Lucene example source code file (IntsRef.java)

This example Lucene source code file (IntsRef.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

comparable, intsref, intsref, object, object, override, override, string, stringbuilder, stringbuilder

The Lucene IntsRef.java source code

package org.apache.lucene.util;

/**
 * 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.
 */

/** Represents int[], as a slice (offset + length) into an
 *  existing int[].
 *
 *  @lucene.internal */
public final class IntsRef implements Comparable<IntsRef> {

  public int[] ints;
  public int offset;
  public int length;

  public IntsRef() {
  }

  public IntsRef(int capacity) {
    ints = new int[capacity];
  }

  public IntsRef(int[] ints, int offset, int length) {
    this.ints = ints;
    this.offset = offset;
    this.length = length;
  }

  public IntsRef(IntsRef other) {
    copy(other);
  }

  @Override
  public Object clone() {
    return new IntsRef(this);
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 0;
    final int end = offset + length;
    for(int i = offset; i < end; i++) {
      result = prime * result + ints[i];
    }
    return result;
  }
  
  @Override
  public boolean equals(Object other) {
    return this.intsEquals((IntsRef) other);
  }

  public boolean intsEquals(IntsRef other) {
    if (length == other.length) {
      int otherUpto = other.offset;
      final int[] otherInts = other.ints;
      final int end = offset + length;
      for(int upto=offset;upto<end;upto++,otherUpto++) {
        if (ints[upto] != otherInts[otherUpto]) {
          return false;
        }
      }
      return true;
    } else {
      return false;
    }
  }

  /** Signed int order comparison */
  public int compareTo(IntsRef other) {
    if (this == other) return 0;

    final int[] aInts = this.ints;
    int aUpto = this.offset;
    final int[] bInts = other.ints;
    int bUpto = other.offset;

    final int aStop = aUpto + Math.min(this.length, other.length);

    while(aUpto < aStop) {
      int aInt = aInts[aUpto++];
      int bInt = bInts[bUpto++];
      if (aInt > bInt) {
        return 1;
      } else if (aInt < bInt) {
        return -1;
      }
    }

    // One is a prefix of the other, or, they are equal:
    return this.length - other.length;
  }

  public void copy(IntsRef other) {
    if (ints == null) {
      ints = new int[other.length];
    } else {
      ints = ArrayUtil.grow(ints, other.length);
    }
    System.arraycopy(other.ints, other.offset, ints, 0, other.length);
    length = other.length;
    offset = 0;
  }

  public void grow(int newLength) {
    if (ints.length < newLength) {
      ints = ArrayUtil.grow(ints, newLength);
    }
  }

  @Override
  public String toString() {
    StringBuilder sb = new StringBuilder();
    sb.append('[');
    final int end = offset + length;
    for(int i=offset;i<end;i++) {
      if (i > offset) {
        sb.append(' ');
      }
      sb.append(Integer.toHexString(ints[i]));
    }
    sb.append(']');
    return sb.toString();
  }
}