/*
* 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;
import java.io.File;
import java.io.IOException;
import org.apache.log4j.Logger;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.filefilter.FileFilterUtils;
import org.apache.commons.io.filefilter.IOFileFilter;
import org.apache.commons.io.filefilter.WildcardFileFilter;
/**
* Explore a whole directory hierarchy, looking for files to tail.
* DirTailingAdaptor will not try to start tailing a file more than once,
* if the file hasn't been modified in the interim.
*
* Offset param is used to track last finished scan.
*
* Mandatory first parameter is a directory with an optional unix style file
* filter. Mandatory second parameter
* is the name of an adaptor to start.
*
* If the specified directory does not exist, the DirTailer will continue
* running, and will start tailing if the directory is later created.
*
*/
public class DirTailingAdaptor extends AbstractAdaptor implements Runnable {
static Logger log = Logger.getLogger(DirTailingAdaptor.class);
Thread scanThread = new Thread(this);
long lastSweepStartTime;
volatile boolean continueScanning=true;
File baseDir;
String baseDirName;
long scanInterval;
String adaptorName; //name of adaptors to start
IOFileFilter fileFilter;
String wildcard = null;
@Override
public void start(long offset) throws AdaptorException {
scanInterval = control.getConfiguration().getInt("adaptor.dirscan.intervalMs", 10000);
scanThread.start();
lastSweepStartTime = offset;
try {
baseDirName = baseDir.getCanonicalPath();
} catch(IOException e) {
throw new AdaptorException(e);
}
}
public void run() {
try {
log.debug("dir tailer starting to scan");
while(continueScanning) {
try {
long sweepStartTime = System.currentTimeMillis();
scanDirHierarchy(baseDir);
lastSweepStartTime=sweepStartTime;
control.reportCommit(this, lastSweepStartTime);
} catch(IOException e) {
log.warn(e);
}
Thread.sleep(scanInterval);
}
} catch(InterruptedException e) {
}
}
/*
* Coded recursively. Base case is a single non-dir file.
*/
private void scanDirHierarchy(File dir) throws IOException {
if(!dir.exists())
return;
if(!dir.isDirectory()) {
//Don't start tailing if we would have gotten it on the last pass
if(dir.lastModified() >= lastSweepStartTime) {
String newAdaptorID = control.processAddCommand(
"add " + adaptorName +" " + type + " " + dir.getCanonicalPath() + " 0");
log.info("DirTailingAdaptor " + adaptorID + " started new adaptor " + newAdaptorID);
}
} else {
log.info("Scanning directory: " + dir.getName());
for(Object f: FileUtils.listFiles(dir, fileFilter, FileFilterUtils.trueFileFilter())) {
scanDirHierarchy((File)f);
}
}
}
@Override
public String getCurrentStatus() {
return (wildcard!=null)?type + " " + baseDirName + " " + wildcard + " " + adaptorName:type + " " + baseDirName + " " + adaptorName;
}
@Override
public String parseArgs(String status) {
String[] args = status.split(" ");
if(args.length == 2){
baseDir = new File(args[0]);
fileFilter = FileFilterUtils.trueFileFilter();
adaptorName = args[1];
}else if(args.length == 3){
baseDir = new File(args[0]);
wildcard = args[1];
fileFilter = new WildcardFileFilter(wildcard);
adaptorName = args[2];
}else{
log.warn("bad syntax in DirTailingAdaptor args");
return null;
}
return (args.length == 2)? baseDir + " " + adaptorName : baseDir + " " + wildcard + " " + adaptorName; //both params mandatory
}
@Override
public long shutdown(AdaptorShutdownPolicy shutdownPolicy)
throws AdaptorException {
continueScanning = false;
return lastSweepStartTime;
}
}