yaml implicit resolver leak #67
Description
Every time when we call yaml.dump, it will call the resolve method:
def resolve(self, kind, value, implicit):
if kind is ScalarNode and implicit[0]:
if value == u'':
resolvers = self.yaml_implicit_resolvers.get(u'', [])
else:
resolvers = self.yaml_implicit_resolvers.get(value[0], [])
resolvers += self.yaml_implicit_resolvers.get(None, [])As show above, the last line resolvers += self.yaml_implicit_resolvers.get(None, []) in resolve will change the yaml_implicit_resolvers inplace by accident, making yaml_implicit_resolvers size become more and more bigger, the yaml.dump will slow down, and finally use up 100% CPU.
reproduce:
import re
import yaml
def test_implicit_resolver_leak():
# Add any custom resolver
tag, regexp = '!any_resolver', re.compile('AnyResolver')
yaml.add_implicit_resolver(tag, regexp)
none_resolvers = yaml.Dumper.yaml_implicit_resolvers.get(None, [])
assert (tag, regexp) in none_resolvers
old_f_resolvers = yaml.Dumper.yaml_implicit_resolvers.get('f', [])
assert (tag, regexp) not in old_f_resolvers
# Dump at least one ScalarNode
yaml.dump(False)
new_f_resolvers = yaml.Dumper.yaml_implicit_resolvers.get('f', [])
assert (tag, regexp) in new_f_resolvers # leak here