diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/java/com/jogamp/common/util/HashUtil.java | 66 | ||||
| -rw-r--r-- | src/java/com/jogamp/common/util/IntIntHashMap.java | 25 |
2 files changed, 79 insertions, 12 deletions
diff --git a/src/java/com/jogamp/common/util/HashUtil.java b/src/java/com/jogamp/common/util/HashUtil.java new file mode 100644 index 0000000..c5a3bff --- /dev/null +++ b/src/java/com/jogamp/common/util/HashUtil.java @@ -0,0 +1,66 @@ +/** + * Copyright 2013 JogAmp Community. 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. + * + * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``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 JogAmp Community 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; 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. + * + * The views and conclusions contained in the software and documentation are those of the + * authors and should not be interpreted as representing official policies, either expressed + * or implied, of JogAmp Community. + */ +package com.jogamp.common.util; + +public class HashUtil { + /** + * Generates a 32bit equally distributed identity hash value + * from <code>addr</code> avoiding XOR collision. + */ + public static int getAddrHash32_EqualDist(long addr) { + // avoid xor collisions of low/high parts + // 31 * x == (x << 5) - x + int hash = 31 + (int) addr ; // lo addr + return ((hash << 5) - hash) + (int) ( addr >>> 32 ) ; // hi addr + } + + /** + * Generates a 32bit equally distributed identity hash value + * from <code>addr</code> and <code>size</code> avoiding XOR collision. + */ + public static int getAddrSizeHash32_EqualDist(long addr, long size) { + // avoid xor collisions of low/high parts + // 31 * x == (x << 5) - x + int hash = 31 + (int) addr ; // lo addr + hash = ((hash << 5) - hash) + (int) ( addr >>> 32 ) ; // hi addr + hash = ((hash << 5) - hash) + (int) size ; // lo size + return ((hash << 5) - hash) + (int) ( size >>> 32 ) ; // hi size + } + + /** + * Generates a 64bit equally distributed hash value + * from <code>addr</code> and <code>size</code> avoiding XOR collisions. + */ + public static long getHash64(long addr, long size) { + // 31 * x == (x << 5) - x + final long hash = 31 + addr; + return ((hash << 5) - hash) + size; + } + + +} diff --git a/src/java/com/jogamp/common/util/IntIntHashMap.java b/src/java/com/jogamp/common/util/IntIntHashMap.java index bd5529e..7909478 100644 --- a/src/java/com/jogamp/common/util/IntIntHashMap.java +++ b/src/java/com/jogamp/common/util/IntIntHashMap.java @@ -207,8 +207,8 @@ public class /*name*/IntIntHashMap/*name*/ implements Cloneable, // @SuppressWarnings(value="cast") public boolean containsKey(/*key*/int/*key*/ key) { - Entry[] t = this.table; - int index = (int) (key & mask); + final Entry[] t = this.table; + final int index = /*keyHash*/key/*keyHash*/ & mask; for (Entry e = t[index]; e != null; e = e.next) { if (e.key == key) { return true; @@ -223,8 +223,8 @@ public class /*name*/IntIntHashMap/*name*/ implements Cloneable, */ // @SuppressWarnings(value="cast") public /*value*/int/*value*/ get(/*key*/int/*key*/ key) { - Entry[] t = this.table; - int index = (int) (key & mask); + final Entry[] t = this.table; + final int index = /*keyHash*/key/*keyHash*/ & mask; for (Entry e = t[index]; e != null; e = e.next) { if (e.key == key) { return e.value; @@ -240,7 +240,7 @@ public class /*name*/IntIntHashMap/*name*/ implements Cloneable, // @SuppressWarnings(value="cast") public /*value*/int/*value*/ put(/*key*/int/*key*/ key, /*value*/int/*value*/ value) { final Entry[] t = this.table; - int index = (int) (key & mask); + final int index = /*keyHash*/key/*keyHash*/ & mask; // Check if key already exists. for (Entry e = t[index]; e != null; e = e.next) { if (e.key != key) { @@ -254,18 +254,18 @@ public class /*name*/IntIntHashMap/*name*/ implements Cloneable, if (size++ >= threshold) { // Rehash. - int newCapacity = 2 * capacity; + final int newCapacity = 2 * capacity; final Entry[] newTable = new Entry[newCapacity]; - /*key*/int/*key*/ bucketmask = newCapacity - 1; + final int newMask = newCapacity - 1; for (int j = 0; j < t.length; j++) { Entry e = t[j]; if (e != null) { t[j] = null; do { Entry next = e.next; - index = (int) (e.key & bucketmask); - e.next = newTable[index]; - newTable[index] = e; + final int index2 = /*keyHash*/e.key/*keyHash*/ & newMask; + e.next = newTable[index2]; + newTable[index2] = e; e = next; } while (e != null); } @@ -273,7 +273,7 @@ public class /*name*/IntIntHashMap/*name*/ implements Cloneable, table = newTable; capacity = newCapacity; threshold = (int) (newCapacity * loadFactor); - mask = capacity - 1; + mask = newMask; } return keyNotFoundValue; } @@ -296,9 +296,10 @@ public class /*name*/IntIntHashMap/*name*/ implements Cloneable, // @SuppressWarnings(value="cast") public /*value*/int/*value*/ remove(/*key*/int/*key*/ key) { final Entry[] t = this.table; - final int index = (int) (key & mask); + final int index = /*keyHash*/key/*keyHash*/ & mask; Entry prev = t[index]; Entry e = prev; + while (e != null) { Entry next = e.next; if (e.key == key) { |