/*
* 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.chukwa.datacollection.adaptor.filetailer;
import org.apache.hadoop.chukwa.ChunkImpl;
import org.apache.hadoop.chukwa.datacollection.ChunkReceiver;
import org.apache.hadoop.chukwa.util.RecordConstants;
import java.util.ArrayList;
/**
* A subclass of FileTailingAdaptor that reads UTF8/ascii
* files and splits records at non-escaped carriage returns
*
*/
public class CharFileTailingAdaptorUTF8NewLineEscaped extends FileTailingAdaptor {
private static final char SEPARATOR = '\n';
private ArrayList<Integer> offsets = new ArrayList<Integer>();
/**
*
* Note: this method uses a temporary ArrayList (shared across instances).
* This means we're copying ints each time. This could be a performance issue.
* Also, 'offsets' never shrinks, and will be of size proportional to the
* largest number of lines ever seen in an event.
*/
@Override
protected int extractRecords(ChunkReceiver eq, long buffOffsetInFile, byte[] buf)
throws InterruptedException
{
String es = RecordConstants.RECORD_SEPARATOR_ESCAPE_SEQ;
for(int i = 0; i < buf.length; ++i) {
// if this is a separator
if(buf[i] == SEPARATOR){
// if possibly preceded by escape sequence (avoid outOfBounds here)
boolean escaped = false; // was it escaped?
if (i-es.length() >= 0){
escaped = true; // maybe (at least there was room for an escape sequence, so let's check for the e.s.)
for (int j = 0; j < es.length(); j++){
if (buf[i-es.length()+j] != es.charAt(j)){
escaped = false;
}
}
}
if (!escaped){
offsets.add(i);
}
}
}
if(offsets.size() > 0) {
int[] offsets_i = new int[offsets.size()];
for(int i = 0; i < offsets_i.length ; ++i)
offsets_i[i] = offsets.get(i);
//make the stream unique to this adaptor
int bytesUsed = offsets_i[offsets_i.length-1] + 1; //char at last offset uses a byte
assert bytesUsed > 0: " shouldn't send empty events";
ChunkImpl chunk = new ChunkImpl(type, toWatch.getAbsolutePath(),
buffOffsetInFile + bytesUsed, buf,this);
chunk.setSeqID(buffOffsetInFile + bytesUsed);
chunk.setRecordOffsets(offsets_i);
eq.add(chunk);
offsets.clear();
return bytesUsed;
}
else
return 0;
}
public String toString() {
return "escaped newline CFTA-UTF8";
}
}