NAME
GlusterFS::GFAPI::FFI::File - GFAPI File API
SYNOPSIS
DESCRIPTION
ATTRIBUTES
fd
originalpath
mode
CONSTRUCTOR
new
options
METHODS
fileno
Return the internal file descriptor (glfd) that is used by the underlying implementation to request I/O operations.
mode
The I/O mode for the file. If the file was created using the Volume-fopen()> function, this will be the value of the mode parameter. This is a read-only attribute.
name
If the file object was created using Volume-fopen()>, the name of the file.
closed
Bool indicating the current state of the file object. This is a read-only attribute; the close() method changes the value.
close
Close the file. A closed file cannot be read or written any more.
discard
This is similar to UNMAP command that is used to return the unused/freed blocks back to the storage system. In this implementation, fallocate with FALLOC_FL_PUNCH_HOLE is used to eventually release the blocks to the filesystem. If the brick has been mounted with '-o discard' option, then the discard request will eventually reach the SCSI storage if the storage device supports UNMAP.
dup
Return a duplicate of File object. This duplicate File class instance encapsulates a duplicate glfd obtained by invoking glfs_dup().
fallocate
This is a Linux-specific sys call, unlike posix_fallocate()
Allows the caller to directly manipulate the allocated disk space for the file for the byte range starting at offset and continuing for length bytes.
fchmod
Change this file's mode
fchown
Change this file's owner and group id
fdatasync
Flush buffer cache pages pertaining to data, but not the ones pertaining to metadata.
fgetsize
Return the size of a file, as reported by fstat()
fgetxattr
Retrieve the value of the extended attribute identified by key for the file.
parameters
key-
Key of extended attribute
size-
If size is specified as zero, we first determine the size of xattr and then allocate a buffer accordingly. If size is non-zero, it is assumed the caller knows the size of xattr.
returns
Value of extended attribute corresponding to key specified.
flistxattr
Retrieve list of extended attributes for the file.
parameters
size-
If size is specified as zero, we first determine the size of list and then allocate a buffer accordingly. If size is non-zero, it is assumed the caller knows the size of the list.
returns
List of extended attributes.
fsetxattr
Set extended attribute of file.
parameters
key-
The key of extended attribute.
key-
The valiue of extended attribute.
key-
Possible values are 0 (default), 1 and 2.
If 0 - xattr will be created if it does not exist, or the value will be replaced if the xattr exists. If 1 - it performs a pure create, which fails if the named attribute already exists. If 2 - it performs a pure replace operation, which fails if the named attribute does not already exist.
fremovexattr
Remove a extended attribute of the file.
parameters
key-
The key of extended attribute.
fstat
Returns Stat object for this file.
returns
Returns the stat information of the file.
fsync
Flush buffer cache pages pertaining to data and metadata.
ftruncate
Truncated the file to a size of length bytes.
If the file previously was larger than this size, the extra data is lost.
If the file previously was shorter, it is extended, and the extended part reads as null bytes.
parameters
length-
Length to truncate the file to in bytes.
lseek
Set the read/write offset position of this file.
The new position is defined by pos relative to how
parameters
pos-
sets new offset position according to 'how'
how-
SEEK_SET- sets offset positionposbytes relative to beginning of file.SEEK_CUR- the position is set relative to the current position.SEEK_END- sets the position relative to the end of the file.
returns
the new offset position
read
Read at most size bytes from the file.
parameters
size-
length of read buffer. If less than 0, then whole file is read. Default is -1.
returns
buffer of size length
readinto
Read up to len(buf) bytes into buf which must be a bytearray. This method is useful when you have to read a large file over multiple read calls. While read() allocates a buffer every time it's invoked, readinto() copies data to an already allocated buffer passed to it.
parameters
buf
returns
the number of bytes read (0 for EOF).
write
Write data to the file.
parameters
data-
The data to be written to file.
returns
The size in bytes actually written
zerofill
Fill length number of bytes with zeroes starting from offset.
parameters
offset-
Start at offset location
length-
Size/length in bytes
BUGS
SEE ALSO
AUTHOR
Ji-Hyeon Gim <potatogim@gluesys.com>
COPYRIGHT AND LICENSE
This software is copyright 2017-2018 by Ji-Hyeon Gim.
This is free software; you can redistribute it and/or modify it under the same terms as the GPLv2/LGPLv3.