mach0data.ic File Reference

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

#include "mtr0types.h"
#include "ut0byte.h"

Functions
static void	mach_write_to_1 (byte *b, ulint n)
	The following function is used to store data in 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 uint8_t	mach_read_from_1 (const byte *b)
	The following function is used to fetch data from one byte. 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)
	Writes a ulint in a compressed form where the first byte codes the length of the stored ulint. More...
static uint32_t	mach_get_compressed_size (ulint n)
	Return the size of an ulint when written in the compressed form. More...
static ulint	mach_read_compressed (const byte *b)
	Read a ulint in a 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_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 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_6 (byte *b, uint64_t n)
	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 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...
static uint64_t	mach_read_next_much_compressed (const byte **b)
	Read a 64-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)
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_swap_byte_order (byte *dest, const byte *from, ulint len)
	Swap byte ordering. More...
static void	mach_write_int_type (byte *dest, const byte *src, ulint len, bool usign)
static void	mach_write_ulonglong (byte *dest, ulonglong src, ulint len, bool usign)
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.

Returns

integer in machine-dependent format

Parameters

n	in: 16-bit integer in canonical 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

Parameters

b	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

b	in: pointer to memory where to write
d	in: 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.

Returns

16-bit integer in canonical format

Parameters

n	in: integer in machine-dependent 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

Parameters

b	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

b	in: pointer to memory where to write
d	in: 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

uint32_t integer (< 2^32) to be stored

Returns

compressed size in bytes

mach_read_compressed()

static ulint mach_read_compressed ( const byte *  b )

inlinestatic

Read a ulint in a compressed form.

Parameters

[in]

b

pointer to memory from where to read

Returns

read integer (< 2^32)

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 to read

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

Parameters

buf	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

uint32_t 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 from where 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

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.

Returns

integer value

Parameters

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

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_next_much_compressed()

static uint64_t mach_read_next_much_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_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_swap_byte_order()

static void mach_swap_byte_order ( byte *  dest, const byte *  from, ulint  len  )

inlinestatic

Swap byte ordering.

Parameters

dest	out: where to write
from	in: where to read from
len	in: length of src

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 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.

Returns

the value read

See also

mach_parse_u64_much_compressed()

Parameters

b	in: pointer to memory from where to 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).

Returns

size in bytes

Parameters

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

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).

Returns

size in bytes

Parameters

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

mach_write_compressed()

static ulint mach_write_compressed ( byte *  b, ulint  n  )

inlinestatic

Writes a ulint in a compressed form where the first byte codes the length of the stored ulint.

We look at the most significant bits of the byte. If the most significant bit is zero, it means 1-byte storage, else if the 2nd bit is 0, it means 2-byte storage, else if 3rd is 0, it means 3-byte storage, else if 4th is 0, it means 4-byte storage, else the storage is 5-byte.

Parameters

[in]	b	pointer to memory where to store
[in]	n	ulint integer (< 2^32) to be stored

Returns

compressed size in bytes

mach_write_int_type()

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

inlinestatic

Parameters

dest	in: where to write
src	in: where to read from
len	in: length of src
usign	in: 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	ulint 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

dest	in: where to write
n	in: 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  n  )

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]	n	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 (< 2^64) 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

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

mach_write_ulonglong()

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

inlinestatic

Parameters

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