pungi/pungi/media_split.py
Lubomír Sedlář d6dc269ef4 Remove FSF address from comments
The address is no longer correct. We can just as well simply point to
the web page describing the license.

Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>
2016-09-23 10:26:43 +02:00

124 lines
3.9 KiB
Python

# -*- coding: utf-8 -*-
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Library General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, see <https://gnu.org/licenses/>.
import os
SIZE_UNITS = {
"b": 1,
"k": 1024,
"M": 1024 ** 2,
"G": 1024 ** 3,
}
def convert_media_size(size):
if isinstance(size, str):
if size[-1] in SIZE_UNITS:
num = int(size[:-1])
units = size[-1]
else:
num = int(size)
units = "b"
result = num * SIZE_UNITS[units]
else:
result = int(size)
if result <= 0:
raise ValueError("Media size must be a positive number: %s" % size)
return result
def convert_file_size(size, block_size=2048):
"""round file size to block"""
blocks = int(size / block_size)
if size % block_size:
blocks += 1
return blocks * block_size
class MediaSplitter(object):
"""
MediaSplitter splits files so that they fit on a media of given size.
Each file added to the spliter has a size in bytes that will be rounded to
the nearest multiple of block size. If the file is sticky, it will be
included on each disk. The files will be on disks in the same order they
are added; there is no re-ordering. The number of disk is thus not the
possible minimum.
"""
def __init__(self, media_size, compose=None):
self.media_size = convert_media_size(media_size)
self.files = [] # to preserve order
self.file_sizes = {}
self.sticky_files = set()
self.compose = compose
def add_file(self, name, size, sticky=False):
name = os.path.normpath(name)
size = int(size)
old_size = self.file_sizes.get(name, None)
if old_size is not None and old_size != size:
raise ValueError("File size mismatch; file: %s; sizes: %s vs %s" % (name, old_size, size))
if size > self.media_size:
raise ValueError("File is larger than media size: %s" % name)
self.files.append(name)
self.file_sizes[name] = size
if sticky:
self.sticky_files.add(name)
@property
def total_size(self):
return sum(self.file_sizes.values())
@property
def total_size_in_blocks(self):
return sum([convert_file_size(i) for i in list(self.file_sizes.values())])
def split(self, first_disk=0, all_disks=0):
all_files = []
sticky_files = []
sticky_files_size = 0
for name in self.files:
if name in self.sticky_files:
sticky_files.append(name)
sticky_files_size += convert_file_size(self.file_sizes[name])
else:
all_files.append(name)
disks = []
disk = {}
# as it would be on single medium (sticky_files just once)
total_size_single = sticky_files_size
while all_files:
name = all_files.pop(0)
size = convert_file_size(self.file_sizes[name])
if not disks or disk["size"] + size > self.media_size:
disk = {"size": sticky_files_size, "files": sticky_files[:]}
disks.append(disk)
disk["files"].append(name)
disk["size"] += size
total_size_single += size
if self.compose:
self.compose.log_debug("MediaSplitter: free space on single media would be %s. Total size of single medium: %s." % (self.media_size - total_size_single, total_size_single))
return disks