/** Handles closing the session. */
private void onClose() {
if (isOpen()) {
LOGGER.debug("Closed session: {}", id);
this.id = 0;
this.state = State.CLOSED;
if (connection != null) connection.close();
client.close();
context.close();
closeListeners.forEach(l -> l.accept(this));
}
}
@Override
public CompletableFuture<Void> close() {
int i = 0;
CompletableFuture<?>[] futures = new CompletableFuture[connections.size()];
for (Connection connection : connections.values()) {
futures[i++] = connection.close();
}
CompletableFuture<Void> future = new CompletableFuture<>();
CompletableFuture.allOf(futures)
.whenComplete(
(result, error) -> {
channelGroup
.close()
.addListener(
channelFuture -> {
future.complete(null);
});
});
return future;
}
/** Sets up the given connection. */
private CompletableFuture<Connection> setupConnection(Connection connection) {
this.connection = connection;
connection.closeListener(
c -> {
if (c.equals(this.connection)) {
this.connection = null;
}
});
connection.exceptionListener(
c -> {
if (c.equals(this.connection)) {
this.connection = null;
}
});
connection.handler(PublishRequest.class, this::handlePublish);
if (id != 0) {
ConnectRequest request = ConnectRequest.builder().withSession(id).build();
CompletableFuture<Connection> future = new CompletableFuture<>();
connection
.send(request)
.whenComplete(
(response, error) -> {
if (isOpen()) {
if (error == null) {
future.complete(connection);
} else {
future.completeExceptionally(error);
}
}
});
return future;
}
return CompletableFuture.completedFuture(connection);
}
/**
* Sends a session request to the given connection.
*
* @param request The request to send.
* @param connection The connection to which to send the request.
* @param future The future to complete once the response is received.
* @param checkOpen Whether to check if the session is open.
* @param <T> The request type.
* @param <U> The response type.
* @return The provided future to be completed once the response is received.
*/
private <T extends Request<T>, U extends Response<U>> CompletableFuture<U> request(
T request,
Connection connection,
CompletableFuture<U> future,
boolean checkOpen,
boolean recordFailures) {
LOGGER.debug("Sending: {}", request);
connection
.<T, U>send(request)
.whenComplete(
(response, error) -> {
if (!checkOpen || isOpen()) {
if (error == null) {
LOGGER.debug("Received: {}", response);
// If the response is an error response, check if the session state has changed.
if (response.status() == Response.Status.ERROR) {
// If the response error is a no leader error, reset the connection and send
// another request.
// If this is the first time we've received a response from a server in this
// iteration,
// set the failure time to keep track of whether the session timed out.
if (response.error() == RaftError.Type.NO_LEADER_ERROR) {
if (recordFailures) setFailureTime();
resetConnection().request(request, future, checkOpen, false);
}
// If the response error is an unknown session error, immediately expire the
// session.
else if (response.error() == RaftError.Type.UNKNOWN_SESSION_ERROR) {
resetConnection().onExpire();
future.completeExceptionally(new IllegalStateException("session expired"));
}
// If the response error is an application or internal error, immediately
// complete the future.
else if (response.error() == RaftError.Type.APPLICATION_ERROR
|| response.error() == RaftError.Type.INTERNAL_ERROR) {
resetFailureTime();
future.completeExceptionally(response.error().createException());
}
// If we've made it this far, for all other error types attempt to resend the
// request.
else {
resetFailureTime()
.resetConnection()
.request(request, future, checkOpen, false);
}
}
// If the response status is OK, reset the failure time and complete the future.
else {
resetFailureTime();
future.complete(response);
}
}
// If an error occurred, attempt to contact the next server recursively.
else {
LOGGER.debug("Request failed: {}", request);
LOGGER.debug("{}", error.getMessage());
resetConnection().request(request, future, checkOpen, recordFailures);
}
} else {
future.completeExceptionally(new IllegalStateException("session not open"));
}
});
return future;
}