/**
* Copyright 2014 Netflix, Inc.
*
* 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.netflix.config;
import com.google.common.base.Splitter;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArrayList;
import org.apache.commons.configuration.AbstractConfiguration;
import org.apache.commons.configuration.Configuration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.base.Splitter;
import com.netflix.config.validation.ValidationException;
/**
* Apply the {@link WatchedUpdateResult} to the configuration.<BR>
*
* If the result is a full result from source, each property in the result is added/set in the configuration. Any
* property that is in the configuration - but not in the result - is deleted if ignoreDeletesFromSource is false.<BR>
*
* If the result is incremental, properties will be added and changed from the partial result in the configuration.
* Deleted properties are deleted from configuration iff ignoreDeletesFromSource is false.
*
* This code is shared by both {@link AbstractPollingScheduler} and {@link DynamicWatchedConfiguration}.
*/
public class DynamicPropertyUpdater {
private static Logger logger = LoggerFactory.getLogger(DynamicPropertyUpdater.class);
/**
* Updates the properties in the config param given the contents of the result param.
*
* @param result
* either an incremental or full set of data
* @param config
* underlying config map
* @param ignoreDeletesFromSource
* if true, deletes will be skipped
*/
public void updateProperties(final WatchedUpdateResult result, final Configuration config,
final boolean ignoreDeletesFromSource) {
if (result == null || !result.hasChanges()) {
return;
}
logger.debug("incremental result? [{}]", result.isIncremental());
logger.debug("ignored deletes from source? [{}]", ignoreDeletesFromSource);
if (!result.isIncremental()) {
Map<String, Object> props = result.getComplete();
if (props == null) {
return;
}
for (Entry<String, Object> entry : props.entrySet()) {
addOrChangeProperty(entry.getKey(), entry.getValue(), config);
}
Set<String> existingKeys = new HashSet<String>();
for (Iterator<String> i = config.getKeys(); i.hasNext();) {
existingKeys.add(i.next());
}
if (!ignoreDeletesFromSource) {
for (String key : existingKeys) {
if (!props.containsKey(key)) {
deleteProperty(key, config);
}
}
}
} else {
Map<String, Object> props = result.getAdded();
if (props != null) {
for (Entry<String, Object> entry : props.entrySet()) {
addOrChangeProperty(entry.getKey(), entry.getValue(), config);
}
}
props = result.getChanged();
if (props != null) {
for (Entry<String, Object> entry : props.entrySet()) {
addOrChangeProperty(entry.getKey(), entry.getValue(), config);
}
}
if (!ignoreDeletesFromSource) {
props = result.getDeleted();
if (props != null) {
for (String name : props.keySet()) {
deleteProperty(name, config);
}
}
}
}
}
/**
* Add or update the property in the underlying config depending on if it exists
*
* @param name
* @param newValue
* @param config
*/
void addOrChangeProperty(final String name, final Object newValue, final Configuration config) {
// We do not want to abort the operation due to failed validation on one property
try {
if (!config.containsKey(name)) {
logger.debug("adding property key [{}], value [{}]", name, newValue);
config.addProperty(name, newValue);
} else {
Object oldValue = config.getProperty(name);
if (newValue != null) {
Object newValueArray;
if (oldValue instanceof CopyOnWriteArrayList && AbstractConfiguration.getDefaultListDelimiter() != '\0'){
newValueArray =
new CopyOnWriteArrayList();
Iterable<String> stringiterator = Splitter.on(AbstractConfiguration.getDefaultListDelimiter()).omitEmptyStrings().trimResults().split((String)newValue);
for(String s :stringiterator){
((CopyOnWriteArrayList) newValueArray).add(s);
}
} else {
newValueArray = newValue;
}
if (!newValueArray.equals(oldValue)) {
logger.debug("updating property key [{}], value [{}]", name, newValue);
config.setProperty(name, newValue);
}
} else if (oldValue != null) {
logger.debug("nulling out property key [{}]", name);
config.setProperty(name, null);
}
}
} catch (ValidationException e) {
logger.warn("Validation failed for property " + name, e);
}
}
/**
* Delete a property in the underlying config
*
* @param key
* @param config
*/
void deleteProperty(final String key, final Configuration config) {
if (config.containsKey(key)) {
logger.debug("deleting property key [" + key + "]");
config.clearProperty(key);
}
}
}