flow::perf::Duration_set Struct Reference

Convenience wrapper around an array<Duration, N>, which stores a duration for each of the N possible clock types in perf::Clock_type. More...

#include <clock_type_fwd.hpp>

Collaboration diagram for flow::perf::Duration_set:

Public Attributes
std::array< Duration, size_t(Clock_type::S_END_SENTINEL)>	m_values
	The underlying data, directly readable and writable by user. NOT ZERO-INITIALIZED ON CONSTRUCTION (or ever). More...

Related Functions
(Note that these are not member functions.)
std::ostream &	operator<< (std::ostream &os, const Duration_set &duration_set)
	Prints string representation of the given Duration_set value to the given ostream. More...
Duration_set &	operator+= (Duration_set &target, const Duration_set &to_add)
	Advances each Duration in the target Duration_set by the given respective addend Durations (negative Duration causes advancing backwards). More...
Duration_set &	operator*= (Duration_set &target, uint64_t mult_scale)
	Scales each Duration in the target Duration_set by the given numerical constant. More...
Duration_set &	operator/= (Duration_set &target, uint64_t div_scale)
	Divides each Duration in the target Duration_set by the given numerical constant. More...

Detailed Description

Convenience wrapper around an array<Duration, N>, which stores a duration for each of the N possible clock types in perf::Clock_type.

It is a completely tight wrapper, not even adding zeroing of the array values on construction. It only adds convenience operations (possibly as free functions), namely some common math (such as scaling all N values by some numeric factor) and stream I/O.

Design rationale

Performance is absolutely key, so this is to be identical to the underlying (and publicly accessible) array in terms of data storage and operations. I wrote this struct to avoid overloading things like operator-(a, b) and operator<<(ostream&, x), when the underlying type of a, b,xis a standardarray`: we don't want to overload such operations on a general type, even if it's only in our namespace. Historically, the first cut simply made non-operator-overload free function versions of such things operating directly on the arrays.

Definition at line 185 of file clock_type_fwd.hpp.

Friends And Related Function Documentation

operator*=()

Duration_set & operator*= ( Duration_set &  target, uint64_t  mult_scale  )

related

Scales each Duration in the target Duration_set by the given numerical constant.

Note

If you plan to use division as well, always first multiply, then divide, to avoid rounding errors (assuming overflow is not a possibility).

Todo:

Maybe allow operator*=(Duration_set) by a potentially negative number; same for division.

Parameters

target	The set of Durations each of which may be modified.
mult_scale	Constant by which to multiply each target Duration.

Returns

Reference to mutable target to enable standard *= semantics.

Definition at line 58 of file clock_type.cpp.

References m_values.

operator+=()

Duration_set & operator+= ( Duration_set &  target, const Duration_set &  to_add  )

related

Advances each Duration in the target Duration_set by the given respective addend Durations (negative Duration causes advancing backwards).

Parameters

target	The set of Durations each of which may be modified.
to_add	The set of Durations each of which is added to a target Duration.

Returns

Reference to mutable target to enable standard += semantics.

Definition at line 38 of file clock_type.cpp.

References m_values.

operator/=()

Duration_set & operator/= ( Duration_set &  target, uint64_t  div_scale  )

related

Divides each Duration in the target Duration_set by the given numerical constant.

Note

If you plan to user multiplication as well, always first multiply, then divide, to avoid rounding errors (and assuming overflow is not a possibility).

Parameters

target	The set of Durations each of which may be modified.
div_scale	Constant by which to divide each target Duration.

Returns

Reference to mutable target to enable standard /= semantics.

Definition at line 68 of file clock_type.cpp.

References m_values.

operator<<()

std::ostream & operator<< ( std::ostream &  os, const Duration_set &  duration_set  )

related

Prints string representation of the given Duration_set value to the given ostream.

Parameters

os	Stream to which to write.
duration_set	Object to serialize.

Returns

os.

Definition at line 93 of file clock_type.cpp.

References m_values, and flow::util::ostream_op_to_string().

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Member Data Documentation

m_values

std::array<Duration, size_t(Clock_type::S_END_SENTINEL)> flow::perf::Duration_set::m_values

The underlying data, directly readable and writable by user. NOT ZERO-INITIALIZED ON CONSTRUCTION (or ever).

Definition at line 188 of file clock_type_fwd.hpp.

Referenced by flow::perf::Checkpointing_timer::Aggregator::create_aggregated_result(), operator*=(), operator+=(), flow::perf::operator+=(), flow::perf::Time_pt_set::operator-(), operator/=(), and operator<<().

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The documentation for this struct was generated from the following file:

• perf/clock_type_fwd.hpp