# -*- coding: utf-8 -*-
"""Classes and functions that create the bandwidth measurements document
(v3bw) used by bandwidth authorities."""
# flake8: noqa: E741
# (E741 ambiguous variable name), when using l.
import copy
import logging
import math
import os
from itertools import combinations
from statistics import mean, median
from stem.descriptor import parse_file
from sbws import __version__
from sbws.globals import (
BW_LINE_SIZE,
MAX_BW_DIFF_PERC,
MIN_REPORT,
PROP276_ROUND_DIG,
SBWS_SCALE_CONSTANT,
SBWS_SCALING,
SPEC_VERSION,
TORFLOW_BW_MARGIN,
TORFLOW_OBS_LAST,
TORFLOW_OBS_MEAN,
TORFLOW_SCALING,
)
from sbws.lib import scaling
from sbws.lib.resultdump import ResultSuccess, _ResultType
from sbws.util.filelock import DirectoryLock
from sbws.util.state import State
from sbws.util.timestamp import (
dt_obj_to_isodt_str,
isostr_to_dt_obj,
now_isodt_str,
now_unixts,
unixts_to_isodt_str,
)
log = logging.getLogger(__name__)
LINE_SEP = "\n"
KEYVALUE_SEP_V1 = "="
KEYVALUE_SEP_V2 = " "
# NOTE: in a future refactor make make all the KeyValues be a dictionary
# with their type, so that it's more similar to stem parser.
# Header KeyValues
# =================
# KeyValues that need to be in a specific order in the Bandwidth File.
HEADER_KEYS_V1_1_ORDERED = ["version"]
# KeyValues that are not initialized from the state file nor the measurements.
# They can also be pass as an argument to `Header` to overwrite default values,
# what is done in unit tests.
# `latest bandwidth` is special cause it gets its value from timestamp, which
# is not a KeyValue, but it's always pass as an argument.
# It could be separaed in other list, but so far there is no need, cause:
# 1. when it's pass to the Header to initialize it, it's just ignored.
# 2. when the file is created, it's took into account.
HEADER_KEYS_V1_1_SELF_INITIALIZED = [
"software",
"software_version",
"file_created",
"latest_bandwidth",
]
# KeyValues that are initialized from arguments.
HEADER_KEYS_V1_1_TO_INIT = [
"earliest_bandwidth",
"generator_started",
]
# number_eligible_relays is the number that ends in the bandwidth file
# ie, have not been excluded by one of the filters in 4. below
# They should be call recent_measurement_included_count to be congruent
# with the other KeyValues.
HEADER_KEYS_V1_2 = [
"number_eligible_relays",
"minimum_number_eligible_relays",
"number_consensus_relays",
"percent_eligible_relays",
"minimum_percent_eligible_relays",
]
# KeyValues added in the Bandwidth File v1.3.0
HEADER_KEYS_V1_3 = [
"scanner_country",
"destinations_countries",
]
# KeyValues that count the number of relays that are in the bandwidth file,
# but ignored by Tor when voting, because they do not have a
# measured bandwidth.
HEADER_RECENT_MEASUREMENTS_EXCLUDED_KEYS = [
# Number of relays that were measured but all the measurements failed
# because of network failures or it was
# not found a suitable helper relay
"recent_measurements_excluded_error_count",
# Number of relays that have successful measurements but the measurements
# were not away from each other in X time (by default 1 day).
"recent_measurements_excluded_near_count",
# Number of relays that have successful measurements and they are away from
# each other but they are not X time recent.
# By default this is 5 days, which is the same time the older
# the measurements can be by default.
"recent_measurements_excluded_old_count",
# Number of relays that have successful measurements and they are away from
# each other and recent
# but the number of measurements are less than X (by default 2).
"recent_measurements_excluded_few_count",
]
# Added in #29591
# NOTE: recent_consensus_count, recent_priority_list_count,
# recent_measurement_attempt_count and recent_priority_relay_count
# are not reset when the scanner is stop.
# They will accumulate the values since the scanner was ever started.
HEADER_KEYS_V1_4 = [
# 1.1 header: the number of different consensuses, that sbws has seen,
# since the last 5 days
"recent_consensus_count",
# 2.4 Number of times a priority list has been created
"recent_priority_list_count",
# 2.5 Number of relays that there were in a priority list
# [50, number of relays in the network * 0.05]
"recent_priority_relay_count",
# 3.6 header: the number of times that sbws has tried to measure any relay,
# since the last 5 days
# This would be the number of times a relays were in a priority list
"recent_measurement_attempt_count",
# 3.7 header: the number of times that sbws has tried to measure any relay,
# since the last 5 days, but it didn't work
# This should be the number of attempts - number of ResultSuccess -
# something else we don't know yet
# So far is the number of ResultError
"recent_measurement_failure_count",
# The time it took to report about half of the network.
"time_to_report_half_network",
] + HEADER_RECENT_MEASUREMENTS_EXCLUDED_KEYS
# Tor version will be obtained from the state file, so it won't be pass as an
# argument, but will be self-initialized.
HEADER_KEYS_V1_4_TO_INIT = ["tor_version"]
# KeyValues that are initialized from arguments, not self-initialized.
HEADER_INIT_KEYS = (
HEADER_KEYS_V1_1_TO_INIT
+ HEADER_KEYS_V1_3
+ HEADER_KEYS_V1_2
+ HEADER_KEYS_V1_4
+ HEADER_KEYS_V1_4_TO_INIT
)
HEADER_INT_KEYS = HEADER_KEYS_V1_2 + HEADER_KEYS_V1_4
# List of all unordered KeyValues currently being used to generate the file
HEADER_UNORDERED_KEYS = (
HEADER_KEYS_V1_1_SELF_INITIALIZED
+ HEADER_KEYS_V1_1_TO_INIT
+ HEADER_KEYS_V1_3
+ HEADER_KEYS_V1_2
+ HEADER_KEYS_V1_4
+ HEADER_KEYS_V1_4_TO_INIT
)
# List of all the KeyValues currently being used to generate the file
HEADER_ALL_KEYS = HEADER_KEYS_V1_1_ORDERED + HEADER_UNORDERED_KEYS
TERMINATOR = "====="
# Bandwidth Lines KeyValues
# =========================
# Num header lines in v1.X.X using all the KeyValues
NUM_LINES_HEADER_V1 = len(HEADER_ALL_KEYS) + 2
LINE_TERMINATOR = TERMINATOR + LINE_SEP
# KeyValue separator in Bandwidth Lines
BWLINE_KEYVALUES_SEP_V1 = " "
# not including in the files the extra bws for now
BWLINE_KEYS_V0 = ["node_id", "bw"]
BWLINE_KEYS_V1_1 = [
"master_key_ed25519",
"nick",
"rtt",
"time",
"success",
"error_stream",
"error_circ",
"error_misc",
# Added in #292951
"error_second_relay",
"error_destination",
]
BWLINE_KEYS_V1_2 = [
"bw_median",
"bw_mean",
"desc_bw_avg",
"desc_bw_bur",
"desc_bw_obs_last",
"desc_bw_obs_mean",
"consensus_bandwidth",
"consensus_bandwidth_is_unmeasured",
]
# There were no bandwidth lines key added in the specification version 1.3
# Added in #292951
BWLINE_KEYS_V1_4 = [
# 1.2 relay: the number of different consensuses, that sbws has seen,
# since the last 5 days, that have this relay
"relay_in_recent_consensus_count",
# 2.6 relay: the number of times a relay was "prioritized" to be measured
# in the recent days (by default 5).
"relay_recent_priority_list_count",
# 3.8 relay: the number of times that sbws has tried to measure
# this relay, since the last 5 days
# This would be the number of times a relay was in a priority list (2.6)
# since once it gets measured, it either returns ResultError,
# ResultSuccess or something else happened that we don't know yet
"relay_recent_measurement_attempt_count",
# 3.9 relay: the number of times that sbws has tried to measure
# this relay, since the last 5 days, but it didn't work
# This should be the number of attempts - number of ResultSuccess -
# something else we don't know yet
# So far is the number of ResultError
"relay_recent_measurement_failure_count",
# Number of error results created in the last 5 days that are excluded.
# This is the sum of all the errors.
"relay_recent_measurements_excluded_error_count",
# The number of successful results, created in the last 5 days,
# that were excluded by a rule, for this relay.
# 'relay_recent_measurements_excluded_error_count' would be the
# sum of the following 3 + the number of error results.
# The number of successful measurements that are not X time away
# from each other (by default 1 day).
"relay_recent_measurements_excluded_near_count",
# The number of successful measurements that are away from each other
# but not X time recent (by default 5 days).
"relay_recent_measurements_excluded_old_count",
# The number of measurements excluded because they are not at least X
# (by default 2).
"relay_recent_measurements_excluded_few_count",
# `vote=0` is used for the relays that were excluded to
# be reported in the bandwidth file and now they are
# reported.
# It tells Tor to do not vote on the relay.
# `unmeasured=1` is used for the same relays and it is
# added in case Tor would vote on them in future versions.
# Maybe these keys should not be included for the relays
# in which vote=1 and unmeasured=0.
"vote",
"unmeasured",
# When there not enough eligible relays (not excluded)
# under_min_report is 1, `vote` is 0.
# Added in #29853.
"under_min_report",
]
BWLINE_KEYS_V1 = (
BWLINE_KEYS_V0 + BWLINE_KEYS_V1_1 + BWLINE_KEYS_V1_2 + BWLINE_KEYS_V1_4
)
# NOTE: tech-debt: assign boolean type to vote and unmeasured,
# when the attributes are defined with a type, as stem does.
BWLINE_INT_KEYS = (
[
"bw",
"rtt",
"success",
"error_stream",
"error_circ",
"error_misc",
]
+ BWLINE_KEYS_V1_2
+ BWLINE_KEYS_V1_4
)
# This is boolean, not int.
BWLINE_INT_KEYS.remove("consensus_bandwidth_is_unmeasured")
[docs]def round_sig_dig(n, digits=PROP276_ROUND_DIG):
"""Round n to 'digits' significant digits in front of the decimal point.
Results less than or equal to 1 are rounded to 1.
Returns an integer.
digits must be greater than 0.
n must be less than or equal to 2**73, to avoid floating point errors.
"""
digits = int(digits)
assert digits >= 1
if n <= 1:
return 1
digits_in_n = int(math.log10(n)) + 1
round_digits = max(digits_in_n - digits, 0)
rounded_n = round(n, -round_digits)
return int(rounded_n)
[docs]def kb_round_x_sig_dig(bw_bs, digits=PROP276_ROUND_DIG):
"""Convert bw_bs from bytes to kilobytes, and round the result to
'digits' significant digits.
Results less than or equal to 1 are rounded up to 1.
Returns an integer.
digits must be greater than 0.
n must be less than or equal to 2**82, to avoid floating point errors.
"""
# avoid double-rounding by using floating-point
bw_kb = bw_bs / 1000.0
return round_sig_dig(bw_kb, digits=digits)
[docs]def num_results_of_type(results, type_str):
return len([r for r in results if r.type == type_str])
# Better way to use enums?
[docs]def result_type_to_key(type_str):
return type_str.replace("-", "_")
[docs]class V3BWLine(object):
"""
Create a Bandwidth List line following the spec version 1.X.X.
:param str node_id: the relay fingerprint
:param int bw: the bandwidth value that directory authorities will include
in their votes.
:param dict kwargs: extra headers.
.. note:: tech-debt: move node_id and bw to kwargs and just ensure that
the required values are in ``**kwargs``
"""
def __init__(self, node_id, bw, **kwargs):
assert isinstance(node_id, str)
assert node_id.startswith("$")
self.node_id = node_id
self.bw = bw
# For now, we do not want to add ``bw_filt`` to the bandwidth file,
# therefore it is set here but not added to ``BWLINE_KEYS_V1``.
[
setattr(self, k, v)
for k, v in kwargs.items()
if k in BWLINE_KEYS_V1 + ["bw_filt"]
]
def __str__(self):
return self.bw_strv1
[docs] @classmethod
def from_results(
cls,
results,
secs_recent=None,
secs_away=None,
min_num=0,
router_statuses_d=None,
):
"""Convert sbws results to relays' Bandwidth Lines
``bs`` stands for Bytes/seconds
``bw_mean`` means the bw is obtained from the mean of the all the
downloads' bandwidth.
Downloads' bandwidth are calculated as the amount of data received
divided by the the time it took to received.
bw = data (Bytes) / time (seconds)
"""
# log.debug("Len success_results %s", len(success_results))
node_id = "$" + results[0].fingerprint
kwargs = dict()
kwargs["nick"] = results[0].nickname
if getattr(results[0], "master_key_ed25519"):
kwargs["master_key_ed25519"] = results[0].master_key_ed25519
kwargs["time"] = cls.last_time_from_results(results)
kwargs.update(cls.result_types_from_results(results))
# If it has not the attribute, return list to be able to call len
# If it has the attribute, but it is None, return also list
kwargs["relay_in_recent_consensus_count"] = str(
max(
[
len(getattr(r, "relay_in_recent_consensus", []) or [])
for r in results
]
)
)
# Workaround for #34309.
# Because of a bug, probably in relaylist, resultdump, relayprioritizer
# or scanner, only the last timestamp is being stored in each result.
# Temporally count the number of timestamps for all results.
# If there is an unexpected failure and the result is not stored, this
# number would be lower than what would be the correct one.
# This should happen rarely or never.
ts = set([])
for r in results:
if getattr(r, "relay_recent_priority_list", None):
ts.update(r.relay_recent_priority_list)
kwargs["relay_recent_priority_list_count"] = str(len(ts))
# Same comment as the previous paragraph.
ts = set()
for r in results:
if getattr(r, "relay_recent_measurement_attempt", None):
ts.update(r.relay_recent_measurement_attempt)
kwargs["relay_recent_measurement_attempt_count"] = str(len(ts))
success_results = [r for r in results if isinstance(r, ResultSuccess)]
# NOTE: The following 4 conditions exclude relays from the bandwidth
# file when the measurements does not satisfy some rules, what makes
# the relay non-`eligible`.
# In BWLINE_KEYS_V1_4 it is explained what they mean.
# In HEADER_RECENT_MEASUREMENTS_EXCLUDED_KEYS it is also
# explained the what it means the strings returned.
# They rules were introduced in #28061 and #27338
# In #28565 we introduce the KeyValues to know why they're excluded.
# In #28563 we report these relays, but make Tor ignore them.
# This might confirm #28042.
# If the relay is non-`eligible`:
# Create a bandwidth line with the relay, but set ``vote=0`` so that
# Tor versions with patch #29806 does not vote on the relay.
# Set ``bw=1`` so that Tor versions without the patch,
# will give the relay low bandwidth.
# Include ``unmeasured=1`` in case Tor would vote on unmeasured relays
# in future versions.
# And return because there are not bandwidth values.
# NOTE: the bandwidth values could still be obtained if:
# 1. ``ResultError`` will store them
# 2. assign ``results_recent = results`` when there is a ``exclusion
# reason.
# This could be done in a better way as part of a refactor #28684.
kwargs["vote"] = 0
kwargs["unmeasured"] = 1
exclusion_reason = None
number_excluded_error = len(results) - len(success_results)
if number_excluded_error > 0:
# then the number of error results is the number of results
kwargs[
"relay_recent_measurements_excluded_error_count"
] = number_excluded_error
if not success_results:
exclusion_reason = "recent_measurements_excluded_error_count"
return (cls(node_id, 1, **kwargs), exclusion_reason)
results_away = cls.results_away_each_other(success_results, secs_away)
number_excluded_near = len(success_results) - len(results_away)
if number_excluded_near > 0:
kwargs[
"relay_recent_measurements_excluded_near_count"
] = number_excluded_near
if not results_away:
exclusion_reason = "recent_measurements_excluded_near_count"
return (cls(node_id, 1, **kwargs), exclusion_reason)
# log.debug("Results away from each other: %s",
# [unixts_to_isodt_str(r.time) for r in results_away])
results_recent = cls.results_recent_than(results_away, secs_recent)
number_excluded_old = len(results_away) - len(results_recent)
if number_excluded_old > 0:
kwargs[
"relay_recent_measurements_excluded_old_count"
] = number_excluded_old
if not results_recent:
exclusion_reason = "recent_measurements_excluded_old_count"
return (cls(node_id, 1, **kwargs), exclusion_reason)
if not len(results_recent) >= min_num:
kwargs["relay_recent_measurements_excluded_few_count"] = len(
results_recent
)
# log.debug('The number of results is less than %s', min_num)
exclusion_reason = "recent_measurements_excluded_few_count"
return (cls(node_id, 1, **kwargs), exclusion_reason)
# Use the last consensus if available, since the results' consensus
# values come from the moment the measurement was made.
if router_statuses_d and node_id in router_statuses_d:
consensus_bandwidth = router_statuses_d[node_id].bandwidth * 1000
consensus_bandwidth_is_unmeasured = router_statuses_d[
node_id
].is_unmeasured
else:
consensus_bandwidth = cls.consensus_bandwidth_from_results(
results_recent
)
consensus_bandwidth_is_unmeasured = (
cls.consensus_bandwidth_is_unmeasured_from_results(
results_recent
)
)
# If there is no last observed bandwidth, there won't be mean either.
desc_bw_obs_last = cls.desc_bw_obs_last_from_results(results_recent)
# Exclude also relays without observed bandwidth, since they can't be
# scaled
if desc_bw_obs_last is None:
# This reason is not counted, not added in the file, but it will
# have vote = 0
return (cls(node_id, 1), "no_observed_bw")
# For any line not excluded, do not include vote and unmeasured
# KeyValues
del kwargs["vote"]
del kwargs["unmeasured"]
rtt = cls.rtt_from_results(results_recent)
if rtt:
kwargs["rtt"] = rtt
bw = cls.bw_median_from_results(results_recent)
# XXX: all the class functions could use the bw_measurements instead of
# obtaining them each time or use a class Measurements.
bw_measurements = scaling.bw_measurements_from_results(results_recent)
kwargs["bw_mean"] = cls.bw_mean_from_results(results_recent)
kwargs["bw_filt"] = scaling.bw_filt(bw_measurements)
kwargs["bw_median"] = cls.bw_median_from_results(results_recent)
kwargs["desc_bw_avg"] = cls.desc_bw_avg_from_results(results_recent)
kwargs["desc_bw_bur"] = cls.desc_bw_bur_from_results(results_recent)
kwargs["consensus_bandwidth"] = consensus_bandwidth
kwargs[
"consensus_bandwidth_is_unmeasured"
] = consensus_bandwidth_is_unmeasured
kwargs["desc_bw_obs_last"] = desc_bw_obs_last
kwargs["desc_bw_obs_mean"] = cls.desc_bw_obs_mean_from_results(
results_recent
)
bwl = cls(node_id, bw, **kwargs)
return bwl, None
[docs] @classmethod
def from_data(cls, data, fingerprint):
assert fingerprint in data
return cls.from_results(data[fingerprint])
[docs] @classmethod
def from_bw_line_v1(cls, line):
assert isinstance(line, str)
kwargs = dict(
[
kv.split(KEYVALUE_SEP_V1)
for kv in line.split(BWLINE_KEYVALUES_SEP_V1)
if kv.split(KEYVALUE_SEP_V1)[0] in BWLINE_KEYS_V1
]
)
for k, v in kwargs.items():
if k in BWLINE_INT_KEYS:
kwargs[k] = int(v)
node_id = kwargs["node_id"]
bw = kwargs["bw"]
del kwargs["node_id"]
del kwargs["bw"]
bw_line = cls(node_id, bw, **kwargs)
return bw_line
[docs] @staticmethod
def results_away_each_other(results, secs_away=None):
# log.debug("Checking whether results are away from each other in %s "
# "secs.", secs_away)
if secs_away is None or len(results) < 2:
return results
for a, b in combinations(results, 2):
if abs(a.time - b.time) > secs_away:
return results
# log.debug("Results are NOT away from each other in at least %ss: %s",
# secs_away, [unixts_to_isodt_str(r.time) for r in results])
return []
[docs] @staticmethod
def results_recent_than(results, secs_recent=None):
if secs_recent is None:
return results
results_recent = list(
filter(lambda x: (now_unixts() - x.time) < secs_recent, results)
)
# if not results_recent:
# log.debug("Results are NOT more recent than %ss: %s",
# secs_recent,
# [unixts_to_isodt_str(r.time) for r in results])
return results_recent
[docs] @staticmethod
def bw_mean_from_results(results):
bws = [
dl["amount"] / dl["duration"]
for r in results
for dl in r.downloads
]
# It's safe to return 0 here, because:
# 1. this value will be the numerator when calculating the ratio.
# 2. `kb_round_x_sig_dig` returns a minimum of 1.
if bws:
return round(mean(bws))
return 0
[docs] @staticmethod
def last_time_from_results(results):
return unixts_to_isodt_str(round(max([r.time for r in results])))
[docs] @staticmethod
def rtt_from_results(results):
# convert from milliseconds to seconds
rtts = [(round(rtt * 1000)) for r in results for rtt in r.rtts]
rtt = round(median(rtts)) if rtts else None
return rtt
[docs] @staticmethod
def result_types_from_results(results):
rt_dict = dict(
[
(
result_type_to_key(rt.value),
num_results_of_type(results, rt.value),
)
for rt in _ResultType
]
)
return rt_dict
[docs] @staticmethod
def desc_bw_avg_from_results(results):
"""Obtain the last descriptor bandwidth average from the results."""
for r in reversed(results):
if r.relay_average_bandwidth is not None:
return r.relay_average_bandwidth
log.warning("Descriptor average bandwidth is None.")
return None
[docs] @staticmethod
def desc_bw_bur_from_results(results):
"""Obtain the last descriptor bandwidth burst from the results."""
for r in reversed(results):
if r.relay_burst_bandwidth is not None:
return r.relay_burst_bandwidth
log.warning("Descriptor burst bandwidth is None.")
return None
[docs] @staticmethod
def consensus_bandwidth_from_results(results):
"""Obtain the last consensus bandwidth from the results."""
for r in reversed(results):
if r.consensus_bandwidth is not None:
return r.consensus_bandwidth
log.warning("Consensus bandwidth is None.")
return None
[docs] @staticmethod
def consensus_bandwidth_is_unmeasured_from_results(results):
"""Obtain the last consensus unmeasured flag from the results."""
for r in reversed(results):
if r.consensus_bandwidth_is_unmeasured is not None:
return r.consensus_bandwidth_is_unmeasured
log.warning("Consensus bandwidth is unmeasured is None.")
return None
[docs] @staticmethod
def desc_bw_obs_mean_from_results(results):
desc_bw_obs_ls = []
for r in results:
if r.relay_observed_bandwidth is not None:
desc_bw_obs_ls.append(r.relay_observed_bandwidth)
if desc_bw_obs_ls:
return round(mean(desc_bw_obs_ls))
log.warning("Descriptor observed bandwidth is None.")
return None
[docs] @staticmethod
def desc_bw_obs_last_from_results(results):
# the last is at the end of the list
for r in reversed(results):
if r.relay_observed_bandwidth is not None:
return r.relay_observed_bandwidth
log.warning("Descriptor observed bandwidth is None.")
return None
@property
def bw_keyvalue_tuple_ls(self):
"""Return list of KeyValue Bandwidth Line tuples."""
# sort the list to generate determinist headers
keyvalue_tuple_ls = sorted(
[(k, v) for k, v in self.__dict__.items() if k in BWLINE_KEYS_V1]
)
return keyvalue_tuple_ls
@property
def bw_keyvalue_v1str_ls(self):
"""Return list of KeyValue Bandwidth Line strings following
spec v1.X.X.
"""
bw_keyvalue_str = [
KEYVALUE_SEP_V1.join([k, str(v)])
for k, v in self.bw_keyvalue_tuple_ls
]
return bw_keyvalue_str
@property
def bw_strv1(self):
"""Return Bandwidth Line string following spec v1.X.X."""
bw_line_str = (
BWLINE_KEYVALUES_SEP_V1.join(self.bw_keyvalue_v1str_ls) + LINE_SEP
)
if len(bw_line_str) > BW_LINE_SIZE:
# if this is the case, probably there are too many KeyValues,
# or the limit needs to be changed in Tor
log.warn(
"The bandwidth line %s is longer than %s",
len(bw_line_str),
BW_LINE_SIZE,
)
return bw_line_str
[docs]class V3BWFile(object):
"""
Create a Bandwidth List file following spec version 1.X.X
:param V3BWHeader v3bwheader: header
:param list v3bwlines: V3BWLines
"""
def __init__(self, v3bwheader, v3bwlines):
self.header = v3bwheader
self.bw_lines = v3bwlines
def __str__(self):
return str(self.header) + "".join(
[str(bw_line) or "" for bw_line in self.bw_lines]
)
[docs] @classmethod
def from_results(
cls,
results,
scanner_country=None,
destinations_countries=None,
state_fpath="",
scale_constant=SBWS_SCALE_CONSTANT,
scaling_method=TORFLOW_SCALING,
torflow_obs=TORFLOW_OBS_LAST,
torflow_cap=TORFLOW_BW_MARGIN,
round_digs=PROP276_ROUND_DIG,
secs_recent=None,
secs_away=None,
min_num=0,
consensus_path=None,
max_bw_diff_perc=MAX_BW_DIFF_PERC,
reverse=False,
):
"""Create V3BWFile class from sbws Results.
:param dict results: see below
:param str state_fpath: path to the state file
:param int scaling_method:
Scaling method to obtain the bandwidth
Possible values: {None, SBWS_SCALING, TORFLOW_SCALING} = {0, 1, 2}
:param int scale_constant: sbws scaling constant
:param int torflow_obs: method to choose descriptor observed bandwidth
:param bool reverse: whether to sort the bw lines descending or not
Results are in the form::
{'relay_fp1': [Result1, Result2, ...],
'relay_fp2': [Result1, Result2, ...]}
"""
log.info("Processing results to generate a bandwidth list file.")
header = V3BWHeader.from_results(
results, scanner_country, destinations_countries, state_fpath
)
bw_lines_raw = []
bw_lines_excluded = []
router_statuses_d = cls.read_router_statuses(consensus_path)
# XXX: Use router_statuses_d to not parse again the file.
number_consensus_relays = cls.read_number_consensus_relays(
consensus_path
)
state = State(state_fpath)
# Create a dictionary with the number of relays excluded by any of the
# of the filtering rules that makes relays non-`eligible`.
# NOTE: In HEADER_RECENT_MEASUREMENTS_EXCLUDED_KEYS it is
# explained what are the KeyValues.
# See also the comments in `from_results`.
exclusion_dict = dict(
[(k, 0) for k in HEADER_RECENT_MEASUREMENTS_EXCLUDED_KEYS]
)
for fp, values in results.items():
# log.debug("Relay fp %s", fp)
line, reason = V3BWLine.from_results(
values, secs_recent, secs_away, min_num, router_statuses_d
)
# If there is no reason it means the line will not be excluded.
if not reason:
bw_lines_raw.append(line)
else:
# Store the excluded lines to include them in the bandwidth
# file.
bw_lines_excluded.append(line)
exclusion_dict[reason] = exclusion_dict.get(reason, 0) + 1
# Add the headers with the number of excluded relays by reason
header.add_relays_excluded_counters(exclusion_dict)
if not bw_lines_raw:
# It could be possible to scale the lines that were successful
# even if excluded, but is not done here.
log.info(
"After applying restrictions to the raw results, "
"there is not any. Scaling can not be applied."
)
# Update the header and log the progress.
cls.update_progress(cls, 0, header, number_consensus_relays, state)
# Set the lines that would be excluded anyway (`vote=0`) with
# `under_min_report=1`
cls.set_under_min_report(bw_lines_excluded)
# Create the bandwidth file with the lines that would be excluded.
return cls(header, bw_lines_excluded)
if scaling_method == SBWS_SCALING:
bw_lines = cls.bw_sbws_scale(bw_lines_raw, scale_constant)
cls.warn_if_not_accurate_enough(bw_lines, scale_constant)
# log.debug(bw_lines[-1])
elif scaling_method == TORFLOW_SCALING:
bw_lines = cls.bw_torflow_scale(
bw_lines_raw,
torflow_obs,
torflow_cap,
round_digs,
router_statuses_d=router_statuses_d,
)
# log.debug(bw_lines[-1])
# Update the header and log the progress.
min_perc = cls.update_progress(
cls, len(bw_lines), header, number_consensus_relays, state
)
# If after scaling the number of lines is less than the percentage
# of lines to report, set them with `under_min_report`.
if not min_perc:
cls.set_under_min_report(bw_lines)
else:
bw_lines = cls.bw_kb(bw_lines_raw)
# log.debug(bw_lines[-1])
# Not using the result for now, just warning
cls.is_max_bw_diff_perc_reached(
bw_lines, max_bw_diff_perc, router_statuses_d
)
header.add_time_report_half_network()
f = cls(header, bw_lines + bw_lines_excluded)
return f
[docs] @classmethod
def from_v1_fpath(cls, fpath):
log.info("Parsing bandwidth file %s", fpath)
with open(fpath) as fd:
text = fd.read()
all_lines = text.split(LINE_SEP)
header, lines = V3BWHeader.from_lines_v1(all_lines)
bw_lines = [V3BWLine.from_bw_line_v1(line) for line in lines]
return cls(header, bw_lines)
[docs] @classmethod
def from_v100_fpath(cls, fpath):
log.info("Parsing bandwidth file %s", fpath)
with open(fpath) as fd:
text = fd.read()
all_lines = text.split(LINE_SEP)
header, lines = V3BWHeader.from_lines_v100(all_lines)
bw_lines = sorted(
[V3BWLine.from_bw_line_v1(l) for l in lines], key=lambda l: l.bw
)
return cls(header, bw_lines)
[docs] @staticmethod
def set_under_min_report(bw_lines):
"""
Mondify the Bandwidth Lines adding the KeyValue `under_min_report`,
`vote`.
"""
log.debug("Setting `under_min_report` to %s lines.", len(bw_lines))
for l in bw_lines:
l.under_min_report = 1
l.vote = 0
[docs] @staticmethod
def bw_kb(bw_lines, reverse=False):
bw_lines_scaled = copy.deepcopy(bw_lines)
for l in bw_lines_scaled:
l.bw = max(round(l.bw / 1000), 1)
return sorted(bw_lines_scaled, key=lambda x: x.bw, reverse=reverse)
[docs] @staticmethod
def bw_sbws_scale(
bw_lines, scale_constant=SBWS_SCALE_CONSTANT, reverse=False
):
"""Return a new V3BwLine list scaled using sbws method.
:param list bw_lines:
bw lines to scale, not self.bw_lines,
since this method will be before self.bw_lines have been
initialized.
:param int scale_constant:
the constant to multiply by the ratio and
the bandwidth to obtain the new bandwidth
:returns list: V3BwLine list
"""
log.debug("Scaling bandwidth using sbws method.")
m = median([l.bw for l in bw_lines])
bw_lines_scaled = copy.deepcopy(bw_lines)
for l in bw_lines_scaled:
# min is to limit the bw to descriptor average-bandwidth
# max to avoid bandwidth with 0 value
l.bw = max(
round(min(l.desc_bw_avg, l.bw * scale_constant / m) / 1000), 1
)
return sorted(bw_lines_scaled, key=lambda x: x.bw, reverse=reverse)
[docs] @staticmethod
def warn_if_not_accurate_enough(
bw_lines, scale_constant=SBWS_SCALE_CONSTANT
):
margin = 0.001
accuracy_ratio = median([l.bw for l in bw_lines]) / scale_constant
log.info(
"The generated lines are within {:.5}% of what they should "
"be".format((1 - accuracy_ratio) * 100)
)
if accuracy_ratio < 1 - margin or accuracy_ratio > 1 + margin:
log.warning(
"There was %f%% error and only +/- %f%% is " "allowed",
(1 - accuracy_ratio) * 100,
margin * 100,
)
[docs] @staticmethod
def is_max_bw_diff_perc_reached(
bw_lines, max_bw_diff_perc=MAX_BW_DIFF_PERC, router_statuses_d=None
):
if router_statuses_d:
sum_consensus_bw = sum(
list(
map(
lambda x: x.bandwidth * 1000,
router_statuses_d.values(),
)
)
)
else:
sum_consensus_bw = sum(
[
l.consensus_bandwidth
for l in bw_lines
if getattr(l, "consensus_bandwidth", None)
]
)
# Because the scaled bandwidth is in KB, but not the stored consensus
# bandwidth, multiply by 1000.
# Do not count the bandwidths for the relays that were excluded
sum_bw = sum([l.bw for l in bw_lines if getattr(l, "vote", 1)]) * 1000
# Percentage difference
diff_perc = (
abs(sum_consensus_bw - sum_bw)
# Avoid ZeroDivisionError
/ (max(1, (sum_consensus_bw + sum_bw)) / 2)
) * 100
log.info(
"The difference between the total consensus bandwidth (%s)"
"and the total measured bandwidth (%s) is %s%%.",
sum_consensus_bw,
sum_bw,
round(diff_perc),
)
if diff_perc > MAX_BW_DIFF_PERC:
log.warning("It is more than %s%%", max_bw_diff_perc)
return True
return False
[docs] @staticmethod
def bw_torflow_scale(
bw_lines,
desc_bw_obs_type=TORFLOW_OBS_MEAN,
cap=TORFLOW_BW_MARGIN,
num_round_dig=PROP276_ROUND_DIG,
reverse=False,
router_statuses_d=None,
):
"""
Obtain final bandwidth measurements applying Torflow's scaling
method.
See details in :ref:`torflow_aggr`.
"""
log.info("Calculating relays' bandwidth using Torflow method.")
bw_lines_tf = copy.deepcopy(bw_lines)
# mean (Torflow's strm_avg)
mu = mean([l.bw_mean for l in bw_lines])
# filtered mean (Torflow's filt_avg)
muf = mean([l.bw_filt for l in bw_lines])
log.debug("mu %s", mu)
log.debug("muf %s", muf)
# Torflow's ``tot_net_bw``, sum of the scaled bandwidth for the relays
# that are in the last consensus
sum_bw = 0
for l in bw_lines_tf:
# First, obtain the observed bandwidth, later check what to do
# if it is 0 or None.
if desc_bw_obs_type == TORFLOW_OBS_LAST:
# In case there's no last, use the mean, because it is possible
# that it went down for a few days, but no more than 5,
# otherwise the mean will be 1
desc_bw_obs = l.desc_bw_obs_last or l.desc_bw_obs_mean
# Assume that if it is not TORFLOW_OBS_LAST, then it is
# TORFLOW_OBS_MEAN
else:
desc_bw_obs = l.desc_bw_obs_mean
# Excerpt from bandwidth-file-spec.txt section 2.3
# A relay's MaxAdvertisedBandwidth limits the bandwidth-avg in its
# descriptor.
# Therefore generators MUST limit a relay's measured bandwidth to
# its descriptor's bandwidth-avg.
# Generators SHOULD NOT limit measured bandwidths based on
# descriptors' bandwidth-observed, because that penalises new
# relays.
# In the case that descriptor average or burst are None,
# ignore them since it must be a bug in ``Resultdump``, already
# logged in x_bw/bandwidth_x_from_results, but scale.
if desc_bw_obs is not None:
if l.desc_bw_bur is not None:
if l.desc_bw_avg is not None:
desc_bw = min(
desc_bw_obs, l.desc_bw_bur, l.desc_bw_avg
)
else:
desc_bw = min(desc_bw_obs, l.desc_bw_bur)
else:
if l.desc_bw_avg is not None:
desc_bw = min(desc_bw_obs, l.desc_bw_avg)
else:
desc_bw = desc_bw_obs
else:
log.warning("Can not scale relay missing descriptor.")
continue
# Torflow's scaling
ratio_stream = l.bw_mean / mu
ratio_stream_filtered = l.bw_filt / muf
ratio = max(ratio_stream, ratio_stream_filtered)
# Assign it to an attribute, so it's not lost before capping and
# rounding
l.bw = ratio * desc_bw
# If the consensus is available, sum only the bw for the relays
# that are in the consensus
if router_statuses_d:
if l.node_id.replace("$", "") in router_statuses_d:
sum_bw += l.bw
# Otherwise sum all bw, for compatibility with tests that were not
# using the consensus file.
else:
sum_bw += l.bw
# Cap maximum bw, only possible when the ``sum_bw`` is calculated.
# Torflow's clipping
hlimit = sum_bw * cap
log.debug("sum_bw: %s, hlimit: %s", sum_bw, hlimit)
for l in bw_lines_tf:
bw_scaled = min(hlimit, l.bw)
# round and convert to KB
l.bw = kb_round_x_sig_dig(bw_scaled, digits=num_round_dig)
return sorted(bw_lines_tf, key=lambda x: x.bw, reverse=reverse)
[docs] @staticmethod
def read_number_consensus_relays(consensus_path):
"""Read the number of relays in the Network from the cached consensus
file."""
num = None
try:
num = len(list(parse_file(consensus_path)))
except (FileNotFoundError, AttributeError):
log.info(
"It is not possible to obtain statistics about the "
"percentage of measured relays because the cached "
"consensus file is not found."
)
log.debug("Number of relays in the network %s", num)
return num
[docs] @staticmethod
def read_router_statuses(consensus_path):
"""Read the router statuses from the cached consensus file."""
router_statuses_d = None
try:
router_statuses_d = dict(
[(r.fingerprint, r) for r in parse_file(consensus_path)]
)
except (FileNotFoundError, AttributeError):
log.warning(
"It is not possible to obtain the last consensus"
"cached file %s.",
consensus_path,
)
return router_statuses_d
[docs] @staticmethod
def measured_progress_stats(
num_bw_lines, number_consensus_relays, min_perc_reached_before
):
"""Statistics about measurements progress,
to be included in the header.
:param list bw_lines: the bw_lines after scaling and applying filters.
:param str consensus_path: the path to the cached consensus file.
:param str state_fpath: the path to the state file
:returns dict, bool: Statistics about the progress made with
measurements and whether the percentage of measured relays has been
reached.
"""
# cached-consensus should be updated every time that scanner get the
# network status or descriptors?
# It will not be updated to the last consensus, but the list of
# measured relays is not either.
assert isinstance(number_consensus_relays, int)
assert isinstance(num_bw_lines, int)
statsd = {}
statsd["number_eligible_relays"] = num_bw_lines
statsd["number_consensus_relays"] = number_consensus_relays
statsd["minimum_number_eligible_relays"] = round(
statsd["number_consensus_relays"] * MIN_REPORT / 100
)
statsd["percent_eligible_relays"] = round(
num_bw_lines * 100 / statsd["number_consensus_relays"]
)
statsd["minimum_percent_eligible_relays"] = MIN_REPORT
if (
statsd["number_eligible_relays"]
< statsd["minimum_number_eligible_relays"]
):
# if min percent was was reached before, warn
# otherwise, debug
if min_perc_reached_before is not None:
log.warning(
"The percentage of the measured relays is less "
"than the %s%% of the relays in the network (%s).",
MIN_REPORT,
statsd["number_consensus_relays"],
)
else:
log.info(
"The percentage of the measured relays is less "
"than the %s%% of the relays in the network (%s).",
MIN_REPORT,
statsd["number_consensus_relays"],
)
return statsd, False
return statsd, True
@property
def is_min_perc(self):
if getattr(self.header, "number_eligible_relays", 0) < getattr(
self.header, "minimum_number_eligible_relays", 0
):
return False
return True
@property
def sum_bw(self):
return sum([l.bw for l in self.bw_lines if hasattr(l, "bw")])
@property
def num(self):
return len(self.bw_lines)
@property
def mean_bw(self):
return mean([l.bw for l in self.bw_lines if hasattr(l, "bw")])
@property
def median_bw(self):
return median([l.bw for l in self.bw_lines if hasattr(l, "bw")])
@property
def max_bw(self):
return max([l.bw for l in self.bw_lines if hasattr(l, "bw")])
@property
def min_bw(self):
return min([l.bw for l in self.bw_lines if hasattr(l, "bw")])
@property
def info_stats(self):
if not self.bw_lines:
return
[
log.info(": ".join([attr, str(getattr(self, attr))]))
for attr in [
"sum_bw",
"mean_bw",
"median_bw",
"num",
"max_bw",
"min_bw",
]
]
[docs] def update_progress(
self, num_bw_lines, header, number_consensus_relays, state
):
"""
Returns True if the minimim percent of Bandwidth Lines was reached
and False otherwise.
Update the header with the progress.
"""
min_perc_reached_before = state.get("min_perc_reached")
if number_consensus_relays is not None:
statsd, success = self.measured_progress_stats(
num_bw_lines, number_consensus_relays, min_perc_reached_before
)
# add statistics about progress always
header.add_stats(**statsd)
if not success:
# From sbws 1.1.0 the lines are reported (#29853) even if they
# are less than the minimum percent.
state["min_perc_reached"] = None
return False
else:
state["min_perc_reached"] = now_isodt_str()
return True
[docs] def bw_line_for_node_id(self, node_id):
"""Returns the bandwidth line for a given node fingerprint.
Used to combine data when plotting.
"""
bwl = [l for l in self.bw_lines if l.node_id == node_id]
if bwl:
return bwl[0]
return None
[docs] def to_plt(self, attrs=["bw"], sorted_by=None):
"""Return bandwidth data in a format useful for matplotlib.
Used from external tool to plot.
"""
x = [i for i in range(0, self.num)]
ys = [[getattr(l, k) for l in self.bw_lines] for k in attrs]
return x, ys, attrs
[docs] def write(self, output):
if output == "/dev/stdout":
log.info("Writing to stdout is not supported.")
return
log.info("Writing v3bw file to %s", output)
# To avoid inconsistent reads, the bandwidth data is written to an
# archive path, then atomically symlinked to 'latest.v3bw'
out_dir = os.path.dirname(output)
out_link = os.path.join(out_dir, "latest.v3bw")
out_link_tmp = out_link + ".tmp"
with DirectoryLock(out_dir):
with open(output, "wt") as fd:
fd.write(str(self.header))
for line in self.bw_lines:
fd.write(str(line))
output_basename = os.path.basename(output)
# To atomically symlink a file, we need to create a temporary link,
# then rename it to the final link name. (POSIX guarantees that
# rename is atomic.)
log.debug(
"Creating symlink {} -> {}.".format(
out_link_tmp, output_basename
)
)
os.symlink(output_basename, out_link_tmp)
log.debug(
"Renaming symlink {} -> {} to {} -> {}.".format(
out_link_tmp, output_basename, out_link, output_basename
)
)
os.rename(out_link_tmp, out_link)