/usr/lib/python2.7/dist-packages/twisted/names/test/test_cache.py is in python-twisted-names 13.2.0-1ubuntu1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 | # Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Tests for L{twisted.names.cache}.
"""
from __future__ import division, absolute_import
import time
from zope.interface.verify import verifyClass
from twisted.trial import unittest
from twisted.names import dns, cache
from twisted.internet import task, interfaces
class Caching(unittest.TestCase):
"""
Tests for L{cache.CacheResolver}.
"""
def test_interface(self):
"""
L{cache.CacheResolver} implements L{interfaces.IResolver}
"""
verifyClass(interfaces.IResolver, cache.CacheResolver)
def test_lookup(self):
c = cache.CacheResolver({
dns.Query(name=b'example.com', type=dns.MX, cls=dns.IN):
(time.time(), ([], [], []))})
return c.lookupMailExchange(b'example.com').addCallback(
self.assertEqual, ([], [], []))
def test_constructorExpires(self):
"""
Cache entries passed into L{cache.CacheResolver.__init__} get
cancelled just like entries added with cacheResult
"""
r = ([dns.RRHeader(b"example.com", dns.A, dns.IN, 60,
dns.Record_A("127.0.0.1", 60))],
[dns.RRHeader(b"example.com", dns.A, dns.IN, 50,
dns.Record_A("127.0.0.1", 50))],
[dns.RRHeader(b"example.com", dns.A, dns.IN, 40,
dns.Record_A("127.0.0.1", 40))])
clock = task.Clock()
query = dns.Query(name=b"example.com", type=dns.A, cls=dns.IN)
c = cache.CacheResolver({ query : (clock.seconds(), r)}, reactor=clock)
# 40 seconds is enough to expire the entry because expiration is based
# on the minimum TTL.
clock.advance(40)
self.assertNotIn(query, c.cache)
return self.assertFailure(
c.lookupAddress(b"example.com"), dns.DomainError)
def test_normalLookup(self):
"""
When a cache lookup finds a cached entry from 1 second ago, it is
returned with a TTL of original TTL minus the elapsed 1 second.
"""
r = ([dns.RRHeader(b"example.com", dns.A, dns.IN, 60,
dns.Record_A("127.0.0.1", 60))],
[dns.RRHeader(b"example.com", dns.A, dns.IN, 50,
dns.Record_A("127.0.0.1", 50))],
[dns.RRHeader(b"example.com", dns.A, dns.IN, 40,
dns.Record_A("127.0.0.1", 40))])
clock = task.Clock()
c = cache.CacheResolver(reactor=clock)
c.cacheResult(dns.Query(name=b"example.com", type=dns.A, cls=dns.IN), r)
clock.advance(1)
def cbLookup(result):
self.assertEquals(result[0][0].ttl, 59)
self.assertEquals(result[1][0].ttl, 49)
self.assertEquals(result[2][0].ttl, 39)
self.assertEquals(result[0][0].name.name, b"example.com")
return c.lookupAddress(b"example.com").addCallback(cbLookup)
def test_cachedResultExpires(self):
"""
Once the TTL has been exceeded, the result is removed from the cache.
"""
r = ([dns.RRHeader(b"example.com", dns.A, dns.IN, 60,
dns.Record_A("127.0.0.1", 60))],
[dns.RRHeader(b"example.com", dns.A, dns.IN, 50,
dns.Record_A("127.0.0.1", 50))],
[dns.RRHeader(b"example.com", dns.A, dns.IN, 40,
dns.Record_A("127.0.0.1", 40))])
clock = task.Clock()
c = cache.CacheResolver(reactor=clock)
query = dns.Query(name=b"example.com", type=dns.A, cls=dns.IN)
c.cacheResult(query, r)
clock.advance(40)
self.assertNotIn(query, c.cache)
return self.assertFailure(
c.lookupAddress(b"example.com"), dns.DomainError)
def test_expiredTTLLookup(self):
"""
When the cache is queried exactly as the cached entry should expire but
before it has actually been cleared, the cache does not return the
expired entry.
"""
r = ([dns.RRHeader(b"example.com", dns.A, dns.IN, 60,
dns.Record_A("127.0.0.1", 60))],
[dns.RRHeader(b"example.com", dns.A, dns.IN, 50,
dns.Record_A("127.0.0.1", 50))],
[dns.RRHeader(b"example.com", dns.A, dns.IN, 40,
dns.Record_A("127.0.0.1", 40))])
clock = task.Clock()
# Make sure timeouts never happen, so entries won't get cleared:
clock.callLater = lambda *args, **kwargs: None
c = cache.CacheResolver({
dns.Query(name=b"example.com", type=dns.A, cls=dns.IN) :
(clock.seconds(), r)}, reactor=clock)
clock.advance(60.1)
return self.assertFailure(
c.lookupAddress(b"example.com"), dns.DomainError)
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