Various utilities. More...

#include <string.h>
#include <algorithm>
#include <chrono>
#include <cmath>
#include <iomanip>
#include <iterator>
#include <ostream>
#include <sstream>
#include <thread>
#include <type_traits>
#include <limits>
#include <random>
#include "db0err.h"
#include "os0atomic.h"
#include <time.h>
#include <ctype.h>
#include <stdarg.h>
#include "ut/ut.h"
#include "ut0dbg.h"
#include "mysql/components/services/log_builtins.h"
#include "mysqld_error.h"
#include "sql/derror.h"
#include "ut0ut.ic"

Classes
struct	ut_strcmp_functor
	Functor that compares two C strings. More...

class	ib::Timer
	For measuring time elapsed. More...

struct	Wait_stats

class	ib::Throttler
	Allows to monitor an event processing times, allowing to throttle the processing to one per throttle_delay_sec. More...

Namespaces
namespace	ut
	This file contains a set of libraries providing overloads for regular dynamic allocation routines which allow for opt-in memory instrumentation through performance schema memory engine (PFS).

namespace	ib

Macros
#define	TEMP_INDEX_PREFIX_STR "\377"
	Index name prefix in fast index creation, as a string constant. More...

#define	UT_RELAX_CPU() __asm__ __volatile__("pause")

#define	UT_LOW_PRIORITY_CPU() ((void)0)

#define	UT_RESUME_PRIORITY_CPU() ((void)0)

#define	ut_2pow_remainder(n, m) ((n) & ((m)-1))
	Calculates fast the remainder of n/m when m is a power of two. More...

#define	ut_2pow_round(n, m) ((n) & ~((m)-1))
	Calculates the biggest multiple of m that is not bigger than n when m is a power of two. More...

#define	ut_calc_align_down(n, m) ut_2pow_round(n, m)
	Align a number down to a multiple of a power of two. More...

#define	ut_calc_align(n, m) (((n) + ((m)-1)) & ~((m)-1))
	Calculates the smallest multiple of m that is not smaller than n when m is a power of two. More...

#define	UT_BITS_IN_BYTES(b) (((b) + 7UL) / 8UL)
	Determine how many bytes (groups of 8 bits) are needed to store the given number of bits. More...

#define	ut_is_2pow(n) UNIV_LIKELY(!((n) & ((n)-1)))
	Determines if a number is zero or a power of two. More...

#define	ut_vsnprintf(buf, size, fmt, ap) ((void)vsnprintf(buf, size, fmt, ap))
	A wrapper for vsnprintf(3), formatted output conversion into a limited buffer. More...

Functions
static void	ut_pair_min (ulint min_hi, ulint min_lo, ulint a_hi, ulint a_lo, ulint b_hi, ulint b_lo)
	Calculate the minimum of two pairs. More...

static int	ut_ulint_cmp (ulint a, ulint b)
	Compares two ulints. More...

static int	ut_pair_cmp (ulint a_h, ulint a_l, ulint b_h, ulint b_l)
	Compare two pairs of integers. More...

constexpr ulint	ut_2_log (ulint n)
	Calculates fast the 2-logarithm of a number, rounded upward to an integer. More...

static uint32_t	ut_2_exp (uint32_t n)
	Calculates 2 to power n. More...

ulint	ut_2_power_up (ulint n)
	Calculates fast the number rounded up to the nearest power of 2. More...

ulint	ut_delay (ulint delay)
	Runs an idle loop on CPU. More...

std::string	ut_get_name (const trx_t trx, const char name)
	Get a fixed-length string, quoted as an SQL identifier. More...

void	ut_print_name (FILE f, const trx_t trx, const char *name)
	Outputs a fixed-length string, quoted as an SQL identifier. More...

char *	ut_format_name (const char name, char formatted, ulint formatted_size)
	Format a table name, quoted as an SQL identifier. More...

void	ut_copy_file (FILE dest, FILE src)
	Catenate files. More...

void	ut_format_byte_value (uint64_t data_bytes, std::string &data_str)
	Convert byte value to string with unit. More...

const char *	ut_strerr (dberr_t num)
	Convert an error number to a human readable text message. More...

template<typename T , typename U >
constexpr bool	ut::can_type_fit_value (const U value)

template<typename T , typename U >
T	ut::clamp (U x)

Variables
ulong	ut::spin_wait_pause_multiplier = 50
	The current value of @innodb_spin_wait_pause_multiplier. More...

Detailed Description

Various utilities.

Created 1/20/1994 Heikki Tuuri

Macro Definition Documentation

◆ TEMP_INDEX_PREFIX_STR

#define TEMP_INDEX_PREFIX_STR "\377"

Index name prefix in fast index creation, as a string constant.

◆ ut_2pow_remainder

#define ut_2pow_remainder	(	n,
		m
	)	((n) & ((m)-1))

Calculates fast the remainder of n/m when m is a power of two.

Parameters

n	in: numerator
m	in: denominator, must be a power of two

Returns: the remainder of n/m

◆ ut_2pow_round

#define ut_2pow_round	(	n,
		m
	)	((n) & ~((m)-1))

Calculates the biggest multiple of m that is not bigger than n when m is a power of two.

In other words, rounds n down to m * k.

Parameters

n	in: number to round down
m	in: alignment, must be a power of two

Returns: n rounded down to the biggest possible integer multiple of m

◆ UT_BITS_IN_BYTES

#define UT_BITS_IN_BYTES ( b ) (((b) + 7UL) / 8UL)

Determine how many bytes (groups of 8 bits) are needed to store the given number of bits.

Parameters

b in: bits

Returns: number of bytes (octets) needed to represent b

◆ ut_calc_align

#define ut_calc_align	(	n,
		m
	)	(((n) + ((m)-1)) & ~((m)-1))

Calculates the smallest multiple of m that is not smaller than n when m is a power of two.

In other words, rounds n up to m * k.

Parameters

n	in: number to round up
m	in: alignment, must be a power of two

Returns: n rounded up to the smallest possible integer multiple of m

◆ ut_calc_align_down

#define ut_calc_align_down	(	n,
		m
	)	ut_2pow_round(n, m)

Align a number down to a multiple of a power of two.

Parameters

n	in: number to round down
m	in: alignment, must be a power of two

Returns: n rounded down to the biggest possible integer multiple of m

◆ ut_is_2pow

#define ut_is_2pow ( n ) UNIV_LIKELY(!((n) & ((n)-1)))

Determines if a number is zero or a power of two.

Parameters

[in] n number

Returns: nonzero if n is zero or a power of two; zero otherwise

◆ UT_LOW_PRIORITY_CPU

#define UT_LOW_PRIORITY_CPU ( ) ((void)0)

◆ UT_RELAX_CPU

#define UT_RELAX_CPU ( ) __asm__ __volatile__("pause")

◆ UT_RESUME_PRIORITY_CPU

#define UT_RESUME_PRIORITY_CPU ( ) ((void)0)

◆ ut_vsnprintf

#define ut_vsnprintf	(	buf,
		size,
		fmt,
		ap
	)	((void)vsnprintf(buf, size, fmt, ap))

A wrapper for vsnprintf(3), formatted output conversion into a limited buffer.

Note: this function DOES NOT return the number of characters that would have been printed if the buffer was unlimited because VC's _vsnprintf() returns -1 in this case and we would need to call _vscprintf() in addition to estimate that but we would need another copy of "ap" for that and VC does not provide va_copy().

Function Documentation

◆ ut_2_exp()

static uint32_t ut_2_exp ( uint32_t n )

inlinestatic

Calculates 2 to power n.

Parameters

[in] n power of 2

Returns: 2 to power n

◆ ut_2_log()

constexpr ulint ut_2_log ( ulint n )

constexpr

Calculates fast the 2-logarithm of a number, rounded upward to an integer.

Returns: logarithm in the base 2, rounded upward in: number; logarithm in the base 2, rounded upward

Parameters

n	in: number != 0

◆ ut_2_power_up()

ulint ut_2_power_up ( ulint n )

Calculates fast the number rounded up to the nearest power of 2.

Parameters

[in] n number != 0

Returns: first power of 2 which is >= n; first power of 2 which is >= n

Parameters

n	in: number != 0

◆ ut_copy_file()

void ut_copy_file	(	FILE *	dest,
		FILE *	src
	)

Catenate files.

Parameters

[in]	dest	Output file
[in]	src	Input file to be appended to output

◆ ut_delay()

ulint ut_delay ( ulint delay )

Runs an idle loop on CPU.

The argument gives the desired delay in microseconds on 100 MHz Pentium + Visual C++. The actual duration depends on a product of delay and the current value of @innodb_spin_wait_pause_multiplier.

Parameters

[in] delay delay in microseconds on 100 MHz Pentium, assuming spin_wait_pause_multiplier is 50 (default).

Returns: dummy value

◆ ut_format_byte_value()

void ut_format_byte_value	(	uint64_t	data_bytes,
		std::string &	data_str
	)

Convert byte value to string with unit.

Parameters

[in]	data_bytes	byte value
[out]	data_str	formatted string

◆ ut_format_name()

char * ut_format_name	(	const char *	name,
		char *	formatted,
		ulint	formatted_size
	)

Format a table name, quoted as an SQL identifier.

If the name contains a slash '/', the result will contain two identifiers separated by a period (.), as in SQL database_name.table_name.

See also: table_name_t

Parameters

[in]	name	table or index name
[out]	formatted	formatted result, will be NUL-terminated
[in]	formatted_size	size of the buffer in bytes

Returns: pointer to 'formatted'

◆ ut_get_name()

std::string ut_get_name	(	const trx_t *	trx,
		const char *	name
	)

Get a fixed-length string, quoted as an SQL identifier.

If the string contains a slash '/', the string will be output as two identifiers separated by a period (.), as in SQL database_name.identifier.

Parameters

[in]	trx	transaction (NULL=no quotes).
[in]	name	table name.

Return values

String quoted as an SQL identifier.

◆ ut_pair_cmp()

static int ut_pair_cmp	(	ulint	a_h,
		ulint	a_l,
		ulint	b_h,
		ulint	b_l
	)

inlinestatic

Compare two pairs of integers.

Parameters

[in]	a_h	more significant part of first pair
[in]	a_l	less significant part of first pair
[in]	b_h	more significant part of second pair
[in]	b_l	less significant part of second pair

Returns: comparison result of (a_h,a_l) and (b_h,b_l)

Return values

-1	if (a_h,a_l) is less than (b_h,b_l)
0	if (a_h,a_l) is equal to (b_h,b_l)
1	if (a_h,a_l) is greater than (b_h,b_l)

◆ ut_pair_min()

static void ut_pair_min	(	ulint *	min_hi,
		ulint *	min_lo,
		ulint	a_hi,
		ulint	a_lo,
		ulint	b_hi,
		ulint	b_lo
	)

inlinestatic

Calculate the minimum of two pairs.

Parameters

[out]	min_hi	MSB of the minimum pair
[out]	min_lo	LSB of the minimum pair
[in]	a_hi	MSB of the first pair
[in]	a_lo	LSB of the first pair
[in]	b_hi	MSB of the second pair
[in]	b_lo	LSB of the second pair

◆ ut_print_name()

void ut_print_name	(	FILE *	f,
		const trx_t *	trx,
		const char *	name
	)

Outputs a fixed-length string, quoted as an SQL identifier.

If the string contains a slash '/', the string will be output as two identifiers separated by a period (.), as in SQL database_name.identifier. in: table name to print

If the string contains a slash '/', the string will be output as two identifiers separated by a period (.), as in SQL database_name.identifier.

Parameters

f	in: output stream
trx	in: transaction
name	in: name to print

◆ ut_strerr()

const char * ut_strerr ( dberr_t num )

Convert an error number to a human readable text message.

The returned string is static and should not be freed or modified.

Returns: string, describing the error in: error number

The returned string is static and should not be freed or modified.

Parameters

[in] num InnoDB internal error number

Returns: string, describing the error

◆ ut_ulint_cmp()

static int ut_ulint_cmp	(	ulint	a,
		ulint	b
	)

inlinestatic

Compares two ulints.

Parameters

[in]	a	ulint
[in]	b	ulint

Returns: 1 if a > b, 0 if a == b, -1 if a < b

Classes

Namespaces

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ TEMP_INDEX_PREFIX_STR

◆ ut_2pow_remainder

◆ ut_2pow_round

◆ UT_BITS_IN_BYTES

◆ ut_calc_align

◆ ut_calc_align_down

◆ ut_is_2pow

◆ UT_LOW_PRIORITY_CPU

◆ UT_RELAX_CPU

◆ UT_RESUME_PRIORITY_CPU

◆ ut_vsnprintf

Function Documentation

◆ ut_2_exp()

◆ ut_2_log()

◆ ut_2_power_up()

◆ ut_copy_file()

◆ ut_delay()

◆ ut_format_byte_value()

◆ ut_format_name()

◆ ut_get_name()

◆ ut_pair_cmp()

◆ ut_pair_min()

◆ ut_print_name()

◆ ut_strerr()

◆ ut_ulint_cmp()