pungi/pungi/media_split.py

134 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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):
def __init__(self, media_size):
self.media_size = convert_media_size(media_size)
self.files = [] # to preserve order
self.file_sizes = {}
self.sticky_files = set()
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 None:
self.files.append(name)
self.file_sizes[name] = size
elif old_size != size:
raise ValueError("File size mismatch; file: %s; sizes: %s vs %s" % (name, old_size, size))
elif size > self.media_size:
raise ValueError("File is larger than media size: %s" % name)
if sticky:
self.sticky_files.add(name)
'''
def load(self, file_name):
f = open(file_name, "r")
for line in f:
line = line.strip()
if not line:
continue
name, size = line.split(" ")
self.add_file(name, size)
f.close()
def scan(self, pattern):
for i in glob.glob(pattern):
self.add_file(i, os.path.getsize(i))
def dump(self, file_name):
f = open(file_name, "w")
for name in self.files:
f.write("%s %s\n" % (os.path.basename(name), self.file_sizes[name]))
f.close()
'''
@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 = {}
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": 0, "files": []}
disks.append(disk)
disk["files"].extend(sticky_files)
disk["size"] += sticky_files_size
disk["files"].append(name)
disk["size"] += convert_file_size(self.file_sizes[name])
return disks