int
db_env_set_func_ioinfo(int (*func_ioinfo)(const char *path,
int fd, u_int32_t *mbytesp, u_int32_t *bytesp, u_int32_t *iosizep));
Description
The Berkeley DB library requires the ability to determine the size and I/O
characteristics of a file. The func_ioinfo argument must conform
to the following interface:
int ioinfo(const char *path, int fd,
u_int32_t *mbytesp, u_int32_t *bytesp, u_int32_t *iosizep);
The path argument is the pathname of the file to be checked, and the
fd argument is an open file descriptor on the file.
If the mbytesp and bytesp arguments are non-NULL, the
ioinfo function must return in them the size of the file: the
number of megabytes in the file into the memory location referenced by
the mbytesp argument, and the number of bytes over and above that
number of megabytes into the memory location referenced by the
bytesp argument.
In addition, if the iosizep argument is non-NULL, the ioinfo
function must return the optimum granularity for I/O operations to the file
in the memory location referenced by it.
The func_ioinfo function must return the value of errno on
failure and 0 on success.
The db_env_set_func_ioinfo interface affects the entire application, not a single
database or database environment.
While the db_env_set_func_ioinfo interface may be used to configure Berkeley DB at any time
during the life of the application, it should normally be called before
making any calls to the db_env_create or db_create functions.
The db_env_set_func_ioinfo function returns a non-zero error value on failure and 0 on success.