virt-manager/virtinst/generatename.py
Cole Robinson 387614c641 generatename: Move libvirt collision handling to callers
Make every caller pass an explicit cb that handles libvirt
collision processing. Makes it easier to see exactly what is going
on at the call impls
2019-06-11 17:54:45 -04:00

69 lines
1.9 KiB
Python

#
# Copyright 2019 Red Hat, Inc.
#
# This work is licensed under the GNU GPLv2 or later.
# See the COPYING file in the top-level directory.
#
import libvirt
def check_libvirt_collision(collision_cb, val):
"""
Run the passed collision function with val as the only argument:
If libvirtError is raised, return False
If no libvirtError raised, return True
"""
check = False
if val is not None:
try:
if collision_cb(val) is not None:
check = True
except libvirt.libvirtError:
pass
return check
def generate_name(base, collision_cb, suffix="",
start_num=1, sep="-", force_num=False):
"""
Generate a new name from the passed base string, verifying it doesn't
collide with the collision callback.
This can be used to generate disk path names from the parent VM or pool
name. Names generated look like 'base-#suffix', ex:
If foobar, and foobar-1.img already exist, and:
base = "foobar"
suffix = ".img"
output = "foobar-2.img"
:param base: The base string to use for the name (e.g. "my-orig-vm-clone")
:param collision_cb: A callback function to check for collision,
receives the generated name as its only arg
:param start_num: The number to start at for generating non colliding names
:param sep: The separator to use between the basename and the
generated number (default is "-")
:param force_num: Force the generated name to always end with a number
"""
base = str(base)
numrange = list(range(start_num, start_num + 100000))
if not force_num:
numrange = [None] + numrange
ret = None
for i in numrange:
tryname = base
if i is not None:
tryname += ("%s%d" % (sep, i))
tryname += suffix
if not collision_cb(tryname):
ret = tryname
break
assert ret
return ret