sourceResolver.hpp

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/**
 * @file
 * @ingroup daq_dpm_libmerge
 * @copyright (c) Copyright ESO 2022
 * All Rights Reserved
 * ESO (eso.org) is an Intergovernmental Organisation, and therefore special legal conditions apply.
 *
 * @brief Declares daq::dpm::SourceResolver.
 */
#ifndef DAQ_DPM_SOURCERESOLVER_HPP
#define DAQ_DPM_SOURCERESOLVER_HPP
 
#include <filesystem>
#include <map>
 
#include <fmt/ostream.h>
#include <nlohmann/json.hpp>
 
namespace daq::dpm {
 
class SourceNotFound : public std::invalid_argument {
    using std::invalid_argument::invalid_argument;
};
 
/**
 * Provides location of fits source file.
 */
class SourceResolver {
public:
    struct SourceFile {
        /**
         * Named by user
         */
        std::string source_name;
        /**
         * [user@]host:/path/
         */
        std::string location;
 
        friend bool operator==(SourceFile const& lhs, SourceFile const& rhs) noexcept {
            return lhs.source_name == rhs.source_name && lhs.location == rhs.location;
        }
        friend bool operator<(SourceFile const& lhs, SourceFile const& rhs) noexcept {
            return lhs.source_name < rhs.source_name ||
                   (lhs.source_name == rhs.source_name && lhs.location < rhs.location);
        }
        friend std::ostream& operator<<(std::ostream& os, SourceFile const& source);
    };
    using Mapping = std::map<SourceFile, std::string>;
    /**
     * Initialize resolver with no content.
     */
    SourceResolver() = default;
    explicit SourceResolver(Mapping mapping);
 
    /**
     * Adds @c path so it is resolved using @c source_name and @c location
     *
     * @param source Source file.
     * @param path Local path to a file @a source_name and @a source will be resolved to.
     */
    void Add(SourceFile const& source, std::filesystem::path const& path);
 
    /**
     * Resolves local file that was previously added with @a Add().
     *
     * @param source Source file.
     * @return Local path to a file @a source_name and @a source resolved to.
     * @throw SourceNotFound if source cannot be resolved.
     */
    auto Resolve(SourceFile const& source) const -> std::filesystem::path;
 
    /**
     * Get native representation of source mapping for serialization.
     */
    auto GetMapping() const noexcept -> Mapping const&;
    void SetMapping(Mapping mapping) noexcept;
 
private:
    Mapping m_mapping;
};
 
// NOLINTNEXTLINE
void to_json(nlohmann::json& j, SourceResolver::Mapping const& p);
// NOLINTNEXTLINE
void from_json(nlohmann::json const& j, SourceResolver::Mapping& p);
 
}  // namespace daq::dpm
 
template <>
struct fmt::formatter<daq::dpm::SourceResolver::SourceFile> : ostream_formatter {};
 
#endif  // DAQ_DPM_SOURCERESOLVER_HPP