| #include "quiche/http2/adapter/oghttp2_session.h" | 
 |  | 
 | #include <cstdint> | 
 | #include <memory> | 
 | #include <utility> | 
 | #include <vector> | 
 |  | 
 | #include "absl/memory/memory.h" | 
 | #include "absl/strings/escaping.h" | 
 | #include "quiche/http2/adapter/header_validator.h" | 
 | #include "quiche/http2/adapter/http2_protocol.h" | 
 | #include "quiche/http2/adapter/http2_util.h" | 
 | #include "quiche/http2/adapter/http2_visitor_interface.h" | 
 | #include "quiche/http2/adapter/noop_header_validator.h" | 
 | #include "quiche/http2/adapter/oghttp2_util.h" | 
 | #include "quiche/spdy/core/spdy_protocol.h" | 
 |  | 
 | namespace http2 { | 
 | namespace adapter { | 
 |  | 
 | namespace { | 
 |  | 
 | using ConnectionError = Http2VisitorInterface::ConnectionError; | 
 | using SpdyFramerError = Http2DecoderAdapter::SpdyFramerError; | 
 |  | 
 | using ::spdy::SpdySettingsIR; | 
 |  | 
 | const uint32_t kMaxAllowedMetadataFrameSize = 65536u; | 
 | const uint32_t kDefaultHpackTableCapacity = 4096u; | 
 | const uint32_t kMaximumHpackTableCapacity = 65536u; | 
 |  | 
 | // Corresponds to NGHTTP2_ERR_CALLBACK_FAILURE. | 
 | const int kSendError = -902; | 
 |  | 
 | // TODO(birenroy): Consider incorporating spdy::FlagsSerializionVisitor here. | 
 | class FrameAttributeCollector : public spdy::SpdyFrameVisitor { | 
 |  public: | 
 |   FrameAttributeCollector() = default; | 
 |   void VisitData(const spdy::SpdyDataIR& data) override { | 
 |     frame_type_ = static_cast<uint8_t>(data.frame_type()); | 
 |     stream_id_ = data.stream_id(); | 
 |     flags_ = (data.fin() ? 0x1 : 0) | (data.padded() ? 0x8 : 0); | 
 |   } | 
 |   void VisitHeaders(const spdy::SpdyHeadersIR& headers) override { | 
 |     frame_type_ = static_cast<uint8_t>(headers.frame_type()); | 
 |     stream_id_ = headers.stream_id(); | 
 |     flags_ = 0x4 | (headers.fin() ? 0x1 : 0) | (headers.padded() ? 0x8 : 0) | | 
 |              (headers.has_priority() ? 0x20 : 0); | 
 |   } | 
 |   void VisitPriority(const spdy::SpdyPriorityIR& priority) override { | 
 |     frame_type_ = static_cast<uint8_t>(priority.frame_type()); | 
 |     frame_type_ = 2; | 
 |     stream_id_ = priority.stream_id(); | 
 |   } | 
 |   void VisitRstStream(const spdy::SpdyRstStreamIR& rst_stream) override { | 
 |     frame_type_ = static_cast<uint8_t>(rst_stream.frame_type()); | 
 |     frame_type_ = 3; | 
 |     stream_id_ = rst_stream.stream_id(); | 
 |     error_code_ = rst_stream.error_code(); | 
 |   } | 
 |   void VisitSettings(const spdy::SpdySettingsIR& settings) override { | 
 |     frame_type_ = static_cast<uint8_t>(settings.frame_type()); | 
 |     frame_type_ = 4; | 
 |     flags_ = (settings.is_ack() ? 0x1 : 0); | 
 |   } | 
 |   void VisitPushPromise(const spdy::SpdyPushPromiseIR& push_promise) override { | 
 |     frame_type_ = static_cast<uint8_t>(push_promise.frame_type()); | 
 |     frame_type_ = 5; | 
 |     stream_id_ = push_promise.stream_id(); | 
 |     flags_ = (push_promise.padded() ? 0x8 : 0); | 
 |   } | 
 |   void VisitPing(const spdy::SpdyPingIR& ping) override { | 
 |     frame_type_ = static_cast<uint8_t>(ping.frame_type()); | 
 |     frame_type_ = 6; | 
 |     flags_ = (ping.is_ack() ? 0x1 : 0); | 
 |   } | 
 |   void VisitGoAway(const spdy::SpdyGoAwayIR& goaway) override { | 
 |     frame_type_ = static_cast<uint8_t>(goaway.frame_type()); | 
 |     frame_type_ = 7; | 
 |     error_code_ = goaway.error_code(); | 
 |   } | 
 |   void VisitWindowUpdate( | 
 |       const spdy::SpdyWindowUpdateIR& window_update) override { | 
 |     frame_type_ = static_cast<uint8_t>(window_update.frame_type()); | 
 |     frame_type_ = 8; | 
 |     stream_id_ = window_update.stream_id(); | 
 |   } | 
 |   void VisitContinuation( | 
 |       const spdy::SpdyContinuationIR& continuation) override { | 
 |     frame_type_ = static_cast<uint8_t>(continuation.frame_type()); | 
 |     stream_id_ = continuation.stream_id(); | 
 |     flags_ = continuation.end_headers() ? 0x4 : 0; | 
 |   } | 
 |   void VisitUnknown(const spdy::SpdyUnknownIR& unknown) override { | 
 |     frame_type_ = static_cast<uint8_t>(unknown.frame_type()); | 
 |     stream_id_ = unknown.stream_id(); | 
 |     flags_ = unknown.flags(); | 
 |   } | 
 |   void VisitAltSvc(const spdy::SpdyAltSvcIR& /*altsvc*/) override {} | 
 |   void VisitPriorityUpdate( | 
 |       const spdy::SpdyPriorityUpdateIR& /*priority_update*/) override {} | 
 |   void VisitAcceptCh(const spdy::SpdyAcceptChIR& /*accept_ch*/) override {} | 
 |  | 
 |   uint32_t stream_id() { return stream_id_; } | 
 |   uint32_t error_code() { return error_code_; } | 
 |   uint8_t frame_type() { return frame_type_; } | 
 |   uint8_t flags() { return flags_; } | 
 |  | 
 |  private: | 
 |   uint32_t stream_id_ = 0; | 
 |   uint32_t error_code_ = 0; | 
 |   uint8_t frame_type_ = 0; | 
 |   uint8_t flags_ = 0; | 
 | }; | 
 |  | 
 | absl::string_view TracePerspectiveAsString(Perspective p) { | 
 |   switch (p) { | 
 |     case Perspective::kClient: | 
 |       return "OGHTTP2_CLIENT"; | 
 |     case Perspective::kServer: | 
 |       return "OGHTTP2_SERVER"; | 
 |   } | 
 |   return "OGHTTP2_SERVER"; | 
 | } | 
 |  | 
 | class RunOnExit { | 
 |  public: | 
 |   RunOnExit() = default; | 
 |   explicit RunOnExit(std::function<void()> f) : f_(std::move(f)) {} | 
 |  | 
 |   RunOnExit(const RunOnExit& other) = delete; | 
 |   RunOnExit& operator=(const RunOnExit& other) = delete; | 
 |   RunOnExit(RunOnExit&& other) = delete; | 
 |   RunOnExit& operator=(RunOnExit&& other) = delete; | 
 |  | 
 |   ~RunOnExit() { | 
 |     if (f_) { | 
 |       f_(); | 
 |     } | 
 |     f_ = {}; | 
 |   } | 
 |  | 
 |   void emplace(std::function<void()> f) { f_ = std::move(f); } | 
 |  | 
 |  private: | 
 |   std::function<void()> f_; | 
 | }; | 
 |  | 
 | Http2ErrorCode GetHttp2ErrorCode(SpdyFramerError error) { | 
 |   switch (error) { | 
 |     case SpdyFramerError::SPDY_NO_ERROR: | 
 |       return Http2ErrorCode::HTTP2_NO_ERROR; | 
 |     case SpdyFramerError::SPDY_INVALID_STREAM_ID: | 
 |     case SpdyFramerError::SPDY_INVALID_CONTROL_FRAME: | 
 |     case SpdyFramerError::SPDY_INVALID_PADDING: | 
 |     case SpdyFramerError::SPDY_INVALID_DATA_FRAME_FLAGS: | 
 |     case SpdyFramerError::SPDY_UNEXPECTED_FRAME: | 
 |       return Http2ErrorCode::PROTOCOL_ERROR; | 
 |     case SpdyFramerError::SPDY_CONTROL_PAYLOAD_TOO_LARGE: | 
 |     case SpdyFramerError::SPDY_INVALID_CONTROL_FRAME_SIZE: | 
 |     case SpdyFramerError::SPDY_OVERSIZED_PAYLOAD: | 
 |       return Http2ErrorCode::FRAME_SIZE_ERROR; | 
 |     case SpdyFramerError::SPDY_DECOMPRESS_FAILURE: | 
 |     case SpdyFramerError::SPDY_HPACK_INDEX_VARINT_ERROR: | 
 |     case SpdyFramerError::SPDY_HPACK_NAME_LENGTH_VARINT_ERROR: | 
 |     case SpdyFramerError::SPDY_HPACK_VALUE_LENGTH_VARINT_ERROR: | 
 |     case SpdyFramerError::SPDY_HPACK_NAME_TOO_LONG: | 
 |     case SpdyFramerError::SPDY_HPACK_VALUE_TOO_LONG: | 
 |     case SpdyFramerError::SPDY_HPACK_NAME_HUFFMAN_ERROR: | 
 |     case SpdyFramerError::SPDY_HPACK_VALUE_HUFFMAN_ERROR: | 
 |     case SpdyFramerError::SPDY_HPACK_MISSING_DYNAMIC_TABLE_SIZE_UPDATE: | 
 |     case SpdyFramerError::SPDY_HPACK_INVALID_INDEX: | 
 |     case SpdyFramerError::SPDY_HPACK_INVALID_NAME_INDEX: | 
 |     case SpdyFramerError::SPDY_HPACK_DYNAMIC_TABLE_SIZE_UPDATE_NOT_ALLOWED: | 
 |     case SpdyFramerError:: | 
 |         SPDY_HPACK_INITIAL_DYNAMIC_TABLE_SIZE_UPDATE_IS_ABOVE_LOW_WATER_MARK: | 
 |     case SpdyFramerError:: | 
 |         SPDY_HPACK_DYNAMIC_TABLE_SIZE_UPDATE_IS_ABOVE_ACKNOWLEDGED_SETTING: | 
 |     case SpdyFramerError::SPDY_HPACK_TRUNCATED_BLOCK: | 
 |     case SpdyFramerError::SPDY_HPACK_FRAGMENT_TOO_LONG: | 
 |     case SpdyFramerError::SPDY_HPACK_COMPRESSED_HEADER_SIZE_EXCEEDS_LIMIT: | 
 |       return Http2ErrorCode::COMPRESSION_ERROR; | 
 |     case SpdyFramerError::SPDY_INTERNAL_FRAMER_ERROR: | 
 |     case SpdyFramerError::SPDY_STOP_PROCESSING: | 
 |     case SpdyFramerError::LAST_ERROR: | 
 |       return Http2ErrorCode::INTERNAL_ERROR; | 
 |   } | 
 |   return Http2ErrorCode::INTERNAL_ERROR; | 
 | } | 
 |  | 
 | bool IsResponse(HeaderType type) { | 
 |   return type == HeaderType::RESPONSE_100 || type == HeaderType::RESPONSE; | 
 | } | 
 |  | 
 | bool StatusIs1xx(absl::string_view status) { | 
 |   return status.size() == 3 && status[0] == '1'; | 
 | } | 
 |  | 
 | // Returns the upper bound on HPACK encoder table capacity. If not specified in | 
 | // the Options, a reasonable default upper bound is used. | 
 | uint32_t HpackCapacityBound(const OgHttp2Session::Options& o) { | 
 |   return o.max_hpack_encoding_table_capacity.value_or( | 
 |       kMaximumHpackTableCapacity); | 
 | } | 
 |  | 
 | bool IsNonAckSettings(const spdy::SpdyFrameIR& frame) { | 
 |   return frame.frame_type() == spdy::SpdyFrameType::SETTINGS && | 
 |          !reinterpret_cast<const SpdySettingsIR&>(frame).is_ack(); | 
 | } | 
 |  | 
 | }  // namespace | 
 |  | 
 | OgHttp2Session::PassthroughHeadersHandler::PassthroughHeadersHandler( | 
 |     OgHttp2Session& session, Http2VisitorInterface& visitor) | 
 |     : session_(session), visitor_(visitor) { | 
 |   if (session_.options_.validate_http_headers) { | 
 |     QUICHE_VLOG(2) << "instantiating regular header validator"; | 
 |     validator_ = std::make_unique<HeaderValidator>(); | 
 |   } else { | 
 |     QUICHE_VLOG(2) << "instantiating noop header validator"; | 
 |     validator_ = std::make_unique<NoopHeaderValidator>(); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::PassthroughHeadersHandler::OnHeaderBlockStart() { | 
 |   result_ = Http2VisitorInterface::HEADER_OK; | 
 |   const bool status = visitor_.OnBeginHeadersForStream(stream_id_); | 
 |   if (!status) { | 
 |     QUICHE_VLOG(1) | 
 |         << "Visitor rejected header block, returning HEADER_CONNECTION_ERROR"; | 
 |     result_ = Http2VisitorInterface::HEADER_CONNECTION_ERROR; | 
 |   } | 
 |   validator_->StartHeaderBlock(); | 
 | } | 
 |  | 
 | Http2VisitorInterface::OnHeaderResult InterpretHeaderStatus( | 
 |     HeaderValidator::HeaderStatus status) { | 
 |   switch (status) { | 
 |     case HeaderValidator::HEADER_OK: | 
 |     case HeaderValidator::HEADER_SKIP: | 
 |       return Http2VisitorInterface::HEADER_OK; | 
 |     case HeaderValidator::HEADER_FIELD_INVALID: | 
 |       return Http2VisitorInterface::HEADER_FIELD_INVALID; | 
 |     case HeaderValidator::HEADER_FIELD_TOO_LONG: | 
 |       return Http2VisitorInterface::HEADER_RST_STREAM; | 
 |   } | 
 |   return Http2VisitorInterface::HEADER_CONNECTION_ERROR; | 
 | } | 
 |  | 
 | void OgHttp2Session::PassthroughHeadersHandler::OnHeader( | 
 |     absl::string_view key, absl::string_view value) { | 
 |   if (result_ != Http2VisitorInterface::HEADER_OK) { | 
 |     QUICHE_VLOG(2) << "Early return; status not HEADER_OK"; | 
 |     return; | 
 |   } | 
 |   const HeaderValidator::HeaderStatus validation_result = | 
 |       validator_->ValidateSingleHeader(key, value); | 
 |   if (validation_result == HeaderValidator::HEADER_SKIP) { | 
 |     return; | 
 |   } | 
 |   if (validation_result != HeaderValidator::HEADER_OK) { | 
 |     QUICHE_VLOG(2) << "Header validation failed with result " | 
 |                    << static_cast<int>(validation_result); | 
 |     result_ = InterpretHeaderStatus(validation_result); | 
 |     return; | 
 |   } | 
 |   result_ = visitor_.OnHeaderForStream(stream_id_, key, value); | 
 | } | 
 |  | 
 | void OgHttp2Session::PassthroughHeadersHandler::OnHeaderBlockEnd( | 
 |     size_t /* uncompressed_header_bytes */, | 
 |     size_t /* compressed_header_bytes */) { | 
 |   if (result_ == Http2VisitorInterface::HEADER_OK) { | 
 |     if (!validator_->FinishHeaderBlock(type_)) { | 
 |       QUICHE_VLOG(1) << "FinishHeaderBlock returned false; returning " | 
 |                         "HEADER_HTTP_MESSAGING"; | 
 |       result_ = Http2VisitorInterface::HEADER_HTTP_MESSAGING; | 
 |     } | 
 |   } | 
 |   if (frame_contains_fin_ && IsResponse(type_) && | 
 |       StatusIs1xx(status_header())) { | 
 |     QUICHE_VLOG(1) << "Unexpected end of stream without final headers"; | 
 |     result_ = Http2VisitorInterface::HEADER_HTTP_MESSAGING; | 
 |   } | 
 |   if (result_ == Http2VisitorInterface::HEADER_OK) { | 
 |     const bool result = visitor_.OnEndHeadersForStream(stream_id_); | 
 |     if (!result) { | 
 |       session_.fatal_visitor_callback_failure_ = true; | 
 |       session_.decoder_.StopProcessing(); | 
 |     } | 
 |   } else { | 
 |     session_.OnHeaderStatus(stream_id_, result_); | 
 |   } | 
 |   frame_contains_fin_ = false; | 
 | } | 
 |  | 
 | // TODO(diannahu): Add checks for request methods. | 
 | bool OgHttp2Session::PassthroughHeadersHandler::CanReceiveBody() const { | 
 |   switch (header_type()) { | 
 |     case HeaderType::REQUEST_TRAILER: | 
 |     case HeaderType::RESPONSE_TRAILER: | 
 |     case HeaderType::RESPONSE_100: | 
 |       return false; | 
 |     case HeaderType::RESPONSE: | 
 |       // 304 responses should not have a body: | 
 |       // https://httpwg.org/specs/rfc7230.html#rfc.section.3.3.2 | 
 |       // Neither should 204 responses: | 
 |       // https://httpwg.org/specs/rfc7231.html#rfc.section.6.3.5 | 
 |       return status_header() != "304" && status_header() != "204"; | 
 |     case HeaderType::REQUEST: | 
 |       return true; | 
 |   } | 
 |   return true; | 
 | } | 
 |  | 
 | // A visitor that extracts an int64_t from each type of a ProcessBytesResult. | 
 | struct OgHttp2Session::ProcessBytesResultVisitor { | 
 |   int64_t operator()(const int64_t bytes) const { return bytes; } | 
 |  | 
 |   int64_t operator()(const ProcessBytesError error) const { | 
 |     switch (error) { | 
 |       case ProcessBytesError::kUnspecified: | 
 |         return -1; | 
 |       case ProcessBytesError::kInvalidConnectionPreface: | 
 |         return -903;  // NGHTTP2_ERR_BAD_CLIENT_MAGIC | 
 |       case ProcessBytesError::kVisitorCallbackFailed: | 
 |         return -902;  // NGHTTP2_ERR_CALLBACK_FAILURE | 
 |     } | 
 |     return -1; | 
 |   } | 
 | }; | 
 |  | 
 | OgHttp2Session::OgHttp2Session(Http2VisitorInterface& visitor, Options options) | 
 |     : visitor_(visitor), | 
 |       options_(options), | 
 |       event_forwarder_([this]() { return !latched_error_; }, *this), | 
 |       receive_logger_( | 
 |           &event_forwarder_, TracePerspectiveAsString(options.perspective), | 
 |           [logging_enabled = GetQuicheFlag(quiche_oghttp2_debug_trace)]() { | 
 |             return logging_enabled; | 
 |           }, | 
 |           this), | 
 |       send_logger_( | 
 |           TracePerspectiveAsString(options.perspective), | 
 |           [logging_enabled = GetQuicheFlag(quiche_oghttp2_debug_trace)]() { | 
 |             return logging_enabled; | 
 |           }, | 
 |           this), | 
 |       headers_handler_(*this, visitor), | 
 |       noop_headers_handler_(/*listener=*/nullptr), | 
 |       connection_window_manager_( | 
 |           kInitialFlowControlWindowSize, | 
 |           [this](size_t window_update_delta) { | 
 |             SendWindowUpdate(kConnectionStreamId, window_update_delta); | 
 |           }, | 
 |           options.should_window_update_fn, | 
 |           /*update_window_on_notify=*/false) { | 
 |   decoder_.set_visitor(&receive_logger_); | 
 |   if (options_.max_header_list_bytes) { | 
 |     // Limit buffering of encoded HPACK data to 2x the decoded limit. | 
 |     decoder_.GetHpackDecoder()->set_max_decode_buffer_size_bytes( | 
 |         2 * *options_.max_header_list_bytes); | 
 |     // Limit the total bytes accepted for HPACK decoding to 4x the limit. | 
 |     decoder_.GetHpackDecoder()->set_max_header_block_bytes( | 
 |         4 * *options_.max_header_list_bytes); | 
 |   } | 
 |   if (IsServerSession()) { | 
 |     remaining_preface_ = {spdy::kHttp2ConnectionHeaderPrefix, | 
 |                           spdy::kHttp2ConnectionHeaderPrefixSize}; | 
 |   } | 
 |   if (options_.max_header_field_size.has_value()) { | 
 |     headers_handler_.SetMaxFieldSize(options_.max_header_field_size.value()); | 
 |   } | 
 |   headers_handler_.SetAllowObsText(options_.allow_obs_text); | 
 | } | 
 |  | 
 | OgHttp2Session::~OgHttp2Session() {} | 
 |  | 
 | void OgHttp2Session::SetStreamUserData(Http2StreamId stream_id, | 
 |                                        void* user_data) { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it != stream_map_.end()) { | 
 |     it->second.user_data = user_data; | 
 |   } | 
 | } | 
 |  | 
 | void* OgHttp2Session::GetStreamUserData(Http2StreamId stream_id) { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it != stream_map_.end()) { | 
 |     return it->second.user_data; | 
 |   } | 
 |   auto p = pending_streams_.find(stream_id); | 
 |   if (p != pending_streams_.end()) { | 
 |     return p->second.user_data; | 
 |   } | 
 |   return nullptr; | 
 | } | 
 |  | 
 | bool OgHttp2Session::ResumeStream(Http2StreamId stream_id) { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it == stream_map_.end() || it->second.outbound_body == nullptr || | 
 |       !write_scheduler_.StreamRegistered(stream_id)) { | 
 |     return false; | 
 |   } | 
 |   it->second.data_deferred = false; | 
 |   write_scheduler_.MarkStreamReady(stream_id, /*add_to_front=*/false); | 
 |   return true; | 
 | } | 
 |  | 
 | int OgHttp2Session::GetStreamSendWindowSize(Http2StreamId stream_id) const { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it != stream_map_.end()) { | 
 |     return it->second.send_window; | 
 |   } | 
 |   return -1; | 
 | } | 
 |  | 
 | int OgHttp2Session::GetStreamReceiveWindowLimit(Http2StreamId stream_id) const { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it != stream_map_.end()) { | 
 |     return it->second.window_manager.WindowSizeLimit(); | 
 |   } | 
 |   return -1; | 
 | } | 
 |  | 
 | int OgHttp2Session::GetStreamReceiveWindowSize(Http2StreamId stream_id) const { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it != stream_map_.end()) { | 
 |     return it->second.window_manager.CurrentWindowSize(); | 
 |   } | 
 |   return -1; | 
 | } | 
 |  | 
 | int OgHttp2Session::GetReceiveWindowSize() const { | 
 |   return connection_window_manager_.CurrentWindowSize(); | 
 | } | 
 |  | 
 | int OgHttp2Session::GetHpackEncoderDynamicTableSize() const { | 
 |   const spdy::HpackEncoder* encoder = framer_.GetHpackEncoder(); | 
 |   return encoder == nullptr ? 0 : encoder->GetDynamicTableSize(); | 
 | } | 
 |  | 
 | int OgHttp2Session::GetHpackEncoderDynamicTableCapacity() const { | 
 |   const spdy::HpackEncoder* encoder = framer_.GetHpackEncoder(); | 
 |   return encoder == nullptr ? kDefaultHpackTableCapacity | 
 |                             : encoder->CurrentHeaderTableSizeSetting(); | 
 | } | 
 |  | 
 | int OgHttp2Session::GetHpackDecoderDynamicTableSize() const { | 
 |   const spdy::HpackDecoderAdapter* decoder = decoder_.GetHpackDecoder(); | 
 |   return decoder == nullptr ? 0 : decoder->GetDynamicTableSize(); | 
 | } | 
 |  | 
 | int OgHttp2Session::GetHpackDecoderSizeLimit() const { | 
 |   const spdy::HpackDecoderAdapter* decoder = decoder_.GetHpackDecoder(); | 
 |   return decoder == nullptr ? 0 : decoder->GetCurrentHeaderTableSizeSetting(); | 
 | } | 
 |  | 
 | int64_t OgHttp2Session::ProcessBytes(absl::string_view bytes) { | 
 |   QUICHE_VLOG(2) << TracePerspectiveAsString(options_.perspective) | 
 |                  << " processing [" << absl::CEscape(bytes) << "]"; | 
 |   return absl::visit(ProcessBytesResultVisitor(), ProcessBytesImpl(bytes)); | 
 | } | 
 |  | 
 | absl::variant<int64_t, OgHttp2Session::ProcessBytesError> | 
 | OgHttp2Session::ProcessBytesImpl(absl::string_view bytes) { | 
 |   if (processing_bytes_) { | 
 |     QUICHE_VLOG(1) << "Returning early; already processing bytes."; | 
 |     return 0; | 
 |   } | 
 |   processing_bytes_ = true; | 
 |   RunOnExit r{[this]() { processing_bytes_ = false; }}; | 
 |  | 
 |   if (options_.blackhole_data_on_connection_error && latched_error_) { | 
 |     return static_cast<int64_t>(bytes.size()); | 
 |   } | 
 |  | 
 |   int64_t preface_consumed = 0; | 
 |   if (!remaining_preface_.empty()) { | 
 |     QUICHE_VLOG(2) << "Preface bytes remaining: " << remaining_preface_.size(); | 
 |     // decoder_ does not understand the client connection preface. | 
 |     size_t min_size = std::min(remaining_preface_.size(), bytes.size()); | 
 |     if (!absl::StartsWith(remaining_preface_, bytes.substr(0, min_size))) { | 
 |       // Preface doesn't match! | 
 |       QUICHE_DLOG(INFO) << "Preface doesn't match! Expected: [" | 
 |                         << absl::CEscape(remaining_preface_) << "], actual: [" | 
 |                         << absl::CEscape(bytes) << "]"; | 
 |       LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                           ConnectionError::kInvalidConnectionPreface); | 
 |       return ProcessBytesError::kInvalidConnectionPreface; | 
 |     } | 
 |     remaining_preface_.remove_prefix(min_size); | 
 |     bytes.remove_prefix(min_size); | 
 |     if (!remaining_preface_.empty()) { | 
 |       QUICHE_VLOG(2) << "Preface bytes remaining: " | 
 |                      << remaining_preface_.size(); | 
 |       return static_cast<int64_t>(min_size); | 
 |     } | 
 |     preface_consumed = min_size; | 
 |   } | 
 |   int64_t result = decoder_.ProcessInput(bytes.data(), bytes.size()); | 
 |   QUICHE_VLOG(2) << "ProcessBytes result: " << result; | 
 |   if (fatal_visitor_callback_failure_) { | 
 |     QUICHE_DCHECK(latched_error_); | 
 |     QUICHE_VLOG(2) << "Visitor callback failed while processing bytes."; | 
 |     return ProcessBytesError::kVisitorCallbackFailed; | 
 |   } | 
 |   if (latched_error_ || result < 0) { | 
 |     QUICHE_VLOG(2) << "ProcessBytes encountered an error."; | 
 |     if (options_.blackhole_data_on_connection_error) { | 
 |       return static_cast<int64_t>(bytes.size() + preface_consumed); | 
 |     } else { | 
 |       return ProcessBytesError::kUnspecified; | 
 |     } | 
 |   } | 
 |   return result + preface_consumed; | 
 | } | 
 |  | 
 | int OgHttp2Session::Consume(Http2StreamId stream_id, size_t num_bytes) { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it == stream_map_.end()) { | 
 |     QUICHE_LOG(ERROR) << "Stream " << stream_id << " not found when consuming " | 
 |                       << num_bytes << " bytes"; | 
 |   } else { | 
 |     it->second.window_manager.MarkDataFlushed(num_bytes); | 
 |   } | 
 |   connection_window_manager_.MarkDataFlushed(num_bytes); | 
 |   return 0;  // Remove? | 
 | } | 
 |  | 
 | void OgHttp2Session::StartGracefulShutdown() { | 
 |   if (IsServerSession()) { | 
 |     if (!queued_goaway_) { | 
 |       EnqueueFrame(std::make_unique<spdy::SpdyGoAwayIR>( | 
 |           std::numeric_limits<int32_t>::max(), spdy::ERROR_CODE_NO_ERROR, | 
 |           "graceful_shutdown")); | 
 |     } | 
 |   } else { | 
 |     QUICHE_LOG(ERROR) << "Graceful shutdown not needed for clients."; | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::EnqueueFrame(std::unique_ptr<spdy::SpdyFrameIR> frame) { | 
 |   if (queued_immediate_goaway_) { | 
 |     // Do not allow additional frames to be enqueued after the GOAWAY. | 
 |     return; | 
 |   } | 
 |  | 
 |   const bool is_non_ack_settings = IsNonAckSettings(*frame); | 
 |   MaybeSetupPreface(is_non_ack_settings); | 
 |  | 
 |   if (frame->frame_type() == spdy::SpdyFrameType::GOAWAY) { | 
 |     queued_goaway_ = true; | 
 |     if (latched_error_) { | 
 |       PrepareForImmediateGoAway(); | 
 |     } | 
 |   } else if (frame->fin() || | 
 |              frame->frame_type() == spdy::SpdyFrameType::RST_STREAM) { | 
 |     auto iter = stream_map_.find(frame->stream_id()); | 
 |     if (iter != stream_map_.end()) { | 
 |       iter->second.half_closed_local = true; | 
 |     } | 
 |     if (frame->frame_type() == spdy::SpdyFrameType::RST_STREAM) { | 
 |       // TODO(diannahu): Condition on existence in the stream map? | 
 |       streams_reset_.insert(frame->stream_id()); | 
 |     } | 
 |   } else if (frame->frame_type() == spdy::SpdyFrameType::WINDOW_UPDATE) { | 
 |     UpdateReceiveWindow( | 
 |         frame->stream_id(), | 
 |         reinterpret_cast<spdy::SpdyWindowUpdateIR&>(*frame).delta()); | 
 |   } else if (is_non_ack_settings) { | 
 |     HandleOutboundSettings( | 
 |         *reinterpret_cast<spdy::SpdySettingsIR*>(frame.get())); | 
 |   } | 
 |   if (frame->stream_id() != 0) { | 
 |     auto result = queued_frames_.insert({frame->stream_id(), 1}); | 
 |     if (!result.second) { | 
 |       ++(result.first->second); | 
 |     } | 
 |   } | 
 |   frames_.push_back(std::move(frame)); | 
 | } | 
 |  | 
 | int OgHttp2Session::Send() { | 
 |   if (sending_) { | 
 |     QUICHE_VLOG(1) << TracePerspectiveAsString(options_.perspective) | 
 |                    << " returning early; already sending."; | 
 |     return 0; | 
 |   } | 
 |   sending_ = true; | 
 |   RunOnExit r{[this]() { sending_ = false; }}; | 
 |  | 
 |   if (fatal_send_error_) { | 
 |     return kSendError; | 
 |   } | 
 |  | 
 |   MaybeSetupPreface(/*sending_outbound_settings=*/false); | 
 |  | 
 |   SendResult continue_writing = SendQueuedFrames(); | 
 |   if (queued_immediate_goaway_) { | 
 |     // If an immediate GOAWAY was queued, then the above flush either sent the | 
 |     // GOAWAY or buffered it to be sent on the next successful flush. In either | 
 |     // case, return early here to avoid sending other frames. | 
 |     return InterpretSendResult(continue_writing); | 
 |   } | 
 |   // Notify on new/pending streams closed due to GOAWAY receipt. | 
 |   CloseGoAwayRejectedStreams(); | 
 |   // Wake streams for writes. | 
 |   while (continue_writing == SendResult::SEND_OK && HasReadyStream()) { | 
 |     const Http2StreamId stream_id = GetNextReadyStream(); | 
 |     // TODO(birenroy): Add a return value to indicate write blockage, so streams | 
 |     // aren't woken unnecessarily. | 
 |     QUICHE_VLOG(1) << "Waking stream " << stream_id << " for writes."; | 
 |     continue_writing = WriteForStream(stream_id); | 
 |   } | 
 |   if (continue_writing == SendResult::SEND_OK) { | 
 |     continue_writing = SendQueuedFrames(); | 
 |   } | 
 |   return InterpretSendResult(continue_writing); | 
 | } | 
 |  | 
 | int OgHttp2Session::InterpretSendResult(SendResult result) { | 
 |   if (result == SendResult::SEND_ERROR) { | 
 |     fatal_send_error_ = true; | 
 |     return kSendError; | 
 |   } else { | 
 |     return 0; | 
 |   } | 
 | } | 
 |  | 
 | bool OgHttp2Session::HasReadyStream() const { | 
 |   return !trailers_ready_.empty() || | 
 |          (write_scheduler_.HasReadyStreams() && connection_send_window_ > 0); | 
 | } | 
 |  | 
 | Http2StreamId OgHttp2Session::GetNextReadyStream() { | 
 |   QUICHE_DCHECK(HasReadyStream()); | 
 |   if (!trailers_ready_.empty()) { | 
 |     const Http2StreamId stream_id = *trailers_ready_.begin(); | 
 |     // WriteForStream() will re-mark the stream as ready, if necessary. | 
 |     write_scheduler_.MarkStreamNotReady(stream_id); | 
 |     return stream_id; | 
 |   } | 
 |   return write_scheduler_.PopNextReadyStream(); | 
 | } | 
 |  | 
 | OgHttp2Session::SendResult OgHttp2Session::MaybeSendBufferedData() { | 
 |   int64_t result = std::numeric_limits<int64_t>::max(); | 
 |   while (result > 0 && !buffered_data_.empty()) { | 
 |     result = visitor_.OnReadyToSend(buffered_data_); | 
 |     if (result > 0) { | 
 |       buffered_data_.erase(0, result); | 
 |     } | 
 |   } | 
 |   if (result < 0) { | 
 |     LatchErrorAndNotify(Http2ErrorCode::INTERNAL_ERROR, | 
 |                         ConnectionError::kSendError); | 
 |     return SendResult::SEND_ERROR; | 
 |   } | 
 |   return buffered_data_.empty() ? SendResult::SEND_OK | 
 |                                 : SendResult::SEND_BLOCKED; | 
 | } | 
 |  | 
 | OgHttp2Session::SendResult OgHttp2Session::SendQueuedFrames() { | 
 |   // Flush any serialized prefix. | 
 |   const SendResult result = MaybeSendBufferedData(); | 
 |   if (result != SendResult::SEND_OK) { | 
 |     return result; | 
 |   } | 
 |   // Serialize and send frames in the queue. | 
 |   while (!frames_.empty()) { | 
 |     const auto& frame_ptr = frames_.front(); | 
 |     FrameAttributeCollector c; | 
 |     frame_ptr->Visit(&c); | 
 |  | 
 |     // DATA frames should never be queued. | 
 |     QUICHE_DCHECK_NE(c.frame_type(), 0); | 
 |  | 
 |     const bool stream_reset = | 
 |         c.stream_id() != 0 && streams_reset_.count(c.stream_id()) > 0; | 
 |     if (stream_reset && | 
 |         c.frame_type() != static_cast<uint8_t>(FrameType::RST_STREAM)) { | 
 |       // The stream has been reset, so any other remaining frames can be | 
 |       // skipped. | 
 |       // TODO(birenroy): inform the visitor of frames that are skipped. | 
 |       DecrementQueuedFrameCount(c.stream_id(), c.frame_type()); | 
 |       frames_.pop_front(); | 
 |       continue; | 
 |     } else if (!IsServerSession() && received_goaway_ && | 
 |                c.stream_id() > | 
 |                    static_cast<uint32_t>(received_goaway_stream_id_)) { | 
 |       // This frame will be ignored by the server, so don't send it. The stream | 
 |       // associated with this frame should have been closed in OnGoAway(). | 
 |       frames_.pop_front(); | 
 |       continue; | 
 |     } | 
 |     // Frames can't accurately report their own length; the actual serialized | 
 |     // length must be used instead. | 
 |     spdy::SpdySerializedFrame frame = framer_.SerializeFrame(*frame_ptr); | 
 |     const size_t frame_payload_length = frame.size() - spdy::kFrameHeaderSize; | 
 |     frame_ptr->Visit(&send_logger_); | 
 |     visitor_.OnBeforeFrameSent(c.frame_type(), c.stream_id(), | 
 |                                frame_payload_length, c.flags()); | 
 |     const int64_t result = visitor_.OnReadyToSend(absl::string_view(frame)); | 
 |     if (result < 0) { | 
 |       LatchErrorAndNotify(Http2ErrorCode::INTERNAL_ERROR, | 
 |                           ConnectionError::kSendError); | 
 |       return SendResult::SEND_ERROR; | 
 |     } else if (result == 0) { | 
 |       // Write blocked. | 
 |       return SendResult::SEND_BLOCKED; | 
 |     } else { | 
 |       frames_.pop_front(); | 
 |  | 
 |       const bool ok = | 
 |           AfterFrameSent(c.frame_type(), c.stream_id(), frame_payload_length, | 
 |                          c.flags(), c.error_code()); | 
 |       if (!ok) { | 
 |         LatchErrorAndNotify(Http2ErrorCode::INTERNAL_ERROR, | 
 |                             ConnectionError::kSendError); | 
 |         return SendResult::SEND_ERROR; | 
 |       } | 
 |       if (static_cast<size_t>(result) < frame.size()) { | 
 |         // The frame was partially written, so the rest must be buffered. | 
 |         buffered_data_.append(frame.data() + result, frame.size() - result); | 
 |         return SendResult::SEND_BLOCKED; | 
 |       } | 
 |     } | 
 |   } | 
 |   return SendResult::SEND_OK; | 
 | } | 
 |  | 
 | bool OgHttp2Session::AfterFrameSent(uint8_t frame_type_int, uint32_t stream_id, | 
 |                                     size_t payload_length, uint8_t flags, | 
 |                                     uint32_t error_code) { | 
 |   const FrameType frame_type = static_cast<FrameType>(frame_type_int); | 
 |   int result = visitor_.OnFrameSent(frame_type_int, stream_id, payload_length, | 
 |                                     flags, error_code); | 
 |   if (result < 0) { | 
 |     return false; | 
 |   } | 
 |   if (stream_id == 0) { | 
 |     if (frame_type == FrameType::SETTINGS) { | 
 |       const bool is_settings_ack = (flags & 0x01); | 
 |       if (is_settings_ack && encoder_header_table_capacity_when_acking_) { | 
 |         framer_.UpdateHeaderEncoderTableSize( | 
 |             encoder_header_table_capacity_when_acking_.value()); | 
 |         encoder_header_table_capacity_when_acking_ = absl::nullopt; | 
 |       } else if (!is_settings_ack) { | 
 |         sent_non_ack_settings_ = true; | 
 |       } | 
 |     } | 
 |     return true; | 
 |   } | 
 |  | 
 |   const bool contains_fin = | 
 |       (frame_type == FrameType::DATA || frame_type == FrameType::HEADERS) && | 
 |       (flags & 0x01) == 0x01; | 
 |   auto it = stream_map_.find(stream_id); | 
 |   const bool still_open_remote = | 
 |       it != stream_map_.end() && !it->second.half_closed_remote; | 
 |   if (contains_fin && still_open_remote && | 
 |       options_.rst_stream_no_error_when_incomplete && IsServerSession()) { | 
 |     // Since the peer has not yet ended the stream, this endpoint should | 
 |     // send a RST_STREAM NO_ERROR. See RFC 7540 Section 8.1. | 
 |     frames_.push_front(std::make_unique<spdy::SpdyRstStreamIR>( | 
 |         stream_id, spdy::SpdyErrorCode::ERROR_CODE_NO_ERROR)); | 
 |     auto queued_result = queued_frames_.insert({stream_id, 1}); | 
 |     if (!queued_result.second) { | 
 |       ++(queued_result.first->second); | 
 |     } | 
 |     it->second.half_closed_remote = true; | 
 |   } | 
 |  | 
 |   DecrementQueuedFrameCount(stream_id, frame_type_int); | 
 |   return true; | 
 | } | 
 |  | 
 | OgHttp2Session::SendResult OgHttp2Session::WriteForStream( | 
 |     Http2StreamId stream_id) { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it == stream_map_.end()) { | 
 |     QUICHE_LOG(ERROR) << "Can't find stream " << stream_id | 
 |                       << " which is ready to write!"; | 
 |     return SendResult::SEND_OK; | 
 |   } | 
 |   StreamState& state = it->second; | 
 |   auto reset_it = streams_reset_.find(stream_id); | 
 |   if (reset_it != streams_reset_.end()) { | 
 |     // The stream has been reset; there's no point in sending DATA or trailing | 
 |     // HEADERS. | 
 |     state.outbound_body = nullptr; | 
 |     state.trailers = nullptr; | 
 |     return SendResult::SEND_OK; | 
 |   } | 
 |  | 
 |   SendResult connection_can_write = SendResult::SEND_OK; | 
 |   if (state.outbound_body == nullptr || | 
 |       (!options_.trailers_require_end_data && state.data_deferred)) { | 
 |     // No data to send, but there might be trailers. | 
 |     if (state.trailers != nullptr) { | 
 |       // Trailers will include END_STREAM, so the data source can be discarded. | 
 |       // Since data_deferred is true, there is no data waiting to be flushed for | 
 |       // this stream. | 
 |       state.outbound_body = nullptr; | 
 |       auto block_ptr = std::move(state.trailers); | 
 |       if (state.half_closed_local) { | 
 |         QUICHE_LOG(ERROR) << "Sent fin; can't send trailers."; | 
 |       } else { | 
 |         SendTrailers(stream_id, std::move(*block_ptr)); | 
 |       } | 
 |     } | 
 |     return SendResult::SEND_OK; | 
 |   } | 
 |   int32_t available_window = | 
 |       std::min({connection_send_window_, state.send_window, | 
 |                 static_cast<int32_t>(max_frame_payload_)}); | 
 |   while (connection_can_write == SendResult::SEND_OK && available_window > 0 && | 
 |          state.outbound_body != nullptr && !state.data_deferred) { | 
 |     auto [length, end_data] = | 
 |         state.outbound_body->SelectPayloadLength(available_window); | 
 |     QUICHE_VLOG(2) << "WriteForStream | length: " << length | 
 |                    << " end_data: " << end_data | 
 |                    << " trailers: " << state.trailers.get(); | 
 |     if (length == 0 && !end_data && | 
 |         (options_.trailers_require_end_data || state.trailers == nullptr)) { | 
 |       // An unproductive call to SelectPayloadLength() results in this stream | 
 |       // entering the "deferred" state only if either no trailers are available | 
 |       // to send, or trailers require an explicit end_data before being sent. | 
 |       state.data_deferred = true; | 
 |       break; | 
 |     } else if (length == DataFrameSource::kError) { | 
 |       // TODO(birenroy): Consider queuing a RST_STREAM INTERNAL_ERROR instead. | 
 |       CloseStream(stream_id, Http2ErrorCode::INTERNAL_ERROR); | 
 |       // No more work on the stream; it has been closed. | 
 |       break; | 
 |     } | 
 |     const bool fin = end_data ? state.outbound_body->send_fin() : false; | 
 |     if (length > 0 || fin) { | 
 |       spdy::SpdyDataIR data(stream_id); | 
 |       data.set_fin(fin); | 
 |       data.SetDataShallow(length); | 
 |       spdy::SpdySerializedFrame header = | 
 |           spdy::SpdyFramer::SerializeDataFrameHeaderWithPaddingLengthField( | 
 |               data); | 
 |       QUICHE_DCHECK(buffered_data_.empty() && frames_.empty()); | 
 |       const bool success = | 
 |           state.outbound_body->Send(absl::string_view(header), length); | 
 |       if (!success) { | 
 |         connection_can_write = SendResult::SEND_BLOCKED; | 
 |         break; | 
 |       } | 
 |       connection_send_window_ -= length; | 
 |       state.send_window -= length; | 
 |       available_window = std::min({connection_send_window_, state.send_window, | 
 |                                    static_cast<int32_t>(max_frame_payload_)}); | 
 |       if (fin) { | 
 |         state.half_closed_local = true; | 
 |         MaybeFinWithRstStream(it); | 
 |       } | 
 |       const bool ok = | 
 |           AfterFrameSent(/* DATA */ 0, stream_id, length, fin ? 0x1 : 0x0, 0); | 
 |       if (!ok) { | 
 |         LatchErrorAndNotify(Http2ErrorCode::INTERNAL_ERROR, | 
 |                             ConnectionError::kSendError); | 
 |         return SendResult::SEND_ERROR; | 
 |       } | 
 |       if (!stream_map_.contains(stream_id)) { | 
 |         // Note: the stream may have been closed if `fin` is true. | 
 |         break; | 
 |       } | 
 |     } | 
 |     if (end_data || (length == 0 && state.trailers != nullptr && | 
 |                      !options_.trailers_require_end_data)) { | 
 |       // If SelectPayloadLength() returned {0, false}, and there are trailers to | 
 |       // send, and the safety feature is disabled, it's okay to send the | 
 |       // trailers. | 
 |       if (state.trailers != nullptr) { | 
 |         auto block_ptr = std::move(state.trailers); | 
 |         if (fin) { | 
 |           QUICHE_LOG(ERROR) << "Sent fin; can't send trailers."; | 
 |         } else { | 
 |           SendTrailers(stream_id, std::move(*block_ptr)); | 
 |         } | 
 |       } | 
 |       state.outbound_body = nullptr; | 
 |     } | 
 |   } | 
 |   // If the stream still exists and has data to send, it should be marked as | 
 |   // ready in the write scheduler. | 
 |   if (stream_map_.contains(stream_id) && !state.data_deferred && | 
 |       state.send_window > 0 && state.outbound_body != nullptr) { | 
 |     write_scheduler_.MarkStreamReady(stream_id, false); | 
 |   } | 
 |   // Streams can continue writing as long as the connection is not write-blocked | 
 |   // and there is additional flow control quota available. | 
 |   if (connection_can_write != SendResult::SEND_OK) { | 
 |     return connection_can_write; | 
 |   } | 
 |   return connection_send_window_ <= 0 ? SendResult::SEND_BLOCKED | 
 |                                       : SendResult::SEND_OK; | 
 | } | 
 |  | 
 | void OgHttp2Session::SerializeMetadata(Http2StreamId stream_id, | 
 |                                        std::unique_ptr<MetadataSource> source) { | 
 |   const uint32_t max_payload_size = | 
 |       std::min(kMaxAllowedMetadataFrameSize, max_frame_payload_); | 
 |   auto payload_buffer = std::make_unique<uint8_t[]>(max_payload_size); | 
 |  | 
 |   while (true) { | 
 |     auto [written, end_metadata] = | 
 |         source->Pack(payload_buffer.get(), max_payload_size); | 
 |     if (written < 0) { | 
 |       // Unable to pack any metadata. | 
 |       return; | 
 |     } | 
 |     QUICHE_DCHECK_LE(static_cast<size_t>(written), max_payload_size); | 
 |     auto payload = absl::string_view( | 
 |         reinterpret_cast<const char*>(payload_buffer.get()), written); | 
 |     EnqueueFrame(std::make_unique<spdy::SpdyUnknownIR>( | 
 |         stream_id, kMetadataFrameType, end_metadata ? kMetadataEndFlag : 0u, | 
 |         std::string(payload))); | 
 |     if (end_metadata) { | 
 |       return; | 
 |     } | 
 |   } | 
 | } | 
 |  | 
 | int32_t OgHttp2Session::SubmitRequest( | 
 |     absl::Span<const Header> headers, | 
 |     std::unique_ptr<DataFrameSource> data_source, void* user_data) { | 
 |   // TODO(birenroy): return an error for the incorrect perspective | 
 |   const Http2StreamId stream_id = next_stream_id_; | 
 |   next_stream_id_ += 2; | 
 |   if (!pending_streams_.empty() || !CanCreateStream()) { | 
 |     // TODO(diannahu): There should probably be a limit to the number of allowed | 
 |     // pending streams. | 
 |     pending_streams_.insert( | 
 |         {stream_id, PendingStreamState{ToHeaderBlock(headers), | 
 |                                        std::move(data_source), user_data}}); | 
 |     StartPendingStreams(); | 
 |   } else { | 
 |     StartRequest(stream_id, ToHeaderBlock(headers), std::move(data_source), | 
 |                  user_data); | 
 |   } | 
 |   return stream_id; | 
 | } | 
 |  | 
 | int OgHttp2Session::SubmitResponse( | 
 |     Http2StreamId stream_id, absl::Span<const Header> headers, | 
 |     std::unique_ptr<DataFrameSource> data_source) { | 
 |   // TODO(birenroy): return an error for the incorrect perspective | 
 |   auto iter = stream_map_.find(stream_id); | 
 |   if (iter == stream_map_.end()) { | 
 |     QUICHE_LOG(ERROR) << "Unable to find stream " << stream_id; | 
 |     return -501;  // NGHTTP2_ERR_INVALID_ARGUMENT | 
 |   } | 
 |   const bool end_stream = data_source == nullptr; | 
 |   if (!end_stream) { | 
 |     // Add data source to stream state | 
 |     iter->second.outbound_body = std::move(data_source); | 
 |     write_scheduler_.MarkStreamReady(stream_id, false); | 
 |   } | 
 |   SendHeaders(stream_id, ToHeaderBlock(headers), end_stream); | 
 |   return 0; | 
 | } | 
 |  | 
 | int OgHttp2Session::SubmitTrailer(Http2StreamId stream_id, | 
 |                                   absl::Span<const Header> trailers) { | 
 |   // TODO(birenroy): Reject trailers when acting as a client? | 
 |   auto iter = stream_map_.find(stream_id); | 
 |   if (iter == stream_map_.end()) { | 
 |     QUICHE_LOG(ERROR) << "Unable to find stream " << stream_id; | 
 |     return -501;  // NGHTTP2_ERR_INVALID_ARGUMENT | 
 |   } | 
 |   StreamState& state = iter->second; | 
 |   if (state.half_closed_local) { | 
 |     QUICHE_LOG(ERROR) << "Stream " << stream_id << " is half closed (local)"; | 
 |     return -514;  // NGHTTP2_ERR_INVALID_STREAM_STATE | 
 |   } | 
 |   if (state.trailers != nullptr) { | 
 |     QUICHE_LOG(ERROR) << "Stream " << stream_id | 
 |                       << " already has trailers queued"; | 
 |     return -514;  // NGHTTP2_ERR_INVALID_STREAM_STATE | 
 |   } | 
 |   if (state.outbound_body == nullptr) { | 
 |     // Enqueue trailers immediately. | 
 |     SendTrailers(stream_id, ToHeaderBlock(trailers)); | 
 |   } else { | 
 |     QUICHE_LOG_IF(ERROR, state.outbound_body->send_fin()) | 
 |         << "DataFrameSource will send fin, preventing trailers!"; | 
 |     // Save trailers so they can be written once data is done. | 
 |     state.trailers = | 
 |         std::make_unique<spdy::Http2HeaderBlock>(ToHeaderBlock(trailers)); | 
 |     if (!options_.trailers_require_end_data || !iter->second.data_deferred) { | 
 |       trailers_ready_.insert(stream_id); | 
 |     } | 
 |   } | 
 |   return 0; | 
 | } | 
 |  | 
 | void OgHttp2Session::SubmitMetadata(Http2StreamId stream_id, | 
 |                                     std::unique_ptr<MetadataSource> source) { | 
 |   SerializeMetadata(stream_id, std::move(source)); | 
 | } | 
 |  | 
 | void OgHttp2Session::SubmitSettings(absl::Span<const Http2Setting> settings) { | 
 |   auto frame = PrepareSettingsFrame(settings); | 
 |   EnqueueFrame(std::move(frame)); | 
 | } | 
 |  | 
 | void OgHttp2Session::OnError(SpdyFramerError error, | 
 |                              std::string detailed_error) { | 
 |   QUICHE_VLOG(1) << "Error: " | 
 |                  << http2::Http2DecoderAdapter::SpdyFramerErrorToString(error) | 
 |                  << " details: " << detailed_error; | 
 |   // TODO(diannahu): Consider propagating `detailed_error`. | 
 |   LatchErrorAndNotify(GetHttp2ErrorCode(error), ConnectionError::kParseError); | 
 | } | 
 |  | 
 | void OgHttp2Session::OnCommonHeader(spdy::SpdyStreamId stream_id, size_t length, | 
 |                                     uint8_t type, uint8_t flags) { | 
 |   highest_received_stream_id_ = std::max(static_cast<Http2StreamId>(stream_id), | 
 |                                          highest_received_stream_id_); | 
 |   if (streams_reset_.contains(stream_id)) { | 
 |     return; | 
 |   } | 
 |   const bool result = visitor_.OnFrameHeader(stream_id, length, type, flags); | 
 |   if (!result) { | 
 |     fatal_visitor_callback_failure_ = true; | 
 |     decoder_.StopProcessing(); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnDataFrameHeader(spdy::SpdyStreamId stream_id, | 
 |                                        size_t length, bool /*fin*/) { | 
 |   auto iter = stream_map_.find(stream_id); | 
 |   if (iter == stream_map_.end() || streams_reset_.contains(stream_id)) { | 
 |     // The stream does not exist; it could be an error or a benign close, e.g., | 
 |     // getting data for a stream this connection recently closed. | 
 |     if (static_cast<Http2StreamId>(stream_id) > highest_processed_stream_id_) { | 
 |       // Receiving DATA before HEADERS is a connection error. | 
 |       LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                           ConnectionError::kWrongFrameSequence); | 
 |     } | 
 |     return; | 
 |   } | 
 |  | 
 |   if (static_cast<int64_t>(length) > | 
 |       connection_window_manager_.CurrentWindowSize()) { | 
 |     // Peer exceeded the connection flow control limit. | 
 |     LatchErrorAndNotify( | 
 |         Http2ErrorCode::FLOW_CONTROL_ERROR, | 
 |         Http2VisitorInterface::ConnectionError::kFlowControlError); | 
 |     return; | 
 |   } | 
 |  | 
 |   if (static_cast<int64_t>(length) > | 
 |       iter->second.window_manager.CurrentWindowSize()) { | 
 |     // Peer exceeded the stream flow control limit. | 
 |     EnqueueFrame(std::make_unique<spdy::SpdyRstStreamIR>( | 
 |         stream_id, spdy::ERROR_CODE_FLOW_CONTROL_ERROR)); | 
 |     return; | 
 |   } | 
 |  | 
 |   const bool result = visitor_.OnBeginDataForStream(stream_id, length); | 
 |   if (!result) { | 
 |     fatal_visitor_callback_failure_ = true; | 
 |     decoder_.StopProcessing(); | 
 |   } | 
 |  | 
 |   if (!iter->second.can_receive_body && length > 0) { | 
 |     EnqueueFrame(std::make_unique<spdy::SpdyRstStreamIR>( | 
 |         stream_id, spdy::ERROR_CODE_PROTOCOL_ERROR)); | 
 |     return; | 
 |   } | 
 |  | 
 |   // Validate against the content-length if it exists. | 
 |   if (iter->second.remaining_content_length.has_value()) { | 
 |     if (length > *iter->second.remaining_content_length) { | 
 |       HandleContentLengthError(stream_id); | 
 |       iter->second.remaining_content_length.reset(); | 
 |     } else { | 
 |       *iter->second.remaining_content_length -= length; | 
 |     } | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnStreamFrameData(spdy::SpdyStreamId stream_id, | 
 |                                        const char* data, size_t len) { | 
 |   // Count the data against flow control, even if the stream is unknown. | 
 |   MarkDataBuffered(stream_id, len); | 
 |  | 
 |   if (!stream_map_.contains(stream_id) || streams_reset_.contains(stream_id)) { | 
 |     // If the stream was unknown due to a protocol error, the visitor was | 
 |     // informed in OnDataFrameHeader(). | 
 |     return; | 
 |   } | 
 |  | 
 |   const bool result = | 
 |       visitor_.OnDataForStream(stream_id, absl::string_view(data, len)); | 
 |   if (!result) { | 
 |     fatal_visitor_callback_failure_ = true; | 
 |     decoder_.StopProcessing(); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnStreamEnd(spdy::SpdyStreamId stream_id) { | 
 |   auto iter = stream_map_.find(stream_id); | 
 |   if (iter != stream_map_.end()) { | 
 |     iter->second.half_closed_remote = true; | 
 |     if (streams_reset_.contains(stream_id)) { | 
 |       return; | 
 |     } | 
 |  | 
 |     // Validate against the content-length if it exists. | 
 |     if (iter->second.remaining_content_length.has_value() && | 
 |         *iter->second.remaining_content_length != 0) { | 
 |       HandleContentLengthError(stream_id); | 
 |       return; | 
 |     } | 
 |  | 
 |     visitor_.OnEndStream(stream_id); | 
 |   } | 
 |  | 
 |   auto queued_frames_iter = queued_frames_.find(stream_id); | 
 |   const bool no_queued_frames = queued_frames_iter == queued_frames_.end() || | 
 |                                 queued_frames_iter->second == 0; | 
 |   if (iter != stream_map_.end() && iter->second.half_closed_local && | 
 |       !IsServerSession() && no_queued_frames) { | 
 |     // From the client's perspective, the stream can be closed if it's already | 
 |     // half_closed_local. | 
 |     CloseStream(stream_id, Http2ErrorCode::HTTP2_NO_ERROR); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnStreamPadLength(spdy::SpdyStreamId stream_id, | 
 |                                        size_t value) { | 
 |   bool result = visitor_.OnDataPaddingLength(stream_id, 1 + value); | 
 |   if (!result) { | 
 |     fatal_visitor_callback_failure_ = true; | 
 |     decoder_.StopProcessing(); | 
 |   } | 
 |   MarkDataBuffered(stream_id, 1 + value); | 
 | } | 
 |  | 
 | void OgHttp2Session::OnStreamPadding(spdy::SpdyStreamId /*stream_id*/, size_t | 
 |                                      /*len*/) { | 
 |   // Flow control was accounted for in OnStreamPadLength(). | 
 |   // TODO(181586191): Pass padding to the visitor? | 
 | } | 
 |  | 
 | spdy::SpdyHeadersHandlerInterface* OgHttp2Session::OnHeaderFrameStart( | 
 |     spdy::SpdyStreamId stream_id) { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it != stream_map_.end() && !streams_reset_.contains(stream_id)) { | 
 |     headers_handler_.set_stream_id(stream_id); | 
 |     headers_handler_.set_header_type( | 
 |         NextHeaderType(it->second.received_header_type)); | 
 |     return &headers_handler_; | 
 |   } else { | 
 |     return &noop_headers_handler_; | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnHeaderFrameEnd(spdy::SpdyStreamId stream_id) { | 
 |   auto it = stream_map_.find(stream_id); | 
 |   if (it != stream_map_.end()) { | 
 |     if (headers_handler_.header_type() == HeaderType::RESPONSE && | 
 |         !headers_handler_.status_header().empty() && | 
 |         headers_handler_.status_header()[0] == '1') { | 
 |       // If response headers carried a 1xx response code, final response headers | 
 |       // should still be forthcoming. | 
 |       headers_handler_.set_header_type(HeaderType::RESPONSE_100); | 
 |     } | 
 |     it->second.received_header_type = headers_handler_.header_type(); | 
 |  | 
 |     // Track the content-length if the headers indicate that a body can follow. | 
 |     it->second.can_receive_body = headers_handler_.CanReceiveBody(); | 
 |     if (it->second.can_receive_body) { | 
 |       it->second.remaining_content_length = headers_handler_.content_length(); | 
 |     } | 
 |  | 
 |     headers_handler_.set_stream_id(0); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnRstStream(spdy::SpdyStreamId stream_id, | 
 |                                  spdy::SpdyErrorCode error_code) { | 
 |   auto iter = stream_map_.find(stream_id); | 
 |   if (iter != stream_map_.end()) { | 
 |     iter->second.half_closed_remote = true; | 
 |     iter->second.outbound_body = nullptr; | 
 |   } else if (static_cast<Http2StreamId>(stream_id) > | 
 |              highest_processed_stream_id_) { | 
 |     // Receiving RST_STREAM before HEADERS is a connection error. | 
 |     LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                         ConnectionError::kWrongFrameSequence); | 
 |     return; | 
 |   } | 
 |   if (streams_reset_.contains(stream_id)) { | 
 |     return; | 
 |   } | 
 |   visitor_.OnRstStream(stream_id, TranslateErrorCode(error_code)); | 
 |   // TODO(birenroy): Consider whether there are outbound frames queued for the | 
 |   // stream. | 
 |   CloseStream(stream_id, TranslateErrorCode(error_code)); | 
 | } | 
 |  | 
 | void OgHttp2Session::OnSettings() { | 
 |   visitor_.OnSettingsStart(); | 
 |   auto settings = std::make_unique<SpdySettingsIR>(); | 
 |   settings->set_is_ack(true); | 
 |   EnqueueFrame(std::move(settings)); | 
 | } | 
 |  | 
 | void OgHttp2Session::OnSetting(spdy::SpdySettingsId id, uint32_t value) { | 
 |   switch (id) { | 
 |     case HEADER_TABLE_SIZE: | 
 |       value = std::min(value, HpackCapacityBound(options_)); | 
 |       if (value < framer_.GetHpackEncoder()->CurrentHeaderTableSizeSetting()) { | 
 |         // Safe to apply a smaller table capacity immediately. | 
 |         QUICHE_VLOG(2) << TracePerspectiveAsString(options_.perspective) | 
 |                        << " applying encoder table capacity " << value; | 
 |         framer_.GetHpackEncoder()->ApplyHeaderTableSizeSetting(value); | 
 |       } else { | 
 |         QUICHE_VLOG(2) | 
 |             << TracePerspectiveAsString(options_.perspective) | 
 |             << " NOT applying encoder table capacity until writing ack: " | 
 |             << value; | 
 |         encoder_header_table_capacity_when_acking_ = value; | 
 |       } | 
 |       break; | 
 |     case ENABLE_PUSH: | 
 |       if (value > 1u) { | 
 |         visitor_.OnInvalidFrame( | 
 |             0, Http2VisitorInterface::InvalidFrameError::kProtocol); | 
 |         // The specification says this is a connection-level protocol error. | 
 |         LatchErrorAndNotify( | 
 |             Http2ErrorCode::PROTOCOL_ERROR, | 
 |             Http2VisitorInterface::ConnectionError::kInvalidSetting); | 
 |         return; | 
 |       } | 
 |       // Aside from validation, this setting is ignored. | 
 |       break; | 
 |     case MAX_CONCURRENT_STREAMS: | 
 |       max_outbound_concurrent_streams_ = value; | 
 |       if (!IsServerSession()) { | 
 |         // We may now be able to start pending streams. | 
 |         StartPendingStreams(); | 
 |       } | 
 |       break; | 
 |     case INITIAL_WINDOW_SIZE: | 
 |       if (value > spdy::kSpdyMaximumWindowSize) { | 
 |         visitor_.OnInvalidFrame( | 
 |             0, Http2VisitorInterface::InvalidFrameError::kFlowControl); | 
 |         // The specification says this is a connection-level flow control error. | 
 |         LatchErrorAndNotify( | 
 |             Http2ErrorCode::FLOW_CONTROL_ERROR, | 
 |             Http2VisitorInterface::ConnectionError::kFlowControlError); | 
 |         return; | 
 |       } else { | 
 |         UpdateStreamSendWindowSizes(value); | 
 |       } | 
 |       break; | 
 |     case MAX_FRAME_SIZE: | 
 |       if (value < kDefaultFramePayloadSizeLimit || | 
 |           value > kMaximumFramePayloadSizeLimit) { | 
 |         visitor_.OnInvalidFrame( | 
 |             0, Http2VisitorInterface::InvalidFrameError::kProtocol); | 
 |         // The specification says this is a connection-level protocol error. | 
 |         LatchErrorAndNotify( | 
 |             Http2ErrorCode::PROTOCOL_ERROR, | 
 |             Http2VisitorInterface::ConnectionError::kInvalidSetting); | 
 |         return; | 
 |       } | 
 |       max_frame_payload_ = value; | 
 |       break; | 
 |     case ENABLE_CONNECT_PROTOCOL: | 
 |       if (value > 1u || (value == 0 && peer_enables_connect_protocol_)) { | 
 |         visitor_.OnInvalidFrame( | 
 |             0, Http2VisitorInterface::InvalidFrameError::kProtocol); | 
 |         LatchErrorAndNotify( | 
 |             Http2ErrorCode::PROTOCOL_ERROR, | 
 |             Http2VisitorInterface::ConnectionError::kInvalidSetting); | 
 |         return; | 
 |       } | 
 |       peer_enables_connect_protocol_ = (value == 1u); | 
 |       break; | 
 |     default: | 
 |       // TODO(bnc): See if C++17 inline constants are allowed in QUICHE. | 
 |       if (id == kMetadataExtensionId) { | 
 |         peer_supports_metadata_ = (value != 0); | 
 |       } else { | 
 |         QUICHE_VLOG(1) << "Unimplemented SETTING id: " << id; | 
 |       } | 
 |   } | 
 |   visitor_.OnSetting({id, value}); | 
 | } | 
 |  | 
 | void OgHttp2Session::OnSettingsEnd() { visitor_.OnSettingsEnd(); } | 
 |  | 
 | void OgHttp2Session::OnSettingsAck() { | 
 |   if (!settings_ack_callbacks_.empty()) { | 
 |     SettingsAckCallback callback = std::move(settings_ack_callbacks_.front()); | 
 |     settings_ack_callbacks_.pop_front(); | 
 |     callback(); | 
 |   } | 
 |  | 
 |   visitor_.OnSettingsAck(); | 
 | } | 
 |  | 
 | void OgHttp2Session::OnPing(spdy::SpdyPingId unique_id, bool is_ack) { | 
 |   visitor_.OnPing(unique_id, is_ack); | 
 |   if (options_.auto_ping_ack && !is_ack) { | 
 |     auto ping = std::make_unique<spdy::SpdyPingIR>(unique_id); | 
 |     ping->set_is_ack(true); | 
 |     EnqueueFrame(std::move(ping)); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnGoAway(spdy::SpdyStreamId last_accepted_stream_id, | 
 |                               spdy::SpdyErrorCode error_code) { | 
 |   if (received_goaway_ && | 
 |       last_accepted_stream_id > | 
 |           static_cast<spdy::SpdyStreamId>(received_goaway_stream_id_)) { | 
 |     // This GOAWAY has a higher `last_accepted_stream_id` than a previous | 
 |     // GOAWAY, a connection-level spec violation. | 
 |     const bool ok = visitor_.OnInvalidFrame( | 
 |         kConnectionStreamId, | 
 |         Http2VisitorInterface::InvalidFrameError::kProtocol); | 
 |     if (!ok) { | 
 |       fatal_visitor_callback_failure_ = true; | 
 |     } | 
 |     LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                         ConnectionError::kInvalidGoAwayLastStreamId); | 
 |     return; | 
 |   } | 
 |  | 
 |   received_goaway_ = true; | 
 |   received_goaway_stream_id_ = last_accepted_stream_id; | 
 |   const bool result = visitor_.OnGoAway(last_accepted_stream_id, | 
 |                                         TranslateErrorCode(error_code), ""); | 
 |   if (!result) { | 
 |     fatal_visitor_callback_failure_ = true; | 
 |     decoder_.StopProcessing(); | 
 |   } | 
 |  | 
 |   // Close the streams above `last_accepted_stream_id`. Only applies if the | 
 |   // session receives a GOAWAY as a client, as we do not support server push. | 
 |   if (last_accepted_stream_id == spdy::kMaxStreamId || IsServerSession()) { | 
 |     return; | 
 |   } | 
 |   std::vector<Http2StreamId> streams_to_close; | 
 |   for (const auto& [stream_id, stream_state] : stream_map_) { | 
 |     if (static_cast<spdy::SpdyStreamId>(stream_id) > last_accepted_stream_id) { | 
 |       streams_to_close.push_back(stream_id); | 
 |     } | 
 |   } | 
 |   for (Http2StreamId stream_id : streams_to_close) { | 
 |     CloseStream(stream_id, Http2ErrorCode::REFUSED_STREAM); | 
 |   } | 
 | } | 
 |  | 
 | bool OgHttp2Session::OnGoAwayFrameData(const char* /*goaway_data*/, size_t | 
 |                                        /*len*/) { | 
 |   // Opaque data is currently ignored. | 
 |   return true; | 
 | } | 
 |  | 
 | void OgHttp2Session::OnHeaders(spdy::SpdyStreamId stream_id, | 
 |                                size_t /*payload_length*/, bool /*has_priority*/, | 
 |                                int /*weight*/, | 
 |                                spdy::SpdyStreamId /*parent_stream_id*/, | 
 |                                bool /*exclusive*/, bool fin, bool /*end*/) { | 
 |   if (stream_id % 2 == 0) { | 
 |     // Server push is disabled; receiving push HEADERS is a connection error. | 
 |     LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                         ConnectionError::kInvalidNewStreamId); | 
 |     return; | 
 |   } | 
 |   if (fin) { | 
 |     headers_handler_.set_frame_contains_fin(); | 
 |   } | 
 |   if (IsServerSession()) { | 
 |     const auto new_stream_id = static_cast<Http2StreamId>(stream_id); | 
 |     if (stream_map_.find(new_stream_id) != stream_map_.end() && fin) { | 
 |       // Not a new stream, must be trailers. | 
 |       return; | 
 |     } | 
 |     if (new_stream_id <= highest_processed_stream_id_) { | 
 |       // A new stream ID lower than the watermark is a connection error. | 
 |       LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                           ConnectionError::kInvalidNewStreamId); | 
 |       return; | 
 |     } | 
 |  | 
 |     if (stream_map_.size() >= max_inbound_concurrent_streams_) { | 
 |       // The new stream would exceed our advertised and acknowledged | 
 |       // MAX_CONCURRENT_STREAMS. For parity with nghttp2, treat this error as a | 
 |       // connection-level PROTOCOL_ERROR. | 
 |       bool ok = visitor_.OnInvalidFrame( | 
 |           stream_id, Http2VisitorInterface::InvalidFrameError::kProtocol); | 
 |       if (!ok) { | 
 |         fatal_visitor_callback_failure_ = true; | 
 |       } | 
 |       LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                           ConnectionError::kExceededMaxConcurrentStreams); | 
 |       return; | 
 |     } | 
 |     if (stream_map_.size() >= pending_max_inbound_concurrent_streams_) { | 
 |       // The new stream would exceed our advertised but unacked | 
 |       // MAX_CONCURRENT_STREAMS. Refuse the stream for parity with nghttp2. | 
 |       EnqueueFrame(std::make_unique<spdy::SpdyRstStreamIR>( | 
 |           stream_id, spdy::ERROR_CODE_REFUSED_STREAM)); | 
 |       const bool ok = visitor_.OnInvalidFrame( | 
 |           stream_id, Http2VisitorInterface::InvalidFrameError::kRefusedStream); | 
 |       if (!ok) { | 
 |         fatal_visitor_callback_failure_ = true; | 
 |         LatchErrorAndNotify(Http2ErrorCode::REFUSED_STREAM, | 
 |                             ConnectionError::kExceededMaxConcurrentStreams); | 
 |       } | 
 |       return; | 
 |     } | 
 |  | 
 |     CreateStream(stream_id); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnWindowUpdate(spdy::SpdyStreamId stream_id, | 
 |                                     int delta_window_size) { | 
 |   constexpr int kMaxWindowValue = 2147483647;  // (1 << 31) - 1 | 
 |   if (stream_id == 0) { | 
 |     if (delta_window_size == 0) { | 
 |       // A PROTOCOL_ERROR, according to RFC 9113 Section 6.9. | 
 |       LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                           ConnectionError::kFlowControlError); | 
 |       return; | 
 |     } | 
 |     if (connection_send_window_ > 0 && | 
 |         delta_window_size > (kMaxWindowValue - connection_send_window_)) { | 
 |       // Window overflow is a FLOW_CONTROL_ERROR. | 
 |       LatchErrorAndNotify(Http2ErrorCode::FLOW_CONTROL_ERROR, | 
 |                           ConnectionError::kFlowControlError); | 
 |       return; | 
 |     } | 
 |     connection_send_window_ += delta_window_size; | 
 |   } else { | 
 |     if (delta_window_size == 0) { | 
 |       // A PROTOCOL_ERROR, according to RFC 9113 Section 6.9. | 
 |       EnqueueFrame(std::make_unique<spdy::SpdyRstStreamIR>( | 
 |           stream_id, spdy::ERROR_CODE_PROTOCOL_ERROR)); | 
 |       return; | 
 |     } | 
 |     auto it = stream_map_.find(stream_id); | 
 |     if (it == stream_map_.end()) { | 
 |       QUICHE_VLOG(1) << "Stream " << stream_id << " not found!"; | 
 |       if (static_cast<Http2StreamId>(stream_id) > | 
 |           highest_processed_stream_id_) { | 
 |         // Receiving WINDOW_UPDATE before HEADERS is a connection error. | 
 |         LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                             ConnectionError::kWrongFrameSequence); | 
 |       } | 
 |       // Do not inform the visitor of a WINDOW_UPDATE for a non-existent stream. | 
 |       return; | 
 |     } else { | 
 |       if (streams_reset_.contains(stream_id)) { | 
 |         return; | 
 |       } | 
 |       if (it->second.send_window > 0 && | 
 |           delta_window_size > (kMaxWindowValue - it->second.send_window)) { | 
 |         // Window overflow is a FLOW_CONTROL_ERROR. | 
 |         EnqueueFrame(std::make_unique<spdy::SpdyRstStreamIR>( | 
 |             stream_id, spdy::ERROR_CODE_FLOW_CONTROL_ERROR)); | 
 |         return; | 
 |       } | 
 |       const bool was_blocked = (it->second.send_window <= 0); | 
 |       it->second.send_window += delta_window_size; | 
 |       if (was_blocked && it->second.send_window > 0) { | 
 |         // The stream was blocked on flow control. | 
 |         QUICHE_VLOG(1) << "Marking stream " << stream_id << " ready to write."; | 
 |         write_scheduler_.MarkStreamReady(stream_id, false); | 
 |       } | 
 |     } | 
 |   } | 
 |   visitor_.OnWindowUpdate(stream_id, delta_window_size); | 
 | } | 
 |  | 
 | void OgHttp2Session::OnPushPromise(spdy::SpdyStreamId /*stream_id*/, | 
 |                                    spdy::SpdyStreamId /*promised_stream_id*/, | 
 |                                    bool /*end*/) { | 
 |   // Server push is disabled; PUSH_PROMISE is an invalid frame. | 
 |   LatchErrorAndNotify(Http2ErrorCode::PROTOCOL_ERROR, | 
 |                       ConnectionError::kInvalidPushPromise); | 
 | } | 
 |  | 
 | void OgHttp2Session::OnContinuation(spdy::SpdyStreamId /*stream_id*/, | 
 |                                     size_t /*payload_length*/, bool /*end*/) {} | 
 |  | 
 | void OgHttp2Session::OnAltSvc(spdy::SpdyStreamId /*stream_id*/, | 
 |                               absl::string_view /*origin*/, | 
 |                               const spdy::SpdyAltSvcWireFormat:: | 
 |                                   AlternativeServiceVector& /*altsvc_vector*/) { | 
 | } | 
 |  | 
 | void OgHttp2Session::OnPriority(spdy::SpdyStreamId /*stream_id*/, | 
 |                                 spdy::SpdyStreamId /*parent_stream_id*/, | 
 |                                 int /*weight*/, bool /*exclusive*/) {} | 
 |  | 
 | void OgHttp2Session::OnPriorityUpdate( | 
 |     spdy::SpdyStreamId /*prioritized_stream_id*/, | 
 |     absl::string_view /*priority_field_value*/) {} | 
 |  | 
 | bool OgHttp2Session::OnUnknownFrame(spdy::SpdyStreamId /*stream_id*/, | 
 |                                     uint8_t /*frame_type*/) { | 
 |   return true; | 
 | } | 
 |  | 
 | void OgHttp2Session::OnUnknownFrameStart(spdy::SpdyStreamId stream_id, | 
 |                                          size_t length, uint8_t type, | 
 |                                          uint8_t flags) { | 
 |   process_metadata_ = false; | 
 |   if (streams_reset_.contains(stream_id)) { | 
 |     return; | 
 |   } | 
 |   if (type == kMetadataFrameType) { | 
 |     QUICHE_DCHECK_EQ(metadata_length_, 0u); | 
 |     visitor_.OnBeginMetadataForStream(stream_id, length); | 
 |     metadata_length_ = length; | 
 |     process_metadata_ = true; | 
 |     end_metadata_ = flags & kMetadataEndFlag; | 
 |  | 
 |     // Empty metadata payloads will not trigger OnUnknownFramePayload(), so | 
 |     // handle that possibility here. | 
 |     MaybeHandleMetadataEndForStream(stream_id); | 
 |   } else { | 
 |     QUICHE_DLOG(INFO) << "Received unexpected frame type " | 
 |                       << static_cast<int>(type); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnUnknownFramePayload(spdy::SpdyStreamId stream_id, | 
 |                                            absl::string_view payload) { | 
 |   if (!process_metadata_) { | 
 |     return; | 
 |   } | 
 |   if (streams_reset_.contains(stream_id)) { | 
 |     return; | 
 |   } | 
 |   if (metadata_length_ > 0) { | 
 |     QUICHE_DCHECK_LE(payload.size(), metadata_length_); | 
 |     const bool payload_success = | 
 |         visitor_.OnMetadataForStream(stream_id, payload); | 
 |     if (payload_success) { | 
 |       metadata_length_ -= payload.size(); | 
 |       MaybeHandleMetadataEndForStream(stream_id); | 
 |     } else { | 
 |       fatal_visitor_callback_failure_ = true; | 
 |       decoder_.StopProcessing(); | 
 |     } | 
 |   } else { | 
 |     QUICHE_DLOG(INFO) << "Unexpected metadata payload for stream " << stream_id; | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::OnHeaderStatus( | 
 |     Http2StreamId stream_id, Http2VisitorInterface::OnHeaderResult result) { | 
 |   QUICHE_DCHECK_NE(result, Http2VisitorInterface::HEADER_OK); | 
 |   QUICHE_VLOG(1) << "OnHeaderStatus(stream_id=" << stream_id | 
 |                  << ", result=" << result << ")"; | 
 |   const bool should_reset_stream = | 
 |       result == Http2VisitorInterface::HEADER_RST_STREAM || | 
 |       result == Http2VisitorInterface::HEADER_FIELD_INVALID || | 
 |       result == Http2VisitorInterface::HEADER_HTTP_MESSAGING; | 
 |   if (should_reset_stream) { | 
 |     const Http2ErrorCode error_code = | 
 |         (result == Http2VisitorInterface::HEADER_RST_STREAM) | 
 |             ? Http2ErrorCode::INTERNAL_ERROR | 
 |             : Http2ErrorCode::PROTOCOL_ERROR; | 
 |     const spdy::SpdyErrorCode spdy_error_code = TranslateErrorCode(error_code); | 
 |     const Http2VisitorInterface::InvalidFrameError frame_error = | 
 |         (result == Http2VisitorInterface::HEADER_RST_STREAM || | 
 |          result == Http2VisitorInterface::HEADER_FIELD_INVALID) | 
 |             ? Http2VisitorInterface::InvalidFrameError::kHttpHeader | 
 |             : Http2VisitorInterface::InvalidFrameError::kHttpMessaging; | 
 |     auto it = streams_reset_.find(stream_id); | 
 |     if (it == streams_reset_.end()) { | 
 |       EnqueueFrame( | 
 |           std::make_unique<spdy::SpdyRstStreamIR>(stream_id, spdy_error_code)); | 
 |  | 
 |       if (result == Http2VisitorInterface::HEADER_FIELD_INVALID || | 
 |           result == Http2VisitorInterface::HEADER_HTTP_MESSAGING) { | 
 |         const bool ok = visitor_.OnInvalidFrame(stream_id, frame_error); | 
 |         if (!ok) { | 
 |           fatal_visitor_callback_failure_ = true; | 
 |           LatchErrorAndNotify(error_code, ConnectionError::kHeaderError); | 
 |         } | 
 |       } | 
 |     } | 
 |   } else if (result == Http2VisitorInterface::HEADER_CONNECTION_ERROR) { | 
 |     fatal_visitor_callback_failure_ = true; | 
 |     LatchErrorAndNotify(Http2ErrorCode::INTERNAL_ERROR, | 
 |                         ConnectionError::kHeaderError); | 
 |   } else if (result == Http2VisitorInterface::HEADER_COMPRESSION_ERROR) { | 
 |     LatchErrorAndNotify(Http2ErrorCode::COMPRESSION_ERROR, | 
 |                         ConnectionError::kHeaderError); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::MaybeSetupPreface(bool sending_outbound_settings) { | 
 |   if (!queued_preface_) { | 
 |     queued_preface_ = true; | 
 |     if (!IsServerSession()) { | 
 |       buffered_data_.assign(spdy::kHttp2ConnectionHeaderPrefix, | 
 |                             spdy::kHttp2ConnectionHeaderPrefixSize); | 
 |     } | 
 |     if (!sending_outbound_settings) { | 
 |       QUICHE_DCHECK(frames_.empty()); | 
 |       // First frame must be a non-ack SETTINGS. | 
 |       EnqueueFrame(PrepareSettingsFrame(GetInitialSettings())); | 
 |     } | 
 |   } | 
 | } | 
 |  | 
 | std::vector<Http2Setting> OgHttp2Session::GetInitialSettings() const { | 
 |   std::vector<Http2Setting> settings; | 
 |   if (!IsServerSession()) { | 
 |     // Disable server push. Note that server push from clients is already | 
 |     // disabled, so the server does not need to send this disabling setting. | 
 |     // TODO(diannahu): Consider applying server push disabling on SETTINGS ack. | 
 |     settings.push_back({Http2KnownSettingsId::ENABLE_PUSH, 0}); | 
 |   } | 
 |   if (options_.max_header_list_bytes) { | 
 |     settings.push_back({Http2KnownSettingsId::MAX_HEADER_LIST_SIZE, | 
 |                         *options_.max_header_list_bytes}); | 
 |   } | 
 |   if (options_.allow_extended_connect && IsServerSession()) { | 
 |     settings.push_back({Http2KnownSettingsId::ENABLE_CONNECT_PROTOCOL, 1u}); | 
 |   } | 
 |   return settings; | 
 | } | 
 |  | 
 | std::unique_ptr<SpdySettingsIR> OgHttp2Session::PrepareSettingsFrame( | 
 |     absl::Span<const Http2Setting> settings) { | 
 |   auto settings_ir = std::make_unique<SpdySettingsIR>(); | 
 |   for (const Http2Setting& setting : settings) { | 
 |     settings_ir->AddSetting(setting.id, setting.value); | 
 |   } | 
 |   return settings_ir; | 
 | } | 
 |  | 
 | void OgHttp2Session::HandleOutboundSettings( | 
 |     const spdy::SpdySettingsIR& settings_frame) { | 
 |   for (const auto& [id, value] : settings_frame.values()) { | 
 |     switch (static_cast<Http2KnownSettingsId>(id)) { | 
 |       case MAX_CONCURRENT_STREAMS: | 
 |         pending_max_inbound_concurrent_streams_ = value; | 
 |         break; | 
 |       case ENABLE_CONNECT_PROTOCOL: | 
 |         if (value == 1u && IsServerSession()) { | 
 |           // Allow extended CONNECT semantics even before SETTINGS are acked, to | 
 |           // make things easier for clients. | 
 |           headers_handler_.SetAllowExtendedConnect(); | 
 |         } | 
 |         break; | 
 |       case HEADER_TABLE_SIZE: | 
 |       case ENABLE_PUSH: | 
 |       case INITIAL_WINDOW_SIZE: | 
 |       case MAX_FRAME_SIZE: | 
 |       case MAX_HEADER_LIST_SIZE: | 
 |         QUICHE_VLOG(2) | 
 |             << "Not adjusting internal state for outbound setting with id " | 
 |             << id; | 
 |         break; | 
 |     } | 
 |   } | 
 |  | 
 |   // Copy the (small) map of settings we are about to send so that we can set | 
 |   // values in the SETTINGS ack callback. | 
 |   settings_ack_callbacks_.push_back( | 
 |       [this, settings_map = settings_frame.values()]() { | 
 |         for (const auto& [id, value] : settings_map) { | 
 |           switch (static_cast<Http2KnownSettingsId>(id)) { | 
 |             case MAX_CONCURRENT_STREAMS: | 
 |               max_inbound_concurrent_streams_ = value; | 
 |               break; | 
 |             case HEADER_TABLE_SIZE: | 
 |               decoder_.GetHpackDecoder()->ApplyHeaderTableSizeSetting(value); | 
 |               break; | 
 |             case INITIAL_WINDOW_SIZE: | 
 |               UpdateStreamReceiveWindowSizes(value); | 
 |               initial_stream_receive_window_ = value; | 
 |               break; | 
 |             case MAX_FRAME_SIZE: | 
 |               decoder_.SetMaxFrameSize(value); | 
 |               break; | 
 |             case ENABLE_PUSH: | 
 |             case MAX_HEADER_LIST_SIZE: | 
 |             case ENABLE_CONNECT_PROTOCOL: | 
 |               QUICHE_VLOG(2) | 
 |                   << "No action required in ack for outbound setting with id " | 
 |                   << id; | 
 |               break; | 
 |           } | 
 |         } | 
 |       }); | 
 | } | 
 |  | 
 | void OgHttp2Session::SendWindowUpdate(Http2StreamId stream_id, | 
 |                                       size_t update_delta) { | 
 |   EnqueueFrame( | 
 |       std::make_unique<spdy::SpdyWindowUpdateIR>(stream_id, update_delta)); | 
 | } | 
 |  | 
 | void OgHttp2Session::SendHeaders(Http2StreamId stream_id, | 
 |                                  spdy::Http2HeaderBlock headers, | 
 |                                  bool end_stream) { | 
 |   auto frame = | 
 |       std::make_unique<spdy::SpdyHeadersIR>(stream_id, std::move(headers)); | 
 |   frame->set_fin(end_stream); | 
 |   EnqueueFrame(std::move(frame)); | 
 | } | 
 |  | 
 | void OgHttp2Session::SendTrailers(Http2StreamId stream_id, | 
 |                                   spdy::Http2HeaderBlock trailers) { | 
 |   auto frame = | 
 |       std::make_unique<spdy::SpdyHeadersIR>(stream_id, std::move(trailers)); | 
 |   frame->set_fin(true); | 
 |   EnqueueFrame(std::move(frame)); | 
 |   trailers_ready_.erase(stream_id); | 
 | } | 
 |  | 
 | void OgHttp2Session::MaybeFinWithRstStream(StreamStateMap::iterator iter) { | 
 |   QUICHE_DCHECK(iter != stream_map_.end() && iter->second.half_closed_local); | 
 |  | 
 |   if (options_.rst_stream_no_error_when_incomplete && IsServerSession() && | 
 |       !iter->second.half_closed_remote) { | 
 |     // Since the peer has not yet ended the stream, this endpoint should | 
 |     // send a RST_STREAM NO_ERROR. See RFC 7540 Section 8.1. | 
 |     EnqueueFrame(std::make_unique<spdy::SpdyRstStreamIR>( | 
 |         iter->first, spdy::SpdyErrorCode::ERROR_CODE_NO_ERROR)); | 
 |     iter->second.half_closed_remote = true; | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::MarkDataBuffered(Http2StreamId stream_id, size_t bytes) { | 
 |   connection_window_manager_.MarkDataBuffered(bytes); | 
 |   if (auto it = stream_map_.find(stream_id); it != stream_map_.end()) { | 
 |     it->second.window_manager.MarkDataBuffered(bytes); | 
 |   } | 
 | } | 
 |  | 
 | OgHttp2Session::StreamStateMap::iterator OgHttp2Session::CreateStream( | 
 |     Http2StreamId stream_id) { | 
 |   WindowManager::WindowUpdateListener listener = | 
 |       [this, stream_id](size_t window_update_delta) { | 
 |         SendWindowUpdate(stream_id, window_update_delta); | 
 |       }; | 
 |   auto [iter, inserted] = stream_map_.try_emplace( | 
 |       stream_id, | 
 |       StreamState(initial_stream_receive_window_, initial_stream_send_window_, | 
 |                   std::move(listener), options_.should_window_update_fn)); | 
 |   if (inserted) { | 
 |     // Add the stream to the write scheduler. | 
 |     const WriteScheduler::StreamPrecedenceType precedence(3); | 
 |     write_scheduler_.RegisterStream(stream_id, precedence); | 
 |  | 
 |     highest_processed_stream_id_ = | 
 |         std::max(highest_processed_stream_id_, stream_id); | 
 |   } | 
 |   return iter; | 
 | } | 
 |  | 
 | void OgHttp2Session::StartRequest(Http2StreamId stream_id, | 
 |                                   spdy::Http2HeaderBlock headers, | 
 |                                   std::unique_ptr<DataFrameSource> data_source, | 
 |                                   void* user_data) { | 
 |   if (received_goaway_) { | 
 |     // Do not start new streams after receiving a GOAWAY. | 
 |     goaway_rejected_streams_.insert(stream_id); | 
 |     return; | 
 |   } | 
 |  | 
 |   auto iter = CreateStream(stream_id); | 
 |   const bool end_stream = data_source == nullptr; | 
 |   if (!end_stream) { | 
 |     iter->second.outbound_body = std::move(data_source); | 
 |     write_scheduler_.MarkStreamReady(stream_id, false); | 
 |   } | 
 |   iter->second.user_data = user_data; | 
 |   SendHeaders(stream_id, std::move(headers), end_stream); | 
 | } | 
 |  | 
 | void OgHttp2Session::StartPendingStreams() { | 
 |   while (!pending_streams_.empty() && CanCreateStream()) { | 
 |     auto& [stream_id, pending_stream] = pending_streams_.front(); | 
 |     StartRequest(stream_id, std::move(pending_stream.headers), | 
 |                  std::move(pending_stream.data_source), | 
 |                  pending_stream.user_data); | 
 |     pending_streams_.pop_front(); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::CloseStream(Http2StreamId stream_id, | 
 |                                  Http2ErrorCode error_code) { | 
 |   const bool result = visitor_.OnCloseStream(stream_id, error_code); | 
 |   if (!result) { | 
 |     latched_error_ = true; | 
 |     decoder_.StopProcessing(); | 
 |   } | 
 |   stream_map_.erase(stream_id); | 
 |   trailers_ready_.erase(stream_id); | 
 |   streams_reset_.erase(stream_id); | 
 |   auto queued_it = queued_frames_.find(stream_id); | 
 |   if (queued_it != queued_frames_.end()) { | 
 |     // Remove any queued frames for this stream. | 
 |     int frames_remaining = queued_it->second; | 
 |     queued_frames_.erase(queued_it); | 
 |     for (auto it = frames_.begin(); | 
 |          frames_remaining > 0 && it != frames_.end();) { | 
 |       if (static_cast<Http2StreamId>((*it)->stream_id()) == stream_id) { | 
 |         it = frames_.erase(it); | 
 |         --frames_remaining; | 
 |       } else { | 
 |         ++it; | 
 |       } | 
 |     } | 
 |   } | 
 |   if (write_scheduler_.StreamRegistered(stream_id)) { | 
 |     write_scheduler_.UnregisterStream(stream_id); | 
 |   } | 
 |  | 
 |   StartPendingStreams(); | 
 | } | 
 |  | 
 | bool OgHttp2Session::CanCreateStream() const { | 
 |   return stream_map_.size() < max_outbound_concurrent_streams_; | 
 | } | 
 |  | 
 | HeaderType OgHttp2Session::NextHeaderType( | 
 |     absl::optional<HeaderType> current_type) { | 
 |   if (IsServerSession()) { | 
 |     if (!current_type) { | 
 |       return HeaderType::REQUEST; | 
 |     } else { | 
 |       QUICHE_DCHECK(current_type == HeaderType::REQUEST); | 
 |       return HeaderType::REQUEST_TRAILER; | 
 |     } | 
 |   } else if (!current_type || | 
 |              current_type.value() == HeaderType::RESPONSE_100) { | 
 |     return HeaderType::RESPONSE; | 
 |   } else { | 
 |     return HeaderType::RESPONSE_TRAILER; | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::LatchErrorAndNotify(Http2ErrorCode error_code, | 
 |                                          ConnectionError error) { | 
 |   if (latched_error_) { | 
 |     // Do not kick a connection when it is down. | 
 |     return; | 
 |   } | 
 |  | 
 |   latched_error_ = true; | 
 |   visitor_.OnConnectionError(error); | 
 |   decoder_.StopProcessing(); | 
 |   EnqueueFrame(std::make_unique<spdy::SpdyGoAwayIR>( | 
 |       highest_processed_stream_id_, TranslateErrorCode(error_code), | 
 |       ConnectionErrorToString(error))); | 
 | } | 
 |  | 
 | void OgHttp2Session::CloseStreamIfReady(uint8_t frame_type, | 
 |                                         uint32_t stream_id) { | 
 |   auto iter = stream_map_.find(stream_id); | 
 |   if (iter == stream_map_.end()) { | 
 |     return; | 
 |   } | 
 |   const StreamState& state = iter->second; | 
 |   if (static_cast<FrameType>(frame_type) == FrameType::RST_STREAM || | 
 |       (state.half_closed_local && state.half_closed_remote)) { | 
 |     CloseStream(stream_id, Http2ErrorCode::HTTP2_NO_ERROR); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::CloseGoAwayRejectedStreams() { | 
 |   for (Http2StreamId stream_id : goaway_rejected_streams_) { | 
 |     const bool result = | 
 |         visitor_.OnCloseStream(stream_id, Http2ErrorCode::REFUSED_STREAM); | 
 |     if (!result) { | 
 |       latched_error_ = true; | 
 |       decoder_.StopProcessing(); | 
 |     } | 
 |   } | 
 |   goaway_rejected_streams_.clear(); | 
 | } | 
 |  | 
 | void OgHttp2Session::PrepareForImmediateGoAway() { | 
 |   queued_immediate_goaway_ = true; | 
 |  | 
 |   // Keep the initial SETTINGS frame if the session has SETTINGS at the front of | 
 |   // the queue but has not sent SETTINGS yet. The session should send initial | 
 |   // SETTINGS before GOAWAY. | 
 |   std::unique_ptr<spdy::SpdyFrameIR> initial_settings; | 
 |   if (!sent_non_ack_settings_ && !frames_.empty() && | 
 |       IsNonAckSettings(*frames_.front())) { | 
 |     initial_settings = std::move(frames_.front()); | 
 |     frames_.pop_front(); | 
 |   } | 
 |  | 
 |   // Remove all pending frames except for RST_STREAMs. It is important to send | 
 |   // RST_STREAMs so the peer knows of errors below the GOAWAY last stream ID. | 
 |   // TODO(diannahu): Consider informing the visitor of dropped frames. This may | 
 |   // mean keeping the frames and invoking a frame-not-sent callback, similar to | 
 |   // nghttp2. Could add a closure to each frame in the frames queue. | 
 |   frames_.remove_if([](const auto& frame) { | 
 |     return frame->frame_type() != spdy::SpdyFrameType::RST_STREAM; | 
 |   }); | 
 |  | 
 |   if (initial_settings != nullptr) { | 
 |     frames_.push_front(std::move(initial_settings)); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::MaybeHandleMetadataEndForStream(Http2StreamId stream_id) { | 
 |   if (metadata_length_ == 0 && end_metadata_) { | 
 |     const bool completion_success = visitor_.OnMetadataEndForStream(stream_id); | 
 |     if (!completion_success) { | 
 |       fatal_visitor_callback_failure_ = true; | 
 |       decoder_.StopProcessing(); | 
 |     } | 
 |     process_metadata_ = false; | 
 |     end_metadata_ = false; | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::DecrementQueuedFrameCount(uint32_t stream_id, | 
 |                                                uint8_t frame_type) { | 
 |   auto iter = queued_frames_.find(stream_id); | 
 |   if (iter == queued_frames_.end()) { | 
 |     QUICHE_LOG(ERROR) << "Unable to find a queued frame count for stream " | 
 |                       << stream_id; | 
 |     return; | 
 |   } | 
 |   if (static_cast<FrameType>(frame_type) != FrameType::DATA) { | 
 |     --iter->second; | 
 |   } | 
 |   if (iter->second == 0) { | 
 |     // TODO(birenroy): Consider passing through `error_code` here. | 
 |     CloseStreamIfReady(frame_type, stream_id); | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::HandleContentLengthError(Http2StreamId stream_id) { | 
 |   EnqueueFrame(std::make_unique<spdy::SpdyRstStreamIR>( | 
 |       stream_id, spdy::ERROR_CODE_PROTOCOL_ERROR)); | 
 | } | 
 |  | 
 | void OgHttp2Session::UpdateReceiveWindow(Http2StreamId stream_id, | 
 |                                          int32_t delta) { | 
 |   if (stream_id == 0) { | 
 |     connection_window_manager_.IncreaseWindow(delta); | 
 |     // TODO(b/181586191): Provide an explicit way to set the desired window | 
 |     // limit, remove the upsize-on-window-update behavior. | 
 |     const int64_t current_window = | 
 |         connection_window_manager_.CurrentWindowSize(); | 
 |     if (current_window > connection_window_manager_.WindowSizeLimit()) { | 
 |       connection_window_manager_.SetWindowSizeLimit(current_window); | 
 |     } | 
 |   } else { | 
 |     auto iter = stream_map_.find(stream_id); | 
 |     if (iter != stream_map_.end()) { | 
 |       WindowManager& manager = iter->second.window_manager; | 
 |       manager.IncreaseWindow(delta); | 
 |       // TODO(b/181586191): Provide an explicit way to set the desired window | 
 |       // limit, remove the upsize-on-window-update behavior. | 
 |       const int64_t current_window = manager.CurrentWindowSize(); | 
 |       if (current_window > manager.WindowSizeLimit()) { | 
 |         manager.SetWindowSizeLimit(current_window); | 
 |       } | 
 |     } | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::UpdateStreamSendWindowSizes(uint32_t new_value) { | 
 |   const int32_t delta = | 
 |       static_cast<int32_t>(new_value) - initial_stream_send_window_; | 
 |   initial_stream_send_window_ = new_value; | 
 |   for (auto& [stream_id, stream_state] : stream_map_) { | 
 |     const int64_t current_window_size = stream_state.send_window; | 
 |     const int64_t new_window_size = current_window_size + delta; | 
 |     if (new_window_size > spdy::kSpdyMaximumWindowSize) { | 
 |       EnqueueFrame(std::make_unique<spdy::SpdyRstStreamIR>( | 
 |           stream_id, spdy::ERROR_CODE_FLOW_CONTROL_ERROR)); | 
 |     } else { | 
 |       stream_state.send_window += delta; | 
 |     } | 
 |     if (current_window_size <= 0 && new_window_size > 0) { | 
 |       write_scheduler_.MarkStreamReady(stream_id, false); | 
 |     } | 
 |   } | 
 | } | 
 |  | 
 | void OgHttp2Session::UpdateStreamReceiveWindowSizes(uint32_t new_value) { | 
 |   for (auto& [stream_id, stream_state] : stream_map_) { | 
 |     stream_state.window_manager.OnWindowSizeLimitChange(new_value); | 
 |   } | 
 | } | 
 |  | 
 | }  // namespace adapter | 
 | }  // namespace http2 |