| /******************************************************************************* |
| * Copyright (c) 2000, 2004 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.core.builder; |
| |
| public class StringSet { |
| |
| // to avoid using Enumerations, walk the individual values skipping nulls |
| public String[] values; |
| public int elementSize; // number of elements in the table |
| public int threshold; |
| |
| public StringSet(int size) { |
| this.elementSize = 0; |
| this.threshold = size; // size represents the expected number of elements |
| int extraRoom = (int) (size * 1.5f); |
| if (this.threshold == extraRoom) |
| extraRoom++; |
| this.values = new String[extraRoom]; |
| } |
| |
| public boolean add(String value) { |
| int length = this.values.length; |
| int index = (value.hashCode() & 0x7FFFFFFF) % length; |
| String current; |
| while ((current = this.values[index]) != null) { |
| if (value.equals(current)) return false; // did not add it since it already existed |
| if (++index == length) index = 0; |
| } |
| this.values[index] = value; |
| |
| // assumes the threshold is never equal to the size of the table |
| if (++elementSize > threshold) rehash(); |
| return true; |
| } |
| |
| public void clear() { |
| for (int i = this.values.length; --i >= 0;) |
| this.values[i] = null; |
| this.elementSize = 0; |
| } |
| |
| public boolean includes(String value) { |
| int length = values.length; |
| int index = (value.hashCode() & 0x7FFFFFFF) % length; |
| String current; |
| while ((current = this.values[index]) != null) { |
| if (value.equals(current)) return true; |
| if (++index == length) index = 0; |
| } |
| return false; |
| } |
| |
| private void rehash() { |
| StringSet newSet = new StringSet(elementSize * 2); // double the number of expected elements |
| String current; |
| for (int i = this.values.length; --i >= 0;) |
| if ((current = this.values[i]) != null) |
| newSet.add(current); |
| |
| this.values = newSet.values; |
| this.elementSize = newSet.elementSize; |
| this.threshold = newSet.threshold; |
| } |
| |
| public String toString() { |
| String s = ""; //$NON-NLS-1$ |
| String value; |
| for (int i = 0, l = this.values.length; i < l; i++) |
| if ((value = this.values[i]) != null) |
| s += value + "\n"; //$NON-NLS-1$ |
| return s; |
| } |
| } |