/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.common.settings.loader;
import org.elasticsearch.common.Nullable;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import static com.google.common.collect.Maps.newHashMap;
/**
* Provides the ability to load settings (in the form of a simple Map) from
* the actual source content that represents them.
*/
public interface SettingsLoader {
static class Helper {
public static Map<String, String> loadNestedFromMap(@Nullable Map map) {
Map<String, String> settings = newHashMap();
if (map == null) {
return settings;
}
StringBuilder sb = new StringBuilder();
List<String> path = new ArrayList<>();
serializeMap(settings, sb, path, map);
return settings;
}
private static void serializeMap(Map<String, String> settings, StringBuilder sb, List<String> path, Map<Object, Object> map) {
for (Map.Entry<Object, Object> entry : map.entrySet()) {
if (entry.getValue() instanceof Map) {
path.add((String) entry.getKey());
serializeMap(settings, sb, path, (Map<Object, Object>) entry.getValue());
path.remove(path.size() - 1);
} else if (entry.getValue() instanceof List) {
path.add((String) entry.getKey());
serializeList(settings, sb, path, (List) entry.getValue());
path.remove(path.size() - 1);
} else {
serializeValue(settings, sb, path, (String) entry.getKey(), entry.getValue());
}
}
}
private static void serializeList(Map<String, String> settings, StringBuilder sb, List<String> path, List list) {
int counter = 0;
for (Object listEle : list) {
if (listEle instanceof Map) {
path.add(Integer.toString(counter));
serializeMap(settings, sb, path, (Map<Object, Object>) listEle);
path.remove(path.size() - 1);
} else if (listEle instanceof List) {
path.add(Integer.toString(counter));
serializeList(settings, sb, path, (List) listEle);
path.remove(path.size() - 1);
} else {
serializeValue(settings, sb, path, Integer.toString(counter), listEle);
}
counter++;
}
}
private static void serializeValue(Map<String, String> settings, StringBuilder sb, List<String> path, String name, Object value) {
if (value == null) {
return;
}
sb.setLength(0);
for (String pathEle : path) {
sb.append(pathEle).append('.');
}
sb.append(name);
settings.put(sb.toString(), value.toString());
}
}
/**
* Loads (parses) the settings from a source string.
*/
Map<String, String> load(String source) throws IOException;
/**
* Loads (parses) the settings from a source bytes.
*/
Map<String, String> load(byte[] source) throws IOException;
}