Prometheus-specific metric representation. More...

#include <metric_exporters.h>

Collaboration diagram for kcenon::monitoring::prometheus_metric_data:

Public Member Functions
std::string	to_prometheus_text () const
	Convert to Prometheus text format.

Public Attributes
std::string	name

metric_type	type

double	value

std::chrono::system_clock::time_point	timestamp

std::unordered_map< std::string, std::string >	labels

std::string	help_text

Private Member Functions
std::string	escape_label_value (const std::string &label_value) const

Detailed Description

Prometheus-specific metric representation.

Definition at line 122 of file metric_exporters.h.

Member Function Documentation

◆ escape_label_value()

std::string kcenon::monitoring::prometheus_metric_data::escape_label_value ( const std::string & label_value ) const

inlineprivate

Definition at line 180 of file metric_exporters.h.

                                                                     {
        std::string escaped = label_value;
        // Escape backslashes, quotes, and newlines
        escaped = std::regex_replace(escaped, std::regex("\\\\"), "\\\\");
        escaped = std::regex_replace(escaped, std::regex("\""), "\\\"");
        escaped = std::regex_replace(escaped, std::regex("\n"), "\\n");
        return escaped;
    }

Referenced by to_prometheus_text().

Here is the caller graph for this function:

◆ to_prometheus_text()

std::string kcenon::monitoring::prometheus_metric_data::to_prometheus_text ( ) const

inline

Convert to Prometheus text format.

Definition at line 133 of file metric_exporters.h.

                                         {
        std::ostringstream ss;
        
        // Add HELP line
        if (!help_text.empty()) {
            ss << "# HELP " << name << " " << help_text << "\n";
        }
        
        // Add TYPE line
        std::string type_str;
        switch (type) {
            case metric_type::counter: type_str = "counter"; break;
            case metric_type::gauge: type_str = "gauge"; break;
            case metric_type::histogram: type_str = "histogram"; break;
            case metric_type::summary: type_str = "summary"; break;
            case metric_type::timer: type_str = "gauge"; break; // Timer as gauge in Prometheus
        }
        ss << "# TYPE " << name << " " << type_str << "\n";
        
        // Add metric line
        ss << name;
        
        if (!labels.empty()) {
            ss << "{";
            bool first = true;
            for (const auto& [key, label_value] : labels) {
                if (!first) ss << ",";
                ss << key << "=\"" << escape_label_value(label_value) << "\"";
                first = false;
            }
            ss << "}";
        }
        
        ss << " " << value;
        
        // Add timestamp if available
        if (timestamp != std::chrono::system_clock::time_point{}) {
            auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(
                timestamp.time_since_epoch()).count();
            ss << " " << ms;
        }
        
        ss << "\n";
        return ss.str();
    }