def test_truncate(self):
# Check that truncate() works as expected
key = b"a" * 32
f = CryptFile(self.file_name, key=key, mode='w+b', block_size=32)
f.write(b"b" * 1237)
f.truncate(15)
f.seek(0)
assert_equal(f.read(), b"b" * 15)
f.truncate(31)
f.seek(0)
assert_equal(f.read(), b"b" * 15 + b"\x00" * 16)
f.truncate(0)
f.seek(0)
assert_equal(len(f.read()), 0)
f.close()
def run():
f = CryptFile(self.file_name, key=key, mode='r+b', block_size=32)
f.truncate(0)
last_data[0] = str(random.getrandbits(128))
f.write(last_data[0])
f.close()
class CachedFileInode(object):
"""
Logical file on-disk. There should be only a single CachedFileInode
instance is per each logical file.
"""
def __init__(self, cachedb, upath, io, filecap, persistent=False):
self.upath = upath
self.closed = False
self.refcnt = 0
self.persistent = persistent
self.invalidated = False
# Use per-file keys for different files, for safer fallback
# in the extremely unlikely event of SHA512 hash collisions
filename, key = cachedb.get_filename_and_key(upath)
filename_state, key_state = cachedb.get_filename_and_key(
upath, b'state')
filename_data, key_data = cachedb.get_filename_and_key(upath, b'data')
self.lock = threading.RLock()
self.dirty = False
self.f = None
self.f_state = None
self.f_data = None
self.stream_f = None
self.stream_offset = 0
self.stream_data = []
open_complete = False
try:
if filecap is None:
# Create new file
raise ValueError()
# Reuse cached metadata
self.f = CryptFile(filename, key=key, mode='r+b')
self.info = json_zlib_load(self.f)
if persistent:
# Reuse cached data
self.f_state = CryptFile(filename_state,
key=key_state,
mode='r+b')
self.f_data = CryptFile(filename_data,
key=key_data,
mode='r+b')
self.block_cache = BlockCachedFile.restore_state(
self.f_data, self.f_state)
open_complete = True
except (IOError, OSError, ValueError):
open_complete = False
if self.f is not None:
self.f.close()
self.f = None
if self.f_state is not None:
self.f_state.close()
if self.f_data is not None:
self.f_data.close()
if not open_complete:
if self.f is None:
self.f = CryptFile(filename, key=key, mode='w+b')
try:
if filecap is not None:
self._load_info(filecap, io, iscap=True)
else:
self.info = ['file', {u'size': 0}]
self.dirty = True
except IOError as err:
os.unlink(filename)
self.f.close()
raise
# Create a data file
self.f_data = CryptFile(filename_data, key=key_data, mode='w+b')
# Block cache on top of data file
self.block_cache = BlockCachedFile(self.f_data,
self.info[1][u'size'])
# Block data state file
self.f_state = CryptFile(filename_state, key=key_state, mode='w+b')
os.utime(self.f.path, None)
os.utime(self.f_data.path, None)
os.utime(self.f_state.path, None)
def _load_info(self, upath, io, iscap=False):
try:
self.info = io.get_info(upath, iscap=iscap)
except (HTTPError, IOError, ValueError) as err:
if isinstance(err, HTTPError) and err.code == 404:
raise IOError(errno.ENOENT, "no such file")
raise IOError(errno.EREMOTEIO, "failed to retrieve information")
self._save_info()
def _save_info(self):
self.f.truncate(0)
self.f.seek(0)
if u'retrieved' not in self.info[1]:
self.info[1][u'retrieved'] = time.time()
json_zlib_dump(self.info, self.f)
def is_fresh(self, lifetime):
if u'retrieved' not in self.info[1]:
return True
return (self.info[1][u'retrieved'] + lifetime >= time.time())
def incref(self):
with self.lock:
self.refcnt += 1
def decref(self):
with self.lock:
self.refcnt -= 1
if self.refcnt <= 0:
self.close()
def close(self):
with self.lock:
if not self.closed:
if self.stream_f is not None:
self.stream_f.close()
self.stream_f = None
self.stream_data = []
self.f_state.seek(0)
self.f_state.truncate(0)
self.block_cache.save_state(self.f_state)
self.f_state.close()
self.block_cache.close()
self.f.close()
if not self.persistent and self.upath is not None and not self.invalidated:
os.unlink(self.f_state.path)
os.unlink(self.f_data.path)
self.closed = True
def _do_rw(self, io, offset, length_or_data, write=False, no_result=False):
if write:
data = length_or_data
length = len(data)
else:
length = length_or_data
self.lock.acquire()
try:
preempted = False
while True:
if write:
pos = self.block_cache.pre_write(offset, length)
else:
pos = self.block_cache.pre_read(offset, length)
if pos is None:
# cache ready
if no_result:
return None
elif write:
return self.block_cache.write(offset, data)
else:
return self.block_cache.read(offset, length)
else:
# cache not ready -- fill it up
c_offset, c_length = pos
if self.stream_f is not None and (
self.stream_offset > c_offset
or c_offset >= self.stream_offset + 3 * 131072):
if not preempted:
# Try to yield to a different in-flight cache operation, in case there
# is one waiting for the lock
preempted = True
self.lock.release()
time.sleep(0)
self.lock.acquire()
continue
self.stream_f.close()
self.stream_f = None
self.stream_data = []
if self.stream_f is None:
self.stream_f = io.get_content(self.info[1][u'ro_uri'],
c_offset,
iscap=True)
self.stream_offset = c_offset
self.stream_data = []
read_offset = self.stream_offset
read_bytes = sum(len(x) for x in self.stream_data)
while read_offset + read_bytes < c_offset + c_length:
block = self.stream_f.read(131072)
if not block:
self.stream_f.close()
self.stream_f = None
self.stream_data = []
break
self.stream_data.append(block)
read_bytes += len(block)
self.stream_offset, self.stream_data = self.block_cache.receive_cached_data(
self.stream_offset, self.stream_data)
except (HTTPError, IOError) as err:
if self.stream_f is not None:
self.stream_f.close()
self.stream_f = None
raise IOError(errno.EREMOTEIO, "I/O error: %s" % (str(err), ))
finally:
self.lock.release()
def get_size(self):
return self.block_cache.get_size()
def get_attr(self):
return dict(type='file', size=self.get_size())
def read(self, io, offset, length):
return self._do_rw(io, offset, length, write=False)
def write(self, io, offset, data):
"""
Write data to file. If *offset* is None, it means append.
"""
with self.lock:
if len(data) > 0:
self.dirty = True
if offset is None:
offset = self.get_size()
self._do_rw(io, offset, data, write=True)
def truncate(self, size):
with self.lock:
if size != self.block_cache.get_size():
self.dirty = True
self.block_cache.truncate(size)
def _buffer_whole_file(self, io):
self._do_rw(io,
0,
self.block_cache.get_size(),
write=False,
no_result=True)
def upload(self, io, parent_cap=None):
with self.lock:
# Buffer all data
self._buffer_whole_file(io)
# Upload the whole file
class Fwrapper(object):
def __init__(self, block_cache):
self.block_cache = block_cache
self.size = block_cache.get_size()
self.f = self.block_cache.get_file()
self.f.seek(0)
def __len__(self):
return self.size
def read(self, size):
return self.f.read(size)
if parent_cap is None:
upath = self.upath
iscap = False
else:
upath = parent_cap + u"/" + ubasename(self.upath)
iscap = True
fw = Fwrapper(self.block_cache)
try:
filecap = io.put_file(upath, fw, iscap=iscap)
except (HTTPError, IOError) as err:
raise IOError(errno.EFAULT, "I/O error: %s" % (str(err), ))
self.info[1][u'ro_uri'] = filecap
self.info[1][u'size'] = self.get_size()
self._save_info()
self.dirty = False
return filecap
def unlink(self):
with self.lock:
if self.upath is not None and not self.invalidated:
os.unlink(self.f.path)
os.unlink(self.f_state.path)
os.unlink(self.f_data.path)
self.upath = None
class CachedFileInode(object):
"""
Logical file on-disk. There should be only a single CachedFileInode
instance is per each logical file.
"""
def __init__(self, cachedb, upath, io, filecap, persistent=False):
self.upath = upath
self.closed = False
self.refcnt = 0
self.persistent = persistent
self.invalidated = False
# Use per-file keys for different files, for safer fallback
# in the extremely unlikely event of SHA512 hash collisions
filename, key = cachedb.get_filename_and_key(upath)
filename_state, key_state = cachedb.get_filename_and_key(upath, b'state')
filename_data, key_data = cachedb.get_filename_and_key(upath, b'data')
self.lock = threading.RLock()
self.dirty = False
self.f = None
self.f_state = None
self.f_data = None
self.stream_f = None
self.stream_offset = 0
self.stream_data = []
open_complete = False
try:
if filecap is None:
# Create new file
raise ValueError()
# Reuse cached metadata
self.f = CryptFile(filename, key=key, mode='r+b')
self.info = json_zlib_load(self.f)
if persistent:
# Reuse cached data
self.f_state = CryptFile(filename_state, key=key_state, mode='r+b')
self.f_data = CryptFile(filename_data, key=key_data, mode='r+b')
self.block_cache = BlockCachedFile.restore_state(self.f_data, self.f_state)
open_complete = True
except (IOError, OSError, ValueError):
open_complete = False
if self.f is not None:
self.f.close()
self.f = None
if self.f_state is not None:
self.f_state.close()
if self.f_data is not None:
self.f_data.close()
if not open_complete:
if self.f is None:
self.f = CryptFile(filename, key=key, mode='w+b')
try:
if filecap is not None:
self._load_info(filecap, io, iscap=True)
else:
self.info = ['file', {u'size': 0}]
self.dirty = True
except IOError as err:
os.unlink(filename)
self.f.close()
raise
# Create a data file
self.f_data = CryptFile(filename_data, key=key_data, mode='w+b')
# Block cache on top of data file
self.block_cache = BlockCachedFile(self.f_data, self.info[1][u'size'])
# Block data state file
self.f_state = CryptFile(filename_state, key=key_state, mode='w+b')
os.utime(self.f.path, None)
os.utime(self.f_data.path, None)
os.utime(self.f_state.path, None)
def _load_info(self, upath, io, iscap=False):
try:
self.info = io.get_info(upath, iscap=iscap)
except (HTTPError, IOError, ValueError) as err:
if isinstance(err, HTTPError) and err.code == 404:
raise IOError(errno.ENOENT, "no such file")
raise IOError(errno.EREMOTEIO, "failed to retrieve information")
self._save_info()
def _save_info(self):
self.f.truncate(0)
self.f.seek(0)
if u'retrieved' not in self.info[1]:
self.info[1][u'retrieved'] = time.time()
json_zlib_dump(self.info, self.f)
def is_fresh(self, lifetime):
if u'retrieved' not in self.info[1]:
return True
return (self.info[1][u'retrieved'] + lifetime >= time.time())
def incref(self):
with self.lock:
self.refcnt += 1
def decref(self):
with self.lock:
self.refcnt -= 1
if self.refcnt <= 0:
self.close()
def close(self):
with self.lock:
if not self.closed:
if self.stream_f is not None:
self.stream_f.close()
self.stream_f = None
self.stream_data = []
self.f_state.seek(0)
self.f_state.truncate(0)
self.block_cache.save_state(self.f_state)
self.f_state.close()
self.block_cache.close()
self.f.close()
if not self.persistent and self.upath is not None and not self.invalidated:
os.unlink(self.f_state.path)
os.unlink(self.f_data.path)
self.closed = True
def _do_rw(self, io, offset, length_or_data, write=False, no_result=False):
if write:
data = length_or_data
length = len(data)
else:
length = length_or_data
self.lock.acquire()
try:
preempted = False
while True:
if write:
pos = self.block_cache.pre_write(offset, length)
else:
pos = self.block_cache.pre_read(offset, length)
if pos is None:
# cache ready
if no_result:
return None
elif write:
return self.block_cache.write(offset, data)
else:
return self.block_cache.read(offset, length)
else:
# cache not ready -- fill it up
c_offset, c_length = pos
if self.stream_f is not None and (self.stream_offset > c_offset or
c_offset >= self.stream_offset + 3*131072):
if not preempted:
# Try to yield to a different in-flight cache operation, in case there
# is one waiting for the lock
preempted = True
self.lock.release()
time.sleep(0)
self.lock.acquire()
continue
self.stream_f.close()
self.stream_f = None
self.stream_data = []
if self.stream_f is None:
self.stream_f = io.get_content(self.info[1][u'ro_uri'], c_offset, iscap=True)
self.stream_offset = c_offset
self.stream_data = []
read_offset = self.stream_offset
read_bytes = sum(len(x) for x in self.stream_data)
while read_offset + read_bytes < c_offset + c_length:
block = self.stream_f.read(131072)
if not block:
self.stream_f.close()
self.stream_f = None
self.stream_data = []
break
self.stream_data.append(block)
read_bytes += len(block)
self.stream_offset, self.stream_data = self.block_cache.receive_cached_data(
self.stream_offset, self.stream_data)
except (HTTPError, IOError) as err:
if self.stream_f is not None:
self.stream_f.close()
self.stream_f = None
raise IOError(errno.EREMOTEIO, "I/O error: %s" % (str(err),))
finally:
self.lock.release()
def get_size(self):
return self.block_cache.get_size()
def get_attr(self):
return dict(type='file', size=self.get_size())
def read(self, io, offset, length):
return self._do_rw(io, offset, length, write=False)
def write(self, io, offset, data):
"""
Write data to file. If *offset* is None, it means append.
"""
with self.lock:
if len(data) > 0:
self.dirty = True
if offset is None:
offset = self.get_size()
self._do_rw(io, offset, data, write=True)
def truncate(self, size):
with self.lock:
if size != self.block_cache.get_size():
self.dirty = True
self.block_cache.truncate(size)
def _buffer_whole_file(self, io):
self._do_rw(io, 0, self.block_cache.get_size(), write=False, no_result=True)
def upload(self, io, parent_cap=None):
with self.lock:
# Buffer all data
self._buffer_whole_file(io)
# Upload the whole file
class Fwrapper(object):
def __init__(self, block_cache):
self.block_cache = block_cache
self.size = block_cache.get_size()
self.f = self.block_cache.get_file()
self.f.seek(0)
def __len__(self):
return self.size
def read(self, size):
return self.f.read(size)
if parent_cap is None:
upath = self.upath
iscap = False
else:
upath = parent_cap + u"/" + ubasename(self.upath)
iscap = True
fw = Fwrapper(self.block_cache)
try:
filecap = io.put_file(upath, fw, iscap=iscap)
except (HTTPError, IOError) as err:
raise IOError(errno.EFAULT, "I/O error: %s" % (str(err),))
self.info[1][u'ro_uri'] = filecap
self.info[1][u'size'] = self.get_size()
self._save_info()
self.dirty = False
return filecap
def unlink(self):
with self.lock:
if self.upath is not None and not self.invalidated:
os.unlink(self.f.path)
os.unlink(self.f_state.path)
os.unlink(self.f_data.path)
self.upath = None