InputFileCatalog.h

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#ifndef art_Framework_IO_Catalog_InputFileCatalog_h
#define art_Framework_IO_Catalog_InputFileCatalog_h

// ======================================================================
//
// Class InputFileCatalog. Services to manage InputFile catalog
//
// ======================================================================

#include "art/Framework/IO/Catalog/FileCatalog.h"
#include "art/Framework/Services/FileServiceInterfaces/CatalogInterface.h"
#include "art/Framework/Services/FileServiceInterfaces/FileTransfer.h"
#include "art/Framework/Services/Registry/ServiceHandle.h"
#include "fhiclcpp/types/Sequence.h"
#include "fhiclcpp/types/TableFragment.h"

#include <string>
#include <vector>

// ----------------------------------------------------------------------

namespace art {
  enum class FileCatalogStatus {
    SUCCESS,
    NO_MORE_FILES,
    DELIVERY_ERROR,
    TRANSFER_ERROR
  };

  class InputFileCatalog : public FileCatalog {
  public:
    struct Config {
      fhicl::Sequence<std::string> namesParameter{fhicl::Name("fileNames")};
    };

    explicit InputFileCatalog(fhicl::TableFragment<Config> const& config);
    virtual ~InputFileCatalog() = default;
    std::size_t
    size() const noexcept
    {
      return fileCatalogItems_.size();
    }
    FileCatalogItem const& currentFile() const;
    size_t currentIndex() const noexcept;
    bool getNextFile(int attempts = 5);
    bool hasNextFile(int attempts = 5);
    void rewind();
    void rewindTo(size_t index);
    bool
    isSearchable() const noexcept
    {
      return searchable_;
    }
    bool
    empty() const noexcept
    {
      return fileCatalogItems_.empty();
    }
    void finish(); // Dispose of the current file.
    std::vector<std::string> const&
    fileSources() const noexcept
    {
      return fileSources_;
    }

    static constexpr size_t indexEnd{std::numeric_limits<size_t>::max()};

  private:
    bool retrieveNextFile(FileCatalogItem& item,
                          int attempts,
                          bool transferOnly = false);
    FileCatalogStatus retrieveNextFileFromCacheOrService(FileCatalogItem& item);
    FileCatalogStatus transferNextFile(FileCatalogItem& item);

    std::vector<std::string> fileSources_;
    std::vector<FileCatalogItem> fileCatalogItems_{{}}; // seed with one item
    FileCatalogItem nextItem_{};
    size_t fileIdx_{indexEnd};
    size_t maxIdx_{};
    bool searchable_{false}; // update value after the service gets configured
    bool nextFileProbed_{false};
    bool hasNextFile_{false};

    ServiceHandle<CatalogInterface> ci_;
    ServiceHandle<FileTransfer> ft_;
  }; // InputFileCatalog

} // namespace art

// ======================================================================

#endif /* art_Framework_IO_Catalog_InputFileCatalog_h */

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