One I/O operation, as observed by KvikIO. More...

Public Member Functions
Duration	duration () const noexcept
	How long the operation took. More...

double	bytes_per_sec () const noexcept
	Throughput of this single operation. More...

Public Attributes
TimePoint	start {}
	When the operation started.

TimePoint	end {}
	When the operation finished.

std::size_t	offset {}
	Byte offset into the file or remote object.

std::size_t	size {}
	Number of bytes requested.

std::size_t	bytes_transferred {}

std::uint64_t	id {}
	Identifies this operation, uniquely within the process.

char const *	http_method {nullptr}
	HTTP method, e.g. `"GET"`. Null for local I/O.

std::string_view	source {}

ObservationKind	kind {ObservationKind::LOGICAL}
	What layer this describes. Always `ObservationKind::LOGICAL` today.

IoBackend	backend {IoBackend::POSIX}
	The backend that carried out the operation.

TransferDirection	direction {TransferDirection::READ}
	The direction of the operation.

MemoryKind	memory_kind {MemoryKind::HOST}
	The kind of memory the caller's buffer lives in.

bool	ok {true}
	False if the operation failed.

Detailed Description

One I/O operation, as observed by KvikIO.

[start, end) covers the operation from issue to completion.

Definition at line 153 of file observation.hpp.

Member Function Documentation

double kvikio::Observation::bytes_per_sec ( ) const

inlinenoexcept

Throughput of this single operation.

Warning: Averaging this across operations does not give the throughput of the program. For that, divide total bytes by a span of elapsed time.

Returns: Bytes per second, or zero if the operation had no measurable duration.

Definition at line 204 of file observation.hpp.

Duration kvikio::Observation::duration ( ) const

inlinenoexcept

How long the operation took.

Definition at line 191 of file observation.hpp.

std::size_t kvikio::Observation::bytes_transferred {}

Number of bytes actually transferred. Differs from size on a short read, and is zero for an operation that failed.

Definition at line 164 of file observation.hpp.

std::string_view kvikio::Observation::source {}

The file path or URL the operation went to. Owned by the handle, and valid only for the duration of the callback. Copy what is needed later.

Definition at line 173 of file observation.hpp.

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