src/bin/lttng-sessiond/stream-class.hpp

   1 /*
   2  * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #ifndef LTTNG_STREAM_CLASS_H
   9 #define LTTNG_STREAM_CLASS_H
  10
  11 #include "field.hpp"
  12
  13 #include <vendor/optional.hpp>
  14
  15 #include <vector>
  16
  17 namespace lttng {
  18 namespace sessiond {
  19 namespace trace {
  20
  21 class trace_class_visitor;
  22
  23 class stream_class {
  24 public:
  25         enum class header_type { COMPACT, LARGE };
  26
  27         /*
  28          * Derived classes must implement _accept_on_event_classes()
  29          * to continue the traversal to the stream class' event classes.
  30          */
  31         void accept(trace_class_visitor& visitor) const;
  32         virtual ~stream_class() = default;
  33
  34         virtual const type* get_packet_context() const;
  35         virtual const type* get_event_header() const;
  36         virtual const type* get_event_context() const;
  37
  38         const unsigned int id;
  39         /*
  40          * header_type is suffixed with '_' to work-around a bug in older
  41          * GCCs (before 6) that do not recognize hidden/shadowed enumeration as valid
  42          * nested-name-specifiers.
  43          */
  44         const header_type header_type_;
  45         const nonstd::optional<std::string> default_clock_class_name;
  46
  47 protected:
  48         stream_class(unsigned int id,
  49                         enum header_type header_type,
  50                         nonstd::optional<std::string> default_clock_class_name = nonstd::nullopt);
  51         virtual void _accept_on_event_classes(trace_class_visitor& trace_class_visitor) const = 0;
  52
  53         lttng::sessiond::trace::type::cuptr _packet_context;
  54         lttng::sessiond::trace::type::cuptr _event_header;
  55         lttng::sessiond::trace::type::cuptr _event_context;
  56 };
  57
  58 } /* namespace trace */
  59 } /* namespace sessiond */
  60 } /* namespace lttng */
  61
  62 #endif /* LTTNG_STREAM_CLASS_H */