def ascii_str(string):
- """
- Convert a string to ascii, or return None if the input is None.
+ """Convert a string to ascii, or return None if the input is None.
This is useful where a parameter may be None by default, or a
string. librbd only accepts ascii, hence the need for conversion.
class RBDImageMetadata(object):
- """RBD image metadata to be used with RBDImageIOWrapper"""
+ """RBD image metadata to be used with RBDImageIOWrapper."""
def __init__(self, image, pool, user, conf):
self.image = image
self.pool = str(pool)
class RBDImageIOWrapper(io.RawIOBase):
- """
- Wrapper to provide standard Python IO interface to RBD images so that they
- can be treated as files.
+ """Wrapper to provide standard Python IO interface to RBD images.
+
+ This enables librbd.Image objects to be treated as standard Python IO
+ objects.
+
+ Calling unimplemented interfaces will raise IOError.
"""
def __init__(self, rbd_meta):
offset = self._offset
total = self._rbd_meta.image.size()
- # (dosaboy): posix files do not barf if you read beyond their length
- # (they just return nothing) but rbd images do so we need to return
- # empty string if we are at the end of the image
+ # NOTE(dosaboy): posix files do not barf if you read beyond their
+ # length (they just return nothing) but rbd images do so we need to
+ # return empty string if we have reached the end of the image.
if (offset >= total):
return ''
LOG.warning(_("flush() not supported in this version of librbd"))
def fileno(self):
- """
- Since rbd image does not have a fileno we raise an IOError (recommended
- for IOBase class implementations - see
- http://docs.python.org/2/library/io.html#io.IOBase)
+ """RBD does not have support for fileno() so we raise IOError.
+
+ Raising IOError is recommended way to notify caller that interface is
+ not supported - see http://docs.python.org/2/library/io.html#io.IOBase
"""
raise IOError("fileno() not supported by RBD()")
class RBDVolumeProxy(object):
- """
- Context manager for dealing with an existing rbd volume.
+ """Context manager for dealing with an existing rbd volume.
This handles connecting to rados and opening an ioctx automatically,
and otherwise acts like a librbd Image object.
class RADOSClient(object):
- """
- Context manager to simplify error handling for connecting to ceph
- """
+ """Context manager to simplify error handling for connecting to ceph."""
def __init__(self, driver, pool=None):
self.driver = driver
self.cluster, self.ioctx = driver._connect_to_rados(pool)
class RBDDriver(driver.VolumeDriver):
- """Implements RADOS block device (RBD) volume commands"""
+ """Implements RADOS block device (RBD) volume commands."""
def __init__(self, *args, **kwargs):
super(RBDDriver, self).__init__(*args, **kwargs)
self.configuration.append_config_values(rbd_opts)
self.rbd = kwargs.get('rbd', rbd)
def check_for_setup_error(self):
- """Returns an error if prerequisites aren't met"""
+ """Returns an error if prerequisites aren't met."""
if rados is None:
msg = _('rados and rbd python libraries not found')
raise exception.VolumeBackendAPIException(data=msg)
self._stats = stats
def get_volume_stats(self, refresh=False):
- """Return the current state of the volume service. If 'refresh' is
- True, run the update first.
+ """Return the current state of the volume service.
+
+ If 'refresh' is True, run the update first.
"""
if refresh:
self._update_volume_stats()
return hasattr(self.rbd, 'RBD_FEATURE_LAYERING')
def create_cloned_volume(self, volume, src_vref):
- """Clone a logical volume"""
+ """Clone a logical volume."""
with RBDVolumeProxy(self, src_vref['name'], read_only=True) as vol:
vol.copy(vol.ioctx, str(volume['name']))
raise exception.VolumeIsBusy(volume_name=volume['name'])
def create_snapshot(self, snapshot):
- """Creates an rbd snapshot"""
+ """Creates an rbd snapshot."""
with RBDVolumeProxy(self, snapshot['volume_name']) as volume:
snap = str(snapshot['name'])
volume.create_snap(snap)
volume.protect_snap(snap)
def delete_snapshot(self, snapshot):
- """Deletes an rbd snapshot"""
+ """Deletes an rbd snapshot."""
with RBDVolumeProxy(self, snapshot['volume_name']) as volume:
snap = str(snapshot['name'])
if self._supports_layering():
pass
def create_export(self, context, volume):
- """Exports the volume"""
+ """Exports the volume."""
pass
def remove_export(self, context, volume):
- """Removes an export for a logical volume"""
+ """Removes an export for a logical volume."""
pass
def initialize_connection(self, volume, connector):
Code Review / openstack-build / cinder-build.git / commitdiff