| /** |
| * 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.storm.trident.topology.state; |
| |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.SortedMap; |
| import java.util.TreeMap; |
| import org.apache.storm.shade.org.apache.zookeeper.KeeperException; |
| import org.apache.storm.utils.Utils; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class RotatingTransactionalState { |
| private static final Logger LOG = LoggerFactory.getLogger(RotatingTransactionalState.class); |
| private TransactionalState state; |
| private String subdir; |
| private TreeMap<Long, Object> curr = new TreeMap<Long, Object>(); |
| |
| public RotatingTransactionalState(TransactionalState state, String subdir) { |
| this.state = state; |
| this.subdir = subdir; |
| state.mkdir(subdir); |
| sync(); |
| LOG.debug("Created {}", this); |
| } |
| |
| public Object getLastState() { |
| if (curr.isEmpty()) { |
| return null; |
| } else { |
| return curr.lastEntry().getValue(); |
| } |
| } |
| |
| public void overrideState(long txid, Object state) { |
| LOG.debug("Overriding state. [txid = {}], [state = {}]", txid, state); |
| LOG.trace("[{}]", this); |
| |
| this.state.setData(txPath(txid), state); |
| curr.put(txid, state); |
| |
| LOG.trace("Overriding state complete. [{}]", this); |
| } |
| |
| public void removeState(long txid) { |
| Object state = null; |
| if (curr.containsKey(txid)) { |
| state = curr.remove(txid); |
| this.state.delete(txPath(txid)); |
| } |
| LOG.debug("Removed [state = {}], [txid = {}]", state, txid); |
| LOG.trace("[{}]", this); |
| } |
| |
| public Object getState(long txid) { |
| final Object state = curr.get(txid); |
| LOG.debug("Getting state. [txid = {}] => [state = {}]", txid, state); |
| LOG.trace("Internal state [{}]", this); |
| return state; |
| } |
| |
| public Object getState(long txid, StateInitializer init) { |
| if (!curr.containsKey(txid)) { |
| SortedMap<Long, Object> prevMap = curr.headMap(txid); |
| SortedMap<Long, Object> afterMap = curr.tailMap(txid); |
| |
| Long prev = null; |
| if (!prevMap.isEmpty()) { |
| prev = prevMap.lastKey(); |
| } |
| |
| Object data; |
| if (afterMap.isEmpty()) { |
| Object prevData; |
| if (prev != null) { |
| prevData = curr.get(prev); |
| } else { |
| prevData = null; |
| } |
| data = init.init(txid, prevData); |
| } else { |
| data = null; |
| } |
| curr.put(txid, data); |
| state.setData(txPath(txid), data); |
| } |
| Object state = curr.get(txid); |
| LOG.debug("Getting or initializing state. [txid = {}] => [state = {}]", txid, state); |
| LOG.trace("[{}]", this); |
| return state; |
| } |
| |
| public Object getPreviousState(long txid) { |
| final SortedMap<Long, Object> prevMap = curr.headMap(txid); |
| Object state; |
| |
| if (prevMap.isEmpty()) { |
| state = null; |
| } else { |
| state = prevMap.get(prevMap.lastKey()); |
| } |
| |
| LOG.debug("Getting previous [state = {}], [txid = {}]", state, txid); |
| LOG.trace("[{}]", this); |
| return state; |
| } |
| |
| public boolean hasCache(long txid) { |
| return curr.containsKey(txid); |
| } |
| |
| /** |
| * Returns null if it was created, the value otherwise. |
| */ |
| public Object getStateOrCreate(long txid, StateInitializer init) { |
| Object state; |
| if (curr.containsKey(txid)) { |
| state = curr.get(txid); |
| } else { |
| getState(txid, init); |
| state = null; |
| } |
| return state; |
| } |
| |
| public void cleanupBefore(long txid) { |
| SortedMap<Long, Object> toDelete = curr.headMap(txid); |
| for (long tx : new HashSet<Long>(toDelete.keySet())) { |
| curr.remove(tx); |
| try { |
| state.delete(txPath(tx)); |
| } catch (RuntimeException e) { |
| // Ignore NoNodeExists exceptions because when sync() it may populate curr with stale data since |
| // zookeeper reads are eventually consistent. |
| if (!Utils.exceptionCauseIsInstanceOf(KeeperException.NoNodeException.class, e)) { |
| throw e; |
| } |
| } |
| } |
| } |
| |
| private void sync() { |
| List<String> txids = state.list(subdir); |
| for (String txid : txids) { |
| Object data = state.getData(txPath(txid)); |
| curr.put(Long.parseLong(txid), data); |
| } |
| } |
| |
| private String txPath(long tx) { |
| return txPath("" + tx); |
| } |
| |
| private String txPath(String tx) { |
| return subdir + "/" + tx; |
| } |
| |
| @Override |
| public String toString() { |
| return "RotatingTransactionalState{" |
| + "state=" + state |
| + ", subdir='" + subdir + '\'' |
| + ", curr=" + curr |
| + '}'; |
| } |
| |
| public static interface StateInitializer { |
| Object init(long txid, Object lastState); |
| } |
| } |