storage.hh

#ifndef __VEREIGN_KVSTORE_STORAGE_HH
#define __VEREIGN_KVSTORE_STORAGE_HH

#include <vereign/bytes/buffer.hh>

namespace vereign::kvstore {

// The vereign RSA master key name.
constexpr const auto VereignKeyName = std::string_view{"vereign_key"};

/**
 * Key/value storage interface.
 */
class Storage {
public:
  /**
   * Locks the storage.
   *
   * The lock must be recursive, meaning that may be called multiple times.
   * Storage::Unlock must be called the same number of times the Storage::Lock was called.
   *
   * Use kvstore::Lock for lock guard and lock with retrials.
   *
   * @throws LockError when the lock is held by another process.
   */
  virtual void Lock() = 0;

  /**
   * Locks the storage.
   *
   * The lock must be recursive, meaning that may be called multiple times.
   * Storage::Unlock must be called the same number of times the Storage::Lock was called.
   *
   * Use kvstore::Lock for lock guard and lock with retrials.
   */
  virtual void Unlock() = 0;

  /**
   * Deletes all the values in the storage.
   */
  virtual void DeleteAll() = 0;

  /**
   * Store bytes value into the storage.
   *
   * @param key The key under which the value will be stored.
   * @param value The bytes that will be stored.
   */
  virtual void PutBytes(const std::string& key, bytes::View value) = 0;

  /**
   * Retrieve bytes value from the storage.
   *
   * @param key The key of the value that will be retrieved.
   * @param value Buffer where the value will be returned.
   *
   * @throws ValueNotFoundError when the key does not exist.
   */
  virtual void GetBytes(const std::string& key, bytes::Buffer& value) = 0;

  /**
   * Store int64_t value into the storage.
   *
   * @param key The key under which the value will be stored.
   * @param value The value that will be stored.
   */
  virtual void PutInt64(const std::string& key, int64_t value) = 0;

  /**
   * Retrieve int64_t value from the storage.
   *
   * @param key The key of the value that will be retrieved.
   * @param value Buffer where the value will be returned.
   *
   * @throws ValueNotFoundError when the key does not exist.
   */
  virtual auto GetInt64(const std::string& key) -> int64_t = 0;

  /**
   * Destroy and cleanup.
   */
  virtual ~Storage() = default;
};

} // namespace vereign::kvstore

#endif // __VEREIGN_KVSTORE_STORAGE_HH