intmap.java

jboss规则引擎

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2005 INRIA, France Telecom
 * 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. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT OWNER 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.
 */
package org.drools.asm.tree.analysis;

/**
 * A fixed size map of integer values.
 * 
 * @author Eric Bruneton
 */
class IntMap {

    private int      size;

    private Object[] keys;

    private int[]    values;

    public IntMap(final int size) {
        this.size = size;
        this.keys = new Object[size];
        this.values = new int[size];
    }

    public int get(final Object key) {
        final int n = this.size;
        final int h = (key.hashCode() & 0x7FFFFFFF) % n;
        int i = h;
        while ( this.keys[i] != key ) {
            i = (i + 1) % n;
            if ( i == h ) {
                throw new RuntimeException( "Cannot find index of " + key );
            }
        }
        return this.values[i];
    }

    public void put(final Object key,
                    final int value) {
        final int n = this.size;
        int i = (key.hashCode() & 0x7FFFFFFF) % n;
        while ( this.keys[i] != null ) {
            i = (i + 1) % n;
        }
        this.keys[i] = key;
        this.values[i] = value;
    }
}