/*
* Copyright 2004-2010 Brian S O'Neill
*
* 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.cojen.util;
import java.util.Arrays;
/**
* KeyFactory generates keys which can be hashed or compared for any kind of
* object including arrays, arrays of arrays, and null. All hashcode
* computations, equality tests, and ordering comparsisons fully recurse into
* arrays.
*
* @author Brian S O'Neill
*/
public class KeyFactory {
static final Object NULL = new Comparable() {
public int compareTo(Object obj) {
return obj == this || obj == null ? 0 : 1;
}
};
public static Object createKey(boolean[] obj) {
return obj == null ? NULL : new BooleanArrayKey(obj);
}
public static Object createKey(byte[] obj) {
return obj == null ? NULL : new ByteArrayKey(obj);
}
public static Object createKey(char[] obj) {
return obj == null ? NULL : new CharArrayKey(obj);
}
public static Object createKey(double[] obj) {
return obj == null ? NULL : new DoubleArrayKey(obj);
}
public static Object createKey(float[] obj) {
return obj == null ? NULL : new FloatArrayKey(obj);
}
public static Object createKey(int[] obj) {
return obj == null ? NULL : new IntArrayKey(obj);
}
public static Object createKey(long[] obj) {
return obj == null ? NULL : new LongArrayKey(obj);
}
public static Object createKey(short[] obj) {
return obj == null ? NULL : new ShortArrayKey(obj);
}
public static Object createKey(Object[] obj) {
return obj == null ? NULL : new ObjectArrayKey(obj);
}
public static Object createKey(Object obj) {
if (obj == null) {
return NULL;
}
if (!obj.getClass().isArray()) {
return obj;
}
if (obj instanceof Object[]) {
return createKey((Object[])obj);
} else if (obj instanceof int[]) {
return createKey((int[])obj);
} else if (obj instanceof float[]) {
return createKey((float[])obj);
} else if (obj instanceof long[]) {
return createKey((long[])obj);
} else if (obj instanceof double[]) {
return createKey((double[])obj);
} else if (obj instanceof byte[]) {
return createKey((byte[])obj);
} else if (obj instanceof char[]) {
return createKey((char[])obj);
} else if (obj instanceof boolean[]) {
return createKey((boolean[])obj);
} else if (obj instanceof short[]) {
return createKey((short[])obj);
} else {
return obj;
}
}
static int hashCode(boolean[] a) {
int hash = 0;
for (int i = a.length; --i >= 0; ) {
hash = (hash << 1) + (a[i] ? 0 : 1);
}
return hash == 0 ? -1 : hash;
}
static int hashCode(byte[] a) {
int hash = 0;
for (int i = a.length; --i >= 0; ) {
hash = (hash << 1) + a[i];
}
return hash == 0 ? -1 : hash;
}
static int hashCode(char[] a) {
int hash = 0;
for (int i = a.length; --i >= 0; ) {
hash = (hash << 1) + a[i];
}
return hash == 0 ? -1 : hash;
}
static int hashCode(double[] a) {
int hash = 0;
for (int i = a.length; --i >= 0; ) {
long v = Double.doubleToLongBits(a[i]);
hash = hash * 31 + (int)(v ^ v >>> 32);
}
return hash == 0 ? -1 : hash;
}
static int hashCode(float[] a) {
int hash = 0;
for (int i = a.length; --i >= 0; ) {
hash = hash * 31 + Float.floatToIntBits(a[i]);
}
return hash == 0 ? -1 : hash;
}
static int hashCode(int[] a) {
int hash = 0;
for (int i = a.length; --i >= 0; ) {
hash = (hash << 1) + a[i];
}
return hash == 0 ? -1 : hash;
}
static int hashCode(long[] a) {
int hash = 0;
for (int i = a.length; --i >= 0; ) {
long v = a[i];
hash = hash * 31 + (int)(v ^ v >>> 32);
}
return hash == 0 ? -1 : hash;
}
static int hashCode(short[] a) {
int hash = 0;
for (int i = a.length; --i >= 0; ) {
hash = (hash << 1) + a[i];
}
return hash == 0 ? -1 : hash;
}
static int hashCode(Object[] a) {
int hash = 0;
for (int i = a.length; --i >= 0; ) {
hash = hash * 31 + hashCode(a[i]);
}
return hash == 0 ? -1 : hash;
}
// Compute object or array hashcode and recurses into arrays within.
static int hashCode(Object a) {
if (a == null) {
return -1;
}
if (!a.getClass().isArray()) {
return a.hashCode();
}
if (a instanceof Object[]) {
return hashCode((Object[])a);
} else if (a instanceof int[]) {
return hashCode((int[])a);
} else if (a instanceof float[]) {
return hashCode((float[])a);
} else if (a instanceof long[]) {
return hashCode((long[])a);
} else if (a instanceof double[]) {
return hashCode((double[])a);
} else if (a instanceof byte[]) {
return hashCode((byte[])a);
} else if (a instanceof char[]) {
return hashCode((char[])a);
} else if (a instanceof boolean[]) {
return hashCode((boolean[])a);
} else if (a instanceof short[]) {
return hashCode((short[])a);
} else {
int hash = a.getClass().hashCode();
return hash == 0 ? -1 : hash;
}
}
// Compares object arrays and recurses into arrays within.
static boolean equals(Object[] a, Object[] b) {
if (a == b) {
return true;
}
if (a == null || b == null) {
return false;
}
int i;
if ((i = a.length) != b.length) {
return false;
}
while (--i >= 0) {
if (!equals(a[i], b[i])) {
return false;
}
}
return true;
}
// Compares objects or arrays and recurses into arrays within.
static boolean equals(Object a, Object b) {
if (a == b) {
return true;
}
if (a == null || b == null) {
return false;
}
Class ac = a.getClass();
if (!(ac.isArray())) {
return a.equals(b);
}
if (ac != b.getClass()) {
return false;
}
if (a instanceof Object[]) {
return equals((Object[])a, (Object[])b);
} else if (a instanceof int[]) {
return Arrays.equals((int[])a, (int[])b);
} else if (a instanceof float[]) {
return Arrays.equals((float[])a, (float[])b);
} else if (a instanceof long[]) {
return Arrays.equals((long[])a, (long[])b);
} else if (a instanceof double[]) {
return Arrays.equals((double[])a, (double[])b);
} else if (a instanceof byte[]) {
return Arrays.equals((byte[])a, (byte[])b);
} else if (a instanceof char[]) {
return Arrays.equals((char[])a, (char[])b);
} else if (a instanceof boolean[]) {
return Arrays.equals((boolean[])a, (boolean[])b);
} else if (a instanceof short[]) {
return Arrays.equals((short[])a, (short[])b);
} else {
return a.equals(b);
}
}
static int compare(boolean[] a, boolean[] b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
int length = Math.min(a.length, b.length);
for (int i=0; i<length; i++) {
int av = a[i] ? 0 : 1;
int bv = b[i] ? 0 : 1;
return av < bv ? -1 : (av > bv ? 1 : 0);
}
return a.length < b.length ? -1 : (a.length > b.length ? 1 : 0);
}
static int compare(byte[] a, byte[] b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
int length = Math.min(a.length, b.length);
for (int i=0; i<length; i++) {
byte av = a[i];
byte bv = b[i];
return av < bv ? -1 : (av > bv ? 1 : 0);
}
return a.length < b.length ? -1 : (a.length > b.length ? 1 : 0);
}
static int compare(char[] a, char[] b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
int length = Math.min(a.length, b.length);
for (int i=0; i<length; i++) {
char av = a[i];
char bv = b[i];
return av < bv ? -1 : (av > bv ? 1 : 0);
}
return a.length < b.length ? -1 : (a.length > b.length ? 1 : 0);
}
static int compare(double[] a, double[] b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
int length = Math.min(a.length, b.length);
for (int i=0; i<length; i++) {
int v = Double.compare(a[i], b[i]);
if (v != 0) {
return v;
}
}
return a.length < b.length ? -1 : (a.length > b.length ? 1 : 0);
}
static int compare(float[] a, float[] b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
int length = Math.min(a.length, b.length);
for (int i=0; i<length; i++) {
int v = Float.compare(a[i], b[i]);
if (v != 0) {
return v;
}
}
return a.length < b.length ? -1 : (a.length > b.length ? 1 : 0);
}
static int compare(int[] a, int[] b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
int length = Math.min(a.length, b.length);
for (int i=0; i<length; i++) {
int av = a[i];
int bv = b[i];
return av < bv ? -1 : (av > bv ? 1 : 0);
}
return a.length < b.length ? -1 : (a.length > b.length ? 1 : 0);
}
static int compare(long[] a, long[] b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
int length = Math.min(a.length, b.length);
for (int i=0; i<length; i++) {
long av = a[i];
long bv = b[i];
return av < bv ? -1 : (av > bv ? 1 : 0);
}
return a.length < b.length ? -1 : (a.length > b.length ? 1 : 0);
}
static int compare(short[] a, short[] b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
int length = Math.min(a.length, b.length);
for (int i=0; i<length; i++) {
short av = a[i];
short bv = b[i];
return av < bv ? -1 : (av > bv ? 1 : 0);
}
return a.length < b.length ? -1 : (a.length > b.length ? 1 : 0);
}
// Compares object arrays and recurses into arrays within.
static int compare(Object[] a, Object[] b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
int length = Math.min(a.length, b.length);
for (int i=0; i<length; i++) {
int v = compare(a[i], b[i]);
if (v != 0) {
return v;
}
}
return a.length < b.length ? -1 : (a.length > b.length ? 1 : 0);
}
// Compares objects or arrays and recurses into arrays within.
static int compare(Object a, Object b) {
if (a == b) {
return 0;
}
if (a == null) {
return 1;
}
if (b == null) {
return -1;
}
Class ac = a.getClass();
if (!(ac.isArray())) {
return ((Comparable)a).compareTo(b);
}
if (ac != b.getClass()) {
throw new ClassCastException();
}
if (a instanceof Object[]) {
return compare((Object[])a, (Object[])b);
} else if (a instanceof int[]) {
return compare((int[])a, (int[])b);
} else if (a instanceof float[]) {
return compare((float[])a, (float[])b);
} else if (a instanceof long[]) {
return compare((long[])a, (long[])b);
} else if (a instanceof double[]) {
return compare((double[])a, (double[])b);
} else if (a instanceof byte[]) {
return compare((byte[])a, (byte[])b);
} else if (a instanceof char[]) {
return compare((char[])a, (char[])b);
} else if (a instanceof boolean[]) {
return compare((boolean[])a, (boolean[])b);
} else if (a instanceof short[]) {
return compare((short[])a, (short[])b);
} else {
throw new ClassCastException();
}
}
protected KeyFactory() {
}
private static interface ArrayKey extends Comparable, java.io.Serializable {
int hashCode();
boolean equals(Object obj);
int compareTo(Object obj);
}
private static class BooleanArrayKey implements ArrayKey {
protected final boolean[] mArray;
private transient int mHash;
BooleanArrayKey(boolean[] array) {
mArray = array;
}
public int hashCode() {
int hash = mHash;
return hash == 0 ? mHash = KeyFactory.hashCode(mArray) : hash;
}
public boolean equals(Object obj) {
return this == obj ? true :
(obj instanceof BooleanArrayKey ?
Arrays.equals(mArray, ((BooleanArrayKey) obj).mArray) : false);
}
public int compareTo(Object obj) {
return compare(mArray, ((BooleanArrayKey) obj).mArray);
}
}
private static class ByteArrayKey implements ArrayKey {
protected final byte[] mArray;
private transient int mHash;
ByteArrayKey(byte[] array) {
mArray = array;
}
public int hashCode() {
int hash = mHash;
return hash == 0 ? mHash = KeyFactory.hashCode(mArray) : hash;
}
public boolean equals(Object obj) {
return this == obj ? true :
(obj instanceof ByteArrayKey ?
Arrays.equals(mArray, ((ByteArrayKey) obj).mArray) : false);
}
public int compareTo(Object obj) {
return compare(mArray, ((ByteArrayKey) obj).mArray);
}
}
private static class CharArrayKey implements ArrayKey {
protected final char[] mArray;
private transient int mHash;
CharArrayKey(char[] array) {
mArray = array;
}
public int hashCode() {
int hash = mHash;
return hash == 0 ? mHash = KeyFactory.hashCode(mArray) : hash;
}
public boolean equals(Object obj) {
return this == obj ? true :
(obj instanceof CharArrayKey ?
Arrays.equals(mArray, ((CharArrayKey) obj).mArray) : false);
}
public int compareTo(Object obj) {
return compare(mArray, ((CharArrayKey) obj).mArray);
}
}
private static class DoubleArrayKey implements ArrayKey {
protected final double[] mArray;
private transient int mHash;
DoubleArrayKey(double[] array) {
mArray = array;
}
public int hashCode() {
int hash = mHash;
return hash == 0 ? mHash = KeyFactory.hashCode(mArray) : hash;
}
public boolean equals(Object obj) {
return this == obj ? true :
(obj instanceof DoubleArrayKey ?
Arrays.equals(mArray, ((DoubleArrayKey) obj).mArray) : false);
}
public int compareTo(Object obj) {
return compare(mArray, ((DoubleArrayKey) obj).mArray);
}
}
private static class FloatArrayKey implements ArrayKey {
protected final float[] mArray;
private transient int mHash;
FloatArrayKey(float[] array) {
mArray = array;
}
public int hashCode() {
int hash = mHash;
return hash == 0 ? mHash = KeyFactory.hashCode(mArray) : hash;
}
public boolean equals(Object obj) {
return this == obj ? true :
(obj instanceof FloatArrayKey ?
Arrays.equals(mArray, ((FloatArrayKey) obj).mArray) : false);
}
public int compareTo(Object obj) {
return compare(mArray, ((FloatArrayKey) obj).mArray);
}
}
private static class IntArrayKey implements ArrayKey {
protected final int[] mArray;
private transient int mHash;
IntArrayKey(int[] array) {
mArray = array;
}
public int hashCode() {
int hash = mHash;
return hash == 0 ? mHash = KeyFactory.hashCode(mArray) : hash;
}
public boolean equals(Object obj) {
return this == obj ? true :
(obj instanceof IntArrayKey ?
Arrays.equals(mArray, ((IntArrayKey) obj).mArray) : false);
}
public int compareTo(Object obj) {
return compare(mArray, ((IntArrayKey) obj).mArray);
}
}
private static class LongArrayKey implements ArrayKey {
protected final long[] mArray;
private transient int mHash;
LongArrayKey(long[] array) {
mArray = array;
}
public int hashCode() {
int hash = mHash;
return hash == 0 ? mHash = KeyFactory.hashCode(mArray) : hash;
}
public boolean equals(Object obj) {
return this == obj ? true :
(obj instanceof LongArrayKey ?
Arrays.equals(mArray, ((LongArrayKey) obj).mArray) : false);
}
public int compareTo(Object obj) {
return compare(mArray, ((LongArrayKey) obj).mArray);
}
}
private static class ShortArrayKey implements ArrayKey {
protected final short[] mArray;
private transient int mHash;
ShortArrayKey(short[] array) {
mArray = array;
}
public int hashCode() {
int hash = mHash;
return hash == 0 ? mHash = KeyFactory.hashCode(mArray) : hash;
}
public boolean equals(Object obj) {
return this == obj ? true :
(obj instanceof ShortArrayKey ?
Arrays.equals(mArray, ((ShortArrayKey) obj).mArray) : false);
}
public int compareTo(Object obj) {
return compare(mArray, ((ShortArrayKey) obj).mArray);
}
}
private static class ObjectArrayKey implements ArrayKey {
protected final Object[] mArray;
private transient int mHash;
ObjectArrayKey(Object[] array) {
mArray = array;
}
public int hashCode() {
int hash = mHash;
return hash == 0 ? mHash = KeyFactory.hashCode(mArray) : hash;
}
public boolean equals(Object obj) {
return this == obj ? true :
(obj instanceof ObjectArrayKey ?
KeyFactory.equals(mArray, ((ObjectArrayKey) obj).mArray) : false);
}
public int compareTo(Object obj) {
return compare(mArray, ((ObjectArrayKey) obj).mArray);
}
}
}