1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 package org.apache.hadoop.chukwa.datacollection.adaptor.filetailer;
20
21
22 import org.apache.hadoop.chukwa.ChunkImpl;
23 import org.apache.hadoop.chukwa.datacollection.ChunkReceiver;
24 import org.apache.hadoop.chukwa.util.RecordConstants;
25
26 import java.util.ArrayList;
27 import java.util.Arrays;
28
29 /**
30 * A subclass of FileTailingAdaptor that reads UTF8/ascii files and splits
31 * records at non-escaped carriage returns
32 *
33 */
34 public class CharFileTailingAdaptorUTF8NewLineEscaped extends
35 FileTailingAdaptor {
36
37 private static final char SEPARATOR = '\n';
38
39 private ArrayList<Integer> offsets = new ArrayList<Integer>();
40
41 /**
42 *
43 * Note: this method uses a temporary ArrayList (shared across instances).
44 * This means we're copying ints each time. This could be a performance issue.
45 * Also, 'offsets' never shrinks, and will be of size proportional to the
46 * largest number of lines ever seen in an event.
47 */
48 @Override
49 protected int extractRecords(ChunkReceiver eq, long buffOffsetInFile,
50 byte[] buf) throws InterruptedException {
51 String es = RecordConstants.RECORD_SEPARATOR_ESCAPE_SEQ;
52 for (int i = 0; i < buf.length; ++i) {
53 // if this is a separator
54 if (buf[i] == SEPARATOR) {
55 // if possibly preceded by escape sequence (avoid outOfBounds here)
56 boolean escaped = false; // was it escaped?
57 if (i - es.length() >= 0) {
58 escaped = true; // maybe (at least there was room for an escape
59 // sequence, so let's check for the e.s.)
60 for (int j = 0; j < es.length(); j++) {
61 if (buf[i - es.length() + j] != es.charAt(j)) {
62 escaped = false;
63 }
64 }
65 }
66 if (!escaped) {
67 offsets.add(i);
68 }
69 }
70 }
71
72 if (offsets.size() > 0) {
73 int[] offsets_i = new int[offsets.size()];
74 for (int i = 0; i < offsets.size(); i++) {
75 try {
76 offsets_i[i] = offsets.get(i);
77 } catch(NullPointerException e) {
78 // Skip offsets 0 where it can be null.
79 }
80 }
81 // make the stream unique to this adaptor
82 int bytesUsed = 0;
83 if(buf.length==offsets_i[offsets_i.length -1]) {
84 // If Separator is last character of stream,
85 // send the record.
86 bytesUsed = offsets_i[offsets_i.length - 2] + 1;
87 } else {
88 // If the last record is partial read,
89 // truncate the record to the n -1 new line.
90 bytesUsed = offsets_i[offsets_i.length - 1] + 1; // char at last
91 }
92 // offset uses a byte
93 assert bytesUsed > 0 : " shouldn't send empty events";
94 ChunkImpl chunk = new ChunkImpl(type, toWatch.getAbsolutePath(),
95 buffOffsetInFile + bytesUsed, Arrays.copyOf(buf, bytesUsed), this);
96
97 chunk.setSeqID(buffOffsetInFile + bytesUsed);
98 chunk.setRecordOffsets(offsets_i);
99 eq.add(chunk);
100
101 offsets.clear();
102 return bytesUsed;
103 } else
104 return 0;
105 }
106
107 public String toString() {
108 return "escaped newline CFTA-UTF8";
109 }
110
111 }