/**
* 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 org.apache.hadoop.util;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
@InterfaceAudience.Private
@InterfaceStability.Unstable
public class UTF8ByteArrayUtils {
/**
* Find the first occurrence of the given byte b in a UTF-8 encoded string
* @param utf a byte array containing a UTF-8 encoded string
* @param start starting offset
* @param end ending position
* @param b the byte to find
* @return position that first byte occures otherwise -1
*/
public static int findByte(byte [] utf, int start, int end, byte b) {
for(int i=start; i<end; i++) {
if (utf[i]==b) {
return i;
}
}
return -1;
}
/**
* Find the first occurrence of the given bytes b in a UTF-8 encoded string
* @param utf a byte array containing a UTF-8 encoded string
* @param start starting offset
* @param end ending position
* @param b the bytes to find
* @return position that first byte occures otherwise -1
*/
public static int findBytes(byte [] utf, int start, int end, byte[] b) {
int matchEnd = end - b.length;
for(int i=start; i<=matchEnd; i++) {
boolean matched = true;
for(int j=0; j<b.length; j++) {
if (utf[i+j] != b[j]) {
matched = false;
break;
}
}
if (matched) {
return i;
}
}
return -1;
}
/**
* Find the nth occurrence of the given byte b in a UTF-8 encoded string
* @param utf a byte array containing a UTF-8 encoded string
* @param start starting offset
* @param length the length of byte array
* @param b the byte to find
* @param n the desired occurrence of the given byte
* @return position that nth occurrence of the given byte if exists; otherwise -1
*/
public static int findNthByte(byte [] utf, int start, int length, byte b, int n) {
int pos = -1;
int nextStart = start;
for (int i = 0; i < n; i++) {
pos = findByte(utf, nextStart, length, b);
if (pos < 0) {
return pos;
}
nextStart = pos + 1;
}
return pos;
}
/**
* Find the nth occurrence of the given byte b in a UTF-8 encoded string
* @param utf a byte array containing a UTF-8 encoded string
* @param b the byte to find
* @param n the desired occurrence of the given byte
* @return position that nth occurrence of the given byte if exists; otherwise -1
*/
public static int findNthByte(byte [] utf, byte b, int n) {
return findNthByte(utf, 0, utf.length, b, n);
}
}