| /* |
| * Copyright 2016-present Open Networking Laboratory |
| * |
| * Licensed 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.onosproject.store.primitives.resources.impl; |
| |
| import static org.slf4j.LoggerFactory.getLogger; |
| import io.atomix.copycat.server.Commit; |
| import io.atomix.copycat.server.Snapshottable; |
| import io.atomix.copycat.server.StateMachineExecutor; |
| import io.atomix.copycat.server.session.ServerSession; |
| import io.atomix.copycat.server.session.SessionListener; |
| import io.atomix.copycat.server.storage.snapshot.SnapshotReader; |
| import io.atomix.copycat.server.storage.snapshot.SnapshotWriter; |
| import io.atomix.resource.ResourceStateMachine; |
| |
| import java.util.Arrays; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Optional; |
| import java.util.Properties; |
| import java.util.Queue; |
| import java.util.concurrent.atomic.AtomicLong; |
| import java.util.stream.Collectors; |
| |
| import org.onlab.util.Match; |
| import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Clear; |
| import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Get; |
| import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.GetChildren; |
| import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Listen; |
| import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Unlisten; |
| import org.onosproject.store.primitives.resources.impl.AtomixDocumentTreeCommands.Update; |
| import org.onosproject.store.primitives.resources.impl.DocumentTreeUpdateResult.Status; |
| import org.onosproject.store.service.DocumentPath; |
| import org.onosproject.store.service.DocumentTree; |
| import org.onosproject.store.service.DocumentTreeEvent; |
| import org.onosproject.store.service.DocumentTreeEvent.Type; |
| import org.onosproject.store.service.IllegalDocumentModificationException; |
| import org.onosproject.store.service.NoSuchDocumentPathException; |
| import org.onosproject.store.service.Versioned; |
| import org.slf4j.Logger; |
| |
| import com.google.common.base.Throwables; |
| import com.google.common.collect.Lists; |
| import com.google.common.collect.Maps; |
| import com.google.common.collect.Queues; |
| |
| /** |
| * State Machine for {@link AtomixDocumentTree} resource. |
| */ |
| public class AtomixDocumentTreeState |
| extends ResourceStateMachine |
| implements SessionListener, Snapshottable { |
| |
| private final Logger log = getLogger(getClass()); |
| private final Map<Long, SessionListenCommits> listeners = new HashMap<>(); |
| private AtomicLong versionCounter = new AtomicLong(0); |
| private final DocumentTree<TreeNodeValue> docTree = new DefaultDocumentTree<>(versionCounter::incrementAndGet); |
| |
| public AtomixDocumentTreeState(Properties properties) { |
| super(properties); |
| } |
| |
| @Override |
| public void snapshot(SnapshotWriter writer) { |
| writer.writeLong(versionCounter.get()); |
| } |
| |
| @Override |
| public void install(SnapshotReader reader) { |
| versionCounter = new AtomicLong(reader.readLong()); |
| } |
| |
| @Override |
| protected void configure(StateMachineExecutor executor) { |
| // Listeners |
| executor.register(Listen.class, this::listen); |
| executor.register(Unlisten.class, this::unlisten); |
| // queries |
| executor.register(Get.class, this::get); |
| executor.register(GetChildren.class, this::getChildren); |
| // commands |
| executor.register(Update.class, this::update); |
| executor.register(Clear.class, this::clear); |
| } |
| |
| protected void listen(Commit<? extends Listen> commit) { |
| Long sessionId = commit.session().id(); |
| listeners.computeIfAbsent(sessionId, k -> new SessionListenCommits()).add(commit); |
| commit.session().onStateChange( |
| state -> { |
| if (state == ServerSession.State.CLOSED |
| || state == ServerSession.State.EXPIRED) { |
| closeListener(commit.session().id()); |
| } |
| }); |
| } |
| |
| protected void unlisten(Commit<? extends Unlisten> commit) { |
| Long sessionId = commit.session().id(); |
| try { |
| SessionListenCommits listenCommits = listeners.get(sessionId); |
| if (listenCommits != null) { |
| listenCommits.remove(commit); |
| } |
| } finally { |
| commit.close(); |
| } |
| } |
| |
| protected Versioned<byte[]> get(Commit<? extends Get> commit) { |
| try { |
| Versioned<TreeNodeValue> value = docTree.get(commit.operation().path()); |
| return value == null ? null : value.map(node -> node == null ? null : node.value()); |
| } catch (IllegalStateException e) { |
| return null; |
| } finally { |
| commit.close(); |
| } |
| } |
| |
| protected Map<String, Versioned<byte[]>> getChildren(Commit<? extends GetChildren> commit) { |
| try { |
| Map<String, Versioned<TreeNodeValue>> children = docTree.getChildren(commit.operation().path()); |
| return children == null |
| ? null : Maps.newHashMap(Maps.transformValues(children, |
| value -> value.map(TreeNodeValue::value))); |
| } finally { |
| commit.close(); |
| } |
| } |
| |
| protected DocumentTreeUpdateResult<byte[]> update(Commit<? extends Update> commit) { |
| DocumentTreeUpdateResult<byte[]> result = null; |
| DocumentPath path = commit.operation().path(); |
| boolean updated = false; |
| Versioned<TreeNodeValue> currentValue = docTree.get(path); |
| try { |
| Match<Long> versionMatch = commit.operation().versionMatch(); |
| Match<byte[]> valueMatch = commit.operation().valueMatch(); |
| |
| if (versionMatch.matches(currentValue == null ? null : currentValue.version()) |
| && valueMatch.matches(currentValue == null ? null : currentValue.value().value())) { |
| if (commit.operation().value() == null) { |
| docTree.removeNode(path); |
| } else { |
| docTree.set(path, new NonTransactionalCommit(commit)); |
| } |
| updated = true; |
| } |
| Versioned<TreeNodeValue> newValue = updated ? docTree.get(path) : currentValue; |
| Status updateStatus = updated |
| ? Status.OK : commit.operation().value() == null ? Status.INVALID_PATH : Status.NOOP; |
| result = new DocumentTreeUpdateResult<>(path, |
| updateStatus, |
| newValue == null |
| ? null : newValue.map(TreeNodeValue::value), |
| currentValue == null |
| ? null : currentValue.map(TreeNodeValue::value)); |
| } catch (IllegalDocumentModificationException e) { |
| result = DocumentTreeUpdateResult.illegalModification(path); |
| } catch (NoSuchDocumentPathException e) { |
| result = DocumentTreeUpdateResult.invalidPath(path); |
| } catch (Exception e) { |
| log.error("Failed to apply {} to state machine", commit.operation(), e); |
| throw Throwables.propagate(e); |
| } finally { |
| if (updated) { |
| if (currentValue != null) { |
| currentValue.value().discard(); |
| } |
| } else { |
| commit.close(); |
| } |
| } |
| notifyListeners(path, result); |
| return result; |
| } |
| |
| protected void clear(Commit<? extends Clear> commit) { |
| try { |
| Queue<DocumentPath> toClearQueue = Queues.newArrayDeque(); |
| Map<String, Versioned<TreeNodeValue>> topLevelChildren = docTree.getChildren(DocumentPath.from("root")); |
| toClearQueue.addAll(topLevelChildren.keySet() |
| .stream() |
| .map(name -> new DocumentPath(name, DocumentPath.from("root"))) |
| .collect(Collectors.toList())); |
| while (!toClearQueue.isEmpty()) { |
| DocumentPath path = toClearQueue.remove(); |
| Map<String, Versioned<TreeNodeValue>> children = docTree.getChildren(path); |
| if (children.size() == 0) { |
| docTree.removeNode(path).value().discard(); |
| } else { |
| children.keySet() |
| .stream() |
| .forEach(name -> toClearQueue.add(new DocumentPath(name, path))); |
| toClearQueue.add(path); |
| } |
| } |
| } finally { |
| commit.close(); |
| } |
| } |
| |
| /** |
| * Interface implemented by tree node values. |
| */ |
| private interface TreeNodeValue { |
| /** |
| * Returns the raw {@code byte[]}. |
| * |
| * @return raw value |
| */ |
| byte[] value(); |
| |
| /** |
| * Discards the value by invoke appropriate clean up actions. |
| */ |
| void discard(); |
| } |
| |
| /** |
| * A {@code TreeNodeValue} that is derived from a non-transactional update |
| * i.e. via any standard tree update operation. |
| */ |
| private class NonTransactionalCommit implements TreeNodeValue { |
| private final Commit<? extends Update> commit; |
| |
| public NonTransactionalCommit(Commit<? extends Update> commit) { |
| this.commit = commit; |
| } |
| |
| @Override |
| public byte[] value() { |
| return commit.operation().value().orElse(null); |
| } |
| |
| @Override |
| public void discard() { |
| commit.close(); |
| } |
| } |
| |
| private void notifyListeners(DocumentPath path, DocumentTreeUpdateResult<byte[]> result) { |
| if (result.status() != Status.OK) { |
| return; |
| } |
| DocumentTreeEvent<byte[]> event = |
| new DocumentTreeEvent<>(path, |
| result.created() ? Type.CREATED : result.newValue() == null ? Type.DELETED : Type.UPDATED, |
| Optional.ofNullable(result.newValue()), |
| Optional.ofNullable(result.oldValue())); |
| |
| listeners.values() |
| .stream() |
| .filter(l -> event.path().isDescendentOf(l.leastCommonAncestorPath())) |
| .forEach(listener -> listener.publish(AtomixDocumentTree.CHANGE_SUBJECT, Arrays.asList(event))); |
| } |
| |
| @Override |
| public void register(ServerSession session) { |
| } |
| |
| @Override |
| public void unregister(ServerSession session) { |
| closeListener(session.id()); |
| } |
| |
| @Override |
| public void expire(ServerSession session) { |
| closeListener(session.id()); |
| } |
| |
| @Override |
| public void close(ServerSession session) { |
| closeListener(session.id()); |
| } |
| |
| private void closeListener(Long sessionId) { |
| SessionListenCommits listenCommits = listeners.remove(sessionId); |
| if (listenCommits != null) { |
| listenCommits.close(); |
| } |
| } |
| |
| private class SessionListenCommits { |
| private final List<Commit<? extends Listen>> commits = Lists.newArrayList(); |
| private DocumentPath leastCommonAncestorPath; |
| |
| public void add(Commit<? extends Listen> commit) { |
| commits.add(commit); |
| recomputeLeastCommonAncestor(); |
| } |
| |
| public void remove(Commit<? extends Unlisten> commit) { |
| // Remove the first listen commit with path matching path in unlisten commit |
| Iterator<Commit<? extends Listen>> iterator = commits.iterator(); |
| while (iterator.hasNext()) { |
| Commit<? extends Listen> listenCommit = iterator.next(); |
| if (listenCommit.operation().path().equals(commit.operation().path())) { |
| iterator.remove(); |
| listenCommit.close(); |
| } |
| } |
| recomputeLeastCommonAncestor(); |
| } |
| |
| public DocumentPath leastCommonAncestorPath() { |
| return leastCommonAncestorPath; |
| } |
| |
| public <M> void publish(String topic, M message) { |
| commits.stream().findAny().ifPresent(commit -> commit.session().publish(topic, message)); |
| } |
| |
| public void close() { |
| commits.forEach(Commit::close); |
| commits.clear(); |
| leastCommonAncestorPath = null; |
| } |
| |
| private void recomputeLeastCommonAncestor() { |
| this.leastCommonAncestorPath = DocumentPath.leastCommonAncestor(commits.stream() |
| .map(c -> c.operation().path()) |
| .collect(Collectors.toList())); |
| } |
| } |
| } |