
*/
public class IntSet {
private static final int DEFAULT_CAPACITY = 101;
private static final float DEFAULT_LOAD_FACTOR = 0.75f;
private IntSetry table[];
private int count;
private int threshold;
private float loadFactor;
public IntSet(int initCapacity, float loadFactor) {
if (initCapacity < 0)
throw new RuntimeException("Capacity Error: " + initCapacity);
if (loadFactor <= 0)
throw new RuntimeException("Load Count Error: " + loadFactor);
if (initCapacity == 0)
initCapacity = 1;
this.loadFactor = loadFactor;
table = new IntSetry[initCapacity];
threshold = (int) (initCapacity * loadFactor);
}
public IntSet() {
this(DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR);
}
public int size() {
return count;
}
public synchronized IntEnumer values() {
return new Enumer();
}
public synchronized boolean contains(int key) {
IntSetry buk[] = table;
int index = (key & Integer.MAX_VALUE) % buk.length;
for (IntSetry e = buk[index]; e != null; e = e.next) {
if (e.key == key) {
return true;
}
}
return false;
}
public synchronized int get(int key) {
IntSetry buk[] = table;
int index = (key & Integer.MAX_VALUE) % buk.length;
for (IntSetry e = buk[index]; e != null; e = e.next) {
if (e.key == key) {
return e.key;
}
}
return 0;
}
protected void rehash() {
int oldCapacity = table.length;
IntSetry oldMap[] = table;
int newCapacity = oldCapacity * 2 + 1;
IntSetry newMap[] = new IntSetry[newCapacity];
threshold = (int) (newCapacity * loadFactor);
table = newMap;
for (int i = oldCapacity; i-- > 0;) {
IntSetry old = oldMap[i];
while (old != null) {
IntSetry e = old;
old = old.next;
int index = (e.key & Integer.MAX_VALUE) % newCapacity;
e.next = newMap[index];
newMap[index] = e;
}
}
}
public synchronized boolean add(int value) {
IntSetry buk[] = table;
int index = (value & Integer.MAX_VALUE) % buk.length;
for (IntSetry e = buk[index]; e != null; e = e.next) {
if (e.key == value) {
return false;
}
}
if (count >= threshold) {
rehash();
buk = table;
index = (value & Integer.MAX_VALUE) % buk.length;
}
IntSetry e = new IntSetry(value, buk[index]);
buk[index] = e;
count++;
return true;
}
public synchronized int remove(int key) {
IntSetry buk[] = table;
int index = (key & Integer.MAX_VALUE) % buk.length;
for (IntSetry e = buk[index], prev = null; e != null; prev = e, e = e.next) {
if (e.key == key) {
if (prev != null) {
prev.next = e.next;
} else {
buk[index] = e.next;
}
count--;
return key;
}
}
return 0;
}
public synchronized void clear() {
IntSetry buk[] = table;
for (int index = buk.length; --index >= 0;)
buk[index] = null;
count = 0;
}
public synchronized String toString() {
int max = size() - 1;
StringBuffer buf = new StringBuffer();
IntEnumer it = this.values();
buf.append("{");
for (int i = 0; i <= max; i++) {
int key = it.nextInt();
buf.append(key);
if (i < max)
buf.append(", ");
}
buf.append("}");
return buf.toString();
}
public static IntEnumer emptyEnumer = new IntEnumer() {
public int nextInt() {
return 0;
}
public boolean hasMoreElements() {
return false;
}
};
private static class IntSetry {
int key;
IntSetry next;
protected IntSetry(int key, IntSetry next) {
this.key = key;
this.next = next;
}
protected Object clone() {
return new IntSetry(key, (next == null ? null : (IntSetry) next.clone()));
}
public int getKey() {
return key;
}
public boolean equals(Object o) {
if (!(o instanceof IntSetry))
return false;
IntSetry e = (IntSetry) o;
return (key == e.getKey());
}
public int hashCode() {
return key;
}
public String toString() {
return Integer.toString(key);
}
}
private class Enumer implements IntEnumer {
IntSetry[] table = IntSet.this.table;
int index = table.length;
IntSetry entry = null;
IntSetry lastReturned = null;
public boolean hasMoreElements() {
while (entry == null && index > 0)
entry = table[--index];
return entry != null;
}
public int nextInt() {
while (entry == null && index > 0)
entry = table[--index];
if (entry != null) {
IntSetry e = lastReturned = entry;
entry = e.next;
return e.key;
}
throw new NoSuchElementException("no more next");
}
}
public int[] toArray() {
int[] _keys = new int[this.size()];
IntEnumer en = this.values();
for (int i = 0; i < _keys.length; i++)
_keys[i] = en.nextInt();
return _keys;
}
}