/usr/share/pyshared/carquinyol/filestore.py is in python-carquinyol-0.88 0.88.0-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 | # Copyright (C) 2008, One Laptop Per Child
#
# 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; either version 2 of the License, or
# (at your option) any later version.
#
# 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 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
import os
import errno
import logging
import tempfile
import gobject
from carquinyol import layoutmanager
class FileStore(object):
"""Handle the storage of one file per entry.
"""
# TODO: add protection against store and retrieve operations on entries
# that are being processed async.
def store(self, uid, file_path, transfer_ownership, completion_cb):
"""Store a file for a given entry.
"""
dir_path = layoutmanager.get_instance().get_entry_path(uid)
if not os.path.exists(dir_path):
os.makedirs(dir_path)
destination_path = layoutmanager.get_instance().get_data_path(uid)
if file_path:
if not os.path.isfile(file_path):
raise ValueError('No file at %r' % file_path)
if transfer_ownership:
try:
logging.debug('FileStore moving from %r to %r', file_path,
destination_path)
os.rename(file_path, destination_path)
completion_cb()
except OSError, e:
if e.errno == errno.EXDEV:
self._async_copy(file_path, destination_path,
completion_cb, unlink_src=True)
else:
raise
else:
self._async_copy(file_path, destination_path, completion_cb,
unlink_src=False)
"""
TODO: How can we support deleting the file of an entry?
elif not file_path and os.path.exists(destination_path):
logging.debug('FileStore: deleting %r' % destination_path)
os.remove(destination_path)
completion_cb()
"""
else:
logging.debug('FileStore: Nothing to do')
completion_cb()
def _async_copy(self, file_path, destination_path, completion_cb,
unlink_src):
"""Start copying a file asynchronously.
"""
logging.debug('FileStore copying from %r to %r', file_path,
destination_path)
async_copy = AsyncCopy(file_path, destination_path, completion_cb,
unlink_src)
async_copy.start()
def retrieve(self, uid, user_id, extension):
"""Place the file associated to a given entry into a directory
where the user can read it. The caller is reponsible for
deleting this file.
"""
file_path = layoutmanager.get_instance().get_data_path(uid)
if not os.path.exists(file_path):
logging.debug('Entry %r doesnt have any file', uid)
return ''
use_instance_dir = os.path.exists('/etc/olpc-security') and \
os.getuid() != user_id
if use_instance_dir:
if not user_id:
raise ValueError('Couldnt determine the current user uid.')
destination_dir = os.path.join(os.environ['HOME'], 'isolation',
'1', 'uid_to_instance_dir', str(user_id))
else:
profile = os.environ.get('SUGAR_PROFILE', 'default')
destination_dir = os.path.join(os.path.expanduser('~'), '.sugar',
profile, 'data')
if not os.path.exists(destination_dir):
os.makedirs(destination_dir)
if extension is None:
extension = ''
elif extension:
extension = '.' + extension
fd, destination_path = tempfile.mkstemp(prefix=uid + '_',
suffix=extension, dir=destination_dir)
os.close(fd)
os.unlink(destination_path)
# Try to hard link from the original file to the targetpath. This can
# fail if the file is in a different filesystem. Do a symlink instead.
try:
os.link(file_path, destination_path)
except OSError, e:
if e.errno == errno.EXDEV:
os.symlink(file_path, destination_path)
else:
raise
# Try to make the original file readable. This can fail if the file is
# in a FAT filesystem.
try:
os.chmod(file_path, 0604)
except OSError, e:
if e.errno != errno.EPERM:
raise
return destination_path
def get_file_path(self, uid):
return layoutmanager.get_instance().get_data_path(uid)
def delete(self, uid):
"""Remove the file associated to a given entry.
"""
file_path = layoutmanager.get_instance().get_data_path(uid)
if os.path.exists(file_path):
os.remove(file_path)
def hard_link_entry(self, new_uid, existing_uid):
existing_file = layoutmanager.get_instance().get_data_path(existing_uid)
new_file = layoutmanager.get_instance().get_data_path(new_uid)
logging.debug('removing %r', new_file)
os.remove(new_file)
logging.debug('hard linking %r -> %r', new_file, existing_file)
os.link(existing_file, new_file)
class AsyncCopy(object):
"""Copy a file in chunks in the idle loop.
"""
CHUNK_SIZE = 65536
def __init__(self, src, dest, completion, unlink_src=False):
self.src = src
self.dest = dest
self.completion = completion
self._unlink_src = unlink_src
self.src_fp = -1
self.dest_fp = -1
self.written = 0
self.size = 0
def _cleanup(self):
os.close(self.src_fp)
os.close(self.dest_fp)
def _copy_block(self, user_data=None):
try:
data = os.read(self.src_fp, AsyncCopy.CHUNK_SIZE)
count = os.write(self.dest_fp, data)
self.written += len(data)
# error writing data to file?
if count < len(data):
logging.error('AC: Error writing %s -> %s: wrote less than '
'expected', self.src, self.dest)
self._complete(RuntimeError(
'Error writing data to destination file'))
return False
# FIXME: emit progress here
# done?
if len(data) < AsyncCopy.CHUNK_SIZE:
self._complete(None)
return False
except Exception, err:
logging.error('AC: Error copying %s -> %s: %r', self.src, self.
dest, err)
self._complete(err)
return False
return True
def _complete(self, *args):
self._cleanup()
if self._unlink_src:
os.unlink(self.src)
self.completion(*args)
def start(self):
self.src_fp = os.open(self.src, os.O_RDONLY)
self.dest_fp = os.open(self.dest, os.O_RDWR | os.O_TRUNC | os.O_CREAT,
0644)
stat = os.fstat(self.src_fp)
self.size = stat[6]
gobject.idle_add(self._copy_block)
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