com.arpnetworking.configuration.triggers.DirectoryTrigger Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of metrics-cluster-aggregator Show documentation
Show all versions of metrics-cluster-aggregator Show documentation
(Re)Aggregates host level statistics across clusters and writes both host and cluster statistics to various destinations.
/*
* Copyright 2014 Groupon.com
*
* 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.
*/
package com.arpnetworking.configuration.triggers;
import com.arpnetworking.commons.builder.OvalBuilder;
import com.arpnetworking.configuration.Trigger;
import com.arpnetworking.logback.annotations.LogValue;
import com.arpnetworking.steno.LogValueMapFactory;
import com.arpnetworking.steno.Logger;
import com.arpnetworking.steno.LoggerFactory;
import com.google.common.base.MoreObjects;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import net.sf.oval.constraint.NotNull;
import java.io.File;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.regex.Pattern;
/**
* Trigger implementation based on the contents of a directory.
* Configurable to either monitor all content or only specific content. The
* FileTrigger is used to determine whether a file changed. This
* is intended to monitor the files in a single directory and is not designed
* to monitor a directory tree (e.g. it is not recursive).
*
* Note: If you are monitoring a directory in which files are created
* and removed this implementation needs to be modified to purge file trigger
* instances when a file is removed!
*
* @author Ville Koskela (ville dot koskela at inscopemetrics dot com)
*/
public final class DirectoryTrigger implements Trigger {
@Override
public boolean evaluateAndReset() {
final boolean exists = _directory.exists() && _directory.isDirectory();
// Track directory contents
if (exists) {
for (final File file : MoreObjects.firstNonNull(_directory.listFiles(), EMPTY_FILE_ARRAY)) {
// Note: To save memory in cases where a directory contains
// temporary files (e.g. create, destroy and never recreate)
// we should remove any triggers for files that no longer exist
// also noting that a deletion should trigger a reload!
// TODO(vkoskela): Implement memory saving [MAI-444]
if (!_evaluationFileTriggers.containsKey(file.getName()) && isFileMonitored(file)) {
LOGGER.debug()
.setMessage("Monitoring new file")
.addData("file", file)
.log();
_evaluationFileTriggers.put(
file.getName(),
new FileTrigger.Builder()
.setFile(file)
.build());
}
}
} else {
_evaluationFileTriggers.clear();
}
// Check files for changes
boolean fileChanged = false;
for (final FileTrigger fileTrigger : _evaluationFileTriggers.values()) {
fileChanged = fileChanged || fileTrigger.evaluateAndReset();
}
// Handle directory creation/removal
if (!_exists.isPresent()) {
LOGGER.debug()
.setMessage("Trigger initialized")
.addData("directory", _directory)
.addData("exists", exists)
.log();
_exists = Optional.of(exists);
return true;
} else if (_exists.get() != exists) {
LOGGER.debug()
.setMessage("Directory created or removed")
.addData("directory", _directory)
.addData("exists", exists)
.log();
_exists = Optional.of(exists);
return true;
}
if (fileChanged) {
LOGGER.debug()
.setMessage("Directory contents changed")
.addData("directory", _directory)
.addData("exists", true)
.log();
}
return fileChanged;
}
private boolean isFileMonitored(final File file) {
if (_fileNames.isEmpty() && _fileNamePatterns.isEmpty()) {
return true;
} else {
if (_fileNames.contains(file.getName())) {
return true;
}
for (final Pattern pattern : _fileNamePatterns) {
if (pattern.matcher(file.getName()).matches()) {
return true;
}
}
}
return false;
}
/**
* Generate a Steno log compatible representation.
*
* @return Steno log compatible representation.
*/
@LogValue
public Object toLogValue() {
return LogValueMapFactory.builder()
.put("directory", _directory)
.put("exists", _exists)
.put("fileNames", _fileNames)
.put("fileNamePatterns", _fileNamePatterns)
.put("evaluationFileTriggers", _evaluationFileTriggers)
.build();
}
@Override
public String toString() {
return toLogValue().toString();
}
private DirectoryTrigger(final Builder builder) {
_directory = builder._directory;
_fileNames = Sets.newHashSet(builder._fileNames);
_fileNamePatterns = builder._fileNamePatterns;
}
private final File _directory;
private final Set _fileNames;
private final List _fileNamePatterns;
private Optional _exists = Optional.empty();
private final Map _evaluationFileTriggers = Maps.newHashMap();
private static final File[] EMPTY_FILE_ARRAY = new File[0];
private static final Logger LOGGER = LoggerFactory.getLogger(DirectoryTrigger.class);
/**
* Builder for DirectoryTrigger.
*/
public static final class Builder extends OvalBuilder {
/**
* Public constructor.
*/
public Builder() {
super(DirectoryTrigger::new);
}
/**
* Set the directory.
*
* @param value The directory.
* @return This Builder instance.
*/
public Builder setDirectory(final File value) {
_directory = value;
return this;
}
/**
* Set the Collection of file names. Optional. Default is
* an empty list (e.g. all files). Cannot be null.
*
* Note: Both the file names and file name patterns must be
* empty (e.g. unset) in order to consider all files in the directory.
*
* @param value The Collection of file names.
* @return This Builder instance.
*/
public Builder setFileNames(final Collection value) {
_fileNames = Lists.newArrayList(value);
return this;
}
/**
* Add a file name.
*
* @param value The file name.
* @return This Builder instance.
*/
public Builder addFileName(final String value) {
if (_fileNames == null) {
_fileNames = Lists.newArrayList(value);
} else {
_fileNames.add(value);
}
return this;
}
/**
* Set the Collection of file name patterns. Optional.
* Default is an empty list (e.g. all files). Cannot be null.
*
* Note: Both the file names and file name patterns must be
* empty (e.g. unset) in order to consider all files in the directory.
*
* @param value The Collection of file name patterns.
* @return This Builder instance.
*/
public Builder setFileNamePatterns(final Collection value) {
_fileNamePatterns = Lists.newArrayList(value);
return this;
}
/**
* Add a file name pattern.
*
* @param value The file name pattern.
* @return This Builder instance.
*/
public Builder addFileNamePattern(final Pattern value) {
if (_fileNamePatterns == null) {
_fileNamePatterns = Lists.newArrayList(value);
} else {
_fileNamePatterns.add(value);
}
return this;
}
@NotNull
private File _directory;
@NotNull
private List _fileNames = Lists.newArrayList();
@NotNull
private List _fileNamePatterns = Lists.newArrayList();
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy