src/bin/lttng-sessiond/trace-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_TRACE_CLASS_H
   9 #define LTTNG_TRACE_CLASS_H
  10
  11 #include "field.hpp"
  12
  13 #include <common/uuid.hpp>
  14
  15 namespace lttng {
  16 namespace sessiond {
  17 namespace trace {
  18
  19 class clock_class;
  20 class stream_class;
  21 class event_class;
  22 class trace_class_visitor;
  23 class trace_class_environment_visitor;
  24
  25 struct abi {
  26         unsigned int bits_per_long;
  27         unsigned int long_alignment;
  28         unsigned int uint8_t_alignment;
  29         unsigned int uint16_t_alignment;
  30         unsigned int uint32_t_alignment;
  31         unsigned int uint64_t_alignment;
  32         enum byte_order byte_order;
  33 };
  34
  35 template <class ValueType>
  36 class environment_field {
  37 public:
  38         environment_field(const char *in_name, const ValueType& in_value) :
  39                 name(in_name), value(in_value)
  40         {
  41         }
  42
  43         const char* const name;
  44         const ValueType& value;
  45 };
  46
  47 class trace_class {
  48 public:
  49
  50         virtual ~trace_class() = default;
  51
  52         /*
  53          * Derived classes must implement the _accept_on_*()
  54          * to continue the traversal to the trace class' children.
  55          */
  56         virtual void accept(trace_class_visitor& trace_class_visitor) const;
  57         virtual void accept(trace_class_environment_visitor& environment_visitor) const = 0;
  58         virtual const lttng::sessiond::trace::type *packet_header() const noexcept = 0;
  59
  60         const struct abi abi;
  61         const lttng_uuid uuid;
  62
  63 protected:
  64         trace_class(const struct abi& abi, const lttng_uuid& trace_uuid);
  65         virtual void _accept_on_clock_classes(trace_class_visitor& trace_class_visitor) const = 0;
  66         virtual void _accept_on_stream_classes(trace_class_visitor& trace_class_visitor) const = 0;
  67 };
  68
  69 class trace_class_environment_visitor {
  70 public:
  71         virtual ~trace_class_environment_visitor() = default;
  72
  73         virtual void visit(const environment_field<int64_t>& field) = 0;
  74         virtual void visit(const environment_field<const char *>& field) = 0;
  75         virtual void visit(const environment_field<std::string>& field);
  76 };
  77
  78 class trace_class_visitor {
  79 public:
  80         using cuptr = std::unique_ptr<trace_class_visitor>;
  81
  82         virtual ~trace_class_visitor() = default;
  83
  84         virtual void visit(const lttng::sessiond::trace::trace_class& trace_class) = 0;
  85         virtual void visit(const lttng::sessiond::trace::clock_class& clock_class) = 0;
  86         virtual void visit(const lttng::sessiond::trace::stream_class& stream_class) = 0;
  87         virtual void visit(const lttng::sessiond::trace::event_class& event_class) = 0;
  88 };
  89
  90 } /* namespace trace */
  91 } /* namespace sessiond */
  92 } /* namespace lttng */
  93
  94 #endif /* LTTNG_TRACE_CLASS_H */