/*
* Copyright (c) 2005- michael lawley and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the GNU Lesser General Public License version 2.1 as published by the Free Software Foundation
* which accompanies this distribution, and is available by writing to
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Contributors:
* michael lawley
*
*
*
*/
package tefkat.model.internal;
import java.util.Arrays;
import java.util.Collection;
/**
* @author lawley
*
*/
public class IntMap {
final private static double LOAD_FACTOR = 1.5;
private int size;
private Entry[] contents;
public IntMap() {
this(5);
}
public IntMap(int initialCapacity) {
int idx = Arrays.binarySearch(primes, initialCapacity);
if (idx >= 0) {
initialCapacity = primes[idx];
} else {
initialCapacity = primes[-idx - 1];
}
contents = new Entry[initialCapacity];
size = 0;
}
public Collection entries() {
return Arrays.asList(contents);
}
public int size() {
return size;
}
public void put(Object key, int val) {
// System.out.println(key + " -> " + val);
if (contents.length < size * LOAD_FACTOR) {
resize();
}
int h = hash(key);
int i;
for (i = 0; null != contents[h] && !contents[h].getKey().equals(key) && i < contents.length; i++) {
h = hash2(h);
}
if (null == contents[h]) {
contents[h] = new Entry(key, val);
size++;
} else if (i >= contents.length) {
throw new IllegalStateException("Map is full - cannot add new entry: " + key + " -> " + val);
} else {
contents[h].setValue(val);
}
}
/**
*
* @param key
*
* @return mapped int or zero if not found
*/
public int get(Object key) {
int h = hash(key);
int i;
for (i = 0; null != contents[h] && !contents[h].getKey().equals(key) && i < contents.length; i++) {
h = hash2(h);
}
if (null == contents[h] || i >= contents.length) {
return 0;
// throw new IllegalArgumentException("Object not found: " + key);
}
return contents[h].getValue();
}
private int hash(Object key) {
return key.hashCode() % contents.length;
}
private int hash2(int hash1) {
return 1 + (hash1 % (contents.length - 1));
}
/**
* Increase the size by a factor of approximately 2
*
*/
private void resize() {
int newSize;
int idx = Arrays.binarySearch(primes, contents.length * 2);
if (idx >= 0) {
newSize= primes[idx];
} else {
newSize = primes[-idx - 1];
}
Entry[] oldContents = contents;
contents = new Entry[newSize];
size = 0;
for (int i = 0; i < oldContents.length; i++) {
Entry entry = oldContents[i];
if (null != entry) {
put(entry.getKey(), entry.getValue());
}
}
}
private static int[] primes = {
/*2, 3,*/ 5, 7, 11, 13, 17, 19, 23, 29,
31, 37, 41, 43, 47, 53, 59, 61, 67, 71,
73, 79, 83, 89, 97, 101, 103, 107, 109, 113,
127, 131, 137, 139, 149, 151, 157, 163, 167, 173,
179, 181, 191, 193, 197, 199, 211, 223, 227, 229,
233, 239, 241, 251, 257, 263, 269, 271, 277, 281,
283, 293, 307, 311, 313, 317, 331, 337, 347, 349,
353, 359, 367, 373, 379, 383, 389, 397, 401, 409,
419, 421, 431, 433, 439, 443, 449, 457, 461, 463,
467, 479, 487, 491, 499, 503, 509, 521, 523, 541,
547, 557, 563, 569, 571, 577, 587, 593, 599, 601,
607, 613, 617, 619, 631, 641, 643, 647, 653, 659,
661, 673, 677, 683, 691, 701, 709, 719, 727, 733,
739, 743, 751, 757, 761, 769, 773, 787, 797, 809,
811, 821, 823, 827, 829, 839, 853, 857, 859, 863,
877, 881, 883, 887, 907, 911, 919, 929, 937, 941,
947, 953, 967, 971, 977, 983, 991, 997, 1009
};
public static class Entry {
public Object key;
public int value;
Entry(Object key, int value) {
this.key = key;
this.value = value;
}
public Object getKey() {
return key;
}
public int getValue() {
return value;
}
public int setValue(int value) {
int old = this.value;
this.value = value;
return old;
}
}
}