sampler.hpp

#pragma once
 
#include <string>
#include <vector>
#include <fstream>
#include <filesystem>
#include <armadillo>
 
class Pipeline;
 
typedef const arma::vec& (Pipeline::*PropertyGetter)() const;
 
namespace details
{
 
struct PropertyToSample
{
    PropertyToSample(const std::string& label, PropertyGetter function):
        label(label),
        function(function)
    {}
 
    std::string label; 
    PropertyGetter function; 
};
 
}; // end namespace details
 
class Sampler
{
public:    
    Sampler(
            const std::filesystem::path& path,
            const arma::uword interval = 60,
            const bool append = false,
            const arma::uvec indicesToSample = {});
 
    void addPropertyToPrint(PropertyGetter samplingFunction);
 
    void addPropertyToPrint(PropertyGetter samplingFunction, const std::string& label);
 
    bool sample(const Pipeline& pipeline, const bool forceSample = false);
 
    const std::filesystem::path& outputDir() const { return m_outputDir; }
 
    static std::string getSampleLabel(PropertyGetter samplingFunction);
 
    static std::filesystem::path makeOutputDir(const std::filesystem::path& path);
 
    Sampler& setIndicesToSample(const arma::uvec& indices);
 
private:
    std::vector<std::ofstream> m_outputFiles;
    std::vector<details::PropertyToSample> m_samplers;
    const std::filesystem::path m_outputDir;
 
    arma::uword m_printInterval = 60;
    arma::uword m_timeOfLastPrint = 0;
    arma::uvec m_indicesToSample {};
 
    bool m_append;
};