content: /**
   * 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.aliyun.odps.mapred.bridge.streaming;
  
  import java.io.IOException;
  
  import com.aliyun.odps.io.Text;
  import com.aliyun.odps.mapred.bridge.streaming.io.LineReader;
  import com.aliyun.odps.mapred.utils.UTF8ByteArrayUtils;
  
  public class StreamKeyValUtil {
  
    /**
     * Find the first occured tab in a UTF-8 encoded string
     *
     * @param utf
     *     a byte array containing a UTF-8 encoded string
     * @param start
     *     starting offset
     * @param length
     *     no. of bytes
     * @return position that first tab occures otherwise -1
     */
    public static int findTab(byte[] utf, int start, int length) {
      for (int i = start; i < (start + length); i++) {
        if (utf[i] == (byte) '\t') {
          return i;
        }
      }
      return -1;
    }
  
    /**
     * Find the first occured tab in a UTF-8 encoded string
     *
     * @param utf
     *     a byte array containing a UTF-8 encoded string
     * @return position that first tab occures otherwise -1
     */
    public static int findTab(byte[] utf) {
      return UTF8ByteArrayUtils.findNthByte(utf, 0,
                                            utf.length, (byte) '\t', 1);
    }
  
    /**
     * split a UTF-8 byte array into key and value
     * assuming that the delimilator is at splitpos.
     *
     * @param utf
     *     utf-8 encoded string
     * @param start
     *     starting offset
     * @param length
     *     no. of bytes
     * @param key
     *     contains key upon the method is returned
     * @param val
     *     contains value upon the method is returned
     * @param splitPos
     *     the split pos
     * @param separatorLength
     *     the length of the separator between key and value
     * @throws IOException
     */
    public static void splitKeyVal(byte[] utf, int start, int length,
                                   Text key, Text val, int splitPos,
                                   int separatorLength) throws IOException {
      if (splitPos < start || splitPos >= (start + length)) {
        throw new IllegalArgumentException("splitPos must be in the range " +
                                           "[" + start + ", " + (start + length) + "]: " + splitPos);
      }
      int keyLen = (splitPos - start);
      int valLen = (start + length) - splitPos - separatorLength;
      key.set(utf, start, keyLen);
      val.set(utf, splitPos + separatorLength, valLen);
    }
  
    /**
     * split a UTF-8 byte array into key and value
     * assuming that the delimilator is at splitpos.
     *
     * @param utf
     *     utf-8 encoded string
     * @param start
     *     starting offset
     * @param length
     *     no. of bytes
     * @param key
     *     contains key upon the method is returned
     * @param val
     *     contains value upon the method is returned
     * @param splitPos
     *     the split pos
     * @throws IOException
     */
    public static void splitKeyVal(byte[] utf, int start, int length,
                                   Text key, Text val, int splitPos) throws IOException {
      splitKeyVal(utf, start, length, key, val, splitPos, 1);
    }
  
  
    /**
     * split a UTF-8 byte array into key and value
     * assuming that the delimilator is at splitpos.
     *
     * @param utf
     *     utf-8 encoded string
     * @param key
     *     contains key upon the method is returned
     * @param val
     *     contains value upon the method is returned
     * @param splitPos
     *     the split pos
     * @param separatorLength
     *     the length of the separator between key and value
     * @throws IOException
     */
    public static void splitKeyVal(byte[] utf, Text key, Text val, int splitPos,
                                   int separatorLength)
        throws IOException {
      splitKeyVal(utf, 0, utf.length, key, val, splitPos, separatorLength);
    }
  
    /**
     * split a UTF-8 byte array into key and value
     * assuming that the delimilator is at splitpos.
     *
     * @param utf
     *     utf-8 encoded string
     * @param key
     *     contains key upon the method is returned
     * @param val
     *     contains value upon the method is returned
     * @param splitPos
     *     the split pos
     * @throws IOException
     */
    public static void splitKeyVal(byte[] utf, Text key, Text val, int splitPos)
        throws IOException {
      splitKeyVal(utf, 0, utf.length, key, val, splitPos, 1);
    }
  
    /**
     * Read a utf8 encoded line from a data input stream.
     *
     * @param lineReader
     *     LineReader to read the line from.
     * @param out
     *     Text to read into
     * @return number of bytes read
     * @throws IOException
     */
    public static int readLine(LineReader lineReader, Text out)
        throws IOException {
      out.clear();
      return lineReader.readLine(out);
    }
  
  }
  