#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: db_env_set_func_seek

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 db_env_set_func_seek method configures all operations performed by a process and all of its threads of control, not operations confined to a single database environment.

Although the db_env_set_func_seek method may be called at any time during the life of the application, it should normally be called before making calls to the db_env_create or db_create methods.

The db_env_set_func_seek method returns a non-zero error value on failure and 0 on success.

Parameters

func_seek

The func_seek parameter is the function which seeks to a specific location in a file.

The fd parameter 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 treated as a backward seek, not a forward one.

The whence parameter specifies where in the file the byte offset is relative to, as described by the IEEE/ANSI Std 1003.1 (POSIX) lseek system call.

The func_seek function must return the value of errno on failure and 0 on success.

See Also