def apply_selector(self, selector, address=None, custom_selector=None):
"""List of servers matching the provided selector(s).
:Parameters:
- `selector`: a callable that takes a Selection as input and returns
a Selection as output. For example, an instance of a read
preference from :mod:`~pymongo.read_preferences`.
- `address` (optional): A server address to select.
- `custom_selector` (optional): A callable that augments server
selection rules. Accepts a list of
:class:`~pymongo.server_description.ServerDescription` objects and
return a list of server descriptions that should be considered
suitable for the desired operation.
.. versionadded:: 3.4
"""
if getattr(selector, 'min_wire_version', 0):
common_wv = self.common_wire_version
if common_wv and common_wv < selector.min_wire_version:
raise ConfigurationError(
"%s requires min wire version %d, but topology's min"
" wire version is %d" %
(selector, selector.min_wire_version, common_wv))
if self.topology_type == TOPOLOGY_TYPE.Unknown:
return []
elif self.topology_type in (TOPOLOGY_TYPE.Single,
TOPOLOGY_TYPE.LoadBalanced):
# Ignore selectors for standalone and load balancer mode.
return self.known_servers
elif address:
# Ignore selectors when explicit address is requested.
description = self.server_descriptions().get(address)
return [description] if description else []
elif self.topology_type == TOPOLOGY_TYPE.Sharded:
# Ignore read preference.
selection = Selection.from_topology_description(self)
else:
selection = selector(Selection.from_topology_description(self))
# Apply custom selector followed by localThresholdMS.
if custom_selector is not None and selection:
selection = selection.with_server_descriptions(
custom_selector(selection.server_descriptions))
return self._apply_local_threshold(selection)
def test_bool(self):
client = single_client()
wait_until(lambda: client.address, "discover primary")
selection = Selection.from_topology_description(
client._topology.description)
self.assertTrue(selection)
self.assertFalse(selection.with_server_descriptions([]))
def test_bool(self):
client = single_client()
wait_until(lambda: client.address, "discover primary")
selection = Selection.from_topology_description(
client._topology.description)
self.assertTrue(selection)
self.assertFalse(selection.with_server_descriptions([]))
def apply_selector(self, selector, address, custom_selector=None):
def apply_local_threshold(selection):
if not selection:
return []
settings = self._topology_settings
# Round trip time in seconds.
fastest = min(
s.round_trip_time for s in selection.server_descriptions)
threshold = settings.local_threshold_ms / 1000.0
return [s for s in selection.server_descriptions
if (s.round_trip_time - fastest) <= threshold]
if getattr(selector, 'min_wire_version', 0):
common_wv = self.common_wire_version
if common_wv and common_wv < selector.min_wire_version:
raise ConfigurationError(
"%s requires min wire version %d, but topology's min"
" wire version is %d" % (selector,
selector.min_wire_version,
common_wv))
if self.topology_type in (TOPOLOGY_TYPE.Single,
TOPOLOGY_TYPE.LoadBalanced):
# Ignore selectors for standalone and load balancer mode.
return self.known_servers
elif address:
# Ignore selectors when explicit address is requested.
description = self.server_descriptions().get(address)
return [description] if description else []
elif self.topology_type == TOPOLOGY_TYPE.Sharded:
# Ignore read preference.
selection = Selection.from_topology_description(self)
else:
selection = selector(Selection.from_topology_description(self))
# Apply custom selector followed by localThresholdMS.
if custom_selector is not None and selection:
selection = selection.with_server_descriptions(
custom_selector(selection.server_descriptions))
return apply_local_threshold(selection)
def apply_selector(self, selector, address):
def apply_local_threshold(selection):
if not selection:
return []
settings = self._topology_settings
# Round trip time in seconds.
fastest = min(
s.round_trip_time for s in selection.server_descriptions)
threshold = settings.local_threshold_ms / 1000.0
return [s for s in selection.server_descriptions
if (s.round_trip_time - fastest) <= threshold]
if getattr(selector, 'min_wire_version', 0):
common_wv = self.common_wire_version
if common_wv and common_wv < selector.min_wire_version:
raise ConfigurationError(
"%s requires min wire version %d, but topology's min"
" wire version is %d" % (selector,
selector.min_wire_version,
common_wv))
if self.topology_type == TOPOLOGY_TYPE.Single:
# Ignore the selector.
return self.known_servers
elif address:
description = self.server_descriptions().get(address)
return [description] if description else []
elif self.topology_type == TOPOLOGY_TYPE.Sharded:
# Ignore the read preference, but apply localThresholdMS.
return apply_local_threshold(
Selection.from_topology_description(self))
else:
return apply_local_threshold(
selector(Selection.from_topology_description(self)))
def apply_selector(self, selector, address):
def apply_local_threshold(selection):
if not selection:
return []
settings = self._topology_settings
# Round trip time in seconds.
fastest = min(s.round_trip_time
for s in selection.server_descriptions)
threshold = settings.local_threshold_ms / 1000.0
return [
s for s in selection.server_descriptions
if (s.round_trip_time - fastest) <= threshold
]
if getattr(selector, 'min_wire_version', 0):
common_wv = self.common_wire_version
if common_wv and common_wv < selector.min_wire_version:
raise ConfigurationError(
"%s requires min wire version %d, but topology's min"
" wire version is %d" %
(selector, selector.min_wire_version, common_wv))
if self.topology_type == TOPOLOGY_TYPE.Single:
# Ignore the selector.
return self.known_servers
elif address:
description = self.server_descriptions().get(address)
return [description] if description else []
elif self.topology_type == TOPOLOGY_TYPE.Sharded:
# Ignore the read preference, but apply localThresholdMS.
return apply_local_threshold(
Selection.from_topology_description(self))
else:
return apply_local_threshold(
selector(Selection.from_topology_description(self)))
def _new_selection(self):
"""A Selection object, initially including all known servers.
Hold the lock when calling this.
"""
return Selection.from_topology_description(self._description)
def _new_selection(self):
"""A Selection object, initially including all known servers.
Hold the lock when calling this.
"""
return Selection.from_topology_description(self._description)
