| 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[]. The {@link #ints} member should never be null; use |
| * {@link #EMPTY_INTS} if necessary. |
| * |
| * @lucene.internal */ |
| public final class IntsRef implements Comparable<IntsRef>, Cloneable { |
| /** An empty integer array for convenience */ |
| public static final int[] EMPTY_INTS = new int[0]; |
| |
| /** The contents of the IntsRef. Should never be {@code null}. */ |
| public int[] ints; |
| /** Offset of first valid integer. */ |
| public int offset; |
| /** Length of used ints. */ |
| public int length; |
| |
| /** Create a IntsRef with {@link #EMPTY_INTS} */ |
| public IntsRef() { |
| ints = EMPTY_INTS; |
| } |
| |
| /** |
| * Create a IntsRef pointing to a new array of size <code>capacity</code>. |
| * Offset and length will both be zero. |
| */ |
| public IntsRef(int capacity) { |
| ints = new int[capacity]; |
| } |
| |
| /** This instance will directly reference ints w/o making a copy. |
| * ints should not be null. |
| */ |
| public IntsRef(int[] ints, int offset, int length) { |
| this.ints = ints; |
| this.offset = offset; |
| this.length = length; |
| assert isValid(); |
| } |
| |
| /** |
| * Returns a shallow clone of this instance (the underlying ints are |
| * <b>not</b> copied and will be shared by both the returned object and this |
| * object. |
| * |
| * @see #deepCopyOf |
| */ |
| @Override |
| public IntsRef clone() { |
| return new IntsRef(ints, offset, length); |
| } |
| |
| @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) { |
| if (other == null) { |
| return false; |
| } |
| if (other instanceof IntsRef) { |
| return this.intsEquals((IntsRef) other); |
| } |
| return false; |
| } |
| |
| 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 */ |
| @Override |
| 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 copyInts(IntsRef other) { |
| if (ints.length - offset < other.length) { |
| ints = new int[other.length]; |
| offset = 0; |
| } |
| System.arraycopy(other.ints, other.offset, ints, offset, other.length); |
| length = other.length; |
| } |
| |
| /** |
| * Used to grow the reference array. |
| * |
| * In general this should not be used as it does not take the offset into account. |
| * @lucene.internal */ |
| public void grow(int newLength) { |
| assert offset == 0; |
| 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(); |
| } |
| |
| /** |
| * Creates a new IntsRef that points to a copy of the ints from |
| * <code>other</code> |
| * <p> |
| * The returned IntsRef will have a length of other.length |
| * and an offset of zero. |
| */ |
| public static IntsRef deepCopyOf(IntsRef other) { |
| IntsRef clone = new IntsRef(); |
| clone.copyInts(other); |
| return clone; |
| } |
| |
| /** |
| * Performs internal consistency checks. |
| * Always returns true (or throws IllegalStateException) |
| */ |
| public boolean isValid() { |
| if (ints == null) { |
| throw new IllegalStateException("ints is null"); |
| } |
| if (length < 0) { |
| throw new IllegalStateException("length is negative: " + length); |
| } |
| if (length > ints.length) { |
| throw new IllegalStateException("length is out of bounds: " + length + ",ints.length=" + ints.length); |
| } |
| if (offset < 0) { |
| throw new IllegalStateException("offset is negative: " + offset); |
| } |
| if (offset > ints.length) { |
| throw new IllegalStateException("offset out of bounds: " + offset + ",ints.length=" + ints.length); |
| } |
| if (offset + length < 0) { |
| throw new IllegalStateException("offset+length is negative: offset=" + offset + ",length=" + length); |
| } |
| if (offset + length > ints.length) { |
| throw new IllegalStateException("offset+length out of bounds: offset=" + offset + ",length=" + length + ",ints.length=" + ints.length); |
| } |
| return true; |
| } |
| } |