package com.flaptor.org.apache.lucene.util;
import java.util.Comparator;
/**
* 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 char[], as a slice (offset + length) into an existing char[].
* The {@link #chars} member should never be null; use
* {@link #EMPTY_ARRAY} if necessary.
* @lucene.internal
*/
public final class CharsRef implements Comparable<CharsRef>, CharSequence {
private static final char[] EMPTY_ARRAY = new char[0];
public char[] chars;
public int offset;
public int length;
/**
* Creates a new {@link CharsRef} initialized an empty array zero-length
*/
public CharsRef() {
this(EMPTY_ARRAY, 0, 0);
}
/**
* Creates a new {@link CharsRef} initialized with an array of the given
* capacity
*/
public CharsRef(int capacity) {
chars = new char[capacity];
}
/**
* Creates a new {@link CharsRef} initialized with the given array, offset and
* length
*/
public CharsRef(char[] chars, int offset, int length) {
assert chars != null;
assert chars.length >= offset + length;
this.chars = chars;
this.offset = offset;
this.length = length;
}
/**
* Creates a new {@link CharsRef} initialized with the given Strings character
* array
*/
public CharsRef(String string) {
this.chars = string.toCharArray();
this.offset = 0;
this.length = chars.length;
}
/**
* Creates a new {@link CharsRef} and copies the contents of the source into
* the new instance.
* @see #copy(CharsRef)
*/
public CharsRef(CharsRef other) {
copy(other);
}
@Override
public Object clone() {
return new CharsRef(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 + chars[i];
}
return result;
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (other instanceof CharsRef) {
return charsEquals((CharsRef) other);
}
if (other instanceof CharSequence) {
final CharSequence seq = (CharSequence) other;
if (length == seq.length()) {
int n = length;
int i = offset;
int j = 0;
while (n-- != 0) {
if (chars[i++] != seq.charAt(j++))
return false;
}
return true;
}
}
return false;
}
public boolean charsEquals(CharsRef other) {
if (length == other.length) {
int otherUpto = other.offset;
final char[] otherChars = other.chars;
final int end = offset + length;
for (int upto = offset; upto < end; upto++, otherUpto++) {
if (chars[upto] != otherChars[otherUpto]) {
return false;
}
}
return true;
} else {
return false;
}
}
/** Signed int order comparison */
public int compareTo(CharsRef other) {
if (this == other)
return 0;
final char[] aChars = this.chars;
int aUpto = this.offset;
final char[] bChars = other.chars;
int bUpto = other.offset;
final int aStop = aUpto + Math.min(this.length, other.length);
while (aUpto < aStop) {
int aInt = aChars[aUpto++];
int bInt = bChars[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;
}
/**
* Copies the given {@link CharsRef} referenced content into this instance
* starting at offset 0.
*
* @param other
* the {@link CharsRef} to copy
*/
public void copy(CharsRef other) {
if (chars == null) {
chars = new char[other.length];
} else {
chars = ArrayUtil2.grow(chars, other.length);
}
System.arraycopy(other.chars, other.offset, chars, 0, other.length);
length = other.length;
offset = 0;
}
public void grow(int newLength) {
if (chars.length < newLength) {
chars = ArrayUtil2.grow(chars, newLength);
}
}
/**
* Copies the given array into this CharsRef starting at offset 0
*/
public void copy(char[] otherChars, int otherOffset, int otherLength) {
grow(otherLength);
System.arraycopy(otherChars, otherOffset, this.chars, 0,
otherLength);
this.offset = 0;
this.length = otherLength;
}
/**
* Appends the given array to this CharsRef
*/
public void append(char[] otherChars, int otherOffset, int otherLength) {
final int newLength = length + otherLength;
grow(this.offset + newLength);
System.arraycopy(otherChars, otherOffset, this.chars, this.offset+length,
otherLength);
this.length += otherLength;
}
@Override
public String toString() {
return new String(chars, offset, length);
}
public int length() {
return length;
}
public char charAt(int index) {
return chars[offset + index];
}
public CharSequence subSequence(int start, int end) {
return new CharsRef(chars, offset + start, offset + end - 1);
}
private final static Comparator<CharsRef> utf16SortedAsUTF8SortOrder = new UTF16SortedAsUTF8Comparator();
public static Comparator<CharsRef> getUTF16SortedAsUTF8Comparator() {
return utf16SortedAsUTF8SortOrder;
}
private static class UTF16SortedAsUTF8Comparator implements Comparator<CharsRef> {
// Only singleton
private UTF16SortedAsUTF8Comparator() {};
public int compare(CharsRef a, CharsRef b) {
if (a == b)
return 0;
final char[] aChars = a.chars;
int aUpto = a.offset;
final char[] bChars = b.chars;
int bUpto = b.offset;
final int aStop = aUpto + Math.min(a.length, b.length);
while (aUpto < aStop) {
char aChar = aChars[aUpto++];
char bChar = bChars[bUpto++];
if (aChar != bChar) {
// http://icu-project.org/docs/papers/utf16_code_point_order.html
/* aChar != bChar, fix up each one if they're both in or above the surrogate range, then compare them */
if (aChar >= 0xd800 && bChar >= 0xd800) {
if (aChar >= 0xe000) {
aChar -= 0x800;
} else {
aChar += 0x2000;
}
if (bChar >= 0xe000) {
bChar -= 0x800;
} else {
bChar += 0x2000;
}
}
/* now aChar and bChar are in code point order */
return (int)aChar - (int)bChar; /* int must be 32 bits wide */
}
}
// One is a prefix of the other, or, they are equal:
return a.length - b.length;
}
}
}