file_backend.hpp

 
#pragma once
 
#include <chrono>
#include <string>
#include <string_view>
 
#include <rapidsmpf/bootstrap/backend.hpp>
#include <rapidsmpf/bootstrap/bootstrap.hpp>
 
namespace rapidsmpf::bootstrap::detail {
 
class FileBackend : public Backend {
  public:
    explicit FileBackend(Context ctx);
 
    ~FileBackend() override;
 
    void put(std::string const& key, std::string_view value) override;
 
    std::string get(std::string const& key, Duration timeout) override;
 
    void barrier() override;
 
    void sync() override;
 
  private:
    Context ctx_;
    std::string coord_dir_;
    std::string kv_dir_;
    std::string barrier_dir_;
    std::size_t barrier_count_{0};
 
    [[nodiscard]] std::string get_kv_path(std::string const& key) const;
 
    [[nodiscard]] std::string get_barrier_path(std::size_t barrier_id) const;
 
    [[nodiscard]] std::string get_rank_alive_path(Rank rank) const;
 
    bool wait_for_file(
        std::string const& path, Duration timeout = std::chrono::seconds{30}
    );
 
    void write_file(std::string const& path, std::string_view content);
 
    std::string read_file(std::string const& path);
 
    void cleanup_coordination_directory();
};
 
}  // namespace rapidsmpf::bootstrap::detail