blob: 1fbc60ce5a8511548b2822ac3d01d2379436dbba [file] [log] [blame]
# Copyright 2017 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Functions for populating enums with ukm events."""
from collections import namedtuple
import os
import sys
import xml.dom.minidom
import extract_histograms
sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'ukm'))
import codegen
EventDetails = namedtuple("EventDetails", "name hash is_obsolete")
def _GetEventDetails(event):
"""Returns a simple struct containing the event details.
Args:
event: An event description as defined in ukm.xml.
Returns:
A struct containing the event name, truncated hash, and whether the event is
considered obsolete.
"""
name = event.getAttribute('name')
# The value is UKM event name hash truncated to 31 bits. This is recorded in
# https://cs.chromium.org/chromium/src/components/ukm/ukm_recorder_impl.cc?q=LogEventHashasUmaHistogram
hash = codegen.HashName(name) & 0x7fffffff
def _HasDirectObsoleteTag(node):
return any(
isinstance(child, xml.dom.minidom.Element)
and child.tagName == 'obsolete' for child in node.childNodes)
# The UKM event is considered obsolete if the event itself is marked as
# obsolete with a tag or all of its metrics are marked as obsolete.
is_event_obsolete = _HasDirectObsoleteTag(event)
are_all_metrics_obsolete = all(
_HasDirectObsoleteTag(metric)
for metric in event.getElementsByTagName('metric'))
return EventDetails(name=name,
hash=hash,
is_obsolete=is_event_obsolete or are_all_metrics_obsolete)
def PopulateEnumWithUkmEvents(doc, enum, ukm_events):
"""Populates the enum node with a list of ukm events.
Args:
doc: The document to create the node in.
enum: The enum node needed to be populated.
ukm_events: A list of ukm event nodes.
"""
event_details = [_GetEventDetails(event) for event in ukm_events]
event_details.sort(key=lambda event: event.hash)
for event in event_details:
node = doc.createElement('int')
node.attributes['value'] = str(event.hash)
label = event.name
# If the event is obsolete, mark it in the int's label.
if event.is_obsolete:
label += ' (Obsolete)'
node.attributes['label'] = label
enum.appendChild(node)
def PopulateEnumsWithUkmEvents(doc, enums, ukm_events):
"""Populates enum nodes in the enums with a list of ukm events
Args:
doc: The document to create the node in.
enums: The enums node to be iterated.
ukm_events: A list of ukm event nodes.
"""
for enum in extract_histograms.IterElementsWithTag(enums, 'enum', 1):
# We only special case 'UkmEventNameHash' currently.
if enum.getAttribute('name') == 'UkmEventNameHash':
PopulateEnumWithUkmEvents(doc, enum, ukm_events)