Package CedarBackup2 :: Package writers :: Module util
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Module util

source code

Provides utilities related to image writers.


Author: Kenneth J. Pronovici <pronovic@ieee.org>

Classes [hide private]
  IsoImage
Represents an ISO filesystem image.
Functions [hide private]
 
validateDevice(device, unittest=False)
Validates a configured device.
source code
 
validateScsiId(scsiId)
Validates a SCSI id string.
source code
 
validateDriveSpeed(driveSpeed)
Validates a drive speed value.
source code
 
readMediaLabel(devicePath)
Reads the media label (volume name) from the indicated device.
source code
Variables [hide private]
  logger = logging.getLogger("CedarBackup2.log.writers.util")
  MKISOFS_COMMAND = ['mkisofs']
  VOLNAME_COMMAND = ['volname']
Function Details [hide private]

validateDevice(device, unittest=False)

source code 

Validates a configured device. The device must be an absolute path, must exist, and must be writable. The unittest flag turns off validation of the device on disk.

Parameters:
  • device - Filesystem device path.
  • unittest - Indicates whether we're unit testing.
Returns:
Device as a string, for instance "/dev/cdrw"
Raises:
  • ValueError - If the device value is invalid.
  • ValueError - If some path cannot be encoded properly.

validateScsiId(scsiId)

source code 

Validates a SCSI id string. SCSI id must be a string in the form [<method>:]scsibus,target,lun. For Mac OS X (Darwin), we also accept the form IO.*Services[/N].

Parameters:
  • scsiId - SCSI id for the device.
Returns:
SCSI id as a string, for instance "ATA:1,0,0"
Raises:
  • ValueError - If the SCSI id string is invalid.

Note: For consistency, if None is passed in, None will be returned.

validateDriveSpeed(driveSpeed)

source code 

Validates a drive speed value. Drive speed must be an integer which is >= 1.

Parameters:
  • driveSpeed - Speed at which the drive writes.
Returns:
Drive speed as an integer
Raises:
  • ValueError - If the drive speed value is invalid.

Note: For consistency, if None is passed in, None will be returned.

readMediaLabel(devicePath)

source code 

Reads the media label (volume name) from the indicated device. The volume name is read using the volname command.

Parameters:
  • devicePath - Device path to read from
Returns:
Media label as a string, or None if there is no name or it could not be read.