Files
logstash-forwarder-java/src/main/java/info/fetter/logstashforwarder/FileWatcher.java

343 lines
13 KiB
Java

package info.fetter.logstashforwarder;
/*
* Copyright 2015 Didier Fetter
*
* Licensed 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.
*
*/
import info.fetter.logstashforwarder.util.LastModifiedFileFilter;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.filefilter.FileFilterUtils;
import org.apache.commons.io.filefilter.IOFileFilter;
import org.apache.commons.io.filefilter.WildcardFileFilter;
import org.apache.commons.io.monitor.FileAlterationObserver;
import org.apache.log4j.Logger;
public class FileWatcher {
private static final Logger logger = Logger.getLogger(FileWatcher.class);
private List<FileAlterationObserver> observerList = new ArrayList<FileAlterationObserver>();
public static final int ONE_DAY = 24 * 3600 * 1000;
private Map<File,FileState> watchMap = new HashMap<File,FileState>();
private Map<File,FileState> changedWatchMap = new HashMap<File,FileState>();
private FileState[] savedStates;
private static int MAX_SIGNATURE_LENGTH = 1024;
public FileWatcher() {
try {
savedStates = Registrar.readStateFromJson();
} catch(Exception e) {
logger.warn("Could not load saved states : " + e.getMessage());
}
}
public void addFilesToWatch(String fileToWatch, Event fields, int deadTime) {
try {
if(fileToWatch.equals("-")) {
addStdIn(fields);
} else if(fileToWatch.contains("*")) {
addWildCardFiles(fileToWatch, fields, deadTime);
} else {
addSingleFile(fileToWatch, fields, deadTime);
}
} catch(Exception e) {
throw new RuntimeException(e);
}
}
public void checkFiles() throws IOException {
logger.debug("Checking files");
logger.trace("==============");
for(FileAlterationObserver observer : observerList) {
observer.checkAndNotify();
}
processModifications();
printWatchMap();
}
public int readFiles(FileReader reader) throws IOException {
logger.debug("Reading files");
logger.trace("==============");
int numberOfLinesRead = reader.readFiles(watchMap.values());
Registrar.writeStateToJson(watchMap.values());
return numberOfLinesRead;
}
private void processModifications() throws IOException {
for(File file : changedWatchMap.keySet()) {
FileState state = changedWatchMap.get(file);
if(logger.isTraceEnabled()) {
logger.trace("Checking file : " + file.getCanonicalPath());
logger.trace("-- Last modified : " + state.getLastModified());
logger.trace("-- Size : " + state.getSize());
logger.trace("-- Directory : " + state.getDirectory());
logger.trace("-- Filename : " + state.getFileName());
}
logger.trace("Determine if file has just been written to");
FileState oldState = watchMap.get(file);
if(oldState != null) {
if(oldState.getSize() > state.getSize()) {
logger.trace("File shorter : file can't be the same");
} else {
if(oldState.getSignatureLength() == state.getSignatureLength() && oldState.getSignature() == state.getSignature()) {
state.setOldFileState(oldState);
logger.trace("Same signature size and value : file is the same");
continue;
} else if(oldState.getSignatureLength() < state.getSignatureLength()){
long signature = FileSigner.computeSignature(state.getRandomAccessFile(), oldState.getSignatureLength());
if(signature == oldState.getSignature()) {
state.setOldFileState(oldState);
logger.trace("Same signature : file is the same");
continue;
} else {
logger.trace("Signature different : file can't be the same");
}
} else if(oldState.getSignatureLength() > state.getSignatureLength()){
logger.trace("Signature shorter : file can't be the same");
}
}
}
if(state.getOldFileState() == null) {
logger.trace("Determine if file has been renamed and/or written to");
for(File otherFile : watchMap.keySet()) {
FileState otherState = watchMap.get(otherFile);
if(otherState != null && state.getSize() >= otherState.getSize() && state.getDirectory().equals(otherState.getDirectory())) {
if(logger.isTraceEnabled()) {
logger.trace("Comparing to : " + otherFile.getCanonicalPath());
}
if(otherState.getSignatureLength() == state.getSignatureLength() && otherState.getSignature() == state.getSignature()) {
state.setOldFileState(otherState);
logger.trace("Same signature size and value : file is the same");
break;
} else if(otherState.getSignatureLength() < state.getSignatureLength()){
long signature = FileSigner.computeSignature(state.getRandomAccessFile(), otherState.getSignatureLength());
if(signature == otherState.getSignature()) {
state.setOldFileState(otherState);
logger.trace("Same signature : file is the same");
break;
} else {
logger.trace("Signature different : file can't be the same");
}
} else if(otherState.getSignatureLength() > state.getSignatureLength()){
logger.trace("Signature shorter : file can't be the same");
}
}
}
}
}
logger.trace("Refreshing file state");
for(File file : changedWatchMap.keySet()) {
if(logger.isTraceEnabled()) {
logger.trace("Refreshing file : " + file.getCanonicalPath());
}
FileState state = changedWatchMap.get(file);
FileState oldState = state.getOldFileState();
if(oldState == null) {
logger.trace("File has been truncated or created, not retrieving pointer");
} else {
logger.trace("File has not been truncated or created, retrieving pointer");
state.setPointer(oldState.getPointer());
oldState.getRandomAccessFile().close();
}
}
logger.trace("Replacing old state");
for(File file : changedWatchMap.keySet()) {
FileState state = changedWatchMap.get(file);
watchMap.put(file, state);
}
// Truncating changedWatchMap
changedWatchMap.clear();
removeMarkedFilesFromWatchMap();
}
private void addSingleFile(String fileToWatch, Event fields, int deadTime) throws Exception {
logger.info("Watching file : " + new File(fileToWatch).getCanonicalPath());
String directory = FilenameUtils.getFullPath(fileToWatch);
String fileName = FilenameUtils.getName(fileToWatch);
IOFileFilter fileFilter = FileFilterUtils.and(
FileFilterUtils.fileFileFilter(),
FileFilterUtils.nameFileFilter(fileName),
new LastModifiedFileFilter(deadTime));
initializeWatchMap(new File(directory), fileFilter, fields);
}
private void addWildCardFiles(String filesToWatch, Event fields, int deadTime) throws Exception {
logger.info("Watching wildcard files : " + filesToWatch);
String directory = FilenameUtils.getFullPath(filesToWatch);
String wildcard = FilenameUtils.getName(filesToWatch);
logger.trace("Directory : " + new File(directory).getCanonicalPath() + ", wildcard : " + wildcard);
IOFileFilter fileFilter = FileFilterUtils.and(
FileFilterUtils.fileFileFilter(),
new WildcardFileFilter(wildcard),
new LastModifiedFileFilter(deadTime));
initializeWatchMap(new File(directory), fileFilter, fields);
}
private void addStdIn(Event fields) {
logger.error("Watching stdin : not implemented yet");
}
private void initializeWatchMap(File directory, IOFileFilter fileFilter, Event fields) throws Exception {
if(!directory.isDirectory()) {
logger.warn("Directory " + directory + " does not exist");
return;
}
FileAlterationObserver observer = new FileAlterationObserver(directory, fileFilter);
FileModificationListener listener = new FileModificationListener(this, fields);
observer.addListener(listener);
observerList.add(observer);
observer.initialize();
for(File file : FileUtils.listFiles(directory, fileFilter, null)) {
FileState savedState = null;
if(savedStates != null) {
for(FileState state : savedStates) {
logger.trace("Comparing file : " + file + " with saved file : " + state.getFile());
if(file.equals(state.getFile())) {
savedState = state;
logger.debug("Match found with saved file " + state.getFile());
}
}
}
if(savedState == null) {
addFileToWatchMap(watchMap, file, fields);
} else {
addSavedFileToWatchMap(savedState, fields);
}
}
}
private void addSavedFileToWatchMap(FileState savedFileState, Event fields) {
try {
File file = savedFileState.getFile();
FileState state = new FileState(file);
state.setFields(fields);
int savedSignatureLength = savedFileState.getSignatureLength();
state.setSignatureLength(savedSignatureLength);
long savedSignature = savedFileState.getSignature();
int signatureLength = (int) (state.getSize() > MAX_SIGNATURE_LENGTH ? MAX_SIGNATURE_LENGTH : state.getSize());
long signature = FileSigner.computeSignature(state.getRandomAccessFile(), signatureLength);
if(signature == savedSignature) {
state.setPointer(savedFileState.getPointer());
logger.debug("Restoring signature of size : " + savedSignatureLength + " on file : " + file + " : " + savedSignature);
} else {
logger.debug("File " + file + " signature has changed");
logger.trace("Setting signature of size : " + signatureLength + " on file : " + file + " : " + signature);
}
state.setSignatureLength(signatureLength);
state.setSignature(signature);
watchMap.put(file, state);
} catch (IOException e) {
logger.error("Caught IOException : " + e.getMessage());
}
}
private void addFileToWatchMap(Map<File,FileState> map, File file, Event fields) {
try {
FileState state = new FileState(file);
state.setFields(fields);
int signatureLength = (int) (state.getSize() > MAX_SIGNATURE_LENGTH ? MAX_SIGNATURE_LENGTH : state.getSize());
state.setSignatureLength(signatureLength);
long signature = FileSigner.computeSignature(state.getRandomAccessFile(), signatureLength);
state.setSignature(signature);
logger.trace("Setting signature of size : " + signatureLength + " on file : " + file + " : " + signature);
map.put(file, state);
} catch(IOException e) {
logger.error("Caught IOException : " + e.getMessage());
}
}
public void onFileChange(File file, Event fields) {
try {
logger.debug("Change detected on file : " + file.getCanonicalPath());
addFileToWatchMap(changedWatchMap, file, fields);
} catch (IOException e) {
logger.error("Caught IOException : " + e.getMessage());
}
}
public void onFileCreate(File file, Event fields) {
try {
logger.debug("Create detected on file : " + file.getCanonicalPath());
addFileToWatchMap(changedWatchMap, file, fields);
} catch (IOException e) {
logger.error("Caught IOException : " + e.getMessage());
}
}
public void onFileDelete(File file) {
try {
logger.debug("Delete detected on file : " + file.getCanonicalPath());
watchMap.get(file).setDeleted();
} catch (IOException e) {
logger.error("Caught IOException : " + e.getMessage());
}
}
private void printWatchMap() throws IOException {
if(logger.isTraceEnabled()) {
logger.trace("WatchMap contents : ");
for(File file : watchMap.keySet()) {
FileState state = watchMap.get(file);
logger.trace("\tFile : " + file.getCanonicalPath() + " marked for deletion : " + state.isDeleted());
}
}
}
private void removeMarkedFilesFromWatchMap() throws IOException {
logger.trace("Removing deleted files from watchMap");
List<File> markedList = null;
for(File file : watchMap.keySet()) {
FileState state = watchMap.get(file);
if(state.isDeleted()) {
if(markedList == null) {
markedList = new ArrayList<File>();
}
markedList.add(file);
}
}
if(markedList != null) {
for(File file : markedList) {
FileState state = watchMap.remove(file);
state.getRandomAccessFile().close();
logger.trace("\tFile : " + file.getCanonicalFile() + " removed");
}
}
}
public void close() throws IOException {
logger.debug("Closing all files");
for(File file : watchMap.keySet()) {
FileState state = watchMap.get(file);
state.getRandomAccessFile().close();
}
}
}