mach0data.h File Reference

Utilities for converting data from the database file to the machine format. More...

#include "mtr0types.h"
#include "univ.i"
#include "mach0data.ic"

Go to the source code of this file.

Functions
static void	mach_write_to_1 (byte *b, ulint n)
	The following function is used to store data in one byte. More...
static uint8_t	mach_read_from_1 (const byte *b)
	The following function is used to fetch data from one byte. More...
static void	mach_write_to_2 (byte *b, ulint n)
	The following function is used to store data in two consecutive bytes. More...
static uint16_t	mach_read_from_2 (const byte *b)
	The following function is used to fetch data from 2 consecutive bytes. More...
static uint16_t	mach_encode_2 (ulint n)
	The following function is used to convert a 16-bit data item to the canonical format, for fast bytewise equality test against memory. More...
static ulint	mach_decode_2 (uint16 n)
	The following function is used to convert a 16-bit data item from the canonical format, for fast bytewise equality test against memory. More...
static void	mach_write_to_3 (byte *b, ulint n)
	The following function is used to store data in 3 consecutive bytes. More...
static uint32_t	mach_read_from_3 (const byte *b)
	The following function is used to fetch data from 3 consecutive bytes. More...
static void	mach_write_to_4 (byte *b, ulint n)
	The following function is used to store data in 4 consecutive bytes. More...
static uint32_t	mach_read_from_4 (const byte *b)
	The following function is used to fetch data from 4 consecutive bytes. More...
static ulint	mach_write_compressed (byte *b, ulint n)
	Write a ulint in a compressed form (1..5 bytes). More...
static uint32_t	mach_get_compressed_size (ulint n)
	Return the size of an ulint when written in the compressed form. More...
static uint32_t	mach_read_next_compressed (const byte **b)
	Read a 32-bit integer in a compressed form. More...
static void	mach_write_to_6 (byte *b, uint64_t id)
	The following function is used to store data in 6 consecutive bytes. More...
static uint64_t	mach_read_from_6 (const byte *b)
	The following function is used to fetch data from 6 consecutive bytes. More...
static void	mach_write_to_7 (byte *b, uint64_t n)
	The following function is used to store data in 7 consecutive bytes. More...
static uint64_t	mach_read_from_7 (const byte *b)
	The following function is used to fetch data from 7 consecutive bytes. More...
static void	mach_write_to_8 (void *b, uint64_t n)
	The following function is used to store data in 8 consecutive bytes. More...
static uint64_t	mach_read_from_8 (const byte *b)
	The following function is used to fetch data from 8 consecutive bytes. More...
static ulint	mach_u64_write_compressed (byte *b, uint64_t n)
	Writes a 64-bit integer in a compressed form (5..9 bytes). More...
static uint64_t	mach_u64_read_next_compressed (const byte **b)
	Read a 64-bit integer in a compressed form. More...
static ulint	mach_u64_write_much_compressed (byte *b, uint64_t n)
	Writes a 64-bit integer in a compressed form (1..11 bytes). More...
static uint64_t	mach_u64_read_much_compressed (const byte *b)
	Reads a 64-bit integer in a compressed form. More...
uint64_t	mach_parse_u64_much_compressed (const byte **ptr, const byte *end_ptr)
	Read a 64-bit integer in a much compressed form. More...
uint32_t	mach_parse_compressed (const byte **ptr, const byte *end_ptr)
	Read a 32-bit integer in a compressed form. More...
static uint64_t	mach_u64_parse_compressed (const byte **ptr, const byte *end_ptr)
	Read a 64-bit integer in a compressed form. More...
static double	mach_double_read (const byte *b)
	Reads a double. More...
static void	mach_double_write (byte *b, double d)
	Writes a double. More...
static float	mach_float_read (const byte *b)
	Reads a float. More...
static void	mach_float_write (byte *b, float d)
	Writes a float. More...
static ulint	mach_read_from_n_little_endian (const byte *buf, ulint buf_size)
	Reads a ulint stored in the little-endian format. More...
static void	mach_write_to_n_little_endian (byte *dest, ulint dest_size, ulint n)
	Writes a ulint in the little-endian format. More...
static ulint	mach_read_from_2_little_endian (const byte *buf)
	Reads a ulint stored in the little-endian format. More...
static void	mach_write_to_2_little_endian (byte *dest, ulint n)
	Writes a ulint in the little-endian format. More...
static uint64_t	mach_read_int_type (const byte *src, ulint len, bool unsigned_type)
	Convert integral type from storage byte order (big endian) to host byte order. More...
static void	mach_write_int_type (byte *dest, const byte *src, ulint len, bool usign)
	Convert integral type from host byte order to (big-endian) storage byte order. More...
static void	mach_write_ulonglong (byte *dest, ulonglong src, ulint len, bool usign)
	Convert a ulonglong integer from host byte order to (big-endian) storage byte order. More...
static uint32_t	mach_read_ulint (const byte *ptr, mlog_id_t type)
	Read 1 to 4 bytes from a file page buffered in the buffer pool. More...

Detailed Description

Utilities for converting data from the database file to the machine format.

Created 11/28/1995 Heikki Tuuri

Function Documentation

mach_decode_2()

static ulint mach_decode_2 ( uint16  n )

inlinestatic

The following function is used to convert a 16-bit data item from the canonical format, for fast bytewise equality test against memory.

Parameters

[in]

n

16-bit integer in canonical format

Returns

integer in machine-dependent format

mach_double_read()

static double mach_double_read ( const byte *  b )

inlinestatic

Reads a double.

It is stored in a little-endian format.

Returns

double read in: pointer to memory from where to read

mach_double_write()

static void mach_double_write ( byte *  b, double  d  )

inlinestatic

Writes a double.

It is stored in a little-endian format.

Parameters

[in]	b	pointer to memory where to write
[in]	d	double

mach_encode_2()

static uint16_t mach_encode_2 ( ulint  n )

inlinestatic

The following function is used to convert a 16-bit data item to the canonical format, for fast bytewise equality test against memory.

Parameters

[in]

n

integer in machine-dependent format

Returns

16-bit integer in canonical format

mach_float_read()

static float mach_float_read ( const byte *  b )

inlinestatic

Reads a float.

It is stored in a little-endian format.

Returns

float read in: pointer to memory from where to read

mach_float_write()

static void mach_float_write ( byte *  b, float  d  )

inlinestatic

Writes a float.

It is stored in a little-endian format.

Parameters

[in]	b	pointer to memory where to write
[in]	d	float

mach_get_compressed_size()

static uint32_t mach_get_compressed_size ( ulint  n )

inlinestatic

Return the size of an ulint when written in the compressed form.

Parameters

[in]

n

ulint integer to be stored

Returns

compressed size in bytes

mach_parse_compressed()

uint32_t mach_parse_compressed	(	const byte **	ptr,
		const byte *	end_ptr
	)

Read a 32-bit integer in a compressed form.

Parameters

[in,out]	ptr	pointer to memory from where to read; advanced by the number of bytes consumed, or set NULL if out of space
[in]	end_ptr	end of the buffer

Returns

unsigned value

mach_parse_u64_much_compressed()

uint64_t mach_parse_u64_much_compressed	(	const byte **	ptr,
		const byte *	end_ptr
	)

Read a 64-bit integer in a much compressed form.

Parameters

[in,out]	ptr	pointer to memory from where to read, advanced by the number of bytes consumed, or set NULL if out of space
[in]	end_ptr	end of the buffer

Returns

unsigned 64-bit integer

mach_read_from_1()

static uint8_t mach_read_from_1 ( const byte *  b )

inlinestatic

The following function is used to fetch data from one byte.

Parameters

[in]

b

pointer to a byte to read

Returns

ulint integer, >= 0, < 256

mach_read_from_2()

static uint16_t mach_read_from_2 ( const byte *  b )

inlinestatic

The following function is used to fetch data from 2 consecutive bytes.

The most significant byte is at the lowest address.

Parameters

[in]

b

pointer to 2 bytes where to store

Returns

2-byte integer, >= 0, < 64k

mach_read_from_2_little_endian()

static ulint mach_read_from_2_little_endian ( const byte *  buf )

inlinestatic

Reads a ulint stored in the little-endian format.

Returns

unsigned long int in: from where to read

mach_read_from_3()

static uint32_t mach_read_from_3 ( const byte *  b )

inlinestatic

The following function is used to fetch data from 3 consecutive bytes.

The most significant byte is at the lowest address.

Parameters

[in]

b

pointer to 3 bytes to read

Returns

32 bit integer

mach_read_from_4()

static uint32_t mach_read_from_4 ( const byte *  b )

inlinestatic

The following function is used to fetch data from 4 consecutive bytes.

The most significant byte is at the lowest address.

Parameters

[in]

b

pointer to 4 bytes to read

Returns

32 bit integer

mach_read_from_6()

static uint64_t mach_read_from_6 ( const byte *  b )

inlinestatic

The following function is used to fetch data from 6 consecutive bytes.

The most significant byte is at the lowest address.

Parameters

[in]

b

pointer to 6 bytes to read

Returns

48-bit integer

mach_read_from_7()

static uint64_t mach_read_from_7 ( const byte *  b )

inlinestatic

The following function is used to fetch data from 7 consecutive bytes.

The most significant byte is at the lowest address.

Parameters

[in]

b

pointer to 7 bytes to read

Returns

56-bit integer

mach_read_from_8()

static uint64_t mach_read_from_8 ( const byte *  b )

inlinestatic

The following function is used to fetch data from 8 consecutive bytes.

The most significant byte is at the lowest address.

Parameters

[in]

b

pointer to 8 bytes to read

Returns

64-bit integer

mach_read_from_n_little_endian()

static ulint mach_read_from_n_little_endian ( const byte *  buf, ulint  buf_size  )

inlinestatic

Reads a ulint stored in the little-endian format.

Parameters

[in]	buf	From where to read.
[in]	buf_size	From how many bytes to read.

Returns

unsigned long int

mach_read_int_type()

static uint64_t mach_read_int_type ( const byte *  src, ulint  len, bool  unsigned_type  )

inlinestatic

Convert integral type from storage byte order (big endian) to host byte order.

Parameters

[in]	src	where to read from
[in]	len	length of src
[in]	unsigned_type	signed or unsigned flag

Returns

integer value

mach_read_next_compressed()

static uint32_t mach_read_next_compressed ( const byte **  b )

inlinestatic

Read a 32-bit integer in a compressed form.

Parameters

[in,out]

b

pointer to memory where to read; advanced by the number of bytes consumed

Returns

unsigned value

mach_read_ulint()

static uint32_t mach_read_ulint ( const byte *  ptr, mlog_id_t  type  )

inlinestatic

Read 1 to 4 bytes from a file page buffered in the buffer pool.

Parameters

[in]	ptr	pointer where to read
[in]	type	MLOG_1BYTE, MLOG_2BYTES, or MLOG_4BYTES

Returns

value read

mach_u64_parse_compressed()

static uint64_t mach_u64_parse_compressed ( const byte **  ptr, const byte *  end_ptr  )

inlinestatic

Read a 64-bit integer in a compressed form.

Parameters

[in,out]	ptr	pointer to memory from where to read; advanced by the number of bytes consumed, or set NULL if out of space
[in]	end_ptr	end of the buffer

Returns

unsigned value

mach_u64_read_much_compressed()

static uint64_t mach_u64_read_much_compressed ( const byte *  b )

inlinestatic

Reads a 64-bit integer in a compressed form.

Parameters

[in]

b

pointer to memory from where to read

Returns

the value read

mach_u64_read_next_compressed()

static uint64_t mach_u64_read_next_compressed ( const byte **  b )

inlinestatic

Read a 64-bit integer in a compressed form.

Parameters

[in,out]

b

pointer to memory where to read; advanced by the number of bytes consumed

Returns

unsigned value

mach_u64_write_compressed()

static ulint mach_u64_write_compressed ( byte *  b, uint64_t  n  )

inlinestatic

Writes a 64-bit integer in a compressed form (5..9 bytes).

Parameters

[in]	b	pointer to memory where to store
[in]	n	64-bit integer to be stored

Returns

size in bytes

mach_u64_write_much_compressed()

static ulint mach_u64_write_much_compressed ( byte *  b, uint64_t  n  )

inlinestatic

Writes a 64-bit integer in a compressed form (1..11 bytes).

Parameters

[in]	b	pointer to memory where to store
[in]	n	64-bit integer to be stored

Returns

size in bytes

mach_write_compressed()

static ulint mach_write_compressed ( byte *  b, ulint  n  )

inlinestatic

Write a ulint in a compressed form (1..5 bytes).

Parameters

[in]	b	pointer to memory where to store
[in]	n	ulint integer to be stored

Returns

stored size in bytes

mach_write_int_type()

static void mach_write_int_type ( byte *  dest, const byte *  src, ulint  len, bool  usign  )

inlinestatic

Convert integral type from host byte order to (big-endian) storage byte order.

Parameters

[in]	dest	where to write
[in]	src	where to read
[in]	len	length of src
[in]	usign	signed or unsigned flag

mach_write_to_1()

static void mach_write_to_1 ( byte *  b, ulint  n  )

inlinestatic

The following function is used to store data in one byte.

Parameters

[in]	b	pointer to byte where to store
[in]	n	One byte integer to be stored, >= 0, < 256

mach_write_to_2()

static void mach_write_to_2 ( byte *  b, ulint  n  )

inlinestatic

The following function is used to store data in two consecutive bytes.

We store the most significant byte to the lower address.

Parameters

[in]	b	pointer to 2 bytes where to store
[in]	n	2-byte integer to be stored, >= 0, < 64k

mach_write_to_2_little_endian()

static void mach_write_to_2_little_endian ( byte *  dest, ulint  n  )

inlinestatic

Writes a ulint in the little-endian format.

Parameters

[in]	dest	where to write
[in]	n	unsigned long int to write

mach_write_to_3()

static void mach_write_to_3 ( byte *  b, ulint  n  )

inlinestatic

The following function is used to store data in 3 consecutive bytes.

We store the most significant byte to the lowest address.

Parameters

[in]	b	pointer to 3 bytes where to store
[in]	n	3 byte integer to be stored

mach_write_to_4()

static void mach_write_to_4 ( byte *  b, ulint  n  )

inlinestatic

The following function is used to store data in 4 consecutive bytes.

We store the most significant byte to the lowest address.

Parameters

[in]	b	pointer to 4 bytes where to store
[in]	n	4 byte integer to be stored

mach_write_to_6()

static void mach_write_to_6 ( byte *  b, uint64_t  id  )

inlinestatic

The following function is used to store data in 6 consecutive bytes.

We store the most significant byte to the lowest address.

Parameters

[in]	b	pointer to 6 bytes where to store
[in]	id	48-bit integer to write

mach_write_to_7()

static void mach_write_to_7 ( byte *  b, uint64_t  n  )

inlinestatic

The following function is used to store data in 7 consecutive bytes.

We store the most significant byte to the lowest address.

Parameters

[in]	b	pointer to 7 bytes where to store
[in]	n	56-bit integer

mach_write_to_8()

static void mach_write_to_8 ( void *  b, uint64_t  n  )

inlinestatic

The following function is used to store data in 8 consecutive bytes.

We store the most significant byte to the lowest address.

Parameters

[in]	b	pointer to 8 bytes where to store
[in]	n	64-bit integer to be stored

mach_write_to_n_little_endian()

static void mach_write_to_n_little_endian ( byte *  dest, ulint  dest_size, ulint  n  )

inlinestatic

Writes a ulint in the little-endian format.

Parameters

[in]	dest	where to write
[in]	dest_size	into how many bytes to write
[in]	n	unsigned long int to write

mach_write_ulonglong()

static void mach_write_ulonglong ( byte *  dest, ulonglong  src, ulint  len, bool  usign  )

inlinestatic

Convert a ulonglong integer from host byte order to (big-endian) storage byte order.

Parameters

[in]	dest	where to write
[in]	src	where to read from
[in]	len	length of dest
[in]	usign	signed or unsigned flag