Madan Jampani | 79924fa | 2016-09-13 13:57:03 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2016-present Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.onosproject.store.primitives.resources.impl; |
| 18 | |
| 19 | import static org.slf4j.LoggerFactory.getLogger; |
| 20 | import io.atomix.copycat.server.Commit; |
| 21 | import io.atomix.copycat.server.Snapshottable; |
| 22 | import io.atomix.copycat.server.StateMachineExecutor; |
| 23 | import io.atomix.copycat.server.session.ServerSession; |
| 24 | import io.atomix.copycat.server.session.SessionListener; |
| 25 | import io.atomix.copycat.server.storage.snapshot.SnapshotReader; |
| 26 | import io.atomix.copycat.server.storage.snapshot.SnapshotWriter; |
| 27 | import io.atomix.resource.ResourceStateMachine; |
| 28 | |
| 29 | import java.util.HashMap; |
| 30 | import java.util.Map; |
| 31 | import java.util.Optional; |
| 32 | import java.util.Properties; |
| 33 | import java.util.Queue; |
| 34 | import java.util.concurrent.atomic.AtomicLong; |
| 35 | import java.util.stream.Collectors; |
| 36 | |
| 37 | import org.onlab.util.Match; |
| 38 | import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Clear; |
| 39 | import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Get; |
| 40 | import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.GetChildren; |
| 41 | import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Listen; |
| 42 | import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Unlisten; |
| 43 | import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Update; |
| 44 | import org.onosproject.store.primitives.resources.impl.DocumentTreeUpdateResult.Status; |
| 45 | import org.onosproject.store.service.DocumentPath; |
| 46 | import org.onosproject.store.service.DocumentTree; |
| 47 | import org.onosproject.store.service.DocumentTreeEvent; |
| 48 | import org.onosproject.store.service.DocumentTreeEvent.Type; |
| 49 | import org.onosproject.store.service.IllegalDocumentModificationException; |
| 50 | import org.onosproject.store.service.NoSuchDocumentPathException; |
| 51 | import org.onosproject.store.service.Versioned; |
| 52 | import org.slf4j.Logger; |
| 53 | |
| 54 | import com.google.common.base.Throwables; |
| 55 | import com.google.common.collect.ImmutableList; |
| 56 | import com.google.common.collect.Maps; |
| 57 | import com.google.common.collect.Queues; |
| 58 | |
| 59 | /** |
| 60 | * State Machine for {@link AtomixDocumentTree} resource. |
| 61 | */ |
| 62 | public class AtomixDocumentTreeState |
| 63 | extends ResourceStateMachine |
| 64 | implements SessionListener, Snapshottable { |
| 65 | |
| 66 | private final Logger log = getLogger(getClass()); |
| 67 | private final Map<Long, Commit<? extends Listen>> listeners = new HashMap<>(); |
Madan Jampani | 2914e4e | 2016-09-13 17:48:56 -0700 | [diff] [blame^] | 68 | private AtomicLong versionCounter = new AtomicLong(0); |
Madan Jampani | 79924fa | 2016-09-13 13:57:03 -0700 | [diff] [blame] | 69 | private final DocumentTree<TreeNodeValue> docTree = new DefaultDocumentTree<>(versionCounter::incrementAndGet); |
| 70 | |
| 71 | public AtomixDocumentTreeState(Properties properties) { |
| 72 | super(properties); |
| 73 | } |
| 74 | |
| 75 | @Override |
| 76 | public void snapshot(SnapshotWriter writer) { |
| 77 | writer.writeLong(versionCounter.get()); |
| 78 | } |
| 79 | |
| 80 | @Override |
| 81 | public void install(SnapshotReader reader) { |
Madan Jampani | 2914e4e | 2016-09-13 17:48:56 -0700 | [diff] [blame^] | 82 | versionCounter = new AtomicLong(reader.readLong()); |
Madan Jampani | 79924fa | 2016-09-13 13:57:03 -0700 | [diff] [blame] | 83 | } |
| 84 | |
| 85 | @Override |
| 86 | protected void configure(StateMachineExecutor executor) { |
| 87 | // Listeners |
| 88 | executor.register(Listen.class, this::listen); |
| 89 | executor.register(Unlisten.class, this::unlisten); |
| 90 | // queries |
| 91 | executor.register(Get.class, this::get); |
| 92 | executor.register(GetChildren.class, this::getChildren); |
| 93 | // commands |
| 94 | executor.register(Update.class, this::update); |
| 95 | executor.register(Clear.class, this::clear); |
| 96 | } |
| 97 | |
| 98 | protected void listen(Commit<? extends Listen> commit) { |
| 99 | Long sessionId = commit.session().id(); |
| 100 | if (listeners.putIfAbsent(sessionId, commit) != null) { |
| 101 | commit.close(); |
| 102 | return; |
| 103 | } |
Madan Jampani | 2914e4e | 2016-09-13 17:48:56 -0700 | [diff] [blame^] | 104 | commit.session().onStateChange( |
Madan Jampani | 79924fa | 2016-09-13 13:57:03 -0700 | [diff] [blame] | 105 | state -> { |
| 106 | if (state == ServerSession.State.CLOSED |
| 107 | || state == ServerSession.State.EXPIRED) { |
| 108 | Commit<? extends Listen> listener = listeners.remove(sessionId); |
| 109 | if (listener != null) { |
| 110 | listener.close(); |
| 111 | } |
| 112 | } |
| 113 | }); |
| 114 | } |
| 115 | |
| 116 | protected void unlisten(Commit<? extends Unlisten> commit) { |
| 117 | try { |
| 118 | closeListener(commit.session().id()); |
| 119 | } finally { |
| 120 | commit.close(); |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | protected Versioned<byte[]> get(Commit<? extends Get> commit) { |
| 125 | try { |
| 126 | Versioned<TreeNodeValue> value = docTree.get(commit.operation().path()); |
| 127 | return value == null ? null : value.map(node -> node == null ? null : node.value()); |
| 128 | } finally { |
| 129 | commit.close(); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | protected Map<String, Versioned<byte[]>> getChildren(Commit<? extends GetChildren> commit) { |
| 134 | try { |
| 135 | Map<String, Versioned<TreeNodeValue>> children = docTree.getChildren(commit.operation().path()); |
| 136 | return children == null |
| 137 | ? null : Maps.newHashMap(Maps.transformValues(children, |
| 138 | value -> value.map(TreeNodeValue::value))); |
| 139 | } finally { |
| 140 | commit.close(); |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | protected DocumentTreeUpdateResult<byte[]> update(Commit<? extends Update> commit) { |
| 145 | DocumentTreeUpdateResult<byte[]> result = null; |
| 146 | DocumentPath path = commit.operation().path(); |
| 147 | boolean updated = false; |
| 148 | Versioned<TreeNodeValue> currentValue = docTree.get(path); |
| 149 | try { |
| 150 | Match<Long> versionMatch = commit.operation().versionMatch(); |
| 151 | Match<byte[]> valueMatch = commit.operation().valueMatch(); |
| 152 | |
| 153 | if (versionMatch.matches(currentValue == null ? null : currentValue.version()) |
| 154 | && valueMatch.matches(currentValue == null ? null : currentValue.value().value())) { |
| 155 | if (commit.operation().value() == null) { |
| 156 | docTree.removeNode(path); |
| 157 | } else { |
| 158 | docTree.set(path, new NonTransactionalCommit(commit)); |
| 159 | } |
| 160 | updated = true; |
| 161 | } |
| 162 | Versioned<TreeNodeValue> newValue = updated ? docTree.get(path) : currentValue; |
| 163 | Status updateStatus = updated |
| 164 | ? Status.OK : commit.operation().value() == null ? Status.INVALID_PATH : Status.NOOP; |
| 165 | result = new DocumentTreeUpdateResult<>(path, |
| 166 | updateStatus, |
| 167 | newValue == null |
| 168 | ? null : newValue.map(TreeNodeValue::value), |
| 169 | currentValue == null |
| 170 | ? null : currentValue.map(TreeNodeValue::value)); |
| 171 | } catch (IllegalDocumentModificationException e) { |
| 172 | result = DocumentTreeUpdateResult.illegalModification(path); |
| 173 | } catch (NoSuchDocumentPathException e) { |
| 174 | result = DocumentTreeUpdateResult.invalidPath(path); |
| 175 | } catch (Exception e) { |
| 176 | log.error("Failed to apply {} to state machine", commit.operation(), e); |
| 177 | throw Throwables.propagate(e); |
| 178 | } finally { |
| 179 | if (updated) { |
| 180 | if (currentValue != null) { |
| 181 | currentValue.value().discard(); |
| 182 | } |
| 183 | } else { |
| 184 | commit.close(); |
| 185 | } |
| 186 | } |
| 187 | notifyListeners(path, result); |
| 188 | return result; |
| 189 | } |
| 190 | |
| 191 | protected void clear(Commit<? extends Clear> commit) { |
| 192 | try { |
| 193 | Queue<DocumentPath> toClearQueue = Queues.newArrayDeque(); |
| 194 | Map<String, Versioned<TreeNodeValue>> topLevelChildren = docTree.getChildren(DocumentPath.from("root")); |
| 195 | toClearQueue.addAll(topLevelChildren.keySet() |
| 196 | .stream() |
| 197 | .map(name -> new DocumentPath(name, DocumentPath.from("root"))) |
| 198 | .collect(Collectors.toList())); |
| 199 | while (!toClearQueue.isEmpty()) { |
| 200 | DocumentPath path = toClearQueue.remove(); |
| 201 | Map<String, Versioned<TreeNodeValue>> children = docTree.getChildren(path); |
| 202 | if (children.size() == 0) { |
| 203 | docTree.removeNode(path).value().discard(); |
| 204 | } else { |
| 205 | children.keySet() |
| 206 | .stream() |
| 207 | .forEach(name -> toClearQueue.add(new DocumentPath(name, path))); |
| 208 | toClearQueue.add(path); |
| 209 | } |
| 210 | } |
| 211 | } finally { |
| 212 | commit.close(); |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * Interface implemented by tree node values. |
| 218 | */ |
| 219 | private interface TreeNodeValue { |
| 220 | /** |
| 221 | * Returns the raw {@code byte[]}. |
| 222 | * |
| 223 | * @return raw value |
| 224 | */ |
| 225 | byte[] value(); |
| 226 | |
| 227 | /** |
| 228 | * Discards the value by invoke appropriate clean up actions. |
| 229 | */ |
| 230 | void discard(); |
| 231 | } |
| 232 | |
| 233 | /** |
| 234 | * A {@code TreeNodeValue} that is derived from a non-transactional update |
| 235 | * i.e. via any standard tree update operation. |
| 236 | */ |
| 237 | private class NonTransactionalCommit implements TreeNodeValue { |
| 238 | private final Commit<? extends Update> commit; |
| 239 | |
| 240 | public NonTransactionalCommit(Commit<? extends Update> commit) { |
| 241 | this.commit = commit; |
| 242 | } |
| 243 | |
| 244 | @Override |
| 245 | public byte[] value() { |
| 246 | return commit.operation().value(); |
| 247 | } |
| 248 | |
| 249 | @Override |
| 250 | public void discard() { |
| 251 | commit.close(); |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | private void notifyListeners(DocumentPath path, DocumentTreeUpdateResult<byte[]> result) { |
| 256 | if (result.status() != Status.OK) { |
| 257 | return; |
| 258 | } |
| 259 | DocumentTreeEvent<byte[]> event = |
| 260 | new DocumentTreeEvent<>(path, |
| 261 | result.created() ? Type.CREATED : result.newValue() == null ? Type.DELETED : Type.UPDATED, |
| 262 | Optional.ofNullable(result.newValue()), |
| 263 | Optional.ofNullable(result.oldValue())); |
Madan Jampani | 2914e4e | 2016-09-13 17:48:56 -0700 | [diff] [blame^] | 264 | listeners.values() |
| 265 | .forEach(commit -> commit.session() |
| 266 | .publish(AtomixDocumentTree.CHANGE_SUBJECT, |
| 267 | ImmutableList.of(event))); |
Madan Jampani | 79924fa | 2016-09-13 13:57:03 -0700 | [diff] [blame] | 268 | } |
| 269 | |
| 270 | @Override |
| 271 | public void register(ServerSession session) { |
| 272 | } |
| 273 | |
| 274 | @Override |
| 275 | public void unregister(ServerSession session) { |
| 276 | closeListener(session.id()); |
| 277 | } |
| 278 | |
| 279 | @Override |
| 280 | public void expire(ServerSession session) { |
| 281 | closeListener(session.id()); |
| 282 | } |
| 283 | |
| 284 | @Override |
| 285 | public void close(ServerSession session) { |
| 286 | closeListener(session.id()); |
| 287 | } |
| 288 | |
| 289 | private void closeListener(Long sessionId) { |
| 290 | Commit<? extends Listen> commit = listeners.remove(sessionId); |
| 291 | if (commit != null) { |
| 292 | commit.close(); |
| 293 | } |
| 294 | } |
| 295 | } |