org.eclipse.jdt.internal.compiler.codegen.DoubleCache Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 2009 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.internal.compiler.codegen;
public class DoubleCache {
private double keyTable[];
private int valueTable[];
private int elementSize;
/**
* Constructs a new, empty hashtable. A default capacity and
* load factor is used. Note that the hashtable will automatically
* grow when it gets full.
*/
public DoubleCache() {
this(13);
}
/**
* Constructs a new, empty hashtable with the specified initial
* capacity.
* @param initialCapacity int
* the initial number of buckets
*/
public DoubleCache(int initialCapacity) {
this.elementSize = 0;
this.keyTable = new double[initialCapacity];
this.valueTable = new int[initialCapacity];
}
/**
* Clears the hash table so that it has no more elements in it.
*/
public void clear() {
for (int i = this.keyTable.length; --i >= 0;) {
this.keyTable[i] = 0.0;
this.valueTable[i] = 0;
}
this.elementSize = 0;
}
/** Returns true if the collection contains an element for the key.
*
* @param key double the key that we are looking for
* @return boolean
*/
public boolean containsKey(double key) {
if (key == 0.0) {
for (int i = 0, max = this.elementSize; i < max; i++) {
if (this.keyTable[i] == 0.0) {
long value1 = Double.doubleToLongBits(key);
long value2 = Double.doubleToLongBits(this.keyTable[i]);
if (value1 == -9223372036854775808L && value2 == -9223372036854775808L)
return true;
if (value1 == 0 && value2 == 0)
return true;
}
}
} else {
for (int i = 0, max = this.elementSize; i < max; i++) {
if (this.keyTable[i] == key) {
return true;
}
}
}
return false;
}
/**
* Puts the specified element into the hashtable, using the specified
* key. The element may be retrieved by doing a get() with the same key.
*
* @param key double the specified key in the hashtable
* @param value int the specified element
* @return int value
*/
public int put(double key, int value) {
if (this.elementSize == this.keyTable.length) {
// resize
System.arraycopy(this.keyTable, 0, (this.keyTable = new double[this.elementSize * 2]), 0, this.elementSize);
System.arraycopy(this.valueTable, 0, (this.valueTable = new int[this.elementSize * 2]), 0, this.elementSize);
}
this.keyTable[this.elementSize] = key;
this.valueTable[this.elementSize] = value;
this.elementSize++;
return value;
}
/**
* Puts the specified element into the hashtable, using the specified
* key. The element may be retrieved by doing a get() with the same key.
*
* @param key double the specified key in the hashtable
* @param value int the specified element
* @return int value
*/
public int putIfAbsent(double key, int value) {
if (key == 0.0) {
for (int i = 0, max = this.elementSize; i < max; i++) {
if (this.keyTable[i] == 0.0) {
long value1 = Double.doubleToLongBits(key);
long value2 = Double.doubleToLongBits(this.keyTable[i]);
if (value1 == -9223372036854775808L && value2 == -9223372036854775808L)
return this.valueTable[i];
if (value1 == 0 && value2 == 0)
return this.valueTable[i];
}
}
} else {
for (int i = 0, max = this.elementSize; i < max; i++) {
if (this.keyTable[i] == key) {
return this.valueTable[i];
}
}
}
if (this.elementSize == this.keyTable.length) {
// resize
System.arraycopy(this.keyTable, 0, (this.keyTable = new double[this.elementSize * 2]), 0, this.elementSize);
System.arraycopy(this.valueTable, 0, (this.valueTable = new int[this.elementSize * 2]), 0, this.elementSize);
}
this.keyTable[this.elementSize] = key;
this.valueTable[this.elementSize] = value;
this.elementSize++;
return -value; // negative when added, assumes value is > 0
}
/**
* Converts to a rather lengthy String.
*
* @return String the ascii representation of the receiver
*/
public String toString() {
int max = this.elementSize;
StringBuffer buf = new StringBuffer();
buf.append("{"); //$NON-NLS-1$
for (int i = 0; i < max; ++i) {
if ((this.keyTable[i] != 0) || ((this.keyTable[i] == 0) &&(this.valueTable[i] != 0))) {
buf.append(this.keyTable[i]).append("->").append(this.valueTable[i]); //$NON-NLS-1$
}
if (i < max) {
buf.append(", "); //$NON-NLS-1$
}
}
buf.append("}"); //$NON-NLS-1$
return buf.toString();
}
}