ceph/src/common/subsys_types.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2018 Red Hat Inc.
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15 #ifndef CEPH_SUBSYS_TYPES_H
  16 #define CEPH_SUBSYS_TYPES_H
  17
  18 #include <algorithm>
  19 #include <array>
  20
  21 enum ceph_subsys_id_t {
  22   ceph_subsys_,   // default
  23 #define SUBSYS(name, log, gather) \
  24   ceph_subsys_##name,
  25 #define DEFAULT_SUBSYS(log, gather)
  26 #include "common/subsys.h"
  27 #undef SUBSYS
  28 #undef DEFAULT_SUBSYS
  29   ceph_subsys_max
  30 };
  31
  32 constexpr static std::size_t ceph_subsys_get_num() {
  33   return static_cast<std::size_t>(ceph_subsys_max);
  34 }
  35
  36 struct ceph_subsys_item_t {
  37   const char* name;
  38   uint8_t log_level;
  39   uint8_t gather_level;
  40 };
  41
  42 constexpr static std::array<ceph_subsys_item_t, ceph_subsys_get_num()>
  43 ceph_subsys_get_as_array() {
  44 #define SUBSYS(name, log, gather) \
  45   ceph_subsys_item_t{ #name, log, gather },
  46 #define DEFAULT_SUBSYS(log, gather) \
  47   ceph_subsys_item_t{ "none", log, gather },
  48
  49   return {
  50 #include "common/subsys.h"
  51   };
  52 #undef SUBSYS
  53 #undef DEFAULT_SUBSYS
  54 }
  55
  56 constexpr static std::uint8_t
  57 ceph_subsys_get_max_default_level(const std::size_t subidx) {
  58   const auto item = ceph_subsys_get_as_array()[subidx];
  59   return std::max(item.log_level, item.gather_level);
  60 }
  61
  62 // Compile time-capable version of std::strlen. Resorting to own
  63 // implementation only because C++17 doesn't mandate constexpr
  64 // on the standard one.
  65 constexpr static std::size_t strlen_ct(const char* const s) {
  66   std::size_t l = 0;
  67   while (s[l] != '\0') {
  68     ++l;
  69   }
  70   return l;
  71 }
  72
  73 constexpr static std::size_t ceph_subsys_max_name_length() {
  74   return std::max({
  75 #define SUBSYS(name, log, gather) \
  76   strlen_ct(#name),
  77 #define DEFAULT_SUBSYS(log, gather) \
  78   strlen_ct("none"),
  79 #include "common/subsys.h"
  80 #undef SUBSYS
  81 #undef DEFAULT_SUBSYS
  82   });
  83 }
  84
  85 #endif // CEPH_SUBSYS_TYPES_H
  86