stats Class Reference [I/O primitives layer]

Collects various I/O statistics. More...

#include <iostats.h>

List of all members.

Public Types
enum	wait_op_type { WAIT_OP_ANY, WAIT_OP_READ, WAIT_OP_WRITE }
Public Member Functions
unsigned	get_reads () const
	Returns total number of reads.
unsigned	get_writes () const
	Returns total number of writes.
int64	get_read_volume () const
	Returns number of bytes read from disks.
int64	get_written_volume () const
	Returns number of bytes written to the disks.
unsigned	get_cached_reads () const
	Returns total number of reads served from cache.
unsigned	get_cached_writes () const
	Returns total number of cached writes.
int64	get_cached_read_volume () const
	Returns number of bytes read from cache.
int64	get_cached_written_volume () const
	Returns number of bytes written to the cache.
double	get_read_time () const
	Time that would be spent in read syscalls if all parallel reads were serialized.
double	get_write_time () const
	Time that would be spent in write syscalls if all parallel writes were serialized.
double	get_pread_time () const
	Period of time when at least one I/O thread was executing a read.
double	get_pwrite_time () const
	Period of time when at least one I/O thread was executing a write.
double	get_pio_time () const
	Period of time when at least one I/O thread was executing a read or a write.
double	get_io_wait_time () const
	I/O wait time counter.
double	get_wait_read_time () const
double	get_wait_write_time () const
double	get_last_reset_time () const
	Return time of the last reset.
	_STXXL_DEPRECATED (void reset())
	Resets I/O time counters (including I/O wait counter).
	_STXXL_DEPRECATED (void _reset_io_wait_time())
	Resets I/O wait time counter.
void	write_started (unsigned_type size_, double now=0.0)
void	write_canceled (unsigned_type size_)
void	write_finished ()
void	write_cached (unsigned_type size_)
void	read_started (unsigned_type size_, double now=0.0)
void	read_canceled (unsigned_type size_)
void	read_finished ()
void	read_cached (unsigned_type size_)
void	wait_started (wait_op_type wait_op)
void	wait_finished (wait_op_type wait_op)

---

Detailed Description

Collects various I/O statistics.

Remarks:

is a singleton

Examples:

algo/test_parallel_sort.cpp.

---

Member Function Documentation

stats::_STXXL_DEPRECATED

(

void

reset()

)

Resets I/O time counters (including I/O wait counter).

stats::_STXXL_DEPRECATED

(

void

_reset_io_wait_time()

)

Resets I/O wait time counter.

int64 stats::get_cached_read_volume

(

)

const [inline]

Returns number of bytes read from cache.

Returns:

number of bytes read from cache

unsigned stats::get_cached_reads

(

)

const [inline]

Returns total number of reads served from cache.

Returns:

total number of cached reads

unsigned stats::get_cached_writes

(

)

const [inline]

Returns total number of cached writes.

Returns:

total number of cached writes

int64 stats::get_cached_written_volume

(

)

const [inline]

Returns number of bytes written to the cache.

Returns:

number of bytes written to cache

double stats::get_io_wait_time

(

)

const [inline]

I/O wait time counter.

Returns:

number of seconds spent in I/O waiting functions request::wait , wait_any and wait_all

double stats::get_last_reset_time

(

)

const [inline]

Return time of the last reset.

Returns:

seconds passed from the last reset()

double stats::get_pio_time

(

)

const [inline]

Period of time when at least one I/O thread was executing a read or a write.

Returns:

seconds spent in I/O

double stats::get_pread_time

(

)

const [inline]

Period of time when at least one I/O thread was executing a read.

Returns:

seconds spent in reading

double stats::get_pwrite_time

(

)

const [inline]

Period of time when at least one I/O thread was executing a write.

Returns:

seconds spent in writing

double stats::get_read_time

(

)

const [inline]

Time that would be spent in read syscalls if all parallel reads were serialized.

Returns:

seconds spent in reading

int64 stats::get_read_volume

(

)

const [inline]

Returns number of bytes read from disks.

Returns:

number of bytes read

unsigned stats::get_reads

(

)

const [inline]

Returns total number of reads.

Returns:

total number of reads

double stats::get_write_time

(

)

const [inline]

Time that would be spent in write syscalls if all parallel writes were serialized.

Returns:

seconds spent in writing

unsigned stats::get_writes

(

)

const [inline]

Returns total number of writes.

Returns:

total number of writes

int64 stats::get_written_volume

(

)

const [inline]

Returns number of bytes written to the disks.

Returns:

number of bytes written

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The documentation for this class was generated from the following files:

• iostats.h
• iostats.cpp