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)