allwpilib/src/Storage.h

/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
/* Open Source Software - may be modified and shared by FRC teams. The code   */
/* must be accompanied by the FIRST BSD license file in the root directory of */
/* the project.                                                               */
/*----------------------------------------------------------------------------*/

#ifndef NT_STORAGE_H_
#define NT_STORAGE_H_

#include <iosfwd>
#include <cstddef>

#include "ntcore.h"

#include "llvm/StringMap.h"

namespace ntimpl {

inline llvm::StringRef MakeStringRef(const NT_String& str) {
  return llvm::StringRef(str.str, str.len);
}

class StorageEntry {
 public:
  StorageEntry() {
    NT_InitValue(&value);
    flags = 0;
  }
  ~StorageEntry() { NT_DisposeValue(&value); }

  NT_Value value;
  unsigned int flags;

  StorageEntry(const StorageEntry&) = delete;
  StorageEntry& operator=(const StorageEntry&) = delete;
};

class Storage {
 public:
  static Storage& GetInstance() {
    if (!m_instance) m_instance = new Storage;
    return *m_instance;
  }

  typedef llvm::StringMap<StorageEntry> EntriesMap;

  EntriesMap& entries() { return m_entries; }
  const EntriesMap& entries() const { return m_entries; }

  void SavePersistent(std::ostream& os) const;
  void LoadPersistent(std::istream& is,
                      void (*warn)(std::size_t line, const char* msg));

 private:
  Storage();
  ~Storage();
  Storage(const Storage&) = delete;
  Storage& operator=(const Storage&) = delete;

  EntriesMap m_entries;

  static Storage* m_instance;
};

}  // namespace ntimpl

#endif  // NT_STORAGE_H_