/**
* Licensed to Cloudera, Inc. under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Cloudera, Inc. 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.cloudera.flume.handlers.debug;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.cloudera.flume.conf.Context;
import com.cloudera.flume.conf.SourceFactory.SourceBuilder;
import com.cloudera.flume.core.Event;
import com.cloudera.flume.core.EventImpl;
import com.cloudera.flume.core.EventSource;
import com.google.common.base.Preconditions;
/**
* This source reads from a text file, takes the contents of each line and makes
* it the body of an event. The current time is used as the timestamp and INFO
* level priority.
*
* This is great for direct comparison to 'grep | wc'
*
* This version uses Buffered readers, hopefully this is faster.
*/
public class TextReaderSource extends EventSource.Base {
static final Logger LOG = LoggerFactory.getLogger(TextReaderSource.class);
String fname;
BufferedReader in;
public TextReaderSource(String fname) {
this.fname = fname;
}
public Event next() throws IOException {
Preconditions.checkState(in != null,
"Need to open source before reading from it");
String s = in.readLine();
if (s == null)
return null;
Event e = new EventImpl(s.getBytes());
updateEventProcessingStats(e);
return e;
}
@Override
public void close() throws IOException {
in.close();
LOG.info("File " + fname + " closed");
}
@Override
public void open() throws IOException {
this.in = new BufferedReader(new FileReader(fname));
LOG.info("File " + fname + " opened");
}
public static SourceBuilder builder() {
return new SourceBuilder() {
@Override
public EventSource build(Context ctx, String... argv) {
if (argv.length != 1) {
throw new IllegalArgumentException("usage: text(filename)");
}
return new TextReaderSource(argv[0]);
}
};
}
}