sbws.lib package¶
Submodules¶
sbws.lib.circuitbuilder module¶
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class
sbws.lib.circuitbuilder.
CircuitBuilder
(args, conf, controller, relay_list, close_circuits_on_exit=True)¶ Bases:
object
The CircuitBuilder interface.
Subclasses must implement their own build_circuit() function. Subclasses may keep additional state if they’d find it helpful.
The primary way to use a CircuitBuilder of any type is to simply create it and then call cb.build_circuit(…) with any options that your CircuitBuilder type needs.
It might be good practice to close circuits as you find you no longer need them, but CircuitBuilder will keep track of existing circuits and close them when it is deleted.
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build_circuit
(*a, **kw)¶ Implementations of this method should build the circuit and return its (str) ID. If it cannot be built, it should return None.
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close_circuit
(circ_id)¶
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relays
¶
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class
sbws.lib.circuitbuilder.
GapsCircuitBuilder
(*a, **kw)¶ Bases:
sbws.lib.circuitbuilder.CircuitBuilder
The build_circuit member function takes a list. Falsey values in the list will be replaced with relays chosen uniformally at random; Truthy values will be assumed to be relays.
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build_circuit
(path)¶ <path> is a list of relays and Falsey values. Relays can be specified by fingerprint or nickname, and fingerprint is highly recommended. Falsey values (like None) will be replaced with relays chosen uniformally at random. A relay will not be in a circuit twice.
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exception
sbws.lib.circuitbuilder.
PathLengthException
(message=None, errors=None)¶ Bases:
Exception
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sbws.lib.circuitbuilder.
valid_circuit_length
(path)¶
sbws.lib.relaylist module¶
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class
sbws.lib.relaylist.
Relay
(fp, cont, ns=None, desc=None)¶ Bases:
object
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address
¶
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average_bandwidth
¶
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bandwidth
¶
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can_exit_to
(host, port)¶ Returns if this relay can MOST LIKELY exit to the given host:port. host can be a hostname, but be warned that we will resolve it locally and use the first (arbitrary/unknown order) result when checking exit policies, which is different than what other parts of the code may do (leaving it up to the exit to resolve the name).
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exit_policy
¶
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fingerprint
¶
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flags
¶
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master_key_ed25519
¶ Obtain ed25519 master key of the relay in server descriptors.
Returns: str, the ed25519 master key base 64 encoded without trailing ‘=’s.
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nickname
¶
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class
sbws.lib.relaylist.
RelayList
(args, conf, controller)¶ Bases:
object
Keeps a list of all relays in the current Tor network and updates it transparently in the background. Provides useful interfaces for getting only relays of a certain type.
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REFRESH_INTERVAL
= 300¶
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bad_exits
¶
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exits
¶
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fast
¶
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guards
¶
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non_exits
¶
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random_relay
()¶
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relays
¶
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sbws.lib.relayprioritizer module¶
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class
sbws.lib.relayprioritizer.
RelayPrioritizer
(args, conf, relay_list, result_dump)¶ Bases:
object
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best_priority
()¶ Return a generator containing the best priority relays.
NOTE: A lower value for priority means better priority. Remember your data structures class in university and consider this something like a min-priority queue.
Priority is calculated as the sum of the “freshness” of each result for a relay. First we determine <oldest_allowed>, the time at which we stop considering results to be valid. From there, a result’s freshness is determined to be the amount of time between when the measurement was made and <oldest_allowed>. Therefore, you should see that a measurement made more recently will have a higher freshness.
We adjust down the freshness for results containing errors. If we ignored errors and didn’t increase a relay’s priority value for them, then we’ll get stuck trying to measure a few relays that have the best priority but are having issues getting measured. If we treated errors with equal weight as successful results, then it would take a while to get around to giving the relay another chance at a getting a successful measurement.
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sbws.lib.resultdump module¶
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class
sbws.lib.resultdump.
Result
(relay, circ, dest_url, scanner_nick, t=None)¶ Bases:
object
A simple struct to pack a measurement result into so that other code can be confident it is handling a well-formed result.
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class
Relay
(fingerprint, nickname, address, master_key_ed25519, average_bandwidth=None)¶ Bases:
object
Implements just enough of a stem RouterStatusEntryV3 for this Result class to be happy
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address
¶
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circ
¶
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dest_url
¶
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fingerprint
¶
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static
from_dict
(d)¶ Given a dict, returns the Result* subtype that is represented by the dict. If we don’t know how to parse the dict into a Result and it’s likely because the programmer forgot to implement something, raises NotImplementedError. If we can’t parse the dict for some other reason, return None.
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master_key_ed25519
¶
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nickname
¶
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relay_average_bandwidth
¶
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scanner
¶
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time
¶
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to_dict
()¶
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type
¶
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version
¶
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class
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class
sbws.lib.resultdump.
ResultDump
(args, conf, end_event)¶ Bases:
object
Runs the enter() method in a new thread and collects new Results on its queue. Writes them to daily result files in the data directory
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enter
()¶ Main loop for the ResultDump thread
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handle_result
(result)¶ Call from ResultDump thread. If we are shutting down, ignores ResultError* types
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results_for_relay
(relay)¶
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store_result
(result)¶ Call from ResultDump thread
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class
sbws.lib.resultdump.
ResultError
(*a, msg=None, **kw)¶ Bases:
sbws.lib.resultdump.Result
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freshness_reduction_factor
¶ When the RelayPrioritizer encounters this Result, how much should it adjust its freshness? (See RelayPrioritizer.best_priority() for more information about “freshness”)
A higher factor makes the freshness lower (making the Result seem older). A lower freshness leads to the relay having better priority, and better priority means it will be measured again sooner.
The value 0.5 was chosen somewhat arbitrarily, but a few weeks of live network testing verifies that sbws is still able to perform useful measurements in a reasonable amount of time.
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static
from_dict
(d)¶ Given a dict, returns the Result* subtype that is represented by the dict. If we don’t know how to parse the dict into a Result and it’s likely because the programmer forgot to implement something, raises NotImplementedError. If we can’t parse the dict for some other reason, return None.
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msg
¶
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to_dict
()¶
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type
¶
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class
sbws.lib.resultdump.
ResultErrorAuth
(*a, **kw)¶ Bases:
sbws.lib.resultdump.ResultError
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freshness_reduction_factor
¶ Override the default ResultError.freshness_reduction_factor because a ResultErrorAuth is most likely not the measured relay’s fault, so we shouldn’t hurt its priority as much. A higher reduction factor means a Result’s effective freshness is reduced more, which makes the relay’s priority better.
The value 0.9 was chosen somewhat arbitrarily.
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static
from_dict
(d)¶ Given a dict, returns the Result* subtype that is represented by the dict. If we don’t know how to parse the dict into a Result and it’s likely because the programmer forgot to implement something, raises NotImplementedError. If we can’t parse the dict for some other reason, return None.
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to_dict
()¶
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type
¶
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class
sbws.lib.resultdump.
ResultErrorCircuit
(*a, **kw)¶ Bases:
sbws.lib.resultdump.ResultError
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freshness_reduction_factor
¶ There are a few instances when it isn’t the relay’s fault that the circuit failed to get built. Maybe someday we’ll try detecting whose fault it most likely was and subclassing ResultErrorCircuit. But for now we don’t. So reduce the freshness slightly more than ResultError does by default so priority isn’t hurt quite as much.
A (hopefully very very rare) example of when a circuit would fail to get built is when the sbws client machine suddenly loses Internet access.
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static
from_dict
(d)¶ Given a dict, returns the Result* subtype that is represented by the dict. If we don’t know how to parse the dict into a Result and it’s likely because the programmer forgot to implement something, raises NotImplementedError. If we can’t parse the dict for some other reason, return None.
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to_dict
()¶
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type
¶
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class
sbws.lib.resultdump.
ResultErrorStream
(*a, **kw)¶ Bases:
sbws.lib.resultdump.ResultError
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static
from_dict
(d)¶ Given a dict, returns the Result* subtype that is represented by the dict. If we don’t know how to parse the dict into a Result and it’s likely because the programmer forgot to implement something, raises NotImplementedError. If we can’t parse the dict for some other reason, return None.
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to_dict
()¶
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type
¶
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static
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class
sbws.lib.resultdump.
ResultSuccess
(rtts, downloads, *a, **kw)¶ Bases:
sbws.lib.resultdump.Result
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downloads
¶
-
static
from_dict
(d)¶ Given a dict, returns the Result* subtype that is represented by the dict. If we don’t know how to parse the dict into a Result and it’s likely because the programmer forgot to implement something, raises NotImplementedError. If we can’t parse the dict for some other reason, return None.
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rtts
¶
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to_dict
()¶
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type
¶
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sbws.lib.resultdump.
load_recent_results_in_datadir
(fresh_days, datadir, success_only=False, on_changed_ipv4=False, on_changed_ipv6=False)¶ Given a data directory, read all results files in it that could have results in them that are still valid. Trim them, and return the valid Results as a list
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sbws.lib.resultdump.
load_result_file
(fname, success_only=False)¶ Reads in all lines from the given file, and parses them into Result structures (or subclasses of Result). Optionally only keeps ResultSuccess. Returns all kept Results as a result dictionary. This function does not care about the age of the results
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sbws.lib.resultdump.
merge_result_dicts
(d1, d2)¶ Given two dictionaries that contain Result data, merge them. Result dictionaries have keys of relay fingerprints and values of lists of results for those relays.
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sbws.lib.resultdump.
trim_results
(fresh_days, result_dict)¶ Given a result dictionary, remove all Results that are no longer valid and return the new dictionary
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sbws.lib.resultdump.
trim_results_ip_changed
(result_dict, on_changed_ipv4=False, on_changed_ipv6=False)¶ When there are results for the same relay with different IPs, create a new results’ dictionary without that relay’s results using an older IP.
Parameters: - result_dict (dict) – a dictionary of results
- on_changed_ipv4 (bool) – whether to trim the results when a relay’s IPv4 changes
- on_changed_ipv6 (bool) – whether to trim the results when a relay’s IPv6 changes
Returns: a new results dictionary
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sbws.lib.resultdump.
write_result_to_datadir
(result, datadir)¶ Can be called from any thread
sbws.lib.v3bwfile module¶
Classes and functions that create the bandwidth measurements document (v3bw) used by bandwidth authorities.
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class
sbws.lib.v3bwfile.
V3BWFile
(v3bwheader, v3bwlines)¶ Bases:
object
Create a Bandwidth List file following spec version 1.1.0
Parameters: - v3bwheader (V3BWHeader) – header
- v3bwlines (list) – V3BWLines
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avg_bw
¶
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classmethod
from_arg_results
(args, conf, results)¶
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num_lines
¶
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total_bw
¶
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write
(output)¶
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class
sbws.lib.v3bwfile.
V3BWHeader
(timestamp, **kwargs)¶ Bases:
object
Create a bandwidth measurements (V3bw) header following bandwidth measurements document spec version 1.1.0.
Parameters: - timestamp (str) – timestamp in Unix Epoch seconds of the most recent generator result.
- version (str) – the spec version
- software (str) – the name of the software that generates this
- software_version (str) – the version of the software
- kwargs (dict) –
extra headers. Currently supported:
- earliest_bandwidth: str, ISO 8601 timestamp in UTC time zone when the first bandwidth was obtained
- generator_started: str, ISO 8601 timestamp in UTC time zone when the generator started
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static
earliest_bandwidth_from_results
(results)¶
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classmethod
from_lines_v110
(lines)¶ Parameters: lines (list) – list of lines to parse Returns: tuple of V3BWHeader object and non-header lines
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classmethod
from_results
(conf, results)¶
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classmethod
from_text_v110
(text)¶ Parameters: text (str) – text to parse Returns: tuple of V3BWHeader object and non-header lines
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static
generator_started_from_file
(conf)¶
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keyvalue_tuple_ls
¶ Return list of all KeyValue tuples
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keyvalue_unordered_tuple_ls
¶ Return list of KeyValue tuples that do not have specific order.
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keyvalue_v110str_ls
¶ Return KeyValue list of strings following spec v1.1.0.
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keyvalue_v200_ls
¶ Return KeyValue list of strings following spec v2.0.0.
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static
latest_bandwidth_from_results
(results)¶
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num_lines
¶
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strv110
¶ Return header string following spec v1.1.0.
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strv200
¶ Return header string following spec v2.0.0.
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class
sbws.lib.v3bwfile.
V3BWLine
(node_id, bw, **kwargs)¶ Bases:
object
Create a Bandwidth List line following the spec version 1.1.0.
Parameters: - node_id (str) –
- bw (int) –
- kwargs (dict) –
extra headers. Currently supported:
- nickname, str
- master_key_ed25519, str
- rtt, int
- time, str
- sucess, int
- error_stream, int
- error_circ, int
- error_misc, int
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static
bw_from_results
(results)¶
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bw_keyvalue_tuple_ls
¶ Return list of KeyValue Bandwidth Line tuples.
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bw_keyvalue_v110str_ls
¶ Return list of KeyValue Bandwidth Line strings following spec v1.1.0.
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bw_strv110
¶ Return Bandwidth Line string following spec v1.1.0.
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classmethod
from_bw_line_v110
(line)¶
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classmethod
from_data
(data, fingerprint)¶
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classmethod
from_results
(results)¶
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static
last_time_from_results
(results)¶
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static
result_types_from_results
(results)¶
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static
rtt_from_results
(results)¶
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sbws.lib.v3bwfile.
avg_bw
(bw_lines)¶
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sbws.lib.v3bwfile.
num_results_of_type
(results, type_str)¶
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sbws.lib.v3bwfile.
read_started_ts
(conf)¶ Read ISO formated timestamp which represents the date and time when scanner started.
Parameters: conf (ConfigParser) – configuration Returns: str, ISO formated timestamp
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sbws.lib.v3bwfile.
result_type_to_key
(type_str)¶
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sbws.lib.v3bwfile.
scale_lines
(bw_lines, scale_constant)¶
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sbws.lib.v3bwfile.
total_bw
(bw_lines)¶
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sbws.lib.v3bwfile.
warn_if_not_accurate_enough
(bw_lines, scale_constant)¶