NexusDescriptorLazy.h

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// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2007 ISIS Rutherford Appleton Laboratory UKRI,
//   NScD Oak Ridge National Laboratory, European Spallation Source,
//   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
// SPDX - License - Identifier: GPL - 3.0 +
#pragma once
 
#include "MantidNexus/DllConfig.h"
#include "MantidNexus/UniqueID.h"
 
#include <concepts>
#include <map>
#include <shared_mutex>
#include <string>
#include <unordered_set>
#include <variant>
#include <vector>
 
namespace Mantid {
namespace Nexus {
 
template <typename T>
concept entryTypes = std::integral<T> || std::floating_point<T> || std::same_as<T, std::string>;
 
class MANTID_NEXUS_DLL NexusDescriptorLazy {
 
public:
  enum class CacheReturnStatus_t {
    NXFOUND,
    NXCACHED,
    NXNOT_DATASET,
    NXDATASET_NOT_FOUND,
    NXWRONG_TYPE,
    NXERROR,
    NXUNSET,
  };
 
  using CacheValue_t = std::variant<float, double, int8_t, uint8_t, int16_t, uint16_t, int32_t, uint32_t, int64_t,
                                    uint64_t, std::string, CacheReturnStatus_t>;
 
  NexusDescriptorLazy(std::string const &filename);
 
  NexusDescriptorLazy() = delete;
 
  // there is no reason to copy this object
  NexusDescriptorLazy &operator=(NexusDescriptorLazy const &nd) = delete;
  NexusDescriptorLazy(NexusDescriptorLazy const &nd) = delete;
  // there is no reason to move this object
  NexusDescriptorLazy &operator=(NexusDescriptorLazy &&nd) = delete;
  NexusDescriptorLazy(NexusDescriptorLazy &&nd) = delete;
 
  ~NexusDescriptorLazy() = default;
 
  inline std::string const &filename() const noexcept { return m_filename; }
 
  inline std::string const &extension() const noexcept { return m_extension; }
 
  std::pair<std::string, std::string> const &firstEntryNameType() const noexcept { return m_firstEntryNameType; };
 
  bool hasRootAttr(std::string const &name) const;
 
  std::map<std::string, std::string> const &getAllEntries() const noexcept { return m_allEntries; }
 
  bool isEntry(std::string const &entryName, std::string const &groupClass) const {
    if (isEntry(entryName)) {
      return m_allEntries.at(entryName) == groupClass;
    } else {
      return false;
    }
  }
 
  bool isEntry(std::string const &entryName) const;
 
  template <typename T>
  std::pair<T, NexusDescriptorLazy::CacheReturnStatus_t> getDataValue(const std::string &datasetAddress) const;
 
  bool classTypeExists(std::string const &classType) const;
 
  bool classTypeExistsChild(const std::string &parentPath, const std::string &classType) const;
 
  std::string getStrData(std::string const &address);
 
private:
  std::map<std::string, std::string> initAllEntries();
  void loadGroups(std::map<std::string, std::string> &allEntries, std::string const &address, unsigned int depth,
                  const unsigned int maxDepth);
 
  const CacheValue_t _getDataValue(const std::string &datasetAddress) const;
 
  std::string const m_filename;
  std::string const m_extension;
  UniqueID<&H5Fclose> m_fileID;
 
  mutable std::unordered_set<std::string> m_rootAttrs;
 
  std::pair<std::string, std::string> m_firstEntryNameType;
 
  mutable std::map<std::string, std::string> m_allEntries;
 
  mutable std::shared_mutex m_readNexusMutex;
 
  mutable std::unordered_set<std::string> m_allMisses;
 
  mutable std::map<std::string, CacheValue_t> m_readEntries;
};
 
} // namespace Nexus
} // namespace Mantid