def from_conf(cls, path=None, **overrides):
"""Initialize instance from YAML configuration file,
writing updates (only to keys, specified by "conf_update_keys") back to it."""
from onedrive import portalocker
import yaml
if path is None:
path = cls.conf_path_default
log.debug("Using default state-file path: %r", path)
path = os.path.expanduser(path)
with open(path, "rb") as src:
portalocker.lock(src, portalocker.LOCK_SH)
conf = yaml.load(src.read())
portalocker.unlock(src)
conf.setdefault("conf_save", path)
conf_cls = dict()
for ns, keys in cls.conf_update_keys.viewitems():
for k in keys:
try:
v = conf.get(ns, dict()).get(k)
except AttributeError:
if not cls.conf_raise_structure_errors:
raise
raise KeyError(
"Unable to get value for configuration parameter"
' "{k}" in section "{ns}", check configuration file (path: {path}) syntax'
" near the aforementioned section/value.".format(ns=ns, k=k, path=path)
)
if v is not None:
conf_cls["{}_{}".format(ns, k)] = conf[ns][k]
conf_cls.update(overrides)
self = cls(**conf_cls)
self.conf_save = conf["conf_save"]
return self
def sync(self):
if not self.conf_save:
return
from onedrive import portalocker
import yaml
retry = False
with open(self.conf_save, "r+b") as src:
portalocker.lock(src, portalocker.LOCK_SH)
conf_raw = src.read()
conf = yaml.load(io.BytesIO(conf_raw)) if conf_raw else dict()
portalocker.unlock(src)
conf_updated = False
for ns, keys in self.conf_update_keys.viewitems():
for k in keys:
v = getattr(self, "{}_{}".format(ns, k), None)
if isinstance(v, unicode):
v = v.encode("utf-8")
if v != conf.get(ns, dict()).get(k):
# log.debug(
# 'Different val ({}.{}): {!r} != {!r}'\
# .format(ns, k, v, conf.get(ns, dict()).get(k)) )
conf.setdefault(ns, dict())[k] = v
conf_updated = True
if conf_updated:
log.debug("Updating configuration file (%r)", src.name)
conf_new = yaml.safe_dump(conf, default_flow_style=False)
if os.name == "nt":
# lockf + tempfile + rename doesn't work on windows due to
# "[Error 32] ... being used by another process",
# so this update can potentially leave broken file there
# Should probably be fixed by someone who uses/knows about windows
portalocker.lock(src, portalocker.LOCK_EX)
src.seek(0)
if src.read() != conf_raw:
retry = True
else:
src.seek(0)
src.truncate()
src.write(conf_new)
src.flush()
portalocker.unlock(src)
else:
with tempfile.NamedTemporaryFile(
prefix="{}.".format(basename(self.conf_save)), dir=dirname(self.conf_save), delete=False
) as tmp:
try:
portalocker.lock(src, portalocker.LOCK_EX)
src.seek(0)
if src.read() != conf_raw:
retry = True
else:
portalocker.lock(tmp, portalocker.LOCK_EX)
tmp.write(conf_new)
os.fchmod(tmp.fileno(), stat.S_IMODE(os.fstat(src.fileno()).st_mode))
os.rename(tmp.name, src.name)
# Non-atomic update for pids that already have fd to old file,
# but (presumably) are waiting for the write-lock to be released
src.seek(0)
src.truncate()
src.write(conf_new)
finally:
try:
os.unlink(tmp.name)
except OSError:
pass
if retry:
log.debug("Configuration file (%r) was changed" " during merge, restarting merge", self.conf_save)
return self.sync()