class MoveFSItemOperation(FSOperationBase):
"""Move a file or directory to the given name"""
__slots__ = ("_source_path", "_destination_path", "_actual_destination_path")
name = "FSItemMove"
def __init__(self, transaction, source_path, destination_path):
super(MoveFSItemOperation, self).__init__(transaction)
self._source_path = Path(source_path).expandvars()
self._destination_path = self._actual_destination_path = Path(destination_path).expandvars()
# if we move into a directory, the filename will just be appended
if self._destination_path.isdir():
self._actual_destination_path = self._destination_path / source_path.basename()
# END handle actual destination
def apply(self):
if self._actual_destination_path.exists():
raise AssertionError("Cannot move item %s onto existing one at %s" %
(self._source_path, self._actual_destination_path))
# END handle existing dsetination
if self._dry_run():
return
self.log.info("moving %s to %s", self._source_path, self._destination_path)
self._source_path.move(self._destination_path)
self._operation_performed = True
def rollback(self):
try:
if not self._operation_performed or not self._actual_destination_path.exists():
return
# fail gracefully
if self._source_path.exists():
raise AssertionError("Cannot move destination %s into existing source %s, source directory should not exist" % (
self._actual_destination_path, self._source_path))
self.log.info("moving %s to %s", self._actual_destination_path, self._source_path)
self._actual_destination_path.move(self._source_path)
finally:
self._reset_state()
# END assure state reset
#{ Interface
def actual_destination(self):
""":return: path to the final destination"""
return self._actual_destination_path
class CreateFSItemOperation(FSOperationBase):
"""Create a directory or file with the given access permissions and ownership. In
case of a file, you may specify an initial content.
For this operation to succeed, the destination path must not exist yet!"""
__slots__ = ("_path", "_content", "_mode", "_uid", "_gid")
name = "CreateFSItem"
def __init__(self, transaction, path, initial_file_content=None, mode=None, uid=None, gid=None):
"""Initialize the operation with a path to create. If initial_file_content is set,
to a string, it will be written in binary mode to a file. If it is unset,
a directory will be created. Non-existing parent-directories will be created.
After creation, the mode will be set if not None, and uid and gid will be set as well to the given
numerical ID if of of them is not None"""
super(CreateFSItemOperation, self).__init__(transaction)
self._assert_posix()
self._path = Path(path)
self._content = initial_file_content
self._mode = mode
self._uid = uid
self._gid = gid
def apply(self):
if self._content and self._path.isdir() or not self._content and self._path.isfile():
raise AssertionError(
"Cannot create item of type directory or file as the an equally named item of different type exists")
# END sanity check
if self._dry_run():
return
if self._path.exists():
return
# end ignore existing items of the same type
# we don't do it the most efficient way, as we could specify certain things in
# at creation. For now, we don't do it though as it shouldn't matter
if self._content:
self.log.info("creating file %s", self._path)
self._path.write_bytes(self._content)
else:
self.log.info("creating directory %s", self._path)
self._path.makedirs()
# END initial creation
self._operation_performed = True
if self._mode is not None:
self._path.chmod(self._mode)
# END handle mode
self.set_user_group(self._path, self._gid, self._uid)
def rollback(self):
try:
if not self._operation_performed or not self._path.exists():
return
if self._content:
self.log.info("Removing file %s", self._path)
self._path.remove()
else:
self.log.info("Removing single directory %s", self._path)
self._path.rmdir()
# END handle removal, safely as we don't recursively delete anything
finally:
self._reset_state()
class RsyncOperation(Operation):
"""An operation which allows to safely copy a source file or directory to a
given destination file or directory.
The location of the rsync-program is currently taken assumed.
@note only works on linux (even though theoretically, rsync might exist on windows"""
__slots__ = ("_source_path",
"_destination_path",
"_actual_destination_path",
"_move_mode",
"_current_path",
"_total_num_files_transferred",
"_num_files_transferred",
"_total_transferred_filesize_bytes",
"_transferred_filesize_bytes",
"_current_total_transferred_filesize_bytes",
"_seen_progress_for_current_file",
"_current_bandwidth",
"_start_time",
'_last_time_left_s',
"_process",
"_destination_existed",
"_actual_destination_existed",
"_max_bandwidth_kb"
)
# -------------------------
# @name Constants
# @{
NUM_FILES = "Number of files transferred: "
TRANSFERRED_BYTES = "Total file size: "
# -- End Constants -- @}
# -------------------------
# @name Configuration
# @{
name = "rsync"
description = "Synchronize directory structures or copy files"
re_is_path = re.compile(r"^/?[\w\-]+(?:/[\w\-\.]+)*$")
re_progress = re.compile(r"(?P<bytes>\d+)\s+(?P<percent>\d+)%\s+(?P<bandwidth>\d+\.\d+\w+/\w)\s+.*")
rsync_path = "/usr/bin/rsync"
rm_path = "/bin/rm"
# -- End Configuration -- @}
def __init__(self, transaction, source, destination, move=False, max_bandwidth_kb=0):
"""initialize an rsync operation with a source and destination path.
If move is True, the source will be deleted after a successful rsync operation.
An operation is successful if there were no error lines in stderr of the process, and if
If the maximum bandwidth is greater 0, the rsync operation will be using no more than the given
bandwidth in kilobytes.
the return code was 0."""
super(RsyncOperation, self).__init__(transaction)
if os.name != "posix":
raise AssertionError("This module only works on posix systems")
# END handle posix
self._source_path = Path(source).expandvars()
self._destination_path = self._actual_destination_path = Path(destination).expandvars()
self._destination_existed = self._destination_path.exists()
# rsync creates at max one parent directory if it does not exist. It will alays put
# directories into other directories, unless you specify a / in the end of source.
#
# In case of files, it will always put them into existing directories, or rename them to the given
# name
if ((self._source_path.isdir() and not self._source_path.tolinuxpath().endswith('/')) or
(self._source_path.isfile() and not self._destination_existed or self._destination_path.isdir())):
self._actual_destination_path = self._destination_path / self._source_path.basename() + "/"
# / as we have to assure it copies the contents of the directory in case of undo
# END assure destination
self._actual_destination_existed = self._actual_destination_path.exists()
self._move_mode = move
self._max_bandwidth_kb = max_bandwidth_kb
self._current_path = None
self._total_num_files_transferred = 0
self._total_transferred_filesize_bytes = 0
self._process = None
self._reset_current_state()
def _reset_current_state(self):
"""Reset the current values that will be counted in the following invokation"""
self._start_time = 0
self._num_files_transferred = 0
self._transferred_filesize_bytes = 0
self._current_total_transferred_filesize_bytes = 0
self._seen_progress_for_current_file = False
self._current_bandwidth = None
self._last_time_left_s = None
def _set_current_file(self, path):
"""set the path of the file being currently transferred, adjust state"""
# if there is progress for the previous file, we count it
# This will make us miss the last file, but its okay ...
if self._seen_progress_for_current_file:
self._num_files_transferred += 1
self._current_total_transferred_filesize_bytes += self._transferred_filesize_bytes
self._transferred_filesize_bytes = 0
self._seen_progress_for_current_file = False
# END handle count
self._current_path = path
def _handle_progress_match(self, match):
"""Check the match regex and adjust our state"""
self._current_bandwidth = match.group("bandwidth")
self._transferred_filesize_bytes = int(match.group("bytes"))
def _update_progress(self, gather_mode=False):
"""Use our state to produce a progresss
@param gather_mode in gather mode, we will just present a count up"""
self._abort_point()
self._seen_progress_for_current_file = True
prog = self._progress()
if gather_mode:
prog.set(self._num_files_transferred, message="Gathering Files ... %i" % self._num_files_transferred)
else:
# remaining bytes
remaining_mbytes = (
self._total_transferred_filesize_bytes - self._current_total_transferred_filesize_bytes) / 1024 ** 2
time_taken = max(1, time.time() - self._start_time)
time_left_s = self._total_transferred_filesize_bytes / \
max(1, (self._current_total_transferred_filesize_bytes / time_taken))
# remaining time
suffix = "second"
divisor = 1
if time_left_s >= 60.0:
divisor = 60
suffix = "minute"
# END handle suffix
if time_left_s > 1:
suffix += "s"
# END handle plural
if self._last_time_left_s is not None:
time_left_s = (time_left_s + self._last_time_left_s) / 2.0 # soften jumps a bit
# END average values
msg = "Transferring %s at %s - %i files left, done in about %i %s" % (
self._current_path, self._current_bandwidth, self._total_num_files_transferred - self._num_files_transferred, int(time_left_s / divisor), suffix)
prog.set(self._num_files_transferred, message=msg)
self._last_time_left_s = time_left_s
# END handle gather mode
def _parse_output_line(self, line):
"""Parse a single line and adjust our state accordingly
@return 1 == file, 2 == progress, 3 == stats, False otherwise"""
# FILENAME
###########
line = line.strip() # strip trailing newline
if self.re_is_path.match(line) is not None:
self._set_current_file(line)
return 1
# END check for path
# PROGRESS
###########
# parse " 27131904 51% 2.44MB/s 0:00:10 "
m = self.re_progress.match(line)
if m:
self._handle_progress_match(m)
self._update_progress()
return 2
# END handle progress
# STATS
###########
if line.startswith(self.NUM_FILES):
self._total_num_files_transferred = int(line[len(self.NUM_FILES):])
return 3
# END check file count
if line.startswith(self.TRANSFERRED_BYTES):
self._total_transferred_filesize_bytes = int(line[len(self.TRANSFERRED_BYTES):].split(" ")[0])
return 3
# END check transferred bytes
return False
def _force_removal(self, destination):
"""Forcefully delete given directory or file, linux only.
@throws OSError"""
self.log.info("about to remove directory at %s ... " % destination)
rval = subprocess.call([self.rm_path, "-Rf", str(destination)])
if rval != 0:
raise OSError("Failed to remove file or directory that we managed to copy previously: %s" % destination)
self.log.info("... done removing destination path")
def _parse_output(self, gather_mode=False):
"""Parse the output of the rsync process and set the progress accordingly
@param gather_mode if True, we will just hang onto the standard output, which
may speed up processing. This way, we only count the line actually
@return error data, chunk-separated, lines are within the data accordingly"""
empty_list = list()
timeout = 0.1
err_data = list()
process = self._process
# GATHER MODE
##################
try:
if gather_mode:
while True:
line = process.stdout.readline().decode()
if not line:
return err_data
if self._parse_output_line(line) == 1:
self._update_progress(gather_mode)
# END update progress only if we parsed something
# END loop forever
return err_data
# END handle stderr
# RUN MODE
###########
# Set stderr to non-blocking to allow simple reads
fl = fcntl.fcntl(process.stderr.fileno(), fcntl.F_GETFL)
fcntl.fcntl(process.stderr.fileno(), fcntl.F_SETFL, fl | os.O_NONBLOCK)
while process.poll() is None:
# stdout is in blocking mode, so we can read lines accordingly
# try to read as many as possible
# as long as there is someting
while select([process.stdout.fileno()], empty_list, empty_list, timeout)[0]:
line = process.stdout.readline().decode()
if not line:
break
self._parse_output_line(line)
# END handle standard output
try:
# from stderr we expect not much output if at all, so poll it from time to time
err = process.stderr.read()
if err:
err_data.append(err)
# END gather errors
except IOError:
# it can happen that the process goes down in the process of reading stdout
# Therefore we fail to read - lets just try again in this case
continue
# END handle invalid reads
time.sleep(timeout)
# END while process is active
finally:
# if we don't close the handles, process will stay around, even if the handle gets
# deleted. Will never get used to that, call it a bug !!! Everytime I fall for this ...
if process.stdout:
process.stdout.close()
if process.stderr:
process.stderr.close()
# END assure f*****g pipes are closed !!!
return err_data
# -------------------------
# @name Interface Implementation
# @{
def apply(self):
try:
# assure that directories will have their content copied, to assure
# the
source = self._source_path
def_args = ("-a", "--append", "--progress", self._source_path, self._destination_path)
def proc(args, gather_mode=False):
self.log.info(" ".join(args))
return subprocess.Popen(args, stdin=None, stdout=subprocess.PIPE, stderr=not gather_mode and subprocess.PIPE or None, shell=False)
# END proc helper
def handle_process(gather_mode=False):
# PARSE OUTPUT
###############
try:
err_chunks = self._parse_output(gather_mode)
if self._current_path is not None:
self._set_current_file(None) # trigger the last file to be registered
self._process.wait()
finally:
if self._process.poll() is None:
self._process.terminate()
# END assure process is terminated
# END if process is still running here, kill it, as we are likely to be in
# an exceptional state (user aborted)
if self._process.returncode != 0 or err_chunks:
raise OSError("rsync failed with error code: %i, error was \n%s" %
(self._process.returncode, "".join(err_chunks)))
# END handle error code
self._process = None
# END handle process
# GATHER RUN
#############
# Gather information about the run to determine the required needs
args = [self.rsync_path, "--dry-run", "--stats"]
args.extend(def_args)
self._progress().setup(round_robin=True, relative=False)
self.log.info("Calculating cost of operation ... ")
self._process = proc(args, True)
handle_process(gather_mode=True)
self._reset_current_state()
# VERIFY FREE SPACE IN DESTINATION
##################################
# destination doesn't necessarily exist, hence we try the parent path as well
# prefer the actual destination, in case its a dir - the parent might already be
# on another mount
for item in [self._destination_path, self._destination_path.dirname()]:
if not item.exists():
continue
# END handle missing items
if not self._total_transferred_filesize_bytes:
self.log.info("Wouldn't do any work - skipping transfer operation")
return
# end abort if nothing to do
fs_info = os.statvfs(item)
free_bytes_at_destination = fs_info.f_bsize * fs_info.f_bavail
if self._total_transferred_filesize_bytes >= free_bytes_at_destination:
msg = "Insufficient disk space available at %s to copy %s - require %iMB, have %iMB" % (
item, self._source_path, self._total_transferred_filesize_bytes / 1024 ** 2, free_bytes_at_destination / 1024 ** 2)
raise OSError(msg)
# END check free space
# END for each item to try
args = [self.rsync_path]
if self._dry_run():
args.append("--dry-run")
# END handle dry-run
if self._max_bandwidth_kb > 0:
args.append("--bwlimit=%i" % self._max_bandwidth_kb)
# END handle bandwidth limit
args.extend(def_args)
# START PROCESS
################
self.log.info("Starting %s" % (" ".join(args)))
self._progress().setup(range=(0, self._total_num_files_transferred), relative=True)
self._start_time = time.time()
self._process = proc(args)
handle_process()
if self._move_mode and not self._dry_run():
self._force_removal(self._source_path)
# END handle movemode
finally:
if self._process and self._process.poll() is not None:
self.log.error("Terminating child forcefully")
try:
self._process.kill()
except OSError:
pass
self._process = None
# END handle process
# END assure process is killed on error
def rollback(self):
# without destination, we couldn't fix anything anyway
if not self._destination_path.exists():
return
# have to reproduce source from destination ?
if not self._source_path.exists():
if self._destination_existed:
self.log.warn("Destination at %s existed - rollback might copy more data than expected" %
self._destination_path)
# END info
self.log.info("Restoring source from destination ...")
t = Transaction(self.log, progress=self._progress())
type(self)(t, self._actual_destination_path + "/", self._source_path)
self.log.info("rolling back rsync from %s to %s", self._actual_destination_path, self._source_path)
if not t.apply().succeeded():
raise IOError(
"Expected copy operation to succeed - rollback failed, destination data exists at %s" % self._destination_path)
# END apply sub-transaction
# END source doesn't exist
# finally remove destination if possible
for destination, existed in ((self._actual_destination_path, self._actual_destination_existed),
(self._destination_path, self._destination_existed)):
if existed:
self.log.warn(
"Refusing deletion of destination during rollback as it existed before the rsync operation at %s" % destination)
continue
# END sanity check
self._force_removal(destination)
# END for each pair of possible paths
# -- End Interface Implementation -- @}
# -------------------------
# @name Interface
# @{
def actual_destination(self):
""":return: the destination that will actually receive the copy"""
return self._actual_destination_path
