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         stream_class(const stream_class&) = delete;
  34         stream_class(stream_class&&) = delete;
  35         stream_class& operator=(stream_class&&) = delete;
  36         stream_class& operator=(const stream_class&) = delete;
  37
  38         virtual const type* packet_context() const;
  39         virtual const type* event_header() const;
  40         virtual const type* event_context() const;
  41
  42         const unsigned int id;
  43         /*
  44          * header_type is suffixed with '_' to work-around a bug in older
  45          * GCCs (before 6) that do not recognize hidden/shadowed enumeration as valid
  46          * nested-name-specifiers.
  47          */
  48         const header_type header_type_;
  49         const nonstd::optional<std::string> default_clock_class_name;
  50
  51 protected:
  52         stream_class(unsigned int id,
  53                         enum header_type header_type,
  54                         nonstd::optional<std::string> default_clock_class_name = nonstd::nullopt);
  55         virtual void _accept_on_event_classes(trace_class_visitor& trace_class_visitor) const = 0;
  56
  57         lttng::sessiond::trace::type::cuptr _packet_context;
  58         lttng::sessiond::trace::type::cuptr _event_header;
  59         lttng::sessiond::trace::type::cuptr _event_context;
  60 };
  61
  62 } /* namespace trace */
  63 } /* namespace sessiond */
  64 } /* namespace lttng */
  65
  66 #endif /* LTTNG_STREAM_CLASS_H */