Mercurial > hg > blitz_condensed
diff src/com/go/trove/util/MultiKey.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/com/go/trove/util/MultiKey.java Sat Mar 21 11:00:06 2009 +0000 @@ -0,0 +1,361 @@ +/* ==================================================================== + * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group + * ==================================================================== + * The Tea Software License, Version 1.1 + * + * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. 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. + * + * 3. The end-user documentation included with the redistribution, + * if any, must include the following acknowledgment: + * "This product includes software developed by the + * Walt Disney Internet Group (http://opensource.go.com/)." + * Alternately, this acknowledgment may appear in the software itself, + * if and wherever such third-party acknowledgments normally appear. + * + * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must + * not be used to endorse or promote products derived from this + * software without prior written permission. For written + * permission, please contact opensource@dig.com. + * + * 5. Products derived from this software may not be called "Tea", + * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet", + * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior + * written permission of the Walt Disney Internet Group. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 WALT DISNEY INTERNET GROUP OR ITS + * 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; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY + * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + * + * For more information about Tea, please see http://opensource.go.com/. + */ + +package com.go.trove.util; + +import java.util.Arrays; + +/****************************************************************************** + * MultiKey allows arrays and arrays of arrays to be used as hashtable keys. + * Hashcode computation and equality tests will fully recurse into the array + * elements. MultiKey can be used in conjunction with {@link Depot} for + * caching against complex keys. + * + * @author Brian S O'Neill + * @version + * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 01/07/09 <!-- $--> + * @see Pair + */ +public class MultiKey implements java.io.Serializable { + /** + * Computes an object hashcode for any kind of object including null, + * arrays, and arrays of arrays. + */ + static int hashCode(Object obj) { + if (obj == null) { + return 0; + } + + Class clazz = obj.getClass(); + + if (!clazz.isArray()) { + return obj.hashCode(); + } + + // Compute hashcode of array. + + int hash = clazz.hashCode(); + + if (obj instanceof Object[]) { + Object[] array = (Object[])obj; + for (int i = array.length; --i >= 0; ) { + hash = hash * 31 + hashCode(array[i]); + } + } + else if (obj instanceof int[]) { + int[] array = (int[])obj; + for (int i = array.length; --i >= 0; ) { + hash = hash * 31 + array[i]; + } + } + else if (obj instanceof float[]) { + float[] array = (float[])obj; + for (int i = array.length; --i >= 0; ) { + hash = hash * 31 + Float.floatToIntBits(array[i]); + } + } + else if (obj instanceof long[]) { + long[] array = (long[])obj; + for (int i = array.length; --i >= 0; ) { + long value = array[i]; + hash = hash * 31 + (int)(value ^ value >>> 32); + } + } + else if (obj instanceof double[]) { + double[] array = (double[])obj; + for (int i = array.length; --i >= 0; ) { + long value = Double.doubleToLongBits(array[i]); + hash = hash * 31 + (int)(value ^ value >>> 32); + } + } + else if (obj instanceof byte[]) { + byte[] array = (byte[])obj; + for (int i = array.length; --i >= 0; ) { + hash = hash * 31 + array[i]; + } + } + else if (obj instanceof char[]) { + char[] array = (char[])obj; + for (int i = array.length; --i >= 0; ) { + hash = hash * 31 + array[i]; + } + } + else if (obj instanceof boolean[]) { + boolean[] array = (boolean[])obj; + for (int i = array.length; --i >= 0; ) { + hash = hash * 31 + (array[i] ? 1 : 0); + } + } + else if (obj instanceof short[]) { + short[] array = (short[])obj; + for (int i = array.length; --i >= 0; ) { + hash = hash * 31 + array[i]; + } + } + + return hash; + } + + /** + * Performans an object equality for any kind of objects including null, + * arrays, and arrays of arrays. + */ + static boolean equals(Object obj1, Object obj2) { + if (obj1 == obj2) { + return true; + } + else if (obj1 == null || obj2 == null) { + return false; + } + + Class clazz1 = obj1.getClass(); + + if (!(clazz1.isArray())) { + return obj1.equals(obj2); + } + + if (clazz1 != obj2.getClass()) { + return false; + } + + // Perform array equality test. + if (obj1 instanceof Object[]) { + // Don't use Arrays.equals for objects since it doesn't + // recurse into arrays of arrays. + Object[] array1 = (Object[])obj1; + Object[] array2 = (Object[])obj2; + + int i; + if ((i = array1.length) != array2.length) { + return false; + } + + while (--i >= 0) { + if (!equals(array1[i], array2[i])) { + return false; + } + } + + return true; + } + else if (obj1 instanceof int[]) { + return Arrays.equals((int[])obj1, (int[])obj2); + } + else if (obj1 instanceof float[]) { + return Arrays.equals((float[])obj1, (float[])obj2); + } + else if (obj1 instanceof long[]) { + return Arrays.equals((long[])obj1, (long[])obj2); + } + else if (obj1 instanceof double[]) { + return Arrays.equals((double[])obj1, (double[])obj2); + } + else if (obj1 instanceof byte[]) { + return Arrays.equals((byte[])obj1, (byte[])obj2); + } + else if (obj1 instanceof char[]) { + return Arrays.equals((char[])obj1, (char[])obj2); + } + else if (obj1 instanceof boolean[]) { + return Arrays.equals((boolean[])obj1, (boolean[])obj2); + } + else if (obj1 instanceof short[]) { + return Arrays.equals((short[])obj1, (short[])obj2); + } + else { + return obj1.equals(obj2); + } + } + + private final Object mComponent; + private final int mHash; + + /** + * Contruct a new MultiKey against a component which may be any kind of + * object including an array, or an array of arrays, or null. + */ + public MultiKey(Object component) { + mComponent = component; + mHash = MultiKey.hashCode(component); + } + + /** + * Returns the original component used to construct this MultiKey. + */ + public Object getComponent() { + return mComponent; + } + + public int hashCode() { + return mHash; + } + + public boolean equals(Object other) { + if (this == other) { + return true; + } + else if (other instanceof MultiKey) { + MultiKey key = (MultiKey)other; + return MultiKey.equals(mComponent, key.mComponent); + } + else { + return false; + } + } + + public String toString() { + StringBuffer buf = new StringBuffer(); + append(buf, mComponent); + return buf.toString(); + } + + private void append(StringBuffer buf, Object obj) { + if (obj == null) { + buf.append("null"); + return; + } + + if (!obj.getClass().isArray()) { + buf.append(obj); + return; + } + + buf.append('['); + + if (obj instanceof Object[]) { + Object[] array = (Object[])obj; + for (int i=0; i<array.length; i++) { + if (i > 0) { + buf.append(','); + } + append(buf, array[i]); + } + } + else if (obj instanceof int[]) { + int[] array = (int[])obj; + for (int i=0; i<array.length; i++) { + if (i > 0) { + buf.append(','); + } + buf.append(array[i]); + } + } + else if (obj instanceof float[]) { + float[] array = (float[])obj; + for (int i=0; i<array.length; i++) { + if (i > 0) { + buf.append(','); + } + buf.append(array[i]); + } + } + else if (obj instanceof long[]) { + long[] array = (long[])obj; + for (int i=0; i<array.length; i++) { + if (i > 0) { + buf.append(','); + } + buf.append(array[i]); + } + } + else if (obj instanceof double[]) { + double[] array = (double[])obj; + for (int i=0; i<array.length; i++) { + if (i > 0) { + buf.append(','); + } + buf.append(array[i]); + } + } + else if (obj instanceof byte[]) { + byte[] array = (byte[])obj; + for (int i=0; i<array.length; i++) { + if (i > 0) { + buf.append(','); + } + buf.append(array[i]); + } + } + else if (obj instanceof char[]) { + char[] array = (char[])obj; + for (int i=0; i<array.length; i++) { + if (i > 0) { + buf.append(','); + } + buf.append(array[i]); + } + } + else if (obj instanceof boolean[]) { + boolean[] array = (boolean[])obj; + for (int i=0; i<array.length; i++) { + if (i > 0) { + buf.append(','); + } + buf.append(array[i]); + } + } + else if (obj instanceof short[]) { + short[] array = (short[])obj; + for (int i=0; i<array.length; i++) { + if (i > 0) { + buf.append(','); + } + buf.append(array[i]); + } + } + else { + buf.append(obj); + } + + buf.append(']'); + } +}