/*
* 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.ElasticsearchParseException;
import org.elasticsearch.common.xcontent.NamedXContentRegistry;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.common.xcontent.XContentType;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Settings loader that loads (parses) the settings in a xcontent format by flattening them
* into a map.
*/
public abstract class XContentSettingsLoader implements SettingsLoader {
public abstract XContentType contentType();
private final boolean allowNullValues;
XContentSettingsLoader(boolean allowNullValues) {
this.allowNullValues = allowNullValues;
}
@Override
public Map<String, String> load(String source) throws IOException {
// It is safe to use EMPTY here because this never uses namedObject
try (XContentParser parser = XContentFactory.xContent(contentType()).createParser(NamedXContentRegistry.EMPTY, source)) {
return load(parser);
}
}
@Override
public Map<String, String> load(byte[] source) throws IOException {
// It is safe to use EMPTY here because this never uses namedObject
try (XContentParser parser = XContentFactory.xContent(contentType()).createParser(NamedXContentRegistry.EMPTY, source)) {
return load(parser);
}
}
public Map<String, String> load(XContentParser jp) throws IOException {
StringBuilder sb = new StringBuilder();
Map<String, String> settings = new HashMap<>();
List<String> path = new ArrayList<>();
XContentParser.Token token = jp.nextToken();
if (token == null) {
return settings;
}
if (token != XContentParser.Token.START_OBJECT) {
throw new ElasticsearchParseException("malformed, expected settings to start with 'object', instead was [{}]", token);
}
serializeObject(settings, sb, path, jp, null);
// ensure we reached the end of the stream
XContentParser.Token lastToken = null;
try {
while (!jp.isClosed() && (lastToken = jp.nextToken()) == null);
} catch (Exception e) {
throw new ElasticsearchParseException(
"malformed, expected end of settings but encountered additional content starting at line number: [{}], "
+ "column number: [{}]",
e, jp.getTokenLocation().lineNumber, jp.getTokenLocation().columnNumber);
}
if (lastToken != null) {
throw new ElasticsearchParseException(
"malformed, expected end of settings but encountered additional content starting at line number: [{}], "
+ "column number: [{}]",
jp.getTokenLocation().lineNumber, jp.getTokenLocation().columnNumber);
}
return settings;
}
private void serializeObject(Map<String, String> settings, StringBuilder sb, List<String> path, XContentParser parser,
String objFieldName) throws IOException {
if (objFieldName != null) {
path.add(objFieldName);
}
String currentFieldName = null;
XContentParser.Token token;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.START_OBJECT) {
serializeObject(settings, sb, path, parser, currentFieldName);
} else if (token == XContentParser.Token.START_ARRAY) {
serializeArray(settings, sb, path, parser, currentFieldName);
} else if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (token == XContentParser.Token.VALUE_NULL) {
serializeValue(settings, sb, path, parser, currentFieldName, true);
} else {
serializeValue(settings, sb, path, parser, currentFieldName, false);
}
}
if (objFieldName != null) {
path.remove(path.size() - 1);
}
}
private void serializeArray(Map<String, String> settings, StringBuilder sb, List<String> path, XContentParser parser, String fieldName)
throws IOException {
XContentParser.Token token;
int counter = 0;
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
if (token == XContentParser.Token.START_OBJECT) {
serializeObject(settings, sb, path, parser, fieldName + '.' + (counter++));
} else if (token == XContentParser.Token.START_ARRAY) {
serializeArray(settings, sb, path, parser, fieldName + '.' + (counter++));
} else if (token == XContentParser.Token.FIELD_NAME) {
fieldName = parser.currentName();
} else if (token == XContentParser.Token.VALUE_NULL) {
serializeValue(settings, sb, path, parser, fieldName + '.' + (counter++), true);
// ignore
} else {
serializeValue(settings, sb, path, parser, fieldName + '.' + (counter++), false);
}
}
}
private void serializeValue(Map<String, String> settings, StringBuilder sb, List<String> path, XContentParser parser, String fieldName,
boolean isNull) throws IOException {
sb.setLength(0);
for (String pathEle : path) {
sb.append(pathEle).append('.');
}
sb.append(fieldName);
String key = sb.toString();
String currentValue = isNull ? null : parser.text();
if (settings.containsKey(key)) {
throw new ElasticsearchParseException(
"duplicate settings key [{}] found at line number [{}], column number [{}], previous value [{}], current value [{}]",
key,
parser.getTokenLocation().lineNumber,
parser.getTokenLocation().columnNumber,
settings.get(key),
currentValue
);
}
if (currentValue == null && !allowNullValues) {
throw new ElasticsearchParseException(
"null-valued setting found for key [{}] found at line number [{}], column number [{}]",
key,
parser.getTokenLocation().lineNumber,
parser.getTokenLocation().columnNumber
);
}
settings.put(key, currentValue);
}
}