gecko-dev/toolkit/components/telemetry/histogram_tools.py

495 lines
19 KiB
Python

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
import collections
import json
import math
import os
import re
import sys
# Constants.
MAX_LABEL_LENGTH = 20
MAX_LABEL_COUNT = 100
# histogram_tools.py is used by scripts from a mozilla-central build tree
# and also by outside consumers, such as the telemetry server. We need
# to ensure that importing things works in both contexts. Therefore,
# unconditionally importing things that are local to the build tree, such
# as buildconfig, is a no-no.
try:
import buildconfig
# Need to update sys.path to be able to find usecounters.
sys.path.append(os.path.join(buildconfig.topsrcdir, 'dom/base/'))
except ImportError:
# Must be in an out-of-tree usage scenario. Trust that whoever is
# running this script knows we need the usecounters module and has
# ensured it's in our sys.path.
pass
from collections import OrderedDict
def table_dispatch(kind, table, body):
"""Call body with table[kind] if it exists. Raise an error otherwise."""
if kind in table:
return body(table[kind])
else:
raise BaseException, "don't know how to handle a histogram of kind %s" % kind
class DefinitionException(BaseException):
pass
def linear_buckets(dmin, dmax, n_buckets):
ret_array = [0] * n_buckets
dmin = float(dmin)
dmax = float(dmax)
for i in range(1, n_buckets):
linear_range = (dmin * (n_buckets - 1 - i) + dmax * (i - 1)) / (n_buckets - 2)
ret_array[i] = int(linear_range + 0.5)
return ret_array
def exponential_buckets(dmin, dmax, n_buckets):
log_max = math.log(dmax);
bucket_index = 2;
ret_array = [0] * n_buckets
current = dmin
ret_array[1] = current
for bucket_index in range(2, n_buckets):
log_current = math.log(current)
log_ratio = (log_max - log_current) / (n_buckets - bucket_index)
log_next = log_current + log_ratio
next_value = int(math.floor(math.exp(log_next) + 0.5))
if next_value > current:
current = next_value
else:
current = current + 1
ret_array[bucket_index] = current
return ret_array
always_allowed_keys = ['kind', 'description', 'cpp_guard', 'expires_in_version',
'alert_emails', 'keyed', 'releaseChannelCollection',
'bug_numbers']
whitelists = None;
try:
whitelist_path = os.path.join(os.path.abspath(os.path.realpath(os.path.dirname(__file__))), 'histogram-whitelists.json')
with open(whitelist_path, 'r') as f:
try:
whitelists = json.load(f)
for name, whitelist in whitelists.iteritems():
whitelists[name] = set(whitelist)
except ValueError, e:
raise BaseException, 'error parsing whitelist (%s)' % whitelist_path
except IOError:
whitelists = None
print 'Unable to parse whitelist (%s). Assuming all histograms are acceptable.' % whitelist_path
class Histogram:
"""A class for representing a histogram definition."""
def __init__(self, name, definition, strict_type_checks=False):
"""Initialize a histogram named name with the given definition.
definition is a dict-like object that must contain at least the keys:
- 'kind': The kind of histogram. Must be one of 'boolean', 'flag',
'count', 'enumerated', 'linear', or 'exponential'.
- 'description': A textual description of the histogram.
- 'strict_type_checks': A boolean indicating whether to use the new, stricter type checks.
The server-side still has to deal with old, oddly typed submissions,
so we have to skip them there by default.
The key 'cpp_guard' is optional; if present, it denotes a preprocessor
symbol that should guard C/C++ definitions associated with the histogram."""
self._strict_type_checks = strict_type_checks
self._is_use_counter = name.startswith("USE_COUNTER2_")
self.verify_attributes(name, definition)
self._name = name
self._description = definition['description']
self._kind = definition['kind']
self._cpp_guard = definition.get('cpp_guard')
self._keyed = definition.get('keyed', False)
self._expiration = definition.get('expires_in_version')
self._labels = definition.get('labels', [])
self.compute_bucket_parameters(definition)
table = {
'boolean': 'BOOLEAN',
'flag': 'FLAG',
'count': 'COUNT',
'enumerated': 'LINEAR',
'categorical': 'CATEGORICAL',
'linear': 'LINEAR',
'exponential': 'EXPONENTIAL',
}
table_dispatch(self.kind(), table,
lambda k: self._set_nsITelemetry_kind(k))
datasets = { 'opt-in': 'DATASET_RELEASE_CHANNEL_OPTIN',
'opt-out': 'DATASET_RELEASE_CHANNEL_OPTOUT' }
value = definition.get('releaseChannelCollection', 'opt-in')
if not value in datasets:
raise DefinitionException, "unknown release channel collection policy for " + name
self._dataset = "nsITelemetry::" + datasets[value]
def name(self):
"""Return the name of the histogram."""
return self._name
def description(self):
"""Return the description of the histogram."""
return self._description
def kind(self):
"""Return the kind of the histogram.
Will be one of 'boolean', 'flag', 'count', 'enumerated', 'categorical', 'linear',
or 'exponential'."""
return self._kind
def expiration(self):
"""Return the expiration version of the histogram."""
return self._expiration
def nsITelemetry_kind(self):
"""Return the nsITelemetry constant corresponding to the kind of
the histogram."""
return self._nsITelemetry_kind
def _set_nsITelemetry_kind(self, kind):
self._nsITelemetry_kind = "nsITelemetry::HISTOGRAM_%s" % kind
def low(self):
"""Return the lower bound of the histogram."""
return self._low
def high(self):
"""Return the high bound of the histogram."""
return self._high
def n_buckets(self):
"""Return the number of buckets in the histogram."""
return self._n_buckets
def cpp_guard(self):
"""Return the preprocessor symbol that should guard C/C++ definitions
associated with the histogram. Returns None if no guarding is necessary."""
return self._cpp_guard
def keyed(self):
"""Returns True if this a keyed histogram, false otherwise."""
return self._keyed
def dataset(self):
"""Returns the dataset this histogram belongs into."""
return self._dataset
def labels(self):
"""Returns a list of labels for a categorical histogram, [] for others."""
return self._labels
def ranges(self):
"""Return an array of lower bounds for each bucket in the histogram."""
table = {
'boolean': linear_buckets,
'flag': linear_buckets,
'count': linear_buckets,
'enumerated': linear_buckets,
'categorical': linear_buckets,
'linear': linear_buckets,
'exponential': exponential_buckets,
}
return table_dispatch(self.kind(), table,
lambda p: p(self.low(), self.high(), self.n_buckets()))
def compute_bucket_parameters(self, definition):
table = {
'boolean': Histogram.boolean_flag_bucket_parameters,
'flag': Histogram.boolean_flag_bucket_parameters,
'count': Histogram.boolean_flag_bucket_parameters,
'enumerated': Histogram.enumerated_bucket_parameters,
'categorical': Histogram.categorical_bucket_parameters,
'linear': Histogram.linear_bucket_parameters,
'exponential': Histogram.exponential_bucket_parameters,
}
table_dispatch(self.kind(), table,
lambda p: self.set_bucket_parameters(*p(definition)))
def verify_attributes(self, name, definition):
global always_allowed_keys
general_keys = always_allowed_keys + ['low', 'high', 'n_buckets']
table = {
'boolean': always_allowed_keys,
'flag': always_allowed_keys,
'count': always_allowed_keys,
'enumerated': always_allowed_keys + ['n_values'],
'categorical': always_allowed_keys + ['labels'],
'linear': general_keys,
'exponential': general_keys,
}
# We removed extended_statistics_ok on the client, but the server-side,
# where _strict_type_checks==False, has to deal with historical data.
if not self._strict_type_checks:
table['exponential'].append('extended_statistics_ok')
table_dispatch(definition['kind'], table,
lambda allowed_keys: Histogram.check_keys(name, definition, allowed_keys))
self.check_name(name)
self.check_field_types(name, definition)
self.check_whitelistable_fields(name, definition)
self.check_expiration(name, definition)
self.check_label_values(name, definition)
def check_name(self, name):
if '#' in name:
raise ValueError, '"#" not permitted for %s' % (name)
# Avoid C++ identifier conflicts between histogram enums and label enum names.
if name.startswith("LABELS_"):
raise ValueError, "Histogram name '%s' can not start with LABELS_" % (name)
# To make it easier to generate C++ identifiers from this etc., we restrict
# the histogram names to a strict pattern.
# We skip this on the server to avoid failures with old Histogram.json revisions.
if self._strict_type_checks:
pattern = '^[a-z][a-z0-9_]+[a-z0-9]$'
if not re.match(pattern, name, re.IGNORECASE):
raise ValueError, "Histogram name '%s' doesn't confirm to '%s'" % (name, pattern)
def check_expiration(self, name, definition):
expiration = definition.get('expires_in_version')
if not expiration:
return
if re.match(r'^[1-9][0-9]*$', expiration):
expiration = expiration + ".0a1"
elif re.match(r'^[1-9][0-9]*\.0$', expiration):
expiration = expiration + "a1"
definition['expires_in_version'] = expiration
def check_label_values(self, name, definition):
labels = definition.get('labels')
if not labels:
return
invalid = filter(lambda l: len(l) > MAX_LABEL_LENGTH, labels)
if len(invalid) > 0:
raise ValueError, 'Label values for %s exceed length limit of %d: %s' % \
(name, MAX_LABEL_LENGTH, ', '.join(invalid))
if len(labels) > MAX_LABEL_COUNT:
raise ValueError, 'Label count for %s exceeds limit of %d' % \
(name, MAX_LABEL_COUNT)
# To make it easier to generate C++ identifiers from this etc., we restrict
# the label values to a strict pattern.
pattern = '^[a-z][a-z0-9_]+[a-z0-9]$'
invalid = filter(lambda l: not re.match(pattern, l, re.IGNORECASE), labels)
if len(invalid) > 0:
raise ValueError, 'Label values for %s are not matching pattern "%s": %s' % \
(name, pattern, ', '.join(invalid))
# Check for the presence of fields that old histograms are whitelisted for.
def check_whitelistable_fields(self, name, definition):
# Use counters don't have any mechanism to add the fields checked here,
# so skip the check for them.
if self._is_use_counter:
return
# In the pipeline we don't have whitelists available.
if whitelists is None:
return
for field in ['alert_emails', 'bug_numbers']:
if field not in definition and name not in whitelists[field]:
raise KeyError, 'New histogram "%s" must have a %s field.' % (name, field)
def check_field_types(self, name, definition):
# Define expected types for the histogram properties.
type_checked_fields = {
"n_buckets": int,
"n_values": int,
"low": int,
"high": int,
"keyed": bool,
"expires_in_version": basestring,
"kind": basestring,
"description": basestring,
"cpp_guard": basestring,
"releaseChannelCollection": basestring,
}
# For list fields we check the items types.
type_checked_list_fields = {
"bug_numbers": int,
"alert_emails": basestring,
"labels": basestring,
}
# For the server-side, where _strict_type_checks==False, we want to
# skip the stricter type checks for these fields for dealing with
# historical data.
coerce_fields = ["low", "high", "n_values", "n_buckets"]
if not self._strict_type_checks:
def try_to_coerce_to_number(v):
try:
return eval(v, {})
except:
return v
for key in [k for k in coerce_fields if k in definition]:
definition[key] = try_to_coerce_to_number(definition[key])
# This handles old "keyed":"true" definitions (bug 1271986).
if definition.get("keyed", None) == "true":
definition["keyed"] = True
def nice_type_name(t):
if t is basestring:
return "string"
return t.__name__
for key, key_type in type_checked_fields.iteritems():
if not key in definition:
continue
if not isinstance(definition[key], key_type):
raise ValueError, ('value for key "{0}" in Histogram "{1}" '
'should be {2}').format(key, name, nice_type_name(key_type))
for key, key_type in type_checked_list_fields.iteritems():
if not key in definition:
continue
if not all(isinstance(x, key_type) for x in definition[key]):
raise ValueError, ('all values for list "{0}" in Histogram "{1}" '
'should be {2}').format(key, name, nice_type_name(key_type))
@staticmethod
def check_keys(name, definition, allowed_keys):
for key in definition.iterkeys():
if key not in allowed_keys:
raise KeyError, '%s not permitted for %s' % (key, name)
def set_bucket_parameters(self, low, high, n_buckets):
self._low = low
self._high = high
self._n_buckets = n_buckets
if whitelists is not None and self._n_buckets > 100 and type(self._n_buckets) is int:
if self._name not in whitelists['n_buckets']:
raise KeyError, ('New histogram "%s" is not permitted to have more than 100 buckets. '
'Histograms with large numbers of buckets use disproportionately high amounts of resources. '
'Contact the Telemetry team (e.g. in #telemetry) if you think an exception ought to be made.' % self._name)
@staticmethod
def boolean_flag_bucket_parameters(definition):
return (1, 2, 3)
@staticmethod
def linear_bucket_parameters(definition):
return (definition.get('low', 1),
definition['high'],
definition['n_buckets'])
@staticmethod
def enumerated_bucket_parameters(definition):
n_values = definition['n_values']
return (1, n_values, n_values + 1)
@staticmethod
def categorical_bucket_parameters(definition):
n_values = len(definition['labels'])
return (1, n_values, n_values + 1)
@staticmethod
def exponential_bucket_parameters(definition):
return (definition.get('low', 1),
definition['high'],
definition['n_buckets'])
# We support generating histograms from multiple different input files, not
# just Histograms.json. For each file's basename, we have a specific
# routine to parse that file, and return a dictionary mapping histogram
# names to histogram parameters.
def from_Histograms_json(filename):
with open(filename, 'r') as f:
try:
histograms = json.load(f, object_pairs_hook=OrderedDict)
except ValueError, e:
raise BaseException, "error parsing histograms in %s: %s" % (filename, e.message)
return histograms
def from_UseCounters_conf(filename):
return usecounters.generate_histograms(filename)
def from_nsDeprecatedOperationList(filename):
operation_regex = re.compile('^DEPRECATED_OPERATION\\(([^)]+)\\)')
histograms = collections.OrderedDict()
with open(filename, 'r') as f:
for line in f:
match = operation_regex.search(line)
if not match:
continue
op = match.group(1)
def add_counter(context):
name = 'USE_COUNTER2_DEPRECATED_%s_%s' % (op, context.upper())
histograms[name] = {
'expires_in_version': 'never',
'kind': 'boolean',
'description': 'Whether a %s used %s' % (context, op)
}
add_counter('document')
add_counter('page')
return histograms
FILENAME_PARSERS = {
'Histograms.json': from_Histograms_json,
'nsDeprecatedOperationList.h': from_nsDeprecatedOperationList,
}
# Similarly to the dance above with buildconfig, usecounters may not be
# available, so handle that gracefully.
try:
import usecounters
FILENAME_PARSERS['UseCounters.conf'] = from_UseCounters_conf
except ImportError:
pass
def from_files(filenames):
"""Return an iterator that provides a sequence of Histograms for
the histograms defined in filenames.
"""
all_histograms = OrderedDict()
for filename in filenames:
parser = FILENAME_PARSERS[os.path.basename(filename)]
histograms = parser(filename)
# OrderedDicts are important, because then the iteration order over
# the parsed histograms is stable, which makes the insertion into
# all_histograms stable, which makes ordering in generated files
# stable, which makes builds more deterministic.
if not isinstance(histograms, OrderedDict):
raise BaseException, "histogram parser didn't provide an OrderedDict"
for (name, definition) in histograms.iteritems():
if all_histograms.has_key(name):
raise DefinitionException, "duplicate histogram name %s" % name
all_histograms[name] = definition
# We require that all USE_COUNTER2_* histograms be defined in a contiguous
# block.
use_counter_indices = filter(lambda x: x[1].startswith("USE_COUNTER2_"),
enumerate(all_histograms.iterkeys()));
if use_counter_indices:
lower_bound = use_counter_indices[0][0]
upper_bound = use_counter_indices[-1][0]
n_counters = upper_bound - lower_bound + 1
if n_counters != len(use_counter_indices):
raise DefinitionException, "use counter histograms must be defined in a contiguous block"
for (name, definition) in all_histograms.iteritems():
yield Histogram(name, definition, strict_type_checks=True)