--- /dev/null
+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();
+ }
+}