telemetry_streaming_service.hpp

/* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * Copyright (C) 2025 Marco Craveiro <marco.craveiro@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 3 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */
#ifndef ORES_COMMS_SERVICE_TELEMETRY_STREAMING_SERVICE_HPP
#define ORES_COMMS_SERVICE_TELEMETRY_STREAMING_SERVICE_HPP
 
#include <mutex>
#include <atomic>
#include <thread>
#include <chrono>
#include <string>
#include <vector>
#include <memory>
#include <condition_variable>
#include <boost/log/sinks/basic_sink_backend.hpp>
#include <boost/log/sinks/frontend_requirements.hpp>
#include <boost/log/core.hpp>
#include <boost/log/sinks/sync_frontend.hpp>
#include "ores.logging/make_logger.hpp"
#include "ores.telemetry/domain/log_record.hpp"
#include "ores.telemetry/domain/resource.hpp"
#include "ores.telemetry/log/telemetry_sink_backend.hpp"
 
namespace ores::comms::net {
class client;
}
 
namespace ores::comms::service {
 
struct telemetry_streaming_options {
    std::string source_name;
 
    std::string source_version;
 
    std::size_t batch_size = 50;
 
    std::chrono::seconds flush_interval{5};
 
    bool retry_on_failure = true;
 
    std::size_t max_pending_records = 1000;
};
 
class telemetry_streaming_service final {
private:
    inline static std::string_view logger_name =
        "ores.comms.service.telemetry_streaming";
 
    static auto& lg() {
        using namespace ores::logging;
        static auto instance = make_logger(logger_name);
        return instance;
    }
 
public:
    explicit telemetry_streaming_service(
        std::shared_ptr<net::client> client,
        telemetry_streaming_options options);
 
    ~telemetry_streaming_service();
 
    // Non-copyable, non-movable
    telemetry_streaming_service(const telemetry_streaming_service&) = delete;
    telemetry_streaming_service& operator=(const telemetry_streaming_service&) = delete;
    telemetry_streaming_service(telemetry_streaming_service&&) = delete;
    telemetry_streaming_service& operator=(telemetry_streaming_service&&) = delete;
 
    void start();
 
    void stop();
 
    [[nodiscard]] bool is_running() const noexcept;
 
    void flush();
 
    [[nodiscard]] std::size_t pending_count() const;
 
    [[nodiscard]] std::uint64_t total_sent() const noexcept;
 
    [[nodiscard]] std::uint64_t total_dropped() const noexcept;
 
private:
    void on_log_record(telemetry::domain::log_record record);
 
    void flush_thread_func();
 
    bool send_batch(std::vector<telemetry::domain::log_record>& records);
 
    std::shared_ptr<net::client> client_;
    telemetry_streaming_options options_;
    std::shared_ptr<telemetry::domain::resource> resource_;
 
    // Sink management
    using sink_t = boost::log::sinks::synchronous_sink<
        telemetry::log::telemetry_sink_backend>;
    boost::shared_ptr<sink_t> sink_;
 
    // Thread-safe record buffer
    mutable std::mutex buffer_mutex_;
    std::vector<telemetry::domain::log_record> buffer_;
    std::condition_variable flush_cv_;
 
    // Background flush thread
    std::thread flush_thread_;
    std::atomic<bool> running_{false};
 
    // Statistics
    std::atomic<std::uint64_t> total_sent_{0};
    std::atomic<std::uint64_t> total_dropped_{0};
};
 
}
 
#endif