odb_data Struct Reference

a "database". More...

#include <odb.h>

Collaboration diagram for odb_data:


Public Attributes
odb_node_t *	node_base
	base memory area of the page
odb_index_t *	hash_base
	base memory of hash table
odb_descr_t *	descr
	the current state of database
odb_hash_mask_t	hash_mask
	== descr->size - 1
unsigned int	sizeof_header
	from base_memory to odb header
unsigned int	offset_node
	from base_memory to node array
void *	base_memory
	base memory of the maped memory
int	fd
	mmaped memory file descriptor
char *	filename
	full path name of sample file
int	ref_count
	reference count
list_head	list
	hash bucket list

Detailed Description

a "database".

this is an in memory only description.

We allow to manage a database inside a mapped file with an "header" of unknown size so odb_open get a parameter to specify the size of this header. A typical use is:

struct header { int etc; ... }; odb_open(&hash, filename, ODB_RW, sizeof(header)); so on this library have no dependency on the header type.

the internal memory layout from base_memory is: the unknown header (sizeof_header) odb_descr_t the node array: (descr->size * sizeof(odb_node_t) entries the hash table: array of odb_index_t indexing the node array (descr->size * BUCKET_FACTOR) entries