| /* |
| * 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 java.util.Arrays; |
| import java.util.Collection; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.LinkedHashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.function.Predicate; |
| import java.util.stream.Collectors; |
| |
| import com.google.common.base.Throwables; |
| import com.google.common.collect.Lists; |
| import com.google.common.collect.Maps; |
| import com.google.common.collect.Sets; |
| import io.atomix.protocols.raft.service.AbstractRaftService; |
| import io.atomix.protocols.raft.service.Commit; |
| import io.atomix.protocols.raft.service.RaftServiceExecutor; |
| import io.atomix.protocols.raft.session.RaftSession; |
| import io.atomix.protocols.raft.storage.snapshot.SnapshotReader; |
| import io.atomix.protocols.raft.storage.snapshot.SnapshotWriter; |
| import org.onlab.util.KryoNamespace; |
| import org.onlab.util.Match; |
| import org.onosproject.store.primitives.MapUpdate; |
| import org.onosproject.store.primitives.TransactionId; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.ContainsKey; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.ContainsValue; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.Get; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.GetOrDefault; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.Put; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.Remove; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.RemoveValue; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.RemoveVersion; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.Replace; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.ReplaceValue; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.ReplaceVersion; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.TransactionBegin; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.TransactionCommit; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.TransactionPrepare; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.TransactionPrepareAndCommit; |
| import org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.TransactionRollback; |
| import org.onosproject.store.serializers.KryoNamespaces; |
| import org.onosproject.store.service.MapEvent; |
| import org.onosproject.store.service.Serializer; |
| import org.onosproject.store.service.TransactionLog; |
| import org.onosproject.store.service.Versioned; |
| |
| import static com.google.common.base.Preconditions.checkState; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapEvents.CHANGE; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.ADD_LISTENER; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.BEGIN; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.CLEAR; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.COMMIT; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.CONTAINS_KEY; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.CONTAINS_VALUE; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.ENTRY_SET; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.GET; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.GET_OR_DEFAULT; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.IS_EMPTY; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.KEY_SET; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.PREPARE; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.PREPARE_AND_COMMIT; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.PUT; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.PUT_AND_GET; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.PUT_IF_ABSENT; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.REMOVE; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.REMOVE_LISTENER; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.REMOVE_VALUE; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.REMOVE_VERSION; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.REPLACE; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.REPLACE_VALUE; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.REPLACE_VERSION; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.ROLLBACK; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.SIZE; |
| import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMapOperations.VALUES; |
| |
| /** |
| * State Machine for {@link AtomixConsistentMap} resource. |
| */ |
| public class AtomixConsistentMapService extends AbstractRaftService { |
| |
| private static final Serializer SERIALIZER = Serializer.using(KryoNamespace.newBuilder() |
| .register(KryoNamespaces.BASIC) |
| .register(AtomixConsistentMapOperations.NAMESPACE) |
| .register(AtomixConsistentMapEvents.NAMESPACE) |
| .nextId(KryoNamespaces.BEGIN_USER_CUSTOM_ID + 100) |
| .register(TransactionScope.class) |
| .register(TransactionLog.class) |
| .register(TransactionId.class) |
| .register(MapEntryValue.class) |
| .register(MapEntryValue.Type.class) |
| .register(new HashMap().keySet().getClass()) |
| .build()); |
| |
| protected Map<Long, RaftSession> listeners = new LinkedHashMap<>(); |
| private Map<String, MapEntryValue> map; |
| protected Set<String> preparedKeys = Sets.newHashSet(); |
| protected Map<TransactionId, TransactionScope> activeTransactions = Maps.newHashMap(); |
| protected long currentVersion; |
| |
| public AtomixConsistentMapService() { |
| map = createMap(); |
| } |
| |
| protected Map<String, MapEntryValue> createMap() { |
| return Maps.newHashMap(); |
| } |
| |
| protected Map<String, MapEntryValue> entries() { |
| return map; |
| } |
| |
| protected Serializer serializer() { |
| return SERIALIZER; |
| } |
| |
| @Override |
| public void snapshot(SnapshotWriter writer) { |
| writer.writeObject(Sets.newHashSet(listeners.keySet()), serializer()::encode); |
| writer.writeObject(preparedKeys, serializer()::encode); |
| writer.writeObject(entries(), serializer()::encode); |
| writer.writeObject(activeTransactions, serializer()::encode); |
| writer.writeLong(currentVersion); |
| } |
| |
| @Override |
| public void install(SnapshotReader reader) { |
| listeners = new LinkedHashMap<>(); |
| for (Long sessionId : reader.<Set<Long>>readObject(serializer()::decode)) { |
| listeners.put(sessionId, getSessions().getSession(sessionId)); |
| } |
| preparedKeys = reader.readObject(serializer()::decode); |
| map = reader.readObject(serializer()::decode); |
| activeTransactions = reader.readObject(serializer()::decode); |
| currentVersion = reader.readLong(); |
| } |
| |
| @Override |
| protected void configure(RaftServiceExecutor executor) { |
| // Listeners |
| executor.register(ADD_LISTENER, (Commit<Void> c) -> listen(c.session())); |
| executor.register(REMOVE_LISTENER, (Commit<Void> c) -> unlisten(c.session())); |
| // Queries |
| executor.register(CONTAINS_KEY, serializer()::decode, this::containsKey, serializer()::encode); |
| executor.register(CONTAINS_VALUE, serializer()::decode, this::containsValue, serializer()::encode); |
| executor.register(ENTRY_SET, (Commit<Void> c) -> entrySet(), serializer()::encode); |
| executor.register(GET, serializer()::decode, this::get, serializer()::encode); |
| executor.register(GET_OR_DEFAULT, serializer()::decode, this::getOrDefault, serializer()::encode); |
| executor.register(IS_EMPTY, (Commit<Void> c) -> isEmpty(), serializer()::encode); |
| executor.register(KEY_SET, (Commit<Void> c) -> keySet(), serializer()::encode); |
| executor.register(SIZE, (Commit<Void> c) -> size(), serializer()::encode); |
| executor.register(VALUES, (Commit<Void> c) -> values(), serializer()::encode); |
| // Commands |
| executor.register(PUT, serializer()::decode, this::put, serializer()::encode); |
| executor.register(PUT_IF_ABSENT, serializer()::decode, this::putIfAbsent, serializer()::encode); |
| executor.register(PUT_AND_GET, serializer()::decode, this::putAndGet, serializer()::encode); |
| executor.register(REMOVE, serializer()::decode, this::remove, serializer()::encode); |
| executor.register(REMOVE_VALUE, serializer()::decode, this::removeValue, serializer()::encode); |
| executor.register(REMOVE_VERSION, serializer()::decode, this::removeVersion, serializer()::encode); |
| executor.register(REPLACE, serializer()::decode, this::replace, serializer()::encode); |
| executor.register(REPLACE_VALUE, serializer()::decode, this::replaceValue, serializer()::encode); |
| executor.register(REPLACE_VERSION, serializer()::decode, this::replaceVersion, serializer()::encode); |
| executor.register(CLEAR, (Commit<Void> c) -> clear(), serializer()::encode); |
| executor.register(BEGIN, serializer()::decode, this::begin, serializer()::encode); |
| executor.register(PREPARE, serializer()::decode, this::prepare, serializer()::encode); |
| executor.register(PREPARE_AND_COMMIT, serializer()::decode, this::prepareAndCommit, serializer()::encode); |
| executor.register(COMMIT, serializer()::decode, this::commit, serializer()::encode); |
| executor.register(ROLLBACK, serializer()::decode, this::rollback, serializer()::encode); |
| } |
| |
| /** |
| * Handles a contains key commit. |
| * |
| * @param commit containsKey commit |
| * @return {@code true} if map contains key |
| */ |
| protected boolean containsKey(Commit<? extends ContainsKey> commit) { |
| MapEntryValue value = entries().get(commit.value().key()); |
| return value != null && value.type() != MapEntryValue.Type.TOMBSTONE; |
| } |
| |
| /** |
| * Handles a contains value commit. |
| * |
| * @param commit containsValue commit |
| * @return {@code true} if map contains value |
| */ |
| protected boolean containsValue(Commit<? extends ContainsValue> commit) { |
| Match<byte[]> valueMatch = Match.ifValue(commit.value().value()); |
| return entries().values().stream() |
| .filter(value -> value.type() != MapEntryValue.Type.TOMBSTONE) |
| .anyMatch(value -> valueMatch.matches(value.value())); |
| } |
| |
| /** |
| * Handles a get commit. |
| * |
| * @param commit get commit |
| * @return value mapped to key |
| */ |
| protected Versioned<byte[]> get(Commit<? extends Get> commit) { |
| return toVersioned(entries().get(commit.value().key())); |
| } |
| |
| /** |
| * Handles a get or default commit. |
| * |
| * @param commit get or default commit |
| * @return value mapped to key |
| */ |
| protected Versioned<byte[]> getOrDefault(Commit<? extends GetOrDefault> commit) { |
| MapEntryValue value = entries().get(commit.value().key()); |
| if (value == null) { |
| return new Versioned<>(commit.value().defaultValue(), 0); |
| } else if (value.type() == MapEntryValue.Type.TOMBSTONE) { |
| return new Versioned<>(commit.value().defaultValue(), value.version); |
| } else { |
| return new Versioned<>(value.value(), value.version); |
| } |
| } |
| |
| /** |
| * Handles a size commit. |
| * |
| * @return number of entries in map |
| */ |
| protected int size() { |
| return (int) entries().values().stream() |
| .filter(value -> value.type() != MapEntryValue.Type.TOMBSTONE) |
| .count(); |
| } |
| |
| /** |
| * Handles an is empty commit. |
| * |
| * @return {@code true} if map is empty |
| */ |
| protected boolean isEmpty() { |
| return entries().values().stream() |
| .noneMatch(value -> value.type() != MapEntryValue.Type.TOMBSTONE); |
| } |
| |
| /** |
| * Handles a keySet commit. |
| * |
| * @return set of keys in map |
| */ |
| protected Set<String> keySet() { |
| return entries().entrySet().stream() |
| .filter(entry -> entry.getValue().type() != MapEntryValue.Type.TOMBSTONE) |
| .map(Map.Entry::getKey) |
| .collect(Collectors.toSet()); |
| } |
| |
| /** |
| * Handles a values commit. |
| * |
| * @return collection of values in map |
| */ |
| protected Collection<Versioned<byte[]>> values() { |
| return entries().entrySet().stream() |
| .filter(entry -> entry.getValue().type() != MapEntryValue.Type.TOMBSTONE) |
| .map(entry -> toVersioned(entry.getValue())) |
| .collect(Collectors.toList()); |
| } |
| |
| /** |
| * Handles a entry set commit. |
| * |
| * @return set of map entries |
| */ |
| protected Set<Map.Entry<String, Versioned<byte[]>>> entrySet() { |
| return entries().entrySet().stream() |
| .filter(entry -> entry.getValue().type() != MapEntryValue.Type.TOMBSTONE) |
| .map(e -> Maps.immutableEntry(e.getKey(), toVersioned(e.getValue()))) |
| .collect(Collectors.toSet()); |
| } |
| |
| /** |
| * Returns a boolean indicating whether the given MapEntryValues are equal. |
| * |
| * @param oldValue the first value to compare |
| * @param newValue the second value to compare |
| * @return indicates whether the two values are equal |
| */ |
| protected boolean valuesEqual(MapEntryValue oldValue, MapEntryValue newValue) { |
| return (oldValue == null && newValue == null) |
| || (oldValue != null && newValue != null && valuesEqual(oldValue.value(), newValue.value())); |
| } |
| |
| /** |
| * Returns a boolean indicating whether the given entry values are equal. |
| * |
| * @param oldValue the first value to compare |
| * @param newValue the second value to compare |
| * @return indicates whether the two values are equal |
| */ |
| protected boolean valuesEqual(byte[] oldValue, byte[] newValue) { |
| return (oldValue == null && newValue == null) |
| || (oldValue != null && newValue != null && Arrays.equals(oldValue, newValue)); |
| } |
| |
| /** |
| * Returns a boolean indicating whether the given MapEntryValue is null or a tombstone. |
| * |
| * @param value the value to check |
| * @return indicates whether the given value is null or is a tombstone |
| */ |
| protected boolean valueIsNull(MapEntryValue value) { |
| return value == null || value.type() == MapEntryValue.Type.TOMBSTONE; |
| } |
| |
| /** |
| * Handles a put commit. |
| * |
| * @param commit put commit |
| * @return map entry update result |
| */ |
| protected MapEntryUpdateResult<String, byte[]> put(Commit<? extends Put> commit) { |
| String key = commit.value().key(); |
| MapEntryValue oldValue = entries().get(key); |
| MapEntryValue newValue = new MapEntryValue(MapEntryValue.Type.VALUE, commit.index(), commit.value().value()); |
| |
| // If the value is null or a tombstone, this is an insert. |
| // Otherwise, only update the value if it has changed to reduce the number of events. |
| if (valueIsNull(oldValue)) { |
| // If the key has been locked by a transaction, return a WRITE_LOCK error. |
| if (preparedKeys.contains(key)) { |
| return new MapEntryUpdateResult<>( |
| MapEntryUpdateResult.Status.WRITE_LOCK, |
| commit.index(), |
| key, |
| toVersioned(oldValue)); |
| } |
| entries().put(commit.value().key(), |
| new MapEntryValue(MapEntryValue.Type.VALUE, newValue.version(), newValue.value())); |
| Versioned<byte[]> result = toVersioned(oldValue); |
| publish(new MapEvent<>(MapEvent.Type.INSERT, "", key, toVersioned(newValue), result)); |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.OK, commit.index(), key, result); |
| } else if (!valuesEqual(oldValue, newValue)) { |
| // If the key has been locked by a transaction, return a WRITE_LOCK error. |
| if (preparedKeys.contains(key)) { |
| return new MapEntryUpdateResult<>( |
| MapEntryUpdateResult.Status.WRITE_LOCK, |
| commit.index(), |
| key, |
| toVersioned(oldValue)); |
| } |
| entries().put(commit.value().key(), |
| new MapEntryValue(MapEntryValue.Type.VALUE, newValue.version(), newValue.value())); |
| Versioned<byte[]> result = toVersioned(oldValue); |
| publish(new MapEvent<>(MapEvent.Type.UPDATE, "", key, toVersioned(newValue), result)); |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.OK, commit.index(), key, result); |
| } |
| // If the value hasn't changed, return a NOOP result. |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.NOOP, commit.index(), key, toVersioned(oldValue)); |
| } |
| |
| /** |
| * Handles a putIfAbsent commit. |
| * |
| * @param commit putIfAbsent commit |
| * @return map entry update result |
| */ |
| protected MapEntryUpdateResult<String, byte[]> putIfAbsent(Commit<? extends Put> commit) { |
| String key = commit.value().key(); |
| MapEntryValue oldValue = entries().get(key); |
| |
| // If the value is null, this is an INSERT. |
| if (valueIsNull(oldValue)) { |
| // If the key has been locked by a transaction, return a WRITE_LOCK error. |
| if (preparedKeys.contains(key)) { |
| return new MapEntryUpdateResult<>( |
| MapEntryUpdateResult.Status.WRITE_LOCK, |
| commit.index(), |
| key, |
| toVersioned(oldValue)); |
| } |
| MapEntryValue newValue = new MapEntryValue( |
| MapEntryValue.Type.VALUE, |
| commit.index(), |
| commit.value().value()); |
| entries().put(commit.value().key(), newValue); |
| Versioned<byte[]> result = toVersioned(newValue); |
| publish(new MapEvent<>(MapEvent.Type.INSERT, "", key, result, null)); |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.OK, commit.index(), key, null); |
| } |
| return new MapEntryUpdateResult<>( |
| MapEntryUpdateResult.Status.PRECONDITION_FAILED, |
| commit.index(), |
| key, |
| toVersioned(oldValue)); |
| } |
| |
| /** |
| * Handles a putAndGet commit. |
| * |
| * @param commit putAndGet commit |
| * @return map entry update result |
| */ |
| protected MapEntryUpdateResult<String, byte[]> putAndGet(Commit<? extends Put> commit) { |
| String key = commit.value().key(); |
| MapEntryValue oldValue = entries().get(key); |
| MapEntryValue newValue = new MapEntryValue(MapEntryValue.Type.VALUE, commit.index(), commit.value().value()); |
| |
| // If the value is null or a tombstone, this is an insert. |
| // Otherwise, only update the value if it has changed to reduce the number of events. |
| if (valueIsNull(oldValue)) { |
| // If the key has been locked by a transaction, return a WRITE_LOCK error. |
| if (preparedKeys.contains(key)) { |
| return new MapEntryUpdateResult<>( |
| MapEntryUpdateResult.Status.WRITE_LOCK, |
| commit.index(), |
| key, |
| toVersioned(oldValue)); |
| } |
| entries().put(commit.value().key(), newValue); |
| Versioned<byte[]> result = toVersioned(newValue); |
| publish(new MapEvent<>(MapEvent.Type.INSERT, "", key, result, null)); |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.OK, commit.index(), key, result); |
| } else if (!valuesEqual(oldValue, newValue)) { |
| // If the key has been locked by a transaction, return a WRITE_LOCK error. |
| if (preparedKeys.contains(key)) { |
| return new MapEntryUpdateResult<>( |
| MapEntryUpdateResult.Status.WRITE_LOCK, |
| commit.index(), |
| key, |
| toVersioned(oldValue)); |
| } |
| entries().put(commit.value().key(), newValue); |
| Versioned<byte[]> result = toVersioned(newValue); |
| publish(new MapEvent<>(MapEvent.Type.UPDATE, "", key, result, toVersioned(oldValue))); |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.OK, commit.index(), key, result); |
| } |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.NOOP, commit.index(), key, toVersioned(oldValue)); |
| } |
| |
| /** |
| * Handles a remove commit. |
| * |
| * @param index the commit index |
| * @param key the key to remove |
| * @param predicate predicate to determine whether to remove the entry |
| * @return map entry update result |
| */ |
| private MapEntryUpdateResult<String, byte[]> removeIf(long index, String key, Predicate<MapEntryValue> predicate) { |
| MapEntryValue value = entries().get(key); |
| |
| // If the value does not exist or doesn't match the predicate, return a PRECONDITION_FAILED error. |
| if (valueIsNull(value) || !predicate.test(value)) { |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.PRECONDITION_FAILED, index, key, null); |
| } |
| |
| // If the key has been locked by a transaction, return a WRITE_LOCK error. |
| if (preparedKeys.contains(key)) { |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.WRITE_LOCK, index, key, null); |
| } |
| |
| // If no transactions are active, remove the key. Otherwise, replace it with a tombstone. |
| if (activeTransactions.isEmpty()) { |
| entries().remove(key); |
| } else { |
| entries().put(key, new MapEntryValue(MapEntryValue.Type.TOMBSTONE, index, null)); |
| } |
| |
| Versioned<byte[]> result = toVersioned(value); |
| publish(new MapEvent<>(MapEvent.Type.REMOVE, "", key, null, result)); |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.OK, index, key, result); |
| } |
| |
| /** |
| * Handles a remove commit. |
| * |
| * @param commit remove commit |
| * @return map entry update result |
| */ |
| protected MapEntryUpdateResult<String, byte[]> remove(Commit<? extends Remove> commit) { |
| return removeIf(commit.index(), commit.value().key(), v -> true); |
| } |
| |
| /** |
| * Handles a removeValue commit. |
| * |
| * @param commit removeValue commit |
| * @return map entry update result |
| */ |
| protected MapEntryUpdateResult<String, byte[]> removeValue(Commit<? extends RemoveValue> commit) { |
| return removeIf(commit.index(), commit.value().key(), v -> |
| valuesEqual(v, new MapEntryValue(MapEntryValue.Type.VALUE, commit.index(), commit.value().value()))); |
| } |
| |
| /** |
| * Handles a removeVersion commit. |
| * |
| * @param commit removeVersion commit |
| * @return map entry update result |
| */ |
| protected MapEntryUpdateResult<String, byte[]> removeVersion(Commit<? extends RemoveVersion> commit) { |
| return removeIf(commit.index(), commit.value().key(), v -> v.version() == commit.value().version()); |
| } |
| |
| /** |
| * Handles a replace commit. |
| * |
| * @param index the commit index |
| * @param key the key to replace |
| * @param newValue the value with which to replace the key |
| * @param predicate a predicate to determine whether to replace the key |
| * @return map entry update result |
| */ |
| private MapEntryUpdateResult<String, byte[]> replaceIf( |
| long index, String key, MapEntryValue newValue, Predicate<MapEntryValue> predicate) { |
| MapEntryValue oldValue = entries().get(key); |
| |
| // If the key is not set or the current value doesn't match the predicate, return a PRECONDITION_FAILED error. |
| if (valueIsNull(oldValue) || !predicate.test(oldValue)) { |
| return new MapEntryUpdateResult<>( |
| MapEntryUpdateResult.Status.PRECONDITION_FAILED, |
| index, |
| key, |
| toVersioned(oldValue)); |
| } |
| |
| // If the key has been locked by a transaction, return a WRITE_LOCK error. |
| if (preparedKeys.contains(key)) { |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.WRITE_LOCK, index, key, null); |
| } |
| |
| entries().put(key, newValue); |
| Versioned<byte[]> result = toVersioned(oldValue); |
| publish(new MapEvent<>(MapEvent.Type.UPDATE, "", key, toVersioned(newValue), result)); |
| return new MapEntryUpdateResult<>(MapEntryUpdateResult.Status.OK, index, key, result); |
| } |
| |
| /** |
| * Handles a replace commit. |
| * |
| * @param commit replace commit |
| * @return map entry update result |
| */ |
| protected MapEntryUpdateResult<String, byte[]> replace(Commit<? extends Replace> commit) { |
| MapEntryValue value = new MapEntryValue(MapEntryValue.Type.VALUE, commit.index(), commit.value().value()); |
| return replaceIf(commit.index(), commit.value().key(), value, v -> true); |
| } |
| |
| /** |
| * Handles a replaceValue commit. |
| * |
| * @param commit replaceValue commit |
| * @return map entry update result |
| */ |
| protected MapEntryUpdateResult<String, byte[]> replaceValue(Commit<? extends ReplaceValue> commit) { |
| MapEntryValue value = new MapEntryValue(MapEntryValue.Type.VALUE, commit.index(), commit.value().newValue()); |
| return replaceIf(commit.index(), commit.value().key(), value, |
| v -> valuesEqual(v.value(), commit.value().oldValue())); |
| } |
| |
| /** |
| * Handles a replaceVersion commit. |
| * |
| * @param commit replaceVersion commit |
| * @return map entry update result |
| */ |
| protected MapEntryUpdateResult<String, byte[]> replaceVersion(Commit<? extends ReplaceVersion> commit) { |
| MapEntryValue value = new MapEntryValue(MapEntryValue.Type.VALUE, commit.index(), commit.value().newValue()); |
| return replaceIf(commit.index(), commit.value().key(), value, |
| v -> v.version() == commit.value().oldVersion()); |
| } |
| |
| /** |
| * Handles a clear commit. |
| * |
| * @return clear result |
| */ |
| protected MapEntryUpdateResult.Status clear() { |
| Iterator<Map.Entry<String, MapEntryValue>> iterator = entries().entrySet().iterator(); |
| Map<String, MapEntryValue> entriesToAdd = new HashMap<>(); |
| while (iterator.hasNext()) { |
| Map.Entry<String, MapEntryValue> entry = iterator.next(); |
| String key = entry.getKey(); |
| MapEntryValue value = entry.getValue(); |
| if (!valueIsNull(value)) { |
| Versioned<byte[]> removedValue = new Versioned<>(value.value(), value.version()); |
| publish(new MapEvent<>(MapEvent.Type.REMOVE, "", key, null, removedValue)); |
| if (activeTransactions.isEmpty()) { |
| iterator.remove(); |
| } else { |
| entriesToAdd.put(key, new MapEntryValue(MapEntryValue.Type.TOMBSTONE, value.version, null)); |
| } |
| } |
| } |
| entries().putAll(entriesToAdd); |
| return MapEntryUpdateResult.Status.OK; |
| } |
| |
| /** |
| * Handles a listen commit. |
| * |
| * @param session listen session |
| */ |
| protected void listen(RaftSession session) { |
| listeners.put(session.sessionId().id(), session); |
| } |
| |
| /** |
| * Handles an unlisten commit. |
| * |
| * @param session unlisten session |
| */ |
| protected void unlisten(RaftSession session) { |
| listeners.remove(session.sessionId().id()); |
| } |
| |
| /** |
| * Handles a begin commit. |
| * |
| * @param commit transaction begin commit |
| * @return transaction state version |
| */ |
| protected long begin(Commit<? extends TransactionBegin> commit) { |
| long version = commit.index(); |
| activeTransactions.put(commit.value().transactionId(), new TransactionScope(version)); |
| return version; |
| } |
| |
| /** |
| * Handles an prepare and commit commit. |
| * |
| * @param commit transaction prepare and commit commit |
| * @return prepare result |
| */ |
| protected PrepareResult prepareAndCommit(Commit<? extends TransactionPrepareAndCommit> commit) { |
| TransactionId transactionId = commit.value().transactionLog().transactionId(); |
| PrepareResult prepareResult = prepare(commit); |
| TransactionScope transactionScope = activeTransactions.remove(transactionId); |
| if (prepareResult == PrepareResult.OK) { |
| this.currentVersion = commit.index(); |
| transactionScope = transactionScope.prepared(commit); |
| commitTransaction(transactionScope); |
| } |
| discardTombstones(); |
| return prepareResult; |
| } |
| |
| /** |
| * Handles an prepare commit. |
| * |
| * @param commit transaction prepare commit |
| * @return prepare result |
| */ |
| protected PrepareResult prepare(Commit<? extends TransactionPrepare> commit) { |
| try { |
| TransactionLog<MapUpdate<String, byte[]>> transactionLog = commit.value().transactionLog(); |
| |
| // Iterate through records in the transaction log and perform isolation checks. |
| for (MapUpdate<String, byte[]> record : transactionLog.records()) { |
| String key = record.key(); |
| |
| // If the record is a VERSION_MATCH then check that the record's version matches the current |
| // version of the state machine. |
| if (record.type() == MapUpdate.Type.VERSION_MATCH && key == null) { |
| if (record.version() > currentVersion) { |
| return PrepareResult.OPTIMISTIC_LOCK_FAILURE; |
| } else { |
| continue; |
| } |
| } |
| |
| // If the prepared keys already contains the key contained within the record, that indicates a |
| // conflict with a concurrent transaction. |
| if (preparedKeys.contains(key)) { |
| return PrepareResult.CONCURRENT_TRANSACTION; |
| } |
| |
| // Read the existing value from the map. |
| MapEntryValue existingValue = entries().get(key); |
| |
| // Note: if the existing value is null, that means the key has not changed during the transaction, |
| // otherwise a tombstone would have been retained. |
| if (existingValue == null) { |
| // If the value is null, ensure the version is equal to the transaction version. |
| if (record.version() != transactionLog.version()) { |
| return PrepareResult.OPTIMISTIC_LOCK_FAILURE; |
| } |
| } else { |
| // If the value is non-null, compare the current version with the record version. |
| if (existingValue.version() > record.version()) { |
| return PrepareResult.OPTIMISTIC_LOCK_FAILURE; |
| } |
| } |
| } |
| |
| // No violations detected. Mark modified keys locked for transactions. |
| transactionLog.records().forEach(record -> { |
| if (record.type() != MapUpdate.Type.VERSION_MATCH) { |
| preparedKeys.add(record.key()); |
| } |
| }); |
| |
| // Update the transaction scope. If the transaction scope is not set on this node, that indicates the |
| // coordinator is communicating with another node. Transactions assume that the client is communicating |
| // with a single leader in order to limit the overhead of retaining tombstones. |
| TransactionScope transactionScope = activeTransactions.get(transactionLog.transactionId()); |
| if (transactionScope == null) { |
| activeTransactions.put( |
| transactionLog.transactionId(), |
| new TransactionScope(transactionLog.version(), commit.value().transactionLog())); |
| return PrepareResult.PARTIAL_FAILURE; |
| } else { |
| activeTransactions.put( |
| transactionLog.transactionId(), |
| transactionScope.prepared(commit)); |
| return PrepareResult.OK; |
| } |
| } catch (Exception e) { |
| getLogger().warn("Failure applying {}", commit, e); |
| throw Throwables.propagate(e); |
| } |
| } |
| |
| /** |
| * Handles an commit commit (ha!). |
| * |
| * @param commit transaction commit commit |
| * @return commit result |
| */ |
| protected CommitResult commit(Commit<? extends TransactionCommit> commit) { |
| TransactionId transactionId = commit.value().transactionId(); |
| TransactionScope transactionScope = activeTransactions.remove(transactionId); |
| if (transactionScope == null) { |
| return CommitResult.UNKNOWN_TRANSACTION_ID; |
| } |
| |
| try { |
| this.currentVersion = commit.index(); |
| return commitTransaction(transactionScope); |
| } catch (Exception e) { |
| getLogger().warn("Failure applying {}", commit, e); |
| throw Throwables.propagate(e); |
| } finally { |
| discardTombstones(); |
| } |
| } |
| |
| /** |
| * Applies committed operations to the state machine. |
| */ |
| private CommitResult commitTransaction(TransactionScope transactionScope) { |
| TransactionLog<MapUpdate<String, byte[]>> transactionLog = transactionScope.transactionLog(); |
| boolean retainTombstones = !activeTransactions.isEmpty(); |
| |
| List<MapEvent<String, byte[]>> eventsToPublish = Lists.newArrayList(); |
| for (MapUpdate<String, byte[]> record : transactionLog.records()) { |
| if (record.type() == MapUpdate.Type.VERSION_MATCH) { |
| continue; |
| } |
| |
| String key = record.key(); |
| checkState(preparedKeys.remove(key), "key is not prepared"); |
| |
| if (record.type() == MapUpdate.Type.LOCK) { |
| continue; |
| } |
| |
| MapEntryValue previousValue = entries().remove(key); |
| MapEntryValue newValue = null; |
| |
| // If the record is not a delete, create a transactional commit. |
| if (record.type() != MapUpdate.Type.REMOVE_IF_VERSION_MATCH) { |
| newValue = new MapEntryValue(MapEntryValue.Type.VALUE, currentVersion, record.value()); |
| } else if (retainTombstones) { |
| // For deletes, if tombstones need to be retained then create and store a tombstone commit. |
| newValue = new MapEntryValue(MapEntryValue.Type.TOMBSTONE, currentVersion, null); |
| } |
| |
| MapEvent<String, byte[]> event; |
| if (newValue != null) { |
| entries().put(key, newValue); |
| if (!valueIsNull(newValue)) { |
| if (!valueIsNull(previousValue)) { |
| event = new MapEvent<>( |
| MapEvent.Type.UPDATE, |
| "", |
| key, |
| toVersioned(newValue), |
| toVersioned(previousValue)); |
| } else { |
| event = new MapEvent<>( |
| MapEvent.Type.INSERT, |
| "", |
| key, |
| toVersioned(newValue), |
| null); |
| } |
| } else { |
| event = new MapEvent<>( |
| MapEvent.Type.REMOVE, |
| "", |
| key, |
| null, |
| toVersioned(previousValue)); |
| } |
| } else { |
| event = new MapEvent<>( |
| MapEvent.Type.REMOVE, |
| "", |
| key, |
| null, |
| toVersioned(previousValue)); |
| } |
| eventsToPublish.add(event); |
| } |
| publish(eventsToPublish); |
| return CommitResult.OK; |
| } |
| |
| /** |
| * Handles an rollback commit (ha!). |
| * |
| * @param commit transaction rollback commit |
| * @return rollback result |
| */ |
| protected RollbackResult rollback(Commit<? extends TransactionRollback> commit) { |
| TransactionId transactionId = commit.value().transactionId(); |
| TransactionScope transactionScope = activeTransactions.remove(transactionId); |
| if (transactionScope == null) { |
| return RollbackResult.UNKNOWN_TRANSACTION_ID; |
| } else if (!transactionScope.isPrepared()) { |
| discardTombstones(); |
| return RollbackResult.OK; |
| } else { |
| try { |
| transactionScope.transactionLog().records() |
| .forEach(record -> { |
| if (record.type() != MapUpdate.Type.VERSION_MATCH) { |
| preparedKeys.remove(record.key()); |
| } |
| }); |
| return RollbackResult.OK; |
| } finally { |
| discardTombstones(); |
| } |
| } |
| |
| } |
| |
| /** |
| * Discards tombstones no longer needed by active transactions. |
| */ |
| private void discardTombstones() { |
| if (activeTransactions.isEmpty()) { |
| Iterator<Map.Entry<String, MapEntryValue>> iterator = entries().entrySet().iterator(); |
| while (iterator.hasNext()) { |
| MapEntryValue value = iterator.next().getValue(); |
| if (value.type() == MapEntryValue.Type.TOMBSTONE) { |
| iterator.remove(); |
| } |
| } |
| } else { |
| long lowWaterMark = activeTransactions.values().stream() |
| .mapToLong(TransactionScope::version) |
| .min().getAsLong(); |
| Iterator<Map.Entry<String, MapEntryValue>> iterator = entries().entrySet().iterator(); |
| while (iterator.hasNext()) { |
| MapEntryValue value = iterator.next().getValue(); |
| if (value.type() == MapEntryValue.Type.TOMBSTONE && value.version < lowWaterMark) { |
| iterator.remove(); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Utility for turning a {@code MapEntryValue} to {@code Versioned}. |
| * @param value map entry value |
| * @return versioned instance |
| */ |
| protected Versioned<byte[]> toVersioned(MapEntryValue value) { |
| return value != null && value.type() != MapEntryValue.Type.TOMBSTONE |
| ? new Versioned<>(value.value(), value.version()) : null; |
| } |
| |
| /** |
| * Publishes an event to listeners. |
| * |
| * @param event event to publish |
| */ |
| private void publish(MapEvent<String, byte[]> event) { |
| publish(Lists.newArrayList(event)); |
| } |
| |
| /** |
| * Publishes events to listeners. |
| * |
| * @param events list of map event to publish |
| */ |
| private void publish(List<MapEvent<String, byte[]>> events) { |
| listeners.values().forEach(session -> { |
| session.publish(CHANGE, serializer()::encode, events); |
| }); |
| } |
| |
| @Override |
| public void onExpire(RaftSession session) { |
| closeListener(session.sessionId().id()); |
| } |
| |
| @Override |
| public void onClose(RaftSession session) { |
| closeListener(session.sessionId().id()); |
| } |
| |
| private void closeListener(Long sessionId) { |
| listeners.remove(sessionId); |
| } |
| |
| /** |
| * Interface implemented by map values. |
| */ |
| protected static class MapEntryValue { |
| protected final Type type; |
| protected final long version; |
| protected final byte[] value; |
| |
| MapEntryValue(Type type, long version, byte[] value) { |
| this.type = type; |
| this.version = version; |
| this.value = value; |
| } |
| |
| /** |
| * Returns the value type. |
| * |
| * @return the value type |
| */ |
| Type type() { |
| return type; |
| } |
| |
| /** |
| * Returns the version of the value. |
| * |
| * @return version |
| */ |
| long version() { |
| return version; |
| } |
| |
| /** |
| * Returns the raw {@code byte[]}. |
| * |
| * @return raw value |
| */ |
| byte[] value() { |
| return value; |
| } |
| |
| /** |
| * Value type. |
| */ |
| enum Type { |
| VALUE, |
| TOMBSTONE, |
| } |
| } |
| |
| /** |
| * Map transaction scope. |
| */ |
| protected static final class TransactionScope { |
| private final long version; |
| private final TransactionLog<MapUpdate<String, byte[]>> transactionLog; |
| |
| private TransactionScope(long version) { |
| this(version, null); |
| } |
| |
| private TransactionScope(long version, TransactionLog<MapUpdate<String, byte[]>> transactionLog) { |
| this.version = version; |
| this.transactionLog = transactionLog; |
| } |
| |
| /** |
| * Returns the transaction version. |
| * |
| * @return the transaction version |
| */ |
| long version() { |
| return version; |
| } |
| |
| /** |
| * Returns whether this is a prepared transaction scope. |
| * |
| * @return whether this is a prepared transaction scope |
| */ |
| boolean isPrepared() { |
| return transactionLog != null; |
| } |
| |
| /** |
| * Returns the transaction commit log. |
| * |
| * @return the transaction commit log |
| */ |
| TransactionLog<MapUpdate<String, byte[]>> transactionLog() { |
| checkState(isPrepared()); |
| return transactionLog; |
| } |
| |
| /** |
| * Returns a new transaction scope with a prepare commit. |
| * |
| * @param commit the prepare commit |
| * @return new transaction scope updated with the prepare commit |
| */ |
| TransactionScope prepared(Commit<? extends TransactionPrepare> commit) { |
| return new TransactionScope(version, commit.value().transactionLog()); |
| } |
| } |
| } |