martinzink commented on code in PR #1779: URL: https://github.com/apache/nifi-minifi-cpp/pull/1779#discussion_r1633200516
########## extensions/standard-processors/modbus/FetchModbusTcp.cpp: ########## @@ -0,0 +1,259 @@ +/** +* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 "FetchModbusTcp.h" + +#include <utils/net/ConnectionHandler.h> + +#include <asio/read.hpp> +#include <range/v3/view/drop.hpp> + +#include "core/Resource.h" + +#include "core/ProcessSession.h" +#include "modbus/Error.h" +#include "modbus/ReadModbusFunctions.h" +#include "utils/net/AsioCoro.h" +#include "utils/net/AsioSocketUtils.h" + +using namespace std::literals::chrono_literals; + +namespace org::apache::nifi::minifi::modbus { + + +void FetchModbusTcp::onSchedule(core::ProcessContext& context, core::ProcessSessionFactory&) { + const auto record_set_writer_name = context.getProperty(RecordSetWriter); + record_set_writer_ = std::dynamic_pointer_cast<core::RecordSetWriter>(context.getControllerService(record_set_writer_name.value_or(""))); + if (!record_set_writer_) + throw Exception{ExceptionType::PROCESS_SCHEDULE_EXCEPTION, "Invalid or missing RecordSetWriter"}; + + // if the required properties are missing or empty even before evaluating the EL expression, then we can throw in onSchedule, before we waste any flow files + if (context.getProperty(Hostname).value_or(std::string{}).empty()) { + throw Exception{ExceptionType::PROCESS_SCHEDULE_EXCEPTION, "missing hostname"}; + } + if (context.getProperty(Port).value_or(std::string{}).empty()) { + throw Exception{ExceptionType::PROCESS_SCHEDULE_EXCEPTION, "missing port"}; + } + if (const auto idle_connection_expiration = context.getProperty<core::TimePeriodValue>(IdleConnectionExpiration); idle_connection_expiration && idle_connection_expiration->getMilliseconds() > 0ms) + idle_connection_expiration_ = idle_connection_expiration->getMilliseconds(); + else + idle_connection_expiration_.reset(); + + if (const auto timeout = context.getProperty<core::TimePeriodValue>(Timeout); timeout && timeout->getMilliseconds() > 0ms) + timeout_duration_ = timeout->getMilliseconds(); + else + timeout_duration_ = 15s; + + if (context.getProperty<bool>(ConnectionPerFlowFile).value_or(false)) + connections_.reset(); + else + connections_.emplace(); + + ssl_context_.reset(); + if (const auto context_name = context.getProperty(SSLContextService); context_name && !IsNullOrEmpty(*context_name)) { + if (auto controller_service = context.getControllerService(*context_name)) { + if (const auto ssl_context_service = std::dynamic_pointer_cast<minifi::controllers::SSLContextService>(context.getControllerService(*context_name))) { + ssl_context_ = utils::net::getSslContext(*ssl_context_service); + } else { + throw Exception(PROCESS_SCHEDULE_EXCEPTION, *context_name + " is not an SSL Context Service"); + } + } else { + throw Exception(PROCESS_SCHEDULE_EXCEPTION, "Invalid controller service: " + *context_name); + } + } + + readDynamicPropertyKeys(context); +} + +void FetchModbusTcp::onTrigger(core::ProcessContext& context, core::ProcessSession& session) { + const auto flow_file = getFlowFile(session); + if (!flow_file) { + logger_->log_error("No flowfile to work on"); + return; + } + + removeExpiredConnections(); + + auto hostname = context.getProperty(Hostname, flow_file.get()).value_or(std::string{}); + auto port = context.getProperty(Port, flow_file.get()).value_or(std::string{}); + + if (hostname.empty() || port.empty()) { + logger_->log_error("[{}] invalid target endpoint: hostname: {}, port: {}", flow_file->getUUIDStr(), + hostname.empty() ? "(empty)" : hostname.c_str(), + port.empty() ? "(empty)" : port.c_str()); + session.transfer(flow_file, Failure); + return; + } + + auto connection_id = utils::net::ConnectionId(std::move(hostname), std::move(port)); + std::shared_ptr<utils::net::ConnectionHandlerBase> handler; + if (!connections_ || !connections_->contains(connection_id)) { + if (ssl_context_) + handler = std::make_shared<utils::net::ConnectionHandler<utils::net::SslSocket>>(connection_id, timeout_duration_, logger_, max_size_of_socket_send_buffer_, &*ssl_context_); + else + handler = std::make_shared<utils::net::ConnectionHandler<utils::net::TcpSocket>>(connection_id, timeout_duration_, logger_, max_size_of_socket_send_buffer_, nullptr); + if (connections_) + (*connections_)[connection_id] = handler; + } else { + handler = (*connections_)[connection_id]; + } + + gsl_Expects(handler); + + processFlowFile(handler, context, session, flow_file); +} + +void FetchModbusTcp::initialize() { + setSupportedProperties(Properties); + setSupportedRelationships(Relationships); +} + +void FetchModbusTcp::readDynamicPropertyKeys(const core::ProcessContext& context) { + dynamic_property_keys_.clear(); + const std::vector<std::string> dynamic_prop_keys = context.getDynamicPropertyKeys(); + for (const auto& key : dynamic_prop_keys) { + dynamic_property_keys_.emplace_back(core::PropertyDefinitionBuilder<>::createProperty(key).withDescription("auto generated").supportsExpressionLanguage(true).build()); + } +} + +std::shared_ptr<core::FlowFile> FetchModbusTcp::getFlowFile(core::ProcessSession& session) const { + if (hasIncomingConnections()) { + return session.get(); + } + return session.create(); +} + +std::unordered_map<std::string, std::unique_ptr<ReadModbusFunction>> FetchModbusTcp::getAddressMap(core::ProcessContext& context, const core::FlowFile& flow_file) { + std::unordered_map<std::string, std::unique_ptr<ReadModbusFunction>> address_map{}; + const auto unit_id_str = context.getProperty(UnitIdentifier, &flow_file).value_or("0"); + const uint8_t unit_id = utils::string::parse<uint8_t>(unit_id_str).value_or(1); + for (const auto& dynamic_property : dynamic_property_keys_) { + if (std::string dynamic_property_value{}; context.getDynamicProperty(dynamic_property, dynamic_property_value, &flow_file)) { + if (auto modbus_func = ReadModbusFunction::parse(++transaction_id_, unit_id, dynamic_property_value); modbus_func) + address_map.emplace(dynamic_property.getName(), std::move(modbus_func)); + } + } + return address_map; +} + +void FetchModbusTcp::removeExpiredConnections() { + if (connections_) { + std::erase_if(*connections_, [this](auto& item) -> bool { + const auto& connection_handler = item.second; + return (!connection_handler || (idle_connection_expiration_ && !connection_handler->hasBeenUsedIn(*idle_connection_expiration_))); + }); + } +} + +void FetchModbusTcp::processFlowFile(const std::shared_ptr<utils::net::ConnectionHandlerBase>& connection_handler, + core::ProcessContext& context, + core::ProcessSession& session, + const std::shared_ptr<core::FlowFile>& flow_file) { + std::unordered_map<std::string, std::string> result_map{}; + const auto address_map = getAddressMap(context, *flow_file); + if (address_map.empty()) { + logger_->log_warn("There are no registers to query"); + session.transfer(flow_file, Failure); + return; + } + + if (auto result = readModbus(connection_handler, address_map); !result) { + connection_handler->reset(); + logger_->log_error("{}", result.error().message()); + session.transfer(flow_file, Failure); + } else { + core::RecordSet record_set; + record_set.push_back(std::move(*result)); + record_set_writer_->write(record_set, flow_file, session); + session.transfer(flow_file, Success); + } +} + +nonstd::expected<core::Record, std::error_code> FetchModbusTcp::readModbus( + const std::shared_ptr<utils::net::ConnectionHandlerBase>& connection_handler, + const std::unordered_map<std::string, std::unique_ptr<ReadModbusFunction>>& address_map) { + nonstd::expected<core::Record, std::error_code> result; + io_context_.restart(); + asio::co_spawn(io_context_, + sendRequestsAndReadResponses(*connection_handler, address_map), + [&result](const std::exception_ptr& exception_ptr, auto res) { + if (exception_ptr) { + result = nonstd::make_unexpected(ModbusExceptionCode::InvalidResponse); + } else { + result = std::move(res); + } + }); + io_context_.run(); + return result; +} + +auto FetchModbusTcp::sendRequestsAndReadResponses(utils::net::ConnectionHandlerBase& connection_handler, + const std::unordered_map<std::string, std::unique_ptr<ReadModbusFunction>>& address_map) -> asio::awaitable<nonstd::expected<core::Record, std::error_code>> { + core::Record result; + for (const auto& [variable, read_modbus_fn] : address_map) { + auto response = co_await sendRequestAndReadResponse(connection_handler, *read_modbus_fn); + if (!response) { + co_return nonstd::make_unexpected(response.error()); + } + result.emplace(variable, std::move(*response)); + } + co_return result; +} + + +auto FetchModbusTcp::sendRequestAndReadResponse(utils::net::ConnectionHandlerBase& connection_handler, + const ReadModbusFunction& read_modbus_function) -> asio::awaitable<nonstd::expected<core::RecordField, std::error_code>> { + std::string result; + if (auto connection_error = co_await connection_handler.setupUsableSocket(io_context_)) // NOLINT + co_return nonstd::make_unexpected(connection_error); Review Comment: Added some explanation in https://github.com/apache/nifi-minifi-cpp/pull/1779/commits/329f1bf27782636e5365ffb38beb1d0557808ba3#diff-9f8b9763f59e4bfc0ab6bfb37c88dbd4a441b99abc14682bc954309aa0c59551R228 -- This is an automated message from the Apache Git Service. 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