Source code for robot.utils.connectioncache

#  Copyright 2008-2015 Nokia Networks
#  Copyright 2016-     Robot Framework Foundation
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  See the License for the specific language governing permissions and
#  limitations under the License.

from typing import Any

from .normalizing import NormalizedDict

Connection = Any

[docs] class ConnectionCache: """Cache for libraries to use with concurrent connections, processes, etc. The cache stores the registered connections (or other objects) and allows switching between them using generated indices, user given aliases or connection objects themselves. This is useful with any library having a need for multiple concurrent connections, processes, etc. This class is used also outside the core framework by SeleniumLibrary, SSHLibrary, etc. Backwards compatibility is thus important when doing changes. """ def __init__(self, no_current_msg='No open connection.'): self._no_current = NoConnection(no_current_msg) self.current = self._no_current #: Current active connection. self._connections = [] self._aliases = NormalizedDict[int]() @property def current_index(self) -> 'int|None': if not self: return None for index, conn in enumerate(self): if conn is self.current: return index + 1 @current_index.setter def current_index(self, index: 'int|None'): if index is None: self.current = self._no_current else: self.current = self._connections[index - 1]
[docs] def register(self, connection: Connection, alias: 'str|None' = None): """Registers given connection with optional alias and returns its index. Given connection is set to be the :attr:`current` connection. If alias is given, it must be a string. Aliases are case and space insensitive. The index of the first connection after initialization, and after :meth:`close_all` or :meth:`empty_cache`, is 1, second is 2, etc. """ self.current = connection self._connections.append(connection) index = len(self._connections) if alias: self._aliases[alias] = index return index
[docs] def switch(self, identifier: 'int|str|Connection') -> Connection: """Switches to the connection specified using the ``identifier``. Identifier can be an index, an alias, or a registered connection. Raises an error if no matching connection is found. Updates :attr:`current` and also returns its new value. """ self.current = self.get_connection(identifier) return self.current
[docs] def get_connection(self, identifier: 'int|str|Connection|None' = None) -> Connection: """Returns the connection specified using the ``identifier``. Identifier can be an index (integer or string), an alias, a registered connection or ``None``. If the identifier is ``None``, returns the current connection if it is active and raises an error if it is not. Raises an error also if no matching connection is found. """ if identifier is None: if not self: self.current.raise_error() return self.current try: index = self.get_connection_index(identifier) except ValueError as err: raise RuntimeError(err.args[0]) return self._connections[index-1]
[docs] def get_connection_index(self, identifier: 'int|str|Connection') -> int: """Returns the index of the connection specified using the ``identifier``. Identifier can be an index (integer or string), an alias, or a registered connection. New in Robot Framework 7.0. :meth:`resolve_alias_or_index` can be used with earlier versions. """ if isinstance(identifier, str) and identifier in self._aliases: return self._aliases[identifier] if identifier in self._connections: return self._connections.index(identifier) + 1 try: index = int(identifier) except (ValueError, TypeError): index = -1 if 0 < index <= len(self._connections): return index raise ValueError(f"Non-existing index or alias '{identifier}'.")
[docs] def resolve_alias_or_index(self, alias_or_index): """Deprecated in RF 7.0. Use :meth:`get_connection_index` instead.""" # This was initially added for SeleniumLibrary in RF 3.1.2. # # The new method was added in RF 7.0. We can loudly deprecate this # earliest in RF 8.0. return self.get_connection_index(alias_or_index)
[docs] def close_all(self, closer_method: str = 'close'): """Closes connections using the specified closer method and empties cache. If simply calling the closer method is not adequate for closing connections, clients should close connections themselves and use :meth:`empty_cache` afterward. """ for conn in self._connections: getattr(conn, closer_method)() self.empty_cache() return self.current
[docs] def empty_cache(self): """Empties the connection cache. Indexes of the new connections starts from 1 after this. """ self.current = self._no_current self._connections = [] self._aliases = NormalizedDict()
__getitem__ = get_connection def __iter__(self): return iter(self._connections) def __len__(self): return len(self._connections) def __bool__(self): return self.current is not self._no_current
[docs] class NoConnection: def __init__(self, message): self.message = message def __getattr__(self, name): if name.startswith('__') and name.endswith('__'): raise AttributeError self.raise_error()
[docs] def raise_error(self): raise RuntimeError(self.message)
def __bool__(self): return False