def test_replace_file(self):
workdir = fileutil.abspath_expanduser_unicode(u"test_replace_file")
fileutil.make_dirs(workdir)
replaced_path = os.path.join(workdir, "replaced")
replacement_path = os.path.join(workdir, "replacement")
# when none of the files exist
self.failUnlessRaises(fileutil.ConflictError, fileutil.replace_file,
replaced_path, replacement_path)
# when only replaced exists
fileutil.write(replaced_path, b"foo")
self.failUnlessRaises(fileutil.ConflictError, fileutil.replace_file,
replaced_path, replacement_path)
self.failUnlessEqual(fileutil.read(replaced_path), b"foo")
# when both replaced and replacement exist
fileutil.write(replacement_path, b"bar")
fileutil.replace_file(replaced_path, replacement_path)
self.failUnlessEqual(fileutil.read(replaced_path), b"bar")
self.failIf(os.path.exists(replacement_path))
# when only replacement exists
os.remove(replaced_path)
fileutil.write(replacement_path, b"bar")
fileutil.replace_file(replaced_path, replacement_path)
self.failUnlessEqual(fileutil.read(replaced_path), b"bar")
self.failIf(os.path.exists(replacement_path))
def _write_downloaded_file(self,
local_path_u,
abspath_u,
file_contents,
is_conflict=False,
now=None):
self._log(
"_write_downloaded_file(%r, <%d bytes>, is_conflict=%r, now=%r)" %
(abspath_u, len(file_contents), is_conflict, now))
# 1. Write a temporary file, say .foo.tmp.
# 2. is_conflict determines whether this is an overwrite or a conflict.
# 3. Set the mtime of the replacement file to be T seconds before the
# current local time.
# 4. Perform a file replacement with backup filename foo.backup,
# replaced file foo, and replacement file .foo.tmp. If any step of
# this operation fails, reclassify as a conflict and stop.
#
# Returns the path of the destination file.
precondition_abspath(abspath_u)
replacement_path_u = abspath_u + u".tmp" # FIXME more unique
backup_path_u = abspath_u + u".backup"
if now is None:
now = time.time()
initial_path_u = os.path.dirname(abspath_u)
fileutil.make_dirs_with_absolute_mode(local_path_u, initial_path_u,
(~self._umask) & 0777)
fileutil.write(replacement_path_u, file_contents)
os.chmod(replacement_path_u, (~self._umask) & 0777)
# FUDGE_SECONDS is used to determine if another process
# has written to the same file concurrently. This is described
# in the Earth Dragon section of our design document:
# docs/proposed/magic-folder/remote-to-local-sync.rst
os.utime(replacement_path_u, (now, now - self.FUDGE_SECONDS))
if is_conflict:
return self._rename_conflicted_file(abspath_u, replacement_path_u)
else:
try:
fileutil.replace_file(abspath_u, replacement_path_u,
backup_path_u)
return abspath_u
except fileutil.ConflictError:
return self._rename_conflicted_file(abspath_u,
replacement_path_u)
def _write_downloaded_file(self, local_path_u, abspath_u, file_contents, is_conflict=False, now=None):
self._log("_write_downloaded_file(%r, <%d bytes>, is_conflict=%r, now=%r)"
% (abspath_u, len(file_contents), is_conflict, now))
# 1. Write a temporary file, say .foo.tmp.
# 2. is_conflict determines whether this is an overwrite or a conflict.
# 3. Set the mtime of the replacement file to be T seconds before the
# current local time.
# 4. Perform a file replacement with backup filename foo.backup,
# replaced file foo, and replacement file .foo.tmp. If any step of
# this operation fails, reclassify as a conflict and stop.
#
# Returns the path of the destination file.
precondition_abspath(abspath_u)
replacement_path_u = abspath_u + u".tmp" # FIXME more unique
backup_path_u = abspath_u + u".backup"
if now is None:
now = time.time()
initial_path_u = os.path.dirname(abspath_u)
fileutil.make_dirs_with_absolute_mode(local_path_u, initial_path_u, (~ self._umask) & 0777)
fileutil.write(replacement_path_u, file_contents)
os.chmod(replacement_path_u, (~ self._umask) & 0777)
# FUDGE_SECONDS is used to determine if another process
# has written to the same file concurrently. This is described
# in the Earth Dragon section of our design document:
# docs/proposed/magic-folder/remote-to-local-sync.rst
os.utime(replacement_path_u, (now, now - self.FUDGE_SECONDS))
if is_conflict:
return self._rename_conflicted_file(abspath_u, replacement_path_u)
else:
try:
fileutil.replace_file(abspath_u, replacement_path_u, backup_path_u)
return abspath_u
except fileutil.ConflictError:
return self._rename_conflicted_file(abspath_u, replacement_path_u)