def _ParseEventTaggingRule(self, event_tagging_expression):
"""Parses an event tagging expression.
This method attempts to detect whether the event tagging expression is valid
objectfilter or dottysql syntax.
Example:
_ParseEventTaggingRule('5 + 5')
# Returns Sum(Literal(5), Literal(5))
Args:
event_tagging_expression (str): event tagging experssion either in
objectfilter or dottysql syntax.
Returns:
efilter.query.Query: efilter query of the event tagging expression.
Raises:
TaggingFileError: when the tagging file cannot be correctly parsed.
"""
if self._OBJECTFILTER_WORDS.search(event_tagging_expression):
syntax = 'objectfilter'
else:
syntax = 'dottysql'
try:
return efilter_query.Query(event_tagging_expression, syntax=syntax)
except efilter_errors.EfilterParseError as exception:
stripped_expression = event_tagging_expression.rstrip()
raise errors.TaggingFileError((
'Unable to parse event tagging expressoin: "{0:s}" with error: '
'{1!s}').format(stripped_expression, exception))
def GetEventTaggingRules(self):
"""Retrieves the event tagging rules from the tagging file.
Returns:
dict[str, EventObjectFilter]: tagging rules, that consists of one or more
filter objects per label.
Raises:
TaggingFileError: if a filter expression cannot be compiled.
"""
rules_per_label = {}
label_name = None
with io.open(self._path, 'r', encoding='utf-8') as tagging_file:
for line in tagging_file.readlines():
line = line.rstrip()
stripped_line = line.lstrip()
if not stripped_line:
label_name = None
continue
if stripped_line[0] == '#':
continue
if not line[0].isspace():
label_name = line
rules_per_label[label_name] = []
elif label_name:
rules_per_label[label_name].append(stripped_line)
filter_objects_per_label = {}
for label_name, rules in rules_per_label.items():
filter_object = event_filter.EventObjectFilter()
try:
filter_rule = ' OR '.join(['({0:s})'.format(rule) for rule in rules])
filter_object.CompileFilter(filter_rule)
except errors.ParseError as exception:
raise errors.TaggingFileError((
'Unable to compile filter for label: {0:s} with error: '
'{1!s}').format(label_name, exception))
# TODO: change other code remove list around filter_object
filter_objects_per_label[label_name] = [filter_object]
return filter_objects_per_label
def GetEventTaggingRules(self):
"""Retrieves the event tagging rules from the tagging file.
Returns:
dict[str, FilterObject]: tagging rules, that consists of one or more
filter objects per label.
Raises:
TaggingFileError: if a filter expression cannot be compiled.
"""
tagging_rules = {}
label_name = None
with io.open(self._path, 'r', encoding='utf-8') as tagging_file:
for line in tagging_file.readlines():
line = line.rstrip()
stripped_line = line.lstrip()
if not stripped_line or stripped_line[0] == '#':
continue
if not line[0].isspace():
label_name = line
tagging_rules[label_name] = []
continue
if not label_name:
continue
filter_object = event_filter.EventObjectFilter()
try:
filter_object.CompileFilter(stripped_line)
except errors.ParseError as exception:
raise errors.TaggingFileError((
'Unable to compile filter for label: {0:s} with error: '
'{1!s}').format(label_name, exception))
if filter_object not in tagging_rules[label_name]:
tagging_rules[label_name].append(filter_object)
return tagging_rules