health_checker.h

Go to the documentation of this file.

// BSD 3-Clause License
// Copyright (c) 2021-2025, 🍀☀🌕🌥 🌊
// See the LICENSE file in the project root for full license information.
 
#pragma once
 
#include "health_status.h"
 
#include <chrono>
#include <functional>
#include <memory>
#include <mutex>
#include <shared_mutex>
#include <string>
#include <string_view>
#include <unordered_map>
 
namespace kcenon::pacs::storage {
// Forward declarations
class index_database;
class file_storage;
}  // namespace kcenon::pacs::storage
 
namespace kcenon::pacs::monitoring {
 
struct health_checker_config {
    std::chrono::seconds check_interval{30};
 
    std::chrono::milliseconds database_timeout{5000};
 
    std::chrono::milliseconds storage_timeout{5000};
 
    double storage_warning_threshold{80.0};
 
    double storage_critical_threshold{95.0};
 
    std::chrono::seconds cache_duration{5};
 
    bool background_checks_enabled{false};
};
 
class health_checker {
public:
    // =========================================================================
    // Type Aliases
    // =========================================================================
 
    using check_callback = std::function<bool(std::string& error_message)>;
 
    // =========================================================================
    // Construction
    // =========================================================================
 
    health_checker();
 
    explicit health_checker(const health_checker_config& config);
 
    ~health_checker();
 
    health_checker(const health_checker&) = delete;
    health_checker& operator=(const health_checker&) = delete;
 
    health_checker(health_checker&& other) noexcept;
    health_checker& operator=(health_checker&& other) noexcept;
 
    // =========================================================================
    // Component Registration
    // =========================================================================
 
    void set_database(kcenon::pacs::storage::index_database* database);
 
    void set_storage(kcenon::pacs::storage::file_storage* storage);
 
    void register_check(std::string_view name, check_callback callback);
 
    void unregister_check(std::string_view name);
 
    // =========================================================================
    // Health Check Operations
    // =========================================================================
 
    [[nodiscard]] health_status check();
 
    [[nodiscard]] bool is_alive() const noexcept;
 
    [[nodiscard]] bool is_ready();
 
    [[nodiscard]] health_status get_cached_status() const;
 
    [[nodiscard]] health_status get_status();
 
    // =========================================================================
    // Metrics Access
    // =========================================================================
 
    void update_association_metrics(std::uint32_t active,
                                    std::uint32_t max,
                                    std::uint64_t total_established,
                                    std::uint64_t total_failed);
 
    void update_storage_metrics(std::uint64_t instances,
                                std::uint64_t studies,
                                std::uint64_t series,
                                std::uint64_t successful_stores,
                                std::uint64_t failed_stores);
 
    void set_version(std::uint16_t major,
                     std::uint16_t minor,
                     std::uint16_t patch,
                     std::string_view build_id = "");
 
    // =========================================================================
    // Configuration
    // =========================================================================
 
    [[nodiscard]] const health_checker_config& config() const noexcept;
 
    void set_config(const health_checker_config& config);
 
private:
    // =========================================================================
    // Internal Check Methods
    // =========================================================================
 
    void check_database(health_status& status);
 
    void check_storage(health_status& status);
 
    void run_custom_checks(health_status& status);
 
    // =========================================================================
    // Member Variables
    // =========================================================================
 
    health_checker_config config_;
 
    kcenon::pacs::storage::index_database* database_{nullptr};
 
    kcenon::pacs::storage::file_storage* storage_{nullptr};
 
    std::unordered_map<std::string, check_callback> custom_checks_;
 
    health_status cached_status_;
 
    std::chrono::system_clock::time_point last_check_time_;
 
    association_metrics associations_;
 
    storage_metrics storage_metrics_;
 
    version_info version_;
 
    mutable std::shared_mutex mutex_;
};
 
}  // namespace kcenon::pacs::monitoring