| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF 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.apache.hadoop.tools.rumen; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.Path; |
| |
| /** |
| * Reading JSON-encoded cluster topology and produce the parsed |
| * {@link LoggedNetworkTopology} object. |
| */ |
| public class ClusterTopologyReader { |
| private LoggedNetworkTopology topology; |
| |
| private void readTopology(JsonObjectMapperParser<LoggedNetworkTopology> parser) |
| throws IOException { |
| try { |
| topology = parser.getNext(); |
| if (topology == null) { |
| throw new IOException( |
| "Input file does not contain valid topology data."); |
| } |
| } finally { |
| parser.close(); |
| } |
| } |
| |
| /** |
| * Constructor. |
| * |
| * @param path |
| * Path to the JSON-encoded topology file, possibly compressed. |
| * @param conf |
| * @throws IOException |
| */ |
| public ClusterTopologyReader(Path path, Configuration conf) |
| throws IOException { |
| JsonObjectMapperParser<LoggedNetworkTopology> parser = new JsonObjectMapperParser<LoggedNetworkTopology>( |
| path, LoggedNetworkTopology.class, conf); |
| readTopology(parser); |
| } |
| |
| /** |
| * Constructor. |
| * |
| * @param input |
| * The input stream for the JSON-encoded topology data. |
| */ |
| public ClusterTopologyReader(InputStream input) throws IOException { |
| JsonObjectMapperParser<LoggedNetworkTopology> parser = new JsonObjectMapperParser<LoggedNetworkTopology>( |
| input, LoggedNetworkTopology.class); |
| readTopology(parser); |
| } |
| |
| /** |
| * Get the {@link LoggedNetworkTopology} object. |
| * |
| * @return The {@link LoggedNetworkTopology} object parsed from the input. |
| */ |
| public LoggedNetworkTopology get() { |
| return topology; |
| } |
| } |