org.codelibs.elasticsearch.taste.common.BitSet Maven / Gradle / Ivy

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/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.codelibs.elasticsearch.taste.common;

import java.io.Serializable;
import java.util.Arrays;

/** A simplified and streamlined version of {@link java.util.BitSet}. */
final class BitSet implements Serializable, Cloneable {

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    private final long[] bits;

    BitSet(final int numBits) {
        int numLongs = numBits >>> 6;
        if ((numBits & 0x3F) != 0) {
            numLongs++;
        }
        bits = new long[numLongs];
    }

    private BitSet(final long[] bits) {
        this.bits = bits;
    }

    boolean get(final int index) {
        // skipping range check for speed
        return (bits[index >>> 6] & 1L << (index & 0x3F)) != 0L;
    }

    void set(final int index) {
        // skipping range check for speed
        bits[index >>> 6] |= 1L << (index & 0x3F);
    }

    void clear(final int index) {
        // skipping range check for speed
        bits[index >>> 6] &= ~(1L << (index & 0x3F));
    }

    void clear() {
        final int length = bits.length;
        for (int i = 0; i < length; i++) {
            bits[i] = 0L;
        }
    }

    @Override
    public BitSet clone() {
        return new BitSet(bits.clone());
    }

    @Override
    public int hashCode() {
        return Arrays.hashCode(bits);
    }

    @Override
    public boolean equals(final Object o) {
        if (!(o instanceof BitSet)) {
            return false;
        }
        final BitSet other = (BitSet) o;
        return Arrays.equals(bits, other.bits);
    }

    @Override
    public String toString() {
        final StringBuilder result = new StringBuilder(64 * bits.length);
        for (final long l : bits) {
            for (int j = 0; j < 64; j++) {
                result.append((l & 1L << j) == 0 ? '0' : '1');
            }
            result.append(' ');
        }
        return result.toString();
    }

}