| /** |
| * 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); |
| } |
| |
| } |
| |