sasindexkey.h File Reference

API for defining binary Index keys for B-Trees. More...

#include <string.h>

Go to the source code of this file.

Classes
struct	SASIndexKey_t
	Index Key Handle structure for binary index B-trees. More...
union	sasindexkeymap_t
	Union of value types and key machine integer types. More...

Typedefs
typedef unsigned long	machine_uint_t
	word size data unit used for binary keys.
typedef unsigned short	machine_uhalf_t
	data unit used to store copy and compare lengths.
typedef struct SASIndexKey_t	SASIndexKey_t
	Index Key Handle structure for binary index B-trees.

Functions
static int	SASIndexKeyCompare (SASIndexKey_t *op_a, SASIndexKey_t *op_b)
	binary key compare logic for Index B-Tree keys. More...
static void	SASIndexKeyCopy (SASIndexKey_t *dest, SASIndexKey_t *src)
	Copy a binary key from source to destination. More...
static size_t	SASIndexKeySize (SASIndexKey_t *key)
	Return the binary index key copy_size. More...
static void	SASIndexKeyInitRef (SASIndexKey_t *dest, void *value)
	Initial a binary key @ destination with a address value. More...
static void	SASIndexKeyInitUInt64 (SASIndexKey_t *dest, unsigned long long value)
	Initial a binary key @ destination with a unsigned 64-bit integer value. More...
static unsigned long long	SASIndexKeyReturn1stUInt64 (SASIndexKey_t *dest)
	Return the value of the 1st binary key as a unsigned 64-bit integer value. More...
static void	SASIndexKeyInitInt64 (SASIndexKey_t *dest, signed long long value)
	Initial a binary key @ destination with a signed 64-bit integer value. More...
static long long	SASIndexKeyReturn1stInt64 (SASIndexKey_t *dest)
	Return the value of the 1st binary key as a signed 64-bit integer value. More...
static void	SASIndexKeyInitDouble (SASIndexKey_t *dest, double value)
	Initial a binary key @ destination with a signed 64-bit integer value. More...
static double	SASIndexKeyReturn1stDouble (SASIndexKey_t *dest)
	Return the value of the 1st binary key as a signed 64-bit integer value. More...

Variables
const unsigned long	machine_sign_mask = (0x80000000)
	mask use to invert the signbit.
const unsigned long	double_exp_mask = (0x7ff00000)
	mask use to invert the exponent.
const unsigned long	double_mask = (0xffffffff)
	mask use to invert the sign and exponent.

Detailed Description

API for defining binary Index keys for B-Trees.

Intialize the SASIndexKey_t structure with a sequence of values to be used as keys for SASIndex_t BTrees.

Todo:

Enhance this API to build larger (multi-part) keys via a streams interface similar to interface in sphlfentry.h. We have enough to here to implement SPHContext_t but a generalized API would make SASIndex_t more useful.

Function Documentation

static int SASIndexKeyCompare ( SASIndexKey_t *  op_a, SASIndexKey_t *  op_b  )

inlinestatic

binary key compare logic for Index B-Tree keys.

Optimized for comparing unsigned long integer word values that are the size of address pointers (void*) Also optimized for early (in the first or only word of the key) misscompare.

Parameters

op_a	Handle of the left SASIndexKey_t.
op_b	Handle of the right SASIndexKey_t.

Returns

an integer value -1 for op_a < op_b, 0 for op_a == op_b, and +1 for op_a > op_b.

static void SASIndexKeyCopy ( SASIndexKey_t *  dest, SASIndexKey_t *  src  )

inlinestatic

Copy a binary key from source to destination.

Use the copy_size to copy the required header and the significant words of key data.

Parameters

dest	Handle of the destination SASIndexKey_t.
src	Handle of the source SASIndexKey_t.

static void SASIndexKeyInitDouble ( SASIndexKey_t *  dest, double  value  )

inlinestatic

Initial a binary key @ destination with a signed 64-bit integer value.

Note

Need to flip the sign bit to get the correct ordering with a mix of signed and unsigned key values.

Parameters

dest	Handle of the destination SASIndexKey_t.
value	signed long long value which will be the key.

static void SASIndexKeyInitInt64 ( SASIndexKey_t *  dest, signed long long  value  )

inlinestatic

Initial a binary key @ destination with a signed 64-bit integer value.

Note

Need to flip the sign bit to get the correct ordering with a mix of signed and unsigned key values.

Parameters

dest	Handle of the destination SASIndexKey_t.
value	signed long long value which will be the key.

static void SASIndexKeyInitRef ( SASIndexKey_t *  dest, void *  value  )

inlinestatic

Initial a binary key @ destination with a address value.

Parameters

dest	Handle of the destination SASIndexKey_t.
value	Address value which will be the key.

static void SASIndexKeyInitUInt64 ( SASIndexKey_t *  dest, unsigned long long  value  )

inlinestatic

Initial a binary key @ destination with a unsigned 64-bit integer value.

Parameters

dest	Handle of the destination SASIndexKey_t.
value	unsigned long long value which will be the key.

static double SASIndexKeyReturn1stDouble ( SASIndexKey_t *  dest )

inlinestatic

Return the value of the 1st binary key as a signed 64-bit integer value.

Parameters

dest	Handle of the source SASIndexKey_t.

Returns

value of the 1st key element as a unsigned 64-bit integer.

static long long SASIndexKeyReturn1stInt64 ( SASIndexKey_t *  dest )

inlinestatic

Return the value of the 1st binary key as a signed 64-bit integer value.

Parameters

dest	Handle of the source SASIndexKey_t.

Returns

value of the 1st key element as a unsigned 64-bit integer.

static unsigned long long SASIndexKeyReturn1stUInt64 ( SASIndexKey_t *  dest )

inlinestatic

Return the value of the 1st binary key as a unsigned 64-bit integer value.

Parameters

dest	Handle of the source SASIndexKey_t.

Returns

value of the 1st key element as a unsigned 64-bit integer.

static size_t SASIndexKeySize ( SASIndexKey_t *  key )

inlinestatic

Return the binary index key copy_size.

Use the copy_size to copy the required header and the significant words of key data.

Parameters

key	Handle of a SASIndexKey_t.

Returns

current copy_size of the referenced key.