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.
*/
import java.util.Comparator;
import org.fastcatsearch.ir.io.BytesBuffer;
import org.fastcatsearch.ir.io.IOUtil;
/**
* Represents byte[], as a slice (offset + length) into an existing byte[]. The {@link #bytes} member should never be null; use
* {@link #EMPTY_BYTES} if necessary.
*
* <p>
* <b>Important note:</b> Unless otherwise noted, Lucene uses this class to represent terms that are encoded as <b>UTF8</b> bytes
* in the index. To convert them to a Java {@link String} (which is UTF16), use {@link #utf8ToString}. Using code like
* {@code new String(bytes, offset, length)} to do this is <b>wrong</b>, as it does not respect the correct character set and may
* return wrong results (depending on the platform's defaults)!
*/
public final class BytesRef extends BytesBuffer implements Comparable<BytesRef>, Cloneable {
/** An empty byte array for convenience */
public static final byte[] EMPTY_BYTES = new byte[0];
/** Create a BytesRef with {@link #EMPTY_BYTES} */
public BytesRef() {
this(EMPTY_BYTES);
}
/**
* This instance will directly reference bytes w/o making a copy. bytes should not be null.
*/
public BytesRef(byte[] bytes, int offset, int length) {
this.bytes = bytes;
this.offset = offset;
this.length = length;
assert isValid();
}
/**
* This instance will directly reference bytes w/o making a copy. bytes should not be null
*/
public BytesRef(byte[] bytes) {
this(bytes, 0, bytes.length);
}
/**
* Create a BytesRef pointing to a new array of size <code>capacity</code>. Offset and length will both be zero.
*/
public BytesRef(int capacity) {
this(new byte[capacity]);
// this.bytes = new byte[capacity];
}
/**
* Initialize the byte[] from the UTF8 bytes for the provided String.
*
* @param text
* This must be well-formed unicode text, with no unpaired surrogates.
*/
public BytesRef(CharSequence text) {
this();
copyChars(text);
}
public void reset(){
offset = 0;
length = bytes.length;
}
/**
* Copies the UTF8 bytes for this string.
*
* @param text
* Must be well-formed unicode text, with no unpaired surrogates or invalid UTF16 code units.
*/
public void copyChars(CharSequence text) {
assert offset == 0; // TODO broken if offset != 0
UnicodeUtil.UTF16toUTF8(text, 0, text.length(), this);
}
/**
* Expert: compares the bytes against another BytesRef, returning true if the bytes are equal.
*
* @param other
* Another BytesRef, should not be null.
* @lucene.internal
*/
public boolean bytesEquals(BytesRef other) {
assert other != null;
if (length == other.length) {
int otherUpto = other.offset;
final byte[] otherBytes = other.bytes;
final int end = offset + length;
for (int upto = offset; upto < end; upto++, otherUpto++) {
if (bytes[upto] != otherBytes[otherUpto]) {
return false;
}
}
return true;
} else {
return false;
}
}
public boolean bytesEquals(BytesRef other, int length) {
assert other != null;
// if (length == other.length) {
int otherUpto = other.offset;
final byte[] otherBytes = other.bytes;
final int end = offset + length;
for (int upto = offset; upto < end; upto++, otherUpto++) {
if (bytes[upto] != otherBytes[otherUpto]) {
return false;
}
}
return true;
// } else {
// return false;
// }
}
@Override
public BytesRef clone() {
return new BytesRef(bytes, offset, length);
}
/**
* Calculates the hash code as required by TermsHash during indexing.
* <p>
* It is defined as:
*
* <pre class="prettyprint">
* int hash = 0;
* for (int i = offset; i < offset + length; i++) {
* hash = 31 * hash + bytes[i];
* }
* </pre>
*/
@Override
public int hashCode() {
int hash = 0;
final int end = offset + length;
for (int i = offset; i < end; i++) {
hash = 31 * hash + bytes[i];
}
return hash;
}
@Override
public boolean equals(Object other) {
if (other == null) {
return false;
}
if (other instanceof BytesRef) {
return this.bytesEquals((BytesRef) other);
}
return false;
}
public int toIntValue(){
return IOUtil.readInt(bytes, offset);
}
public long toLongValue(){
return IOUtil.readLong(bytes, offset);
}
public char[] toACharArray(){
char[] result = new char[length];
for (int i = 0; i < length; i++) {
result[i] = (char) bytes[offset + i];
}
return result;
}
public char[] toUCharArray(){
char[] result = new char[length / 2];
int pos = 0;
for (int i = 0; i < length; i+=2) {
result[pos++] = (char) IOUtil.readShort(bytes, i);
}
return result;
}
public String toStringValue() {
return new String(bytes, offset, length);
}
/** Returns hex encoded bytes, eg [0x6c 0x75 0x63 0x65 0x6e 0x65] */
@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(bytes[i] & 0xff));
}
sb.append(']');
return sb.toString();
}
/**
* Copies the bytes from the given {@link BytesRef}
* <p>
* NOTE: if this would exceed the array size, this method creates a new reference array.
*/
public void copyBytes(BytesRef other) {
if (bytes.length - offset < other.length) {
bytes = new byte[other.length];
offset = 0;
}
System.arraycopy(other.bytes, other.offset, bytes, offset, other.length);
length = other.length;
}
public BytesRef duplicate() {
byte[] bytes = new byte[length];
System.arraycopy(this.bytes, this.offset, bytes, 0, length);
return new BytesRef(bytes, 0, length);
}
/**
* Appends the bytes from the given {@link BytesRef}
* <p>
* NOTE: if this would exceed the array size, this method creates a new reference array.
*/
public void append(BytesRef other) {
int newLen = length + other.length;
if (bytes.length - offset < newLen) {
byte[] newBytes = new byte[newLen];
System.arraycopy(bytes, offset, newBytes, 0, length);
offset = 0;
bytes = newBytes;
}
System.arraycopy(other.bytes, other.offset, bytes, length + offset, other.length);
length = newLen;
}
public void append(byte[] other, int off, int len) {
int newLen = this.length + length;
if (bytes.length - offset < newLen) {
byte[] newBytes = new byte[newLen];
System.arraycopy(bytes, offset, newBytes, 0, length);
offset = 0;
bytes = newBytes;
}
System.arraycopy(other, off, bytes, length + offset, len);
length = newLen;
}
/**
* 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; // NOTE: senseless if offset != 0
bytes = ArrayUtil.grow(bytes, newLength);
}
/**
* Creates a new BytesRef that points to a copy of the bytes from <code>other</code>
* <p>
* The returned BytesRef will have a length of other.length and an offset of zero.
*/
public static BytesRef deepCopyOf(BytesRef other) {
BytesRef copy = new BytesRef();
copy.copyBytes(other);
return copy;
}
/**
* Performs internal consistency checks. Always returns true (or throws IllegalStateException)
*/
public boolean isValid() {
if (bytes == null) {
throw new IllegalStateException("bytes is null");
}
if (length < 0) {
throw new IllegalStateException("length is negative: " + length);
}
if (length > bytes.length) {
throw new IllegalStateException("length is out of bounds: " + length + ",bytes.length=" + bytes.length);
}
if (offset < 0) {
throw new IllegalStateException("offset is negative: " + offset);
}
if (offset > bytes.length) {
throw new IllegalStateException("offset out of bounds: " + offset + ",bytes.length=" + bytes.length);
}
if (offset + length < 0) {
throw new IllegalStateException("offset+length is negative: offset=" + offset + ",length=" + length);
}
if (offset + length > bytes.length) {
throw new IllegalStateException("offset+length out of bounds: offset=" + offset + ",length=" + length
+ ",bytes.length=" + bytes.length);
}
return true;
}
@Override
public int compareTo(BytesRef other) {
if(bytes == null && (other == null || other.bytes == null))
return 0;
else if(bytes == null)
return -1;
else if(other == null || other.bytes == null)
return 1;
int l = (length < other.length) ? length : other.length;
if(l == 0){
return length - other.length;
}
//오름차순.
for (int i = 0; i < l; i++) {
if(bytes[offset + i] != other.bytes[other.offset + i]){
return (bytes[offset + i] & 0xff) - (other.bytes[other.offset + i] & 0xff);
}
}
return length - other.length;
}
public int compareNumberTo(BytesRef other) {
if(bytes == null && (other == null || other.bytes == null))
return 0;
else if(bytes == null)
return -1;
else if(other == null || other.bytes == null)
return 1;
int l = (length < other.length) ? length : other.length;
if(l == 0){
return length - other.length;
}
//오름차순.
if(bytes[offset] >= 0 && other.bytes[other.offset] < 0){
return 1;
}else if(bytes[offset] < 0 && other.bytes[other.offset] >= 0){
return -1;
}else{
//부호가 같은 경우
for (int i = 0; i < l; i++) {
if(bytes[offset + i] != other.bytes[other.offset + i]){
return (bytes[offset + i] & 0xff) - (other.bytes[other.offset + i] & 0xff);
}
}
}
return length - other.length;
}
public int remaining() {
return length - offset;
}
}