sbws.util package

Submodules

sbws.util.config module

Util functions to manage sbws configuration files.

sbws.util.config.configure_logging(args, conf)

sbws.util.config.get_config(args)

Get ConfigParser interpolating all configuration files.

sbws.util.config.validate_config(conf)

Checks the given conf for bad values or bad combinations of values. If there’s something wrong, returns False and a list of error messages. Otherwise, return True and an empty list

sbws.util.filelock module

class sbws.util.filelock.DirectoryLock(dname)

Bases: sbws.util.filelock._FLock

Holds a lock on a file in dname so that other sbws processes/threads won’t try to read/write while we are reading/writing in this directory.

>>> with DirectoryLock(dname):
>>>     # do some reading/writing in dname
>>> # no longer have the lock

Note: The directory must already exist.

Parameters:dname (str) – Name of directory for which we want to obtain a lock

class sbws.util.filelock.FileLock(fname)

Bases: sbws.util.filelock._FLock

Holds a lock on fname so that other sbws processes/threads won’t try to read/write while we are reading/writing this file.

>>> with FileLock(fname):
>>>     # do some reading/writing of fname
>>> # no longer have the lock

Parameters:fname (str) – Name of the file for which we want to obtain a lock

sbws.util.parser module

sbws.util.parser.create_parser()

sbws.util.state module

class sbws.util.state.State(fname)

Bases: object

State allows one to atomically access and update a simple state file on disk across threads and across processes.

To put it blunty, due to limited developer time and his inability to quickly find a way to safely access and update more complex data types (namely, collections like list, set, and dict), you may only store simple types of data as enumerated in _ALLOWED_TYPES. Keys must be strings.

Data is stored as JSON on disk in the provided file file.

>>> state = State('foo.state')
>>> # state == {}

>>> state['linux'] = True
>>> # 'foo.state' now exists on disk with the JSON for {'linux': True}

>>> # We read 'foo.state' from disk in order to get the most up-to-date
>>> #     state info. Pretend another process has updated 'linux' to be
>>> #     False
>>> state['linux']
>>> # returns False

>>> # Pretend another process has added the user's age to the state file.
>>> #     As before, we read the state file from disk for the most
>>> #     up-to-date info.
>>> state['age']
>>> # Returns 14

>>> # We now set their name. We read the state file first, set the option,
>>> #     and then write it out.
>>> state['name'] = 'John'

>>> # We can do many of the same things with a State object as with a dict
>>> for key in state: print(key)
>>> # Prints 'linux', 'age', and 'name'

get(key, d=None)

Implements a dictionary get method reading and locking a json file.

sbws.util.stem module

sbws.util.stem.add_event_listener(controller, func, event)

sbws.util.stem.attach_stream_to_circuit_listener(controller, circ_id)

Returns a function that should be given to add_event_listener(). It looks for newly created streams and attaches them to the given circ_id

sbws.util.stem.circuit_str(controller, circ_id)

sbws.util.stem.get_socks_info(controller)

Returns the first SocksPort Tor is configured to listen on, in the form of an (address, port) tuple

sbws.util.stem.init_controller(port=None, path=None, set_custom_stream_settings=True)

sbws.util.stem.is_bootstrapped(c)

sbws.util.stem.launch_tor(conf)

sbws.util.stem.only_relays_with_bandwidth(controller, relays, min_bw=None, max_bw=None)

Given a list of relays, only return those that optionally have above min_bw and optionally have below max_bw, inclusively. If neither min_bw nor max_bw are given, essentially just returns the input list of relays.

sbws.util.stem.parse_user_torrc_config(torrc, torrc_text)

Parse the user configuration torrc text call extra_lines to a dictionary suitable to use with stem and return a new torrc dictionary that merges that dictionary with the existing torrc. Example:

[tor] extra_lines =

Log debug file /tmp/tor-debug.log NumCPUs 1

sbws.util.stem.remove_event_listener(controller, func)

sbws.util.stem.set_torrc_options_can_fail(controller)

Set options that can fail, at runtime.

They can be set at launch, but since the may fail because they are not supported in some Tor versions, it’s easier to try one by one at runtime and ignore the ones that fail.

sbws.util.stem.set_torrc_runtime_options(controller)

Set torrc options at runtime.

sbws.util.userquery module

sbws.util.userquery.query_yes_no(question, default='yes')

Ask a yes/no question via input() and return the user’s answer.

Parameters:

• question (str) – Prompt given to the user.
• default (str) – The assumed answer if th user just hits Enter. It must be 'yes' (the default if no default is given), 'no', or None (meaning an answer is required from the user).

Returns:

True if we ended up with a ‘yes’ answer, otherwise False.

Module contents