# Copyright (C) 2014 Combox author(s). See AUTHORS.
#
# This file is part of Combox.
#
# Combox 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, either version 3 of the License, or
# (at your option) any later version.
#
# Combox 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
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Combox (see COPYING). If not, see
# <http://www.gnu.org/licenses/>.
import os
from os import path
from sys import exit
from glob import glob
from combox.config import get_nodedirs
def relative_path(p, config):
"""Returns the relative path to the `p' w. r. t combox directory.
p: path to a directory or file.
config: a dictionary that contains configuration information about
combox.
"""
combox_dir = '%s/' % config['combox_dir']
return p.partition(combox_dir)[2]
def mk_nodedir(directory, config):
"""
Creates directory `directory' inside the nodes.
config: a dictionary containing configuration info about combox.
"""
nodes = get_nodedirs(config)
rel_path = relative_path(directory, config)
for node in nodes:
dir_path = path.join(node, rel_path)
try:
os.mkdir(dir_path)
except OSError, e:
print e, "Something wrong. report bug to sravik@bgsu.edu"
def purge_dir(p):
"""
Purge everything under the given directory `p'.
Directory `p' itself is not deleted.
"""
p = path.abspath(p)
if path.isfile(p):
return os.remove(p)
for f in os.listdir(p):
f_path = path.join(p, f)
if path.isfile(f_path):
os.remove(f_path)
else:
purge_dir(f_path)
os.rmdir(f_path)
def split_data(data, n):
"""Split data into `n' parts and return them as an array.
data: Stream of bytes or string
n: Number of parts the file has to be split.
"""
d_parts = []
# File size in bytes.
data_size = len(data)
# No. of bytes for each data part.
part_size = data_size / n
# Take note of remaining bytes; this is non-zero when data_size is
# not divisible by `n'.
rem_bytes = data_size % n
start = 0
end = part_size
while end <= data_size:
d_parts.append(data[start:end])
start = end
end = end + part_size
# read the remaining bytes into the last data part.
end += start + rem_bytes
d_parts[n-1] += data[start:end]
return d_parts
def glue_data(d_parts):
"""Glue different parts of the data to one.
d_parts: Array containing different parts of the data. Each part
is a sequence of bytes.
"""
data = ''
for part in d_parts:
data += part
return data
def read_file(filename):
"""Read file and return it as a string.
filename: Absolute pathname of the file.
"""
file_ = None
try:
file_ = open(filename, 'rb')
except IOError:
print "ERROR: opening %s" % (filename)
exit(1)
return file_.read()
def write_file(filename, filecontent):
"""Write `filecontent' to `filename'.
filename: Absolute pathname of the file.
filecontent: String/bytstream to write to filename.
"""
file_ = None
try:
file_ = open(filename, 'wb')
file_.write(filecontent)
except IOError:
print "ERROR: creating and writing content to %s" % (filename)
exit(1)
def write_shards(shards, directories, shard_basename):
"""Write shards to respective files respective files.
shard: list of strings (ciphers or data).
directories: absolute path of directories to which it shards must be written to.
shard_basename: base name of the shard.
"""
shard_no = 0
for directory in directories:
# partial filename of the shard
p_filename = path.join(directory, shard_basename)
shard_name = "%s.shard%s" % (p_filename, shard_no)
write_file(shard_name, shards[shard_no])
shard_no += 1
def read_shards(directories, shard_basename):
"""Read the shards from directory and return it as a list.
directories: absolute path of directories from which to read the shards.
shard_basename: base name of the shard.
"""
# get the names of the file shards
file_shards = []
for directory in directories:
filename_glob = "%s.shard*" % path.join(directory, shard_basename)
file_shard = glob(filename_glob)[0]
file_shards.append(file_shard)
shards = []
for file_shard in sorted(file_shards):
shard_content = read_file(file_shard)
shards.append(shard_content)
return shards
