@Override
@SuppressWarnings("unchecked")
public Listener onEvent(String event, Consumer listener) {
return eventListeners
.computeIfAbsent(Assert.notNull(event, "event"), e -> new Listeners<>())
.add(Assert.notNull(listener, "listener"));
}
/**
* @throws IllegalStateException if candidate is not positive or if term, logIndex or logTerm
* are negative
*/
@Override
public VoteRequest build() {
super.build();
Assert.stateNot(request.term < 0, "term must not be negative");
Assert.stateNot(request.logIndex < 0, "log index must not be negative");
Assert.stateNot(request.logTerm < 0, "log term must not be negative");
return request;
}
@Override
public <T extends Operation<U>, U> StateMachineExecutor register(
Class<T> type, Function<Commit<T>, U> callback) {
Assert.notNull(type, "type");
Assert.notNull(callback, "callback");
operations.put(type, callback);
return this;
}
/**
* Sets the maximum number of allows entries per segment, returning the builder for method
* chaining.
*
* <p>The maximum entry count dictates when logs should roll over to new segments. As entries
* are written to a segment of the log, if the entry count in that segment meets the configured
* maximum entry count, the log will create a new segment and append new entries to that
* segment.
*
* <p>By default, the maximum entries per segment is {@code 1024 * 1024}.
*
* @param maxEntriesPerSegment The maximum number of entries allowed per segment.
* @return The storage builder.
* @throws IllegalArgumentException If the {@code maxEntriesPerSegment} not greater than the
* default max entries per segment
*/
public Builder withMaxEntriesPerSegment(int maxEntriesPerSegment) {
Assert.arg(maxEntriesPerSegment > 0, "max entries per segment must be positive");
Assert.argNot(
maxEntriesPerSegment > DEFAULT_MAX_ENTRIES_PER_SEGMENT,
"max entries per segment cannot be greater than " + DEFAULT_MAX_ENTRIES_PER_SEGMENT);
storage.maxEntriesPerSegment = maxEntriesPerSegment;
return this;
}
private Builder(Address clientAddress, Address serverAddress, Collection<Address> members) {
this.members = Assert.notNull(members, "members");
Serializer serializer = new Serializer();
this.clientAddress = Assert.notNull(clientAddress, "clientAddress");
this.clientBuilder = CopycatClient.builder(members).withSerializer(serializer.clone());
this.serverBuilder =
CopycatServer.builder(clientAddress, serverAddress, members)
.withSerializer(serializer.clone());
}
/** @throws IllegalStateException if status is OK and members is null */
@Override
public RegisterResponse build() {
super.build();
Assert.stateNot(
response.status == Status.OK && response.members == null, "members cannot be null");
Assert.stateNot(
response.status == Status.OK && response.timeout <= 0, "timeout must be positive");
return response;
}
public ClientSession(
UUID clientId, Transport transport, Collection<Address> members, Serializer serializer) {
this.clientId = Assert.notNull(clientId, "clientId");
this.client = Assert.notNull(transport, "transport").client();
this.members = new HashSet<>(Assert.notNull(members, "members"));
this.context =
new SingleThreadContext(
"copycat-client-" + clientId.toString(),
Assert.notNull(serializer, "serializer").clone());
this.connectMembers = new ArrayList<>(members);
}
private ClientSession(
ClientConnection connection,
ClientSessionState state,
ThreadContext context,
ConnectionStrategy connectionStrategy) {
this.connection = Assert.notNull(connection, "connection");
this.state = Assert.notNull(state, "state");
this.manager = new ClientSessionManager(connection, state, context, connectionStrategy);
ClientSequencer sequencer = new ClientSequencer(state);
this.listener = new ClientSessionListener(connection, state, sequencer, context);
this.submitter = new ClientSessionSubmitter(connection, state, sequencer, context);
}
@Override
public <T extends Operation<Void>> StateMachineExecutor register(
Class<T> type, Consumer<Commit<T>> callback) {
Assert.notNull(type, "type");
Assert.notNull(callback, "callback");
operations.put(
type,
(Function<Commit<T>, Void>)
commit -> {
callback.accept(commit);
return null;
});
return this;
}
@Override
public CompletableFuture<Void> listen(Address address, Consumer<Connection> listener) {
Assert.notNull(address, "address");
Assert.notNull(listener, "listener");
if (listening) return CompletableFuture.completedFuture(null);
ThreadContext context = ThreadContext.currentContextOrThrow();
synchronized (this) {
if (listenFuture == null) {
listenFuture = new CompletableFuture<>();
listen(address, listener, context);
}
}
return listenFuture;
}
/**
* Sets the maximum segment size in bytes, returning the builder for method chaining.
*
* <p>The maximum segment size dictates when logs should roll over to new segments. As entries
* are written to a segment of the log, once the size of the segment surpasses the configured
* maximum segment size, the log will create a new segment and append new entries to that
* segment.
*
* <p>By default, the maximum segment size is {@code 1024 * 1024 * 32}.
*
* @param maxSegmentSize The maximum segment size in bytes.
* @return The storage builder.
* @throws IllegalArgumentException If the {@code maxSegmentSize} is not positive
*/
public Builder withMaxSegmentSize(int maxSegmentSize) {
Assert.arg(
maxSegmentSize > SegmentDescriptor.BYTES,
"maxSegmentSize must be greater than " + SegmentDescriptor.BYTES);
storage.maxSegmentSize = maxSegmentSize;
return this;
}
/**
* Returns a boolean value indicating whether the selector state would be changed by the given
* members.
*/
private boolean changed(Address leader, Collection<Address> servers) {
Assert.notNull(servers, "servers");
Assert.argNot(servers.isEmpty(), "servers list cannot be empty");
if (this.leader != null && leader == null) {
return true;
} else if (this.leader == null && leader != null) {
Assert.arg(servers.contains(leader), "leader must be present in servers list");
return true;
} else if (this.leader != null && !this.leader.equals(leader)) {
Assert.arg(servers.contains(leader), "leader must be present in servers list");
return true;
} else if (!matches(this.servers, servers)) {
return true;
}
return false;
}
/** @throws IllegalStateException if {@code term} is negative */
@Override
public VoteResponse build() {
super.build();
if (response.status == Response.Status.OK) {
Assert.stateNot(response.term < 0, "term cannot be negative");
}
return response;
}
@Override
public Snapshot complete() {
Buffer buffer = FileBuffer.allocate(file.file(), SnapshotDescriptor.BYTES);
try (SnapshotDescriptor descriptor = new SnapshotDescriptor(buffer)) {
Assert.stateNot(descriptor.locked(), "cannot complete locked snapshot descriptor");
descriptor.lock();
}
return super.complete();
}
@Override
public synchronized SnapshotReader reader() {
Assert.state(file.file().exists(), "missing snapshot file: %s", file.file());
Buffer buffer = FileBuffer.allocate(file.file(), SnapshotDescriptor.BYTES);
SnapshotDescriptor descriptor = new SnapshotDescriptor(buffer);
int length = buffer.position(SnapshotDescriptor.BYTES).readInt();
return openReader(
new SnapshotReader(
buffer.mark().limit(SnapshotDescriptor.BYTES + Integer.BYTES + length),
this,
store.serializer()),
descriptor);
}
@Override
public Session publish(String event, Object message) {
Assert.notNull(event, "event");
context
.executor()
.execute(
() -> {
Listeners<Object> listeners = eventListeners.get(event);
if (listeners != null) {
listeners.accept(message);
}
});
return this;
}
SnapshotWriter(Buffer buffer, Snapshot snapshot, Serializer serializer) {
this.buffer = Assert.notNull(buffer, "buffer");
this.snapshot = Assert.notNull(snapshot, "snapshot");
this.serializer = Assert.notNull(serializer, "serializer");
}
/**
* Sets the log directory, returning the builder for method chaining.
*
* <p>The log will write segment files into the provided directory. If multiple {@link Storage}
* objects are located on the same machine, they write logs to different directories.
*
* @param directory The log directory.
* @return The storage builder.
* @throws NullPointerException If the {@code directory} is {@code null}
*/
public Builder withDirectory(String directory) {
return withDirectory(new File(Assert.notNull(directory, "directory")));
}
@Override
public Listener<Session> onClose(Consumer<Session> listener) {
return closeListeners.add(Assert.notNull(listener, "listener"));
}
/**
* Sets the log directory, returning the builder for method chaining.
*
* <p>The log will write segment files into the provided directory. If multiple {@link Storage}
* objects are located on the same machine, they write logs to different directories.
*
* @param directory The log directory.
* @return The storage builder.
* @throws NullPointerException If the {@code directory} is {@code null}
*/
public Builder withDirectory(File directory) {
storage.directory = Assert.notNull(directory, "directory");
return this;
}
@Override
public Listener<Session> onOpen(Consumer<Session> listener) {
return openListeners.add(Assert.notNull(listener, "listener"));
}
/** @throws NullPointerException if {@code directory} is null */
public Storage(String directory) {
this(new File(Assert.notNull(directory, "directory")));
}
public Storage(StorageLevel storageLevel) {
this.storageLevel = Assert.notNull(storageLevel, "storageLevel");
}
/**
* Sets the percentage of entries in the segment that must be cleaned before a segment can be
* compacted, returning the builder for method chaining.
*
* <p>The compaction threshold is used during {@link
* io.atomix.copycat.server.storage.compaction.Compaction#MINOR minor compaction} to determine
* the set of segments to compact. By default, the compaction threshold is {@code 0.5}.
* Increasing the compaction threshold will increase the number of {@link
* io.atomix.copycat.server.storage.entry.Entry entries} that must be cleaned from the segment
* before compaction and thus decrease the likelihood that a segment will be compacted.
* Conversely, decreasing the compaction threshold will increase the frequency of compaction at
* the cost of unnecessary I/O.
*
* @see io.atomix.copycat.server.storage.compaction.MinorCompactionManager
* @param threshold The segment compact threshold.
* @return The storage builder.
*/
public Builder withCompactionThreshold(double threshold) {
storage.compactionThreshold =
Assert.argNot(threshold, threshold <= 0, "threshold must be positive");
return this;
}
/**
* Sets the major compaction interval, returning the builder for method chaining.
*
* <p>The major compaction interval dictates the interval at which the {@link
* io.atomix.copycat.server.storage.compaction.MajorCompactionManager} should evaluate {@link
* Segment}s in the log for major compaction. Because of the performance costs of major
* compaction, it is recommended that the major compaction interval be at least an order of
* magnitude greater than the minor compaction interval.
*
* @see io.atomix.copycat.server.storage.compaction.MajorCompactionManager
* @see io.atomix.copycat.server.storage.compaction.MajorCompactionTask
* @param interval The major compaction interval.
* @return The storage builder.
*/
public Builder withMajorCompactionInterval(Duration interval) {
storage.majorCompactionInterval = Assert.notNull(interval, "interval");
return this;
}
/**
* Sets the request member.
*
* @param member The request member.
* @return The request builder.
* @throws NullPointerException if {@code member} is null
*/
public Builder withMember(Address member) {
request.member = Assert.notNull(member, "member");
return this;
}
public ResourceManagerState(ResourceRegistry registry) {
this.registry = Assert.notNull(registry, "registry");
}
/**
* Sets the maximum size of snapshot files on disk, returning the builder for method chaining.
*
* <p>The maximum snapshot size dictates the size in bytes of a single snapshot file on disk.
* Reducing the maximum snapshot file size can help ensure that the system is not bogged down
* with storing and replicating snapshots. By default, snapshots are practically unlimited with
* a 2GB limit, but in practice they should be fairly small.
*
* @param maxSnapshotSize The maximum snapshot size in bytes.
* @return The storage builder.
* @throws IllegalArgumentException if the {@code maxSnapshotSize} is not positive or is less
* than {@code 64}
*/
public Builder withMaxSnapshotSize(int maxSnapshotSize) {
storage.maxSnapshotSize =
Assert.arg(maxSnapshotSize, maxSnapshotSize >= 64, "max snapshot size must be positive");
return this;
}
/** @throws IllegalStateException if member is null */
@Override
public LeaveRequest build() {
super.build();
Assert.state(request.member != null, "member cannot be null");
return request;
}
/**
* Sets the number of log compaction threads, returning the builder for method chaining.
*
* <p>The compaction thread count dictates the parallelism with which the log {@link
* io.atomix.copycat.server.storage.compaction.Compactor} can rewrite segments in the log. By
* default, the log uses {@code Runtime.getRuntime().availableProcessors() / 2} compaction
* threads.
*
* @param compactionThreads The number of log compaction threads.
* @return The storage builder.
* @throws IllegalArgumentException if {@code compactionThreads} is not positive
*/
public Builder withCompactionThreads(int compactionThreads) {
storage.compactionThreads =
Assert.arg(
compactionThreads, compactionThreads > 0, "compactionThreads must be positive");
return this;
}