src/clock-correlation-validator/clock-correlation-validator.hpp

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2024 EfficiOS, Inc.
   5  */
   6
   7 #ifndef CLOCK_CORRELATION_VALIDATOR_CLOCK_CORRELATION_VALIDATOR_HPP
   8 #define CLOCK_CORRELATION_VALIDATOR_CLOCK_CORRELATION_VALIDATOR_HPP
   9
  10 #include "cpp-common/bt2/message.hpp"
  11
  12 #include "clock-correlation-validator/clock-correlation-validator.h"
  13
  14 namespace bt2ccv {
  15
  16 class ClockCorrelationError final : public std::runtime_error
  17 {
  18 public:
  19     enum class Type
  20     {
  21         ExpectingNoClockClassGotOne =
  22             BT_CLOCK_CORRELATION_VALIDATOR_ERROR_TYPE_EXPECTING_NO_CLOCK_CLASS_GOT_ONE,
  23         ExpectingOriginUnixGotNone =
  24             BT_CLOCK_CORRELATION_VALIDATOR_ERROR_TYPE_EXPECTING_ORIGIN_UNIX_GOT_NONE,
  25         ExpectingOriginUnixGotOther =
  26             BT_CLOCK_CORRELATION_VALIDATOR_ERROR_TYPE_EXPECTING_ORIGIN_UNIX_GOT_OTHER,
  27         ExpectingOriginUuidGotNone =
  28             BT_CLOCK_CORRELATION_VALIDATOR_ERROR_TYPE_EXPECTING_ORIGIN_UUID_GOT_NONE,
  29         ExpectingOriginUuidGotUnix =
  30             BT_CLOCK_CORRELATION_VALIDATOR_ERROR_TYPE_EXPECTING_ORIGIN_UUID_GOT_UNIX,
  31         ExpectingOriginUuidGotNoUuid =
  32             BT_CLOCK_CORRELATION_VALIDATOR_ERROR_TYPE_EXPECTING_ORIGIN_UUID_GOT_NO_UUID,
  33         ExpectingOriginUuidGotOtherUuid =
  34             BT_CLOCK_CORRELATION_VALIDATOR_ERROR_TYPE_EXPECTING_ORIGIN_UUID_GOT_OTHER_UUID,
  35         ExpectingOriginNoUuidGotNone =
  36             BT_CLOCK_CORRELATION_VALIDATOR_ERROR_TYPE_EXPECTING_ORIGIN_NO_UUID_GOT_NONE,
  37         ExpectingOriginNoUuidGotOther =
  38             BT_CLOCK_CORRELATION_VALIDATOR_ERROR_TYPE_EXPECTING_ORIGIN_NO_UUID_GOT_OTHER,
  39     };
  40
  41     explicit ClockCorrelationError(
  42         Type type, const bt2s::optional<bt2c::UuidView> expectedUuid,
  43         const bt2::OptionalBorrowedObject<bt2::ConstClockClass> actualClockCls,
  44         const bt2::OptionalBorrowedObject<bt2::ConstClockClass> expectedClockCls,
  45         const bt2::OptionalBorrowedObject<bt2::ConstStreamClass> streamCls) noexcept :
  46         std::runtime_error {"Clock classes are not correlatable"},
  47         _mType {type}, _mExpectedUuid {expectedUuid}, _mActualClockCls {actualClockCls},
  48         _mExpectedClockCls {expectedClockCls}, _mStreamCls {streamCls}
  49
  50     {
  51     }
  52
  53     Type type() const noexcept
  54     {
  55         return _mType;
  56     }
  57
  58     bt2s::optional<bt2c::UuidView> expectedUuid() const noexcept
  59     {
  60         return _mExpectedUuid;
  61     }
  62
  63     bt2::OptionalBorrowedObject<bt2::ConstClockClass> actualClockCls() const noexcept
  64     {
  65         return _mActualClockCls;
  66     }
  67
  68     bt2::OptionalBorrowedObject<bt2::ConstClockClass> expectedClockCls() const noexcept
  69     {
  70         return _mExpectedClockCls;
  71     }
  72
  73     bt2::OptionalBorrowedObject<bt2::ConstStreamClass> streamCls() const noexcept
  74     {
  75         return _mStreamCls;
  76     }
  77
  78 private:
  79     Type _mType;
  80     bt2s::optional<bt2c::UuidView> _mExpectedUuid;
  81     bt2::OptionalBorrowedObject<bt2::ConstClockClass> _mActualClockCls;
  82     bt2::OptionalBorrowedObject<bt2::ConstClockClass> _mExpectedClockCls;
  83     bt2::OptionalBorrowedObject<bt2::ConstStreamClass> _mStreamCls;
  84 };
  85
  86 class ClockCorrelationValidator final
  87 {
  88 private:
  89     enum class PropsExpectation
  90     {
  91         /* We haven't recorded clock properties yet. */
  92         Unset,
  93
  94         /* Expect to have no clock. */
  95         None,
  96
  97         /* Expect a clock with a Unix epoch origin. */
  98         OriginUnix,
  99
 100         /* Expect a clock without a Unix epoch origin, but with a UUID. */
 101         OriginOtherUuid,
 102
 103         /* Expect a clock without a Unix epoch origin and without a UUID. */
 104         OriginOtherNoUuid,
 105     };
 106
 107 public:
 108     void validate(const bt2::ConstMessage msg)
 109     {
 110         if (!msg.isStreamBeginning() && !msg.isMessageIteratorInactivity()) {
 111             return;
 112         }
 113
 114         this->_validate(msg);
 115     }
 116
 117 private:
 118     void _validate(const bt2::ConstMessage msg);
 119
 120     PropsExpectation _mExpectation = PropsExpectation::Unset;
 121
 122     /*
 123      * Expected UUID of the clock, if `_mExpectation` is
 124      * `PropsExpectation::ORIGIN_OTHER_UUID`.
 125      *
 126      * If the origin of the clock is the Unix epoch, then the UUID is
 127      * irrelevant because the clock will have a correlation with other
 128      * clocks having the same origin.
 129      */
 130     bt2c::Uuid _mUuid;
 131
 132     /*
 133      * Expected clock class, if `_mExpectation` is
 134      * `ClockExpectation::ORIGIN_OTHER_NO_UUID`.
 135      *
 136      * If the first analyzed clock class has an unknown origin and no
 137      * UUID, then all subsequent analyzed clock classes must be the same
 138      * instance.
 139      *
 140      * To make sure that the clock class pointed to by this member
 141      * doesn't get freed and another one reallocated at the same
 142      * address, which could potentially bypass the clock expectation
 143      * check, we keep a strong reference, ensuring that the clock class
 144      * lives at least as long as the owner of this validator.
 145      */
 146     bt2::ConstClockClass::Shared _mClockClass;
 147 };
 148
 149 } /* namespace bt2ccv */
 150
 151 #endif /* CLOCK_CORRELATION_VALIDATOR_CLOCK_CORRELATION_VALIDATOR_HPP */