Berkeley DB

db_env_set_func_seek

						#include <db.h>
						int
						db_env_set_func_seek(int (*func_seek)(int fd, size_t pgsize,
						db_pgno_t pageno, u_int32_t relative, int rewind, int whence));
					

Description

The Berkeley DB library requires the ability to specify that a subsequent read from or write to a file will occur at a specific location in that file. The func_seek argument must conform to the following interface:

int seek(int fd, size_t pgsize, db_pgno_t pageno, 
u_int32_t relative, int rewind, int whence); 

The fd argument is an open file descriptor on the file.

The seek function must cause a subsequent read from or write to the file to occur at a byte offset specified by the calculation:

(pgsize * pageno) + relative 

If rewind is non-zero, the byte offset is ...