Rocket.Chat.ReactNative/ios/Pods/Flipper-RSocket/rsocket/statemachine/RSocketStateMachine.cpp

1237 lines
39 KiB
C++

// Copyright (c) Facebook, Inc. and its affiliates.
//
// 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.
#include "rsocket/statemachine/RSocketStateMachine.h"
#include <folly/ExceptionWrapper.h>
#include <folly/Format.h>
#include <folly/Optional.h>
#include <folly/String.h>
#include <folly/io/async/EventBaseManager.h>
#include <folly/lang/Assume.h>
#include "rsocket/DuplexConnection.h"
#include "rsocket/RSocketConnectionEvents.h"
#include "rsocket/RSocketParameters.h"
#include "rsocket/RSocketResponder.h"
#include "rsocket/RSocketStats.h"
#include "rsocket/framing/Frame.h"
#include "rsocket/framing/FrameSerializer.h"
#include "rsocket/framing/FrameTransportImpl.h"
#include "rsocket/internal/ClientResumeStatusCallback.h"
#include "rsocket/internal/ScheduledSubscriber.h"
#include "rsocket/internal/WarmResumeManager.h"
#include "rsocket/statemachine/ChannelRequester.h"
#include "rsocket/statemachine/ChannelResponder.h"
#include "rsocket/statemachine/FireAndForgetResponder.h"
#include "rsocket/statemachine/RequestResponseRequester.h"
#include "rsocket/statemachine/RequestResponseResponder.h"
#include "rsocket/statemachine/StreamRequester.h"
#include "rsocket/statemachine/StreamResponder.h"
#include "rsocket/statemachine/StreamStateMachineBase.h"
#include "yarpl/flowable/Subscription.h"
#include "yarpl/single/SingleSubscriptions.h"
namespace rsocket {
namespace {
void disconnectError(
std::shared_ptr<yarpl::flowable::Subscriber<Payload>> subscriber) {
std::runtime_error exn{"RSocket connection is disconnected or closed"};
subscriber->onSubscribe(yarpl::flowable::Subscription::create());
subscriber->onError(std::move(exn));
}
void disconnectError(
std::shared_ptr<yarpl::single::SingleObserver<Payload>> observer) {
auto exn = folly::make_exception_wrapper<std::runtime_error>(
"RSocket connection is disconnected or closed");
observer->onSubscribe(yarpl::single::SingleSubscriptions::empty());
observer->onError(std::move(exn));
}
} // namespace
RSocketStateMachine::RSocketStateMachine(
std::shared_ptr<RSocketResponder> requestResponder,
std::unique_ptr<KeepaliveTimer> keepaliveTimer,
RSocketMode mode,
std::shared_ptr<RSocketStats> stats,
std::shared_ptr<RSocketConnectionEvents> connectionEvents,
std::shared_ptr<ResumeManager> resumeManager,
std::shared_ptr<ColdResumeHandler> coldResumeHandler)
: RSocketStateMachine(
std::make_shared<RSocketResponderAdapter>(
std::move(requestResponder)),
std::move(keepaliveTimer),
mode,
std::move(stats),
std::move(connectionEvents),
std::move(resumeManager),
std::move(coldResumeHandler)) {}
RSocketStateMachine::RSocketStateMachine(
std::shared_ptr<RSocketResponderCore> requestResponder,
std::unique_ptr<KeepaliveTimer> keepaliveTimer,
RSocketMode mode,
std::shared_ptr<RSocketStats> stats,
std::shared_ptr<RSocketConnectionEvents> connectionEvents,
std::shared_ptr<ResumeManager> resumeManager,
std::shared_ptr<ColdResumeHandler> coldResumeHandler)
: mode_{mode},
stats_{stats ? stats : RSocketStats::noop()},
// Streams initiated by a client MUST use odd-numbered and streams
// initiated by the server MUST use even-numbered stream identifiers
nextStreamId_(mode == RSocketMode::CLIENT ? 1 : 2),
resumeManager_(std::move(resumeManager)),
requestResponder_{std::move(requestResponder)},
keepaliveTimer_{std::move(keepaliveTimer)},
coldResumeHandler_{std::move(coldResumeHandler)},
connectionEvents_{connectionEvents} {
CHECK(resumeManager_)
<< "provide ResumeManager::makeEmpty() instead of nullptr";
// We deliberately do not "open" input or output to avoid having c'tor on the
// stack when processing any signals from the connection. See ::connect and
// ::onSubscribe.
CHECK(requestResponder_);
stats_->socketCreated();
VLOG(2) << "Creating RSocketStateMachine";
}
RSocketStateMachine::~RSocketStateMachine() {
// this destructor can be called from a different thread because the stream
// automatons destroyed on different threads can be the last ones referencing
// this.
VLOG(3) << "~RSocketStateMachine";
// We rely on SubscriptionPtr and SubscriberPtr to dispatch appropriate
// terminal signals.
DCHECK(!resumeCallback_);
DCHECK(isDisconnected()); // the instance should be closed by via
// close method
}
void RSocketStateMachine::setResumable(bool resumable) {
// We should set this flag before we are connected
DCHECK(isDisconnected());
isResumable_ = resumable;
}
void RSocketStateMachine::connectServer(
std::shared_ptr<FrameTransport> frameTransport,
const SetupParameters& setupParams) {
setResumable(setupParams.resumable);
setProtocolVersionOrThrow(setupParams.protocolVersion, frameTransport);
connect(std::move(frameTransport));
sendPendingFrames();
}
bool RSocketStateMachine::resumeServer(
std::shared_ptr<FrameTransport> frameTransport,
const ResumeParameters& resumeParams) {
const folly::Optional<int64_t> clientAvailable =
(resumeParams.clientPosition == kUnspecifiedResumePosition)
? folly::none
: folly::make_optional(
resumeManager_->impliedPosition() - resumeParams.clientPosition);
const int64_t serverAvailable =
resumeManager_->lastSentPosition() - resumeManager_->firstSentPosition();
const int64_t serverDelta =
resumeManager_->lastSentPosition() - resumeParams.serverPosition;
if (frameTransport) {
stats_->socketDisconnected();
}
closeFrameTransport(
std::runtime_error{"Connection being resumed, dropping old connection"});
setProtocolVersionOrThrow(resumeParams.protocolVersion, frameTransport);
connect(std::move(frameTransport));
const auto result = resumeFromPositionOrClose(
resumeParams.serverPosition, resumeParams.clientPosition);
stats_->serverResume(
clientAvailable,
serverAvailable,
serverDelta,
result ? RSocketStats::ResumeOutcome::SUCCESS
: RSocketStats::ResumeOutcome::FAILURE);
return result;
}
void RSocketStateMachine::connectClient(
std::shared_ptr<FrameTransport> transport,
SetupParameters params) {
auto const version = params.protocolVersion == ProtocolVersion::Unknown
? ProtocolVersion::Latest
: params.protocolVersion;
setProtocolVersionOrThrow(version, transport);
setResumable(params.resumable);
Frame_SETUP frame(
(params.resumable ? FrameFlags::RESUME_ENABLE : FrameFlags::EMPTY_) |
(params.payload.metadata ? FrameFlags::METADATA : FrameFlags::EMPTY_),
version.major,
version.minor,
getKeepaliveTime(),
Frame_SETUP::kMaxLifetime,
std::move(params.token),
std::move(params.metadataMimeType),
std::move(params.dataMimeType),
std::move(params.payload));
// TODO: when the server returns back that it doesn't support resumability, we
// should retry without resumability
VLOG(3) << "Out: " << frame;
connect(std::move(transport));
// making sure we send setup frame first
outputFrame(frameSerializer_->serializeOut(std::move(frame)));
// then the rest of the cached frames will be sent
sendPendingFrames();
}
void RSocketStateMachine::resumeClient(
ResumeIdentificationToken token,
std::shared_ptr<FrameTransport> transport,
std::unique_ptr<ClientResumeStatusCallback> resumeCallback,
ProtocolVersion version) {
// Cold-resumption. Set the serializer.
if (!frameSerializer_) {
CHECK(coldResumeHandler_);
coldResumeInProgress_ = true;
}
setProtocolVersionOrThrow(
version == ProtocolVersion::Unknown ? ProtocolVersion::Latest : version,
transport);
Frame_RESUME resumeFrame(
std::move(token),
resumeManager_->impliedPosition(),
resumeManager_->firstSentPosition(),
frameSerializer_->protocolVersion());
VLOG(3) << "Out: " << resumeFrame;
// Disconnect a previous client if there is one.
disconnect(std::runtime_error{"Resuming client on a different connection"});
setResumable(true);
reconnect(std::move(transport), std::move(resumeCallback));
outputFrame(frameSerializer_->serializeOut(std::move(resumeFrame)));
}
void RSocketStateMachine::connect(std::shared_ptr<FrameTransport> transport) {
VLOG(2) << "Connecting to transport " << transport.get();
CHECK(isDisconnected());
CHECK(transport);
// Keep a reference to the argument, make sure the instance survives until
// setFrameProcessor() returns. There can be terminating signals processed in
// that call which will nullify frameTransport_.
frameTransport_ = transport;
CHECK(frameSerializer_);
frameSerializer_->preallocateFrameSizeField() =
transport->isConnectionFramed();
if (connectionEvents_) {
connectionEvents_->onConnected();
}
// Keep a reference to stats, as processing frames might close this instance.
auto const stats = stats_;
frameTransport_->setFrameProcessor(shared_from_this());
stats->socketConnected();
}
void RSocketStateMachine::sendPendingFrames() {
DCHECK(!resumeCallback_);
StreamsWriterImpl::sendPendingFrames();
// TODO: turn on only after setup frame was received
if (keepaliveTimer_) {
keepaliveTimer_->start(shared_from_this());
}
}
void RSocketStateMachine::disconnect(folly::exception_wrapper ex) {
VLOG(2) << "Disconnecting transport";
if (isDisconnected()) {
return;
}
if (connectionEvents_) {
connectionEvents_->onDisconnected(ex);
}
closeFrameTransport(std::move(ex));
if (connectionEvents_) {
connectionEvents_->onStreamsPaused();
}
stats_->socketDisconnected();
}
void RSocketStateMachine::close(
folly::exception_wrapper ex,
StreamCompletionSignal signal) {
if (isClosed()) {
return;
}
isClosed_ = true;
stats_->socketClosed(signal);
VLOG(6) << "close";
if (auto resumeCallback = std::move(resumeCallback_)) {
resumeCallback->onResumeError(
ConnectionException(ex ? ex.get_exception()->what() : "RS closing"));
}
closeStreams(signal);
closeFrameTransport(ex);
if (auto connectionEvents = std::move(connectionEvents_)) {
connectionEvents->onClosed(std::move(ex));
}
if (closeCallback_) {
closeCallback_->remove(*this);
}
}
void RSocketStateMachine::closeFrameTransport(folly::exception_wrapper ex) {
if (isDisconnected()) {
DCHECK(!resumeCallback_);
return;
}
// Stop scheduling keepalives since the socket is now disconnected
if (keepaliveTimer_) {
keepaliveTimer_->stop();
}
if (auto resumeCallback = std::move(resumeCallback_)) {
resumeCallback->onResumeError(ConnectionException(
ex ? ex.get_exception()->what() : "connection closing"));
}
// Echo the exception to the frameTransport only if the frameTransport started
// closing with error. Otherwise we sent some error frame over the wire and
// we are closing the transport cleanly.
if (frameTransport_) {
frameTransport_->close();
frameTransport_ = nullptr;
}
}
void RSocketStateMachine::disconnectOrCloseWithError(Frame_ERROR&& errorFrame) {
if (isResumable_) {
std::runtime_error exn{errorFrame.payload_.moveDataToString()};
disconnect(std::move(exn));
} else {
closeWithError(std::move(errorFrame));
}
}
void RSocketStateMachine::closeWithError(Frame_ERROR&& error) {
VLOG(3) << "closeWithError "
<< error.payload_.data->cloneAsValue().moveToFbString();
StreamCompletionSignal signal;
switch (error.errorCode_) {
case ErrorCode::INVALID_SETUP:
signal = StreamCompletionSignal::INVALID_SETUP;
break;
case ErrorCode::UNSUPPORTED_SETUP:
signal = StreamCompletionSignal::UNSUPPORTED_SETUP;
break;
case ErrorCode::REJECTED_SETUP:
signal = StreamCompletionSignal::REJECTED_SETUP;
break;
case ErrorCode::CONNECTION_ERROR:
// StreamCompletionSignal::CONNECTION_ERROR is reserved for
// frameTransport errors
// ErrorCode::CONNECTION_ERROR is a normal Frame_ERROR error code which has
// nothing to do with frameTransport
case ErrorCode::APPLICATION_ERROR:
case ErrorCode::REJECTED:
case ErrorCode::RESERVED:
case ErrorCode::CANCELED:
case ErrorCode::INVALID:
default:
signal = StreamCompletionSignal::ERROR;
}
std::runtime_error exn{error.payload_.cloneDataToString()};
if (frameSerializer_) {
outputFrameOrEnqueue(frameSerializer_->serializeOut(std::move(error)));
}
close(std::move(exn), signal);
}
void RSocketStateMachine::reconnect(
std::shared_ptr<FrameTransport> newFrameTransport,
std::unique_ptr<ClientResumeStatusCallback> resumeCallback) {
CHECK(newFrameTransport);
CHECK(resumeCallback);
CHECK(!resumeCallback_);
CHECK(isResumable_);
CHECK(mode_ == RSocketMode::CLIENT);
// TODO: output frame buffer should not be written to the new connection until
// we receive resume ok
resumeCallback_ = std::move(resumeCallback);
connect(std::move(newFrameTransport));
}
void RSocketStateMachine::requestStream(
Payload request,
std::shared_ptr<yarpl::flowable::Subscriber<Payload>> responseSink) {
if (isDisconnected()) {
disconnectError(std::move(responseSink));
return;
}
auto const streamId = getNextStreamId();
auto stateMachine = std::make_shared<StreamRequester>(
shared_from_this(), streamId, std::move(request));
const auto result = streams_.emplace(streamId, stateMachine);
DCHECK(result.second);
stateMachine->subscribe(std::move(responseSink));
}
std::shared_ptr<yarpl::flowable::Subscriber<Payload>>
RSocketStateMachine::requestChannel(
Payload request,
bool hasInitialRequest,
std::shared_ptr<yarpl::flowable::Subscriber<Payload>> responseSink) {
if (isDisconnected()) {
disconnectError(std::move(responseSink));
return nullptr;
}
auto const streamId = getNextStreamId();
std::shared_ptr<ChannelRequester> stateMachine;
if (hasInitialRequest) {
stateMachine = std::make_shared<ChannelRequester>(
std::move(request), shared_from_this(), streamId);
} else {
stateMachine =
std::make_shared<ChannelRequester>(shared_from_this(), streamId);
}
const auto result = streams_.emplace(streamId, stateMachine);
DCHECK(result.second);
stateMachine->subscribe(std::move(responseSink));
return stateMachine;
}
void RSocketStateMachine::requestResponse(
Payload request,
std::shared_ptr<yarpl::single::SingleObserver<Payload>> responseSink) {
if (isDisconnected()) {
disconnectError(std::move(responseSink));
return;
}
auto const streamId = getNextStreamId();
auto stateMachine = std::make_shared<RequestResponseRequester>(
shared_from_this(), streamId, std::move(request));
const auto result = streams_.emplace(streamId, stateMachine);
DCHECK(result.second);
stateMachine->subscribe(std::move(responseSink));
}
void RSocketStateMachine::closeStreams(StreamCompletionSignal signal) {
while (!streams_.empty()) {
auto it = streams_.begin();
auto streamStateMachine = std::move(it->second);
streams_.erase(it);
streamStateMachine->endStream(signal);
}
}
void RSocketStateMachine::processFrame(std::unique_ptr<folly::IOBuf> frame) {
if (isClosed()) {
VLOG(4) << "StateMachine has been closed. Discarding incoming frame";
return;
}
if (!ensureOrAutodetectFrameSerializer(*frame)) {
constexpr auto msg = "Cannot detect protocol version";
closeWithError(Frame_ERROR::connectionError(msg));
return;
}
const auto frameType = frameSerializer_->peekFrameType(*frame);
stats_->frameRead(frameType);
const auto optStreamId = frameSerializer_->peekStreamId(*frame, false);
if (!optStreamId) {
constexpr auto msg = "Cannot decode stream ID";
closeWithError(Frame_ERROR::connectionError(msg));
return;
}
const auto frameLength = frame->computeChainDataLength();
const auto streamId = *optStreamId;
handleFrame(streamId, frameType, std::move(frame));
resumeManager_->trackReceivedFrame(
frameLength, frameType, streamId, getConsumerAllowance(streamId));
}
void RSocketStateMachine::onTerminal(folly::exception_wrapper ex) {
if (isResumable_) {
disconnect(std::move(ex));
return;
}
const auto termSignal = ex ? StreamCompletionSignal::CONNECTION_ERROR
: StreamCompletionSignal::CONNECTION_END;
close(std::move(ex), termSignal);
}
void RSocketStateMachine::onKeepAliveFrame(
ResumePosition resumePosition,
std::unique_ptr<folly::IOBuf> data,
bool keepAliveRespond) {
resumeManager_->resetUpToPosition(resumePosition);
if (mode_ == RSocketMode::SERVER) {
if (keepAliveRespond) {
sendKeepalive(FrameFlags::EMPTY_, std::move(data));
} else {
closeWithError(Frame_ERROR::connectionError("keepalive without flag"));
}
} else {
if (keepAliveRespond) {
closeWithError(Frame_ERROR::connectionError(
"client received keepalive with respond flag"));
} else if (keepaliveTimer_) {
keepaliveTimer_->keepaliveReceived();
}
stats_->keepaliveReceived();
}
}
void RSocketStateMachine::onMetadataPushFrame(
std::unique_ptr<folly::IOBuf> metadata) {
requestResponder_->handleMetadataPush(std::move(metadata));
}
void RSocketStateMachine::onResumeOkFrame(ResumePosition resumePosition) {
if (!resumeCallback_) {
constexpr auto msg = "Received RESUME_OK while not resuming";
closeWithError(Frame_ERROR::connectionError(msg));
return;
}
if (!resumeManager_->isPositionAvailable(resumePosition)) {
auto const msg = folly::sformat(
"Client cannot resume, server position {} is not available",
resumePosition);
closeWithError(Frame_ERROR::connectionError(msg));
return;
}
if (coldResumeInProgress_) {
setNextStreamId(resumeManager_->getLargestUsedStreamId());
for (const auto& it : resumeManager_->getStreamResumeInfos()) {
const auto streamId = it.first;
const StreamResumeInfo& streamResumeInfo = it.second;
if (streamResumeInfo.requester == RequestOriginator::LOCAL &&
streamResumeInfo.streamType == StreamType::STREAM) {
auto subscriber = coldResumeHandler_->handleRequesterResumeStream(
streamResumeInfo.streamToken, streamResumeInfo.consumerAllowance);
auto stateMachine = std::make_shared<StreamRequester>(
shared_from_this(), streamId, Payload());
// Set requested to true (since cold resumption)
stateMachine->setRequested(streamResumeInfo.consumerAllowance);
const auto result = streams_.emplace(streamId, stateMachine);
DCHECK(result.second);
stateMachine->subscribe(
std::make_shared<ScheduledSubscriptionSubscriber<Payload>>(
std::move(subscriber),
*folly::EventBaseManager::get()->getEventBase()));
}
}
coldResumeInProgress_ = false;
}
auto resumeCallback = std::move(resumeCallback_);
resumeCallback->onResumeOk();
resumeFromPosition(resumePosition);
}
void RSocketStateMachine::onErrorFrame(
StreamId streamId,
ErrorCode errorCode,
Payload payload) {
if (streamId != 0) {
if (!ensureNotInResumption()) {
return;
}
// we ignore messages for streams which don't exist
if (auto stateMachine = getStreamStateMachine(streamId)) {
if (errorCode != ErrorCode::APPLICATION_ERROR) {
// Encapsulate non-user errors with runtime_error, which is more
// suitable for LOGging.
stateMachine->handleError(
std::runtime_error(payload.moveDataToString()));
} else {
// Don't expose user errors
stateMachine->handleError(ErrorWithPayload(std::move(payload)));
}
}
} else {
// TODO: handle INVALID_SETUP, UNSUPPORTED_SETUP, REJECTED_SETUP
if ((errorCode == ErrorCode::CONNECTION_ERROR ||
errorCode == ErrorCode::REJECTED_RESUME) &&
resumeCallback_) {
auto resumeCallback = std::move(resumeCallback_);
resumeCallback->onResumeError(
ResumptionException(payload.cloneDataToString()));
// fall through
}
close(
std::runtime_error(payload.moveDataToString()),
StreamCompletionSignal::ERROR);
}
}
void RSocketStateMachine::onSetupFrame() {
// this should be processed in SetupResumeAcceptor
onUnexpectedFrame(0);
}
void RSocketStateMachine::onResumeFrame() {
// this should be processed in SetupResumeAcceptor
onUnexpectedFrame(0);
}
void RSocketStateMachine::onReservedFrame() {
onUnexpectedFrame(0);
}
void RSocketStateMachine::onLeaseFrame() {
onUnexpectedFrame(0);
}
void RSocketStateMachine::onExtFrame() {
onUnexpectedFrame(0);
}
void RSocketStateMachine::onUnexpectedFrame(StreamId streamId) {
auto&& msg = folly::sformat("Unexpected frame for stream {}", streamId);
closeWithError(Frame_ERROR::connectionError(msg));
}
void RSocketStateMachine::handleFrame(
StreamId streamId,
FrameType frameType,
std::unique_ptr<folly::IOBuf> payload) {
switch (frameType) {
case FrameType::KEEPALIVE: {
Frame_KEEPALIVE frame;
if (!deserializeFrameOrError(frame, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << frame;
onKeepAliveFrame(
frame.position_,
std::move(frame.data_),
!!(frame.header_.flags & FrameFlags::KEEPALIVE_RESPOND));
return;
}
case FrameType::METADATA_PUSH: {
Frame_METADATA_PUSH frame;
if (!deserializeFrameOrError(frame, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << frame;
onMetadataPushFrame(std::move(frame.metadata_));
return;
}
case FrameType::RESUME_OK: {
Frame_RESUME_OK frame;
if (!deserializeFrameOrError(frame, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << frame;
onResumeOkFrame(frame.position_);
return;
}
case FrameType::ERROR: {
Frame_ERROR frame;
if (!deserializeFrameOrError(frame, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << frame;
onErrorFrame(streamId, frame.errorCode_, std::move(frame.payload_));
return;
}
case FrameType::SETUP:
onSetupFrame();
return;
case FrameType::RESUME:
onResumeFrame();
return;
case FrameType::RESERVED:
onReservedFrame();
return;
case FrameType::LEASE:
onLeaseFrame();
return;
case FrameType::REQUEST_N: {
Frame_REQUEST_N frameRequestN;
if (!deserializeFrameOrError(frameRequestN, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << frameRequestN;
onRequestNFrame(streamId, frameRequestN.requestN_);
break;
}
case FrameType::CANCEL: {
VLOG(3) << mode_ << " In: " << Frame_CANCEL(streamId);
onCancelFrame(streamId);
break;
}
case FrameType::PAYLOAD: {
Frame_PAYLOAD framePayload;
if (!deserializeFrameOrError(framePayload, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << framePayload;
onPayloadFrame(
streamId,
std::move(framePayload.payload_),
framePayload.header_.flagsFollows(),
framePayload.header_.flagsComplete(),
framePayload.header_.flagsNext());
break;
}
case FrameType::REQUEST_CHANNEL: {
Frame_REQUEST_CHANNEL frame;
if (!deserializeFrameOrError(frame, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << frame;
onRequestChannelFrame(
streamId,
frame.requestN_,
std::move(frame.payload_),
frame.header_.flagsComplete(),
frame.header_.flagsNext(),
frame.header_.flagsFollows());
break;
}
case FrameType::REQUEST_STREAM: {
Frame_REQUEST_STREAM frame;
if (!deserializeFrameOrError(frame, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << frame;
onRequestStreamFrame(
streamId,
frame.requestN_,
std::move(frame.payload_),
frame.header_.flagsFollows());
break;
}
case FrameType::REQUEST_RESPONSE: {
Frame_REQUEST_RESPONSE frame;
if (!deserializeFrameOrError(frame, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << frame;
onRequestResponseFrame(
streamId, std::move(frame.payload_), frame.header_.flagsFollows());
break;
}
case FrameType::REQUEST_FNF: {
Frame_REQUEST_FNF frame;
if (!deserializeFrameOrError(frame, std::move(payload))) {
return;
}
VLOG(3) << mode_ << " In: " << frame;
onFireAndForgetFrame(
streamId, std::move(frame.payload_), frame.header_.flagsFollows());
break;
}
case FrameType::EXT:
onExtFrame();
return;
default: {
stats_->unknownFrameReceived();
// per rsocket spec, we will ignore any other unknown frames
return;
}
}
}
std::shared_ptr<StreamStateMachineBase>
RSocketStateMachine::getStreamStateMachine(StreamId streamId) {
const auto&& it = streams_.find(streamId);
if (it == streams_.end()) {
return nullptr;
}
// we are purposely making a copy of the reference here to avoid problems with
// lifetime of the stateMachine when a terminating signal is delivered which
// will cause the stateMachine to be destroyed while in one of its methods
return it->second;
}
bool RSocketStateMachine::ensureNotInResumption() {
if (resumeCallback_) {
// during the time when we are resuming we are can't receive any other
// than connection level frames which drives the resumption
// TODO(lehecka): this assertion should be handled more elegantly using
// different state machine
constexpr auto msg = "Received stream frame while resuming";
LOG(ERROR) << msg;
closeWithError(Frame_ERROR::connectionError(msg));
return false;
}
return true;
}
void RSocketStateMachine::onRequestNFrame(
StreamId streamId,
uint32_t requestN) {
if (!ensureNotInResumption()) {
return;
}
// we ignore messages for streams which don't exist
if (auto stateMachine = getStreamStateMachine(streamId)) {
stateMachine->handleRequestN(requestN);
}
}
void RSocketStateMachine::onCancelFrame(StreamId streamId) {
if (!ensureNotInResumption()) {
return;
}
// we ignore messages for streams which don't exist
if (auto stateMachine = getStreamStateMachine(streamId)) {
stateMachine->handleCancel();
}
}
void RSocketStateMachine::onPayloadFrame(
StreamId streamId,
Payload payload,
bool flagsFollows,
bool flagsComplete,
bool flagsNext) {
if (!ensureNotInResumption()) {
return;
}
// we ignore messages for streams which don't exist
if (auto stateMachine = getStreamStateMachine(streamId)) {
stateMachine->handlePayload(
std::move(payload), flagsComplete, flagsNext, flagsFollows);
}
}
void RSocketStateMachine::onRequestStreamFrame(
StreamId streamId,
uint32_t requestN,
Payload payload,
bool flagsFollows) {
if (!ensureNotInResumption() || !isNewStreamId(streamId)) {
return;
}
auto stateMachine =
std::make_shared<StreamResponder>(shared_from_this(), streamId, requestN);
const auto result = streams_.emplace(streamId, stateMachine);
DCHECK(result.second); // ensured by calling isNewStreamId
stateMachine->handlePayload(std::move(payload), false, false, flagsFollows);
}
void RSocketStateMachine::onRequestChannelFrame(
StreamId streamId,
uint32_t requestN,
Payload payload,
bool flagsComplete,
bool flagsNext,
bool flagsFollows) {
if (!ensureNotInResumption() || !isNewStreamId(streamId)) {
return;
}
auto stateMachine = std::make_shared<ChannelResponder>(
shared_from_this(), streamId, requestN);
const auto result = streams_.emplace(streamId, stateMachine);
DCHECK(result.second); // ensured by calling isNewStreamId
stateMachine->handlePayload(
std::move(payload), flagsComplete, flagsNext, flagsFollows);
}
void RSocketStateMachine::onRequestResponseFrame(
StreamId streamId,
Payload payload,
bool flagsFollows) {
if (!ensureNotInResumption() || !isNewStreamId(streamId)) {
return;
}
auto stateMachine =
std::make_shared<RequestResponseResponder>(shared_from_this(), streamId);
const auto result = streams_.emplace(streamId, stateMachine);
DCHECK(result.second); // ensured by calling isNewStreamId
stateMachine->handlePayload(std::move(payload), false, false, flagsFollows);
}
void RSocketStateMachine::onFireAndForgetFrame(
StreamId streamId,
Payload payload,
bool flagsFollows) {
if (!ensureNotInResumption() || !isNewStreamId(streamId)) {
return;
}
auto stateMachine =
std::make_shared<FireAndForgetResponder>(shared_from_this(), streamId);
const auto result = streams_.emplace(streamId, stateMachine);
DCHECK(result.second); // ensured by calling isNewStreamId
stateMachine->handlePayload(std::move(payload), false, false, flagsFollows);
}
bool RSocketStateMachine::isNewStreamId(StreamId streamId) {
if (frameSerializer_->protocolVersion() > ProtocolVersion{0, 0} &&
!registerNewPeerStreamId(streamId)) {
return false;
}
return true;
}
std::shared_ptr<yarpl::flowable::Subscriber<Payload>>
RSocketStateMachine::onNewStreamReady(
StreamId streamId,
StreamType streamType,
Payload payload,
std::shared_ptr<yarpl::flowable::Subscriber<Payload>> response) {
if (coldResumeHandler_ && streamType != StreamType::FNF) {
auto streamToken =
coldResumeHandler_->generateStreamToken(payload, streamId, streamType);
resumeManager_->onStreamOpen(
streamId, RequestOriginator::REMOTE, streamToken, streamType);
}
switch (streamType) {
case StreamType::CHANNEL:
return requestResponder_->handleRequestChannel(
std::move(payload), streamId, std::move(response));
case StreamType::STREAM:
requestResponder_->handleRequestStream(
std::move(payload), streamId, std::move(response));
return nullptr;
case StreamType::REQUEST_RESPONSE:
// the other overload method should be called
CHECK(false);
folly::assume_unreachable();
case StreamType::FNF:
requestResponder_->handleFireAndForget(std::move(payload), streamId);
return nullptr;
default:
CHECK(false) << "unknown value: " << streamType;
folly::assume_unreachable();
}
}
void RSocketStateMachine::onNewStreamReady(
StreamId streamId,
StreamType streamType,
Payload payload,
std::shared_ptr<yarpl::single::SingleObserver<Payload>> response) {
CHECK(streamType == StreamType::REQUEST_RESPONSE);
if (coldResumeHandler_) {
auto streamToken =
coldResumeHandler_->generateStreamToken(payload, streamId, streamType);
resumeManager_->onStreamOpen(
streamId, RequestOriginator::REMOTE, streamToken, streamType);
}
requestResponder_->handleRequestResponse(
std::move(payload), streamId, std::move(response));
}
void RSocketStateMachine::sendKeepalive(std::unique_ptr<folly::IOBuf> data) {
sendKeepalive(FrameFlags::KEEPALIVE_RESPOND, std::move(data));
}
void RSocketStateMachine::sendKeepalive(
FrameFlags flags,
std::unique_ptr<folly::IOBuf> data) {
Frame_KEEPALIVE pingFrame(
flags, resumeManager_->impliedPosition(), std::move(data));
VLOG(3) << mode_ << " Out: " << pingFrame;
outputFrameOrEnqueue(frameSerializer_->serializeOut(std::move(pingFrame)));
stats_->keepaliveSent();
}
bool RSocketStateMachine::isPositionAvailable(ResumePosition position) const {
return resumeManager_->isPositionAvailable(position);
}
bool RSocketStateMachine::resumeFromPositionOrClose(
ResumePosition serverPosition,
ResumePosition clientPosition) {
DCHECK(!resumeCallback_);
DCHECK(!isDisconnected());
DCHECK(mode_ == RSocketMode::SERVER);
const bool clientPositionExist =
(clientPosition == kUnspecifiedResumePosition) ||
clientPosition <= resumeManager_->impliedPosition();
if (clientPositionExist &&
resumeManager_->isPositionAvailable(serverPosition)) {
Frame_RESUME_OK resumeOkFrame{resumeManager_->impliedPosition()};
VLOG(3) << "Out: " << resumeOkFrame;
frameTransport_->outputFrameOrDrop(
frameSerializer_->serializeOut(std::move(resumeOkFrame)));
resumeFromPosition(serverPosition);
return true;
}
auto const msg = folly::to<std::string>(
"Cannot resume server, client lastServerPosition=",
serverPosition,
" firstClientPosition=",
clientPosition,
" is not available. Last reset position is ",
resumeManager_->firstSentPosition());
closeWithError(Frame_ERROR::connectionError(msg));
return false;
}
void RSocketStateMachine::resumeFromPosition(ResumePosition position) {
DCHECK(!resumeCallback_);
DCHECK(!isDisconnected());
DCHECK(resumeManager_->isPositionAvailable(position));
if (connectionEvents_) {
connectionEvents_->onStreamsResumed();
}
resumeManager_->sendFramesFromPosition(position, *frameTransport_);
auto frames = consumePendingOutputFrames();
for (auto& frame : frames) {
outputFrameOrEnqueue(std::move(frame));
}
if (!isDisconnected() && keepaliveTimer_) {
keepaliveTimer_->start(shared_from_this());
}
}
bool RSocketStateMachine::shouldQueue() {
// if we are resuming we cant send any frames until we receive RESUME_OK
return isDisconnected() || resumeCallback_;
}
void RSocketStateMachine::fireAndForget(Payload request) {
auto const streamId = getNextStreamId();
Frame_REQUEST_FNF frame{streamId, FrameFlags::EMPTY_, std::move(request)};
outputFrameOrEnqueue(frameSerializer_->serializeOut(std::move(frame)));
}
void RSocketStateMachine::metadataPush(std::unique_ptr<folly::IOBuf> metadata) {
Frame_METADATA_PUSH metadataPushFrame{std::move(metadata)};
outputFrameOrEnqueue(
frameSerializer_->serializeOut(std::move(metadataPushFrame)));
}
void RSocketStateMachine::outputFrame(std::unique_ptr<folly::IOBuf> frame) {
DCHECK(!isDisconnected());
const auto frameType = frameSerializer_->peekFrameType(*frame);
stats_->frameWritten(frameType);
if (isResumable_) {
auto streamIdPtr = frameSerializer_->peekStreamId(*frame, false);
CHECK(streamIdPtr) << "Error in serialized frame.";
resumeManager_->trackSentFrame(
*frame, frameType, *streamIdPtr, getConsumerAllowance(*streamIdPtr));
}
frameTransport_->outputFrameOrDrop(std::move(frame));
}
uint32_t RSocketStateMachine::getKeepaliveTime() const {
return keepaliveTimer_
? static_cast<uint32_t>(keepaliveTimer_->keepaliveTime().count())
: Frame_SETUP::kMaxKeepaliveTime;
}
bool RSocketStateMachine::isDisconnected() const {
return !frameTransport_;
}
bool RSocketStateMachine::isClosed() const {
return isClosed_;
}
void RSocketStateMachine::writeNewStream(
StreamId streamId,
StreamType streamType,
uint32_t initialRequestN,
Payload payload) {
if (coldResumeHandler_ && streamType != StreamType::FNF) {
const auto streamToken =
coldResumeHandler_->generateStreamToken(payload, streamId, streamType);
resumeManager_->onStreamOpen(
streamId, RequestOriginator::LOCAL, streamToken, streamType);
}
StreamsWriterImpl::writeNewStream(
streamId, streamType, initialRequestN, std::move(payload));
}
void RSocketStateMachine::onStreamClosed(StreamId streamId) {
streams_.erase(streamId);
resumeManager_->onStreamClosed(streamId);
}
bool RSocketStateMachine::ensureOrAutodetectFrameSerializer(
const folly::IOBuf& firstFrame) {
if (frameSerializer_) {
return true;
}
if (mode_ != RSocketMode::SERVER) {
// this should never happen as clients are initized with FrameSerializer
// instance
DCHECK(false);
return false;
}
auto serializer = FrameSerializer::createAutodetectedSerializer(firstFrame);
if (!serializer) {
LOG(ERROR) << "unable to detect protocol version";
return false;
}
VLOG(2) << "detected protocol version" << serializer->protocolVersion();
frameSerializer_ = std::move(serializer);
frameSerializer_->preallocateFrameSizeField() =
frameTransport_ && frameTransport_->isConnectionFramed();
return true;
}
size_t RSocketStateMachine::getConsumerAllowance(StreamId streamId) const {
auto const it = streams_.find(streamId);
return it != streams_.end() ? it->second->getConsumerAllowance() : 0;
}
void RSocketStateMachine::registerCloseCallback(
RSocketStateMachine::CloseCallback* callback) {
closeCallback_ = callback;
}
DuplexConnection* RSocketStateMachine::getConnection() {
return frameTransport_ ? frameTransport_->getConnection() : nullptr;
}
void RSocketStateMachine::setProtocolVersionOrThrow(
ProtocolVersion version,
const std::shared_ptr<FrameTransport>& transport) {
CHECK(version != ProtocolVersion::Unknown);
// TODO(lehecka): this is a temporary guard to make sure the transport is
// explicitly closed when exceptions are thrown. The right solution is to
// automatically close duplex connection in the destructor when unique_ptr
// is released
auto transportGuard = folly::makeGuard([&] { transport->close(); });
if (frameSerializer_) {
if (frameSerializer_->protocolVersion() != version) {
// serializer is not interchangeable, it would screw up resumability
throw std::runtime_error{"Protocol version mismatch"};
}
} else {
auto frameSerializer = FrameSerializer::createFrameSerializer(version);
if (!frameSerializer) {
throw std::runtime_error{"Invalid protocol version"};
}
frameSerializer_ = std::move(frameSerializer);
frameSerializer_->preallocateFrameSizeField() =
frameTransport_ && frameTransport_->isConnectionFramed();
}
transportGuard.dismiss();
}
StreamId RSocketStateMachine::getNextStreamId() {
constexpr auto limit =
static_cast<uint32_t>(std::numeric_limits<int32_t>::max() - 2);
auto const streamId = nextStreamId_;
if (streamId >= limit) {
throw std::runtime_error{"Ran out of stream IDs"};
}
CHECK_EQ(0, streams_.count(streamId))
<< "Next stream ID already exists in the streams map";
nextStreamId_ += 2;
return streamId;
}
void RSocketStateMachine::setNextStreamId(StreamId streamId) {
nextStreamId_ = streamId + 2;
}
bool RSocketStateMachine::registerNewPeerStreamId(StreamId streamId) {
DCHECK_NE(0, streamId);
if (nextStreamId_ % 2 == streamId % 2) {
// if this is an unknown stream to the socket and this socket is
// generating such stream ids, it is an incoming frame on the stream which
// no longer exist
return false;
}
if (streamId <= lastPeerStreamId_) {
// receiving frame for a stream which no longer exists
return false;
}
lastPeerStreamId_ = streamId;
return true;
}
bool RSocketStateMachine::hasStreams() const {
return !streams_.empty();
}
} // namespace rsocket