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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 com.graphhopper.storage;
import java.util.Arrays;
/**
* Idea and most of the code is from Lucene. But the variables are final, except for the array content.
*/
public final class IntsRef implements Comparable {
/**
* An IntsRef with an array of size 0.
*/
public static final IntsRef EMPTY = new IntsRef(0, false);
/**
* The contents of the IntsRef. Cannot be {@code null}.
*/
public final int[] ints;
/**
* Offset of first valid integer.
*/
public final int offset;
/**
* Length of used ints.
*/
public final int length;
/**
* Create a IntsRef pointing to a new int array of size capacity leading to capacity*32 bits.
* Offset will be zero and length will be the capacity.
*/
public IntsRef(int capacity) {
this(capacity, true);
}
private IntsRef(int capacity, boolean checked) {
if (checked && capacity == 0)
throw new IllegalArgumentException("Use instance EMPTY instead of capacity 0");
ints = new int[capacity];
length = capacity;
offset = 0;
}
/**
* 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();
}
@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;
}
/**
* Creates a new IntsRef that points to a copy of the ints from
* other
*
* The returned IntsRef will have a length of other.length
* and an offset of zero.
*/
public static IntsRef deepCopyOf(IntsRef other) {
return new IntsRef(Arrays.copyOfRange(other.ints, other.offset, other.offset + other.length), 0, other.length);
}
/**
* 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;
}
@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();
}
public boolean isEmpty() {
for (int i = 0; i < ints.length; i++) {
if (ints[i] != 0)
return false;
}
return true;
}
}