diskimage-builder/diskimage_builder/block_device/utils.py
Andreas Florath 3d48a528c1 Refactor: block-device handling (local loop)
Block device handling can be somewhat complex - especially
when taking things like md, lvm or encryption into account.

This patch factors out the creation and deletion of the local
loop image device handling into a python library.

The main propose of this patch is to implement the needed
infrastructure.  Based on this, more advanced functions can be added.
Example: (advanced) partitioning, LVM, handling different boot
scenarios (BIOS, UEFI, ...), possibility of handling multiple images
(local loop image, iSCSI, physical hard disk, ...), handling of
different filesystems for different partitions / LVs.

Change-Id: Ib626b36a00f8a5dc3dbde8df3e2619a2438eaaf1
Signed-off-by: Andreas Florath <andreas@florath.net>
2016-09-08 04:31:01 +00:00

74 lines
2.3 KiB
Python

# Copyright 2016 Andreas Florath (andreas@florath.net)
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
SIZE_SPECS = [
["TiB", 1024**4],
["GiB", 1024**3],
["MiB", 1024**2],
["KiB", 1024**1],
["TB", 1000**4],
["GB", 1000**3],
["MB", 1000**2],
["KB", 1000**1],
["T", 1000**4],
["G", 1000**3],
["M", 1000**2],
["K", 1000**1],
["B", 1],
["", 1], # No unit -> size is given in bytes
]
def _split_size_spec(size_spec):
for spec_key, spec_value in SIZE_SPECS:
if len(spec_key) == 0:
return size_spec, spec_key
if size_spec.endswith(spec_key):
return size_spec[:-len(spec_key)], spec_key
raise RuntimeError("size_spec [%s] not known" % size_spec)
def _get_unit_factor(unit_str):
for spec_key, spec_value in SIZE_SPECS:
if unit_str == spec_key:
return spec_value
raise RuntimeError("unit_str [%s] not known" % unit_str)
def parse_abs_size_spec(size_spec):
size_cnt_str, size_unit_str = _split_size_spec(size_spec)
unit_factor = _get_unit_factor(size_unit_str)
return int(unit_factor * (
float(size_cnt_str) if len(size_cnt_str) > 0 else 1))
def convert_to_utf8(jdata):
"""Convert to UTF8.
The json parser returns unicode strings. Because in
some python implementations unicode strings are not
compatible with utf8 strings - especially when using
as keys in dictionaries - this function recursively
converts the json data.
"""
if isinstance(jdata, unicode):
return jdata.encode('utf-8')
elif isinstance(jdata, dict):
return {convert_to_utf8(key): convert_to_utf8(value)
for key, value in jdata.iteritems()}
elif isinstance(jdata, list):
return [convert_to_utf8(je) for je in jdata]
else:
return jdata