| /* |
| * 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.solr.client.solrj.io; |
| |
| import java.io.IOException; |
| import java.util.Date; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| |
| import org.apache.solr.client.solrj.io.stream.CloudSolrStream; |
| import org.apache.solr.client.solrj.io.stream.StreamContext; |
| import org.apache.solr.common.params.ModifiableSolrParams; |
| |
| import static org.apache.solr.common.params.CommonParams.SORT; |
| import static org.apache.solr.common.params.CommonParams.VERSION_FIELD; |
| |
| |
| /** |
| * The Model cache keeps a local in-memory copy of models |
| */ |
| |
| public class ModelCache { |
| |
| private LRU models; |
| private String defaultZkHost; |
| private SolrClientCache solrClientCache; |
| |
| public ModelCache(int size, |
| String defaultZkHost, |
| SolrClientCache solrClientCache) { |
| this.models = new LRU(size); |
| this.defaultZkHost = defaultZkHost; |
| this.solrClientCache = solrClientCache; |
| } |
| |
| public Tuple getModel(String collection, |
| String modelID, |
| long checkMillis) throws IOException { |
| return getModel(defaultZkHost, collection, modelID, checkMillis); |
| } |
| |
| public Tuple getModel(String zkHost, |
| String collection, |
| String modelID, |
| long checkMillis) throws IOException { |
| Model model = null; |
| long currentTime = new Date().getTime(); |
| synchronized (this) { |
| model = models.get(modelID); |
| if(model != null && ((currentTime - model.getLastChecked()) <= checkMillis)) { |
| return model.getTuple(); |
| } |
| |
| if(model != null){ |
| //model is expired |
| models.remove(modelID); |
| } |
| } |
| |
| //Model is not in cache or has expired so fetch the model |
| ModifiableSolrParams params = new ModifiableSolrParams(); |
| params.set("q","name_s:"+modelID); |
| params.set("fl", "terms_ss, idfs_ds, weights_ds, iteration_i, _version_"); |
| params.set(SORT, "iteration_i desc"); |
| StreamContext streamContext = new StreamContext(); |
| streamContext.setSolrClientCache(solrClientCache); |
| CloudSolrStream stream = new CloudSolrStream(zkHost, collection, params); |
| stream.setStreamContext(streamContext); |
| Tuple tuple = null; |
| try { |
| stream.open(); |
| tuple = stream.read(); |
| if (tuple.EOF) { |
| return null; |
| } |
| } finally { |
| stream.close(); |
| } |
| |
| synchronized (this) { |
| //check again to see if another thread has updated the same model |
| Model m = models.get(modelID); |
| if (m != null) { |
| Tuple t = m.getTuple(); |
| long v = t.getLong(VERSION_FIELD); |
| if (v >= tuple.getLong(VERSION_FIELD)) { |
| return t; |
| } else { |
| models.put(modelID, new Model(tuple, currentTime)); |
| return tuple; |
| } |
| } else { |
| models.put(modelID, new Model(tuple, currentTime)); |
| return tuple; |
| } |
| } |
| } |
| |
| private static class Model { |
| private Tuple tuple; |
| private long lastChecked; |
| |
| public Model(Tuple tuple, long lastChecked) { |
| this.tuple = tuple; |
| this.lastChecked = lastChecked; |
| } |
| |
| public Tuple getTuple() { |
| return tuple; |
| } |
| |
| public long getLastChecked() { |
| return lastChecked; |
| } |
| } |
| |
| private static class LRU extends LinkedHashMap<String, Model> { |
| |
| private int maxSize; |
| |
| public LRU(int maxSize) { |
| this.maxSize = maxSize; |
| } |
| |
| public boolean removeEldestEntry(@SuppressWarnings({"rawtypes"})Map.Entry eldest) { |
| if(size()> maxSize) { |
| return true; |
| } else { |
| return false; |
| } |
| } |
| } |
| } |