backend.hpp

#pragma once
 
#include "imports.h"
#include "memory.hpp"
 
namespace cppgres {
 
enum q { backend };
 
namespace backend_type {
 
enum type {
  invalid = B_INVALID,
  backend = B_BACKEND,
  autovac_launcher = B_AUTOVAC_LAUNCHER,
  autovac_worker = B_AUTOVAC_WORKER,
  bg_worker = B_BG_WORKER,
  wal_sender = B_WAL_SENDER,
#if PG_MAJORVERSION_NUM >= 17
  slotsync_worker = B_SLOTSYNC_WORKER,
  standalone_backend = B_STANDALONE_BACKEND,
#endif
  archiver = B_ARCHIVER,
  bg_writer = B_BG_WRITER,
  checkpointer = B_CHECKPOINTER,
  startup = B_STARTUP,
  wal_receiver = B_WAL_RECEIVER,
#if PG_MAJORVERSION_NUM >= 17
  wal_summarizer = B_WAL_SUMMARIZER,
#endif
  wal_writer = B_WAL_WRITER,
  logger = B_LOGGER
};
}
 
struct backend {
  static backend_type::type type() { return static_cast<backend_type::type>(::MyBackendType); };
 
  template <typename T> requires requires(T t, int code) {
    { t(code) };
  }
  static void atexit(T &&func) {
    T *raw_mem = top_memory_context().alloc<T>();
    T *allocation = new (raw_mem) T(std::forward<T>(func));
 
    ffi_guard{::on_proc_exit}(
        [](int code, ::Datum datum) {
          T *func = reinterpret_cast<T *>(DatumGetPointer(datum));
          (*func)(code);
        },
        PointerGetDatum(allocation));
  }
};
 
} // namespace cppgres