def _solve_rules(self, rules, metrics):
"""
solve the rules using the given metrics.
metrics must contains all needed metrics.
:param list[Rule] rules: the
:param metrics:
:return:
:raises:
pyparsing.ParseException
"""
results = {}
root_table = SymbolTable('root', ())
for metric_name, values in metrics.items():
# bind to allow "rmq & rmq:xxx"
root_table.add_object(Bind(metric_name, Constant(bool(values))))
# bind to allow "rmq:latency" etc
root_table.add_subtable(
SymbolTable(
metric_name,
tuple(Bind(k, Constant(v)) for k, v in values.items())))
# build the symbol table for all rules (as boolean)
rules_symbols = SymbolTable('rules', ())
root_table.add_subtable(rules_symbols)
for rule in rules:
rule_name_ = rule['name']
rules_symbols.add_object(
Bind(
rule_name_,
BooleanVariable(
partial(get_rule_result,
rule_name=rule_name_,
rule=rule))))
rules_symbols.add_subtable(
SymbolTable(rule_name_, (Bind(
'since',
DurationVariable(
partial(get_since, rule_name=rule_name_,
rule=rule))), )))
parse_manager = EvaluableParseManager(root_table, grammar)
for rule in rules:
expression_ = rule['expression']
try:
results[rule['name']] = parse_manager.parse(expression_)(
results)
except pyparsing.ParseException as e:
logger.debug("error while parsing %r: %s", expression_, e)
raise
return results
