org.eclipse.jdt.internal.core.util.HashSetOfCharArrayArray.java Source code

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Here is the source code for org.eclipse.jdt.internal.core.util.HashSetOfCharArrayArray.java

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/*******************************************************************************
 * Copyright (c) 2000, 2009 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.util;

import org.eclipse.jdt.core.compiler.CharOperation;

/**
 * HashSet of char[][]
 */
public final class HashSetOfCharArrayArray implements Cloneable {

    // to avoid using Enumerations, walk the individual tables skipping nulls
    public char[][][] set;

    public int elementSize; // number of elements in the table
    int threshold;

    public HashSetOfCharArrayArray() {
        this(13);
    }

    public HashSetOfCharArrayArray(int size) {

        this.elementSize = 0;
        this.threshold = size; // size represents the expected number of elements
        int extraRoom = (int) (size * 1.75f);
        if (this.threshold == extraRoom)
            extraRoom++;
        this.set = new char[extraRoom][][];
    }

    @Override
    public Object clone() throws CloneNotSupportedException {
        HashSetOfCharArrayArray result = (HashSetOfCharArrayArray) super.clone();
        result.elementSize = this.elementSize;
        result.threshold = this.threshold;

        int length = this.set.length;
        result.set = new char[length][][];
        System.arraycopy(this.set, 0, result.set, 0, length);

        return result;
    }

    public boolean contains(char[][] array) {
        int length = this.set.length;
        int index = hashCode(array) % length;
        int arrayLength = array.length;
        char[][] currentArray;
        while ((currentArray = this.set[index]) != null) {
            if (currentArray.length == arrayLength && CharOperation.equals(currentArray, array))
                return true;
            if (++index == length) {
                index = 0;
            }
        }
        return false;
    }

    private int hashCode(char[][] element) {
        return hashCode(element, element.length);
    }

    private int hashCode(char[][] element, int length) {
        int hash = 0;
        for (int i = length - 1; i >= 0; i--)
            hash = Util.combineHashCodes(hash, CharOperation.hashCode(element[i]));
        return hash & 0x7FFFFFFF;
    }

    public char[][] add(char[][] array) {
        int length = this.set.length;
        int index = hashCode(array) % length;
        int arrayLength = array.length;
        char[][] currentArray;
        while ((currentArray = this.set[index]) != null) {
            if (currentArray.length == arrayLength && CharOperation.equals(currentArray, array))
                return this.set[index] = array;
            if (++index == length) {
                index = 0;
            }
        }
        this.set[index] = array;

        // assumes the threshold is never equal to the size of the table
        if (++this.elementSize > this.threshold)
            rehash();
        return array;
    }

    public char[][] remove(char[][] array) {
        int length = this.set.length;
        int index = hashCode(array) % length;
        int arrayLength = array.length;
        char[][] currentArray;
        while ((currentArray = this.set[index]) != null) {
            if (currentArray.length == arrayLength && CharOperation.equals(currentArray, array)) {
                char[][] existing = this.set[index];
                this.elementSize--;
                this.set[index] = null;
                rehash();
                return existing;
            }
            if (++index == length) {
                index = 0;
            }
        }
        return null;
    }

    private void rehash() {
        HashSetOfCharArrayArray newHashSet = new HashSetOfCharArrayArray(this.elementSize * 2); // double the number of expected elements
        char[][] currentArray;
        for (int i = this.set.length; --i >= 0;)
            if ((currentArray = this.set[i]) != null)
                newHashSet.add(currentArray);

        this.set = newHashSet.set;
        this.threshold = newHashSet.threshold;
    }

    public int size() {
        return this.elementSize;
    }

    @Override
    public String toString() {
        StringBuffer buffer = new StringBuffer();
        for (int i = 0, length = this.set.length; i < length; i++) {
            char[][] arrayArray = this.set[i];
            if (arrayArray != null) {
                buffer.append("{"); //$NON-NLS-1$
                for (int j = 0, length2 = arrayArray.length; j < length2; j++) {
                    char[] array = arrayArray[j];
                    buffer.append('{');
                    for (int k = 0, length3 = array.length; k < length3; k++) {
                        buffer.append('\'');
                        buffer.append(array[k]);
                        buffer.append('\'');
                        if (k != length3 - 1)
                            buffer.append(", "); //$NON-NLS-1$
                    }
                    buffer.append('}');
                    if (j != length2 - 1)
                        buffer.append(", "); //$NON-NLS-1$
                }
                buffer.append("}"); //$NON-NLS-1$
                if (i != length - 1)
                    buffer.append('\n');
            }
        }
        return buffer.toString();
    }
}