GFS_PIO_SET_VIEW_INDEX(3)

NAME
gfs_pio_set_view_index - change file view to an individual fragment

SYNOPSIS

#include <gfarm/gfarm.h>

char *gfs_pio_set_view_index (GFS_File gf, int fragment_number, int fragment_index, char *host, int flags);

DESCRIPTION

gfs_pio_set_view_index() changes the process's view of the data in the file specified by gf to a file fragment with the index fragment_index.

When creating a new file, it is necessary to specify the total number of file fragments fragment_number. Every parallel process should specify the same fragment_number for the corresponding file. When the file exists, GFARM_FILE_DONTCARE can be specified. If fragment_number is different from the total fragment number of the existent file, it is erroneous.

host is used for explicitly specifying a filesystem node. If host is NULL, appropriate filesystem node is chosen.

Values of flag are constructed by a bitwise-inclusive-OR of the following list.

GFARM_FILE_SEQUENTIAL
    File will be accessed sequentially.

GFARM_FILE_REPLICATE
    File may be replicated to a local filesystem when accessing remotely. This flag cannot be specified with GFARM_FILE_NOT_REPLICATE.

GFARM_FILE_NOT_REPLICATE
    File may not be replicated to a local filesystem when accessing remotely. This flag cannot be specified with GFARM_FILE_REPLICATE.

By default, Gfarm files are accessed as a whole file in global file view where each fragment can be seamlessly accessed.

RETURN VALUES

NULL
    The function terminated successfully.

GFARM_ERR_NO_MEMORY
    Insufficient memory was available.

GFARM_ERR_OPERATION_NOT_PERMITTED
    The file is not a regular fragmented file.

GFARM_ERR_FRAGMENT_NUMBER_DOES_NOT_MATCH
    The total number of file fragments is different from the existence one.

GFARM_ERR_INVALID_ARGUMENT
    Invalid arguments are specified, for instance, GFARM_FILE_DONTCARE is specified as the total number of fragments of a newly created file.

Others
    An error except the above occurred. The reason is shown by its pointed strings.

SEE ALSO

gfs_pio_create(3), gfs_pio_open(3), gfs_pio_set_view_local(3)