notifications_interface.h raw

   1  // Copyright (c) 2023-present The Bitcoin Core developers
   2  // Distributed under the MIT software license, see the accompanying
   3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4  
   5  #ifndef BITCOIN_KERNEL_NOTIFICATIONS_INTERFACE_H
   6  #define BITCOIN_KERNEL_NOTIFICATIONS_INTERFACE_H
   7  
   8  #include <cstdint>
   9  #include <variant>
  10  
  11  class CBlockIndex;
  12  enum class SynchronizationState;
  13  struct bilingual_str;
  14  
  15  namespace kernel {
  16  
  17  //! Result type for use with std::variant to indicate that an operation should be interrupted.
  18  struct Interrupted{};
  19  enum class Warning;
  20  
  21  
  22  //! Simple result type for functions that need to propagate an interrupt status and don't have other return values.
  23  using InterruptResult = std::variant<std::monostate, Interrupted>;
  24  
  25  template <typename T>
  26  bool IsInterrupted(const T& result)
  27  {
  28      return std::holds_alternative<kernel::Interrupted>(result);
  29  }
  30  
  31  /**
  32   * A base class defining functions for notifying about certain kernel
  33   * events.
  34   */
  35  class Notifications
  36  {
  37  public:
  38      virtual ~Notifications() = default;
  39  
  40      [[nodiscard]] virtual InterruptResult blockTip(SynchronizationState state, const CBlockIndex& index, double verification_progress) { return {}; }
  41      virtual void headerTip(SynchronizationState state, int64_t height, int64_t timestamp, bool presync) {}
  42      virtual void progress(const bilingual_str& title, int progress_percent, bool resume_possible) {}
  43      virtual void warningSet(Warning id, const bilingual_str& message) {}
  44      virtual void warningUnset(Warning id) {}
  45  
  46      //! The flush error notification is sent to notify the user that an error
  47      //! occurred while flushing block data to disk. Kernel code may ignore flush
  48      //! errors that don't affect the immediate operation it is trying to
  49      //! perform. Applications can choose to handle the flush error notification
  50      //! by logging the error, or notifying the user, or triggering an early
  51      //! shutdown as a precaution against causing more errors.
  52      virtual void flushError(const bilingual_str& message) {}
  53  
  54      //! The fatal error notification is sent to notify the user when an error
  55      //! occurs in kernel code that can't be recovered from. After this
  56      //! notification is sent, whatever function triggered the error should also
  57      //! return an error code or raise an exception. Applications can choose to
  58      //! handle the fatal error notification by logging the error, or notifying
  59      //! the user, or triggering an early shutdown as a precaution against
  60      //! causing more errors.
  61      virtual void fatalError(const bilingual_str& message) {}
  62  };
  63  } // namespace kernel
  64  
  65  #endif // BITCOIN_KERNEL_NOTIFICATIONS_INTERFACE_H
  66