# Copyright (C) 2015 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 hashlib import sha512
from os import path
from sys import exit
from glob import glob
from combox.config import get_nodedirs
def relative_path(p, config, comboxd=True):
"""Returns the relative path to the `p' w. r. t combox or node directory.
If `comboxd' is True, the relative path is w. r. t combox
directory.
If `comboxd' is False, the relative path is w. r. t node
directory.
p: path to a directory or file.
config: a dictionary that contains configuration information about
combox.
"""
directory = None
if comboxd:
directory = '%s/' % config['combox_dir']
else:
for node in get_nodedirs(config):
if p.startswith(node):
directory = '%s/' % node
if directory is None:
err_msg = "invalid path %s" % p
raise ValueError, err_msg
return p.partition(directory)[2]
def cb_path(node_path, config):
"""
Returns abs. path of file (in combox dir.) given the node_path.
"""
if node_path[:-1].endswith('shard'):
# partition function is used to remove the `.shard.N' from the
# file name.
rel_file_path = relative_path(node_path,
config,
False).partition('.shard')[0]
file_cb_path = path.join(config['combox_dir'],
rel_file_path)
else:
file_cb_path = path.join(config['combox_dir'],
relative_path(node_path, config, False))
return file_cb_path
def node_path(cb_path, config, isfile):
"""Returns abs. path of file (in node dir.) given the cb_path (combox dir. path).
If cb_path is a file, it returns the path to its shard in the
first node directory.
isfile: True if cb_path is a file.
"""
if isfile:
# partition function is used to remove the `.shard.N' from the
# file name.
rel_file_path = relative_path(cb_path, config)
file_node_path = path.join(get_nodedirs(config)[0],
rel_file_path)
file_node_path = "%s.shard0" % file_node_path
else:
file_node_path = path.join(get_nodedirs(config)[0],
relative_path(cb_path, config))
return file_node_path
def node_paths(cb_path, config, isfile):
"""Returns list of abs. path of file (in node dir.) the cb_path.
If cb_path is a file, it returns a list of abs. path names of
shards of the file in the node directories.
isfile: True if cb_path is a file
"""
n_paths = []
nodes = get_nodedirs(config)
rel_path = relative_path(cb_path, config)
if isfile:
shard_no = 0
for node in nodes:
file_shard = '%s.shard%d' % (rel_path, shard_no)
n_path = path.join(node, file_shard)
n_paths.append(n_path)
shard_no += 1
else:
for node in nodes:
n_path = path.join(node, rel_path)
n_paths.append(n_path)
return n_paths
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)
mk_dir(dir_path)
def mk_dir(directory):
"""Creates directory"""
try:
os.mkdir(directory)
except OSError, e:
print e, "Something wrong. report bug to sravik@bgsu.edu"
def rm_nodedir(directory, config):
"""
Removes 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)
rm_path(dir_path)
def rm_path(fpath):
"""Removes fpath.
fpath can be a file or a empty directory.
"""
try:
if path.isfile(fpath):
os.remove(fpath)
elif path.isdir(fpath):
os.rmdir(fpath)
except OSError, e:
print e, "Something wrong. report bug to sravik@bgsu.edu"
def move_nodedir(src, dest, config):
"""
Moves directory `directory' inside the nodes from old to new location.
src: old path to the directory
dest: new path to the directory
config: a dictionary containing configuration info about combox.
"""
nodes = get_nodedirs(config)
src_rel_path = relative_path(src, config)
dest_rel_path = relative_path(dest, config)
for node in nodes:
src_dir_path = path.join(node, src_rel_path)
dest_dir_path = path.join(node, dest_rel_path)
try:
os.rename(src_dir_path, dest_dir_path)
except OSError, e:
print e, "Something wrong. report bug to sravik@bgsu.edu"
def rm_shards(fpath, config):
"""
Removes the file shards of `fpath' in the node directories.
fpath: is the path to a file in the combox directory.
config: a dictionary containing configuration info about combox.
"""
nodes = get_nodedirs(config)
rel_path = relative_path(fpath, config)
for node in nodes:
shard_glob = "%s.shard*" % path.join(node, rel_path)
shard_glob = glob(shard_glob)
if not len(shard_glob):
# shard was already deleted.
continue
# there's always only one shard in each node directory. So,
# the glob() will alawys return a list of size 1.
shard = shard_glob[0]
try:
os.remove(shard)
except OSError, e:
print e, "Something wrong. report bug to sravik@bgsu.edu"
def move_shards(src, dest, config):
"""Move the shards in node directories.
This function is used when a file is moved to different location
inside the combox directory. It moves the shards to the
corresponding location in the node directories.
src: old path to the file that was moved.
dest: new path to the file that was moved.
config: a dictionary containing configuration info about combox.
"""
nodes = get_nodedirs(config)
src_rel_path = relative_path(src, config)
dest_rel_path = relative_path(dest, config)
for node in nodes:
src_shard_glob = "%s.shard*" % path.join(node, src_rel_path)
# there's always only one shard in each node directory.
glob_list = glob(src_shard_glob)
if glob_list:
src_shard = glob_list[0]
else:
# shards are not there!, so we return.
return
# get shard number
shard_no = src_shard.partition('.shard')[2]
dest_shard = "%s.shard%s" % (path.join(node, dest_rel_path),
shard_no)
try:
os.rename(src_shard, dest_shard)
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 hash_file(filename, file_content=None):
"""Does a SHA512 hash on the contents of file.
Returns the hexdigest of the file content's hash.
filename: Absolute pathname of the file.
file_content: If not None, hash of file_content is returned.
"""
if not file_content:
file_content = read_file(filename)
return sha512(file_content).hexdigest()
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
def no_of_shards(cb_path, config):
"""Returns the no. of shards that exists for `cb_path' in node directories.
cb_path: path to file in combox directory.
"""
no_shards_there = 0
shard_paths = node_paths(cb_path, config, isfile=True)
for shard in shard_paths:
if path.isfile(shard):
no_shards_there += 1
return no_shards_there