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author | shmel1k <shmel1k@ydb.tech> | 2023-11-26 18:16:14 +0300 |
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committer | shmel1k <shmel1k@ydb.tech> | 2023-11-26 18:43:30 +0300 |
commit | b8cf9e88f4c5c64d9406af533d8948deb050d695 (patch) | |
tree | 218eb61fb3c3b96ec08b4d8cdfef383104a87d63 /contrib/python/Twisted/py2/twisted/names/resolve.py | |
parent | 523f645a83a0ec97a0332dbc3863bb354c92a328 (diff) | |
download | ydb-b8cf9e88f4c5c64d9406af533d8948deb050d695.tar.gz |
add kikimr_configure
Diffstat (limited to 'contrib/python/Twisted/py2/twisted/names/resolve.py')
-rw-r--r-- | contrib/python/Twisted/py2/twisted/names/resolve.py | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/contrib/python/Twisted/py2/twisted/names/resolve.py b/contrib/python/Twisted/py2/twisted/names/resolve.py new file mode 100644 index 0000000000..0cd39eb1c3 --- /dev/null +++ b/contrib/python/Twisted/py2/twisted/names/resolve.py @@ -0,0 +1,99 @@ +# -*- test-case-name: twisted.names.test.test_resolve -*- +# Copyright (c) Twisted Matrix Laboratories. +# See LICENSE for details. + +""" +Lookup a name using multiple resolvers. + +Future Plans: This needs someway to specify which resolver answered +the query, or someway to specify (authority|ttl|cache behavior|more?) +""" + +from __future__ import division, absolute_import + +from zope.interface import implementer + +from twisted.internet import defer, interfaces +from twisted.names import dns, common, error + + +class FailureHandler: + def __init__(self, resolver, query, timeout): + self.resolver = resolver + self.query = query + self.timeout = timeout + + + def __call__(self, failure): + # AuthoritativeDomainErrors should halt resolution attempts + failure.trap(dns.DomainError, defer.TimeoutError, NotImplementedError) + return self.resolver(self.query, self.timeout) + + + +@implementer(interfaces.IResolver) +class ResolverChain(common.ResolverBase): + """ + Lookup an address using multiple L{IResolver}s + """ + def __init__(self, resolvers): + """ + @type resolvers: L{list} + @param resolvers: A L{list} of L{IResolver} providers. + """ + common.ResolverBase.__init__(self) + self.resolvers = resolvers + + + def _lookup(self, name, cls, type, timeout): + """ + Build a L{dns.Query} for the given parameters and dispatch it + to each L{IResolver} in C{self.resolvers} until an answer or + L{error.AuthoritativeDomainError} is returned. + + @type name: C{str} + @param name: DNS name to resolve. + + @type type: C{int} + @param type: DNS record type. + + @type cls: C{int} + @param cls: DNS record class. + + @type timeout: Sequence of C{int} + @param timeout: Number of seconds after which to reissue the query. + When the last timeout expires, the query is considered failed. + + @rtype: L{Deferred} + @return: A L{Deferred} which fires with a three-tuple of lists of + L{twisted.names.dns.RRHeader} instances. The first element of the + tuple gives answers. The second element of the tuple gives + authorities. The third element of the tuple gives additional + information. The L{Deferred} may instead fail with one of the + exceptions defined in L{twisted.names.error} or with + C{NotImplementedError}. + """ + if not self.resolvers: + return defer.fail(error.DomainError()) + q = dns.Query(name, type, cls) + d = self.resolvers[0].query(q, timeout) + for r in self.resolvers[1:]: + d = d.addErrback( + FailureHandler(r.query, q, timeout) + ) + return d + + + def lookupAllRecords(self, name, timeout=None): + # XXX: Why is this necessary? dns.ALL_RECORDS queries should + # be handled just the same as any other type by _lookup + # above. If I remove this method all names tests still + # pass. See #6604 -rwall + if not self.resolvers: + return defer.fail(error.DomainError()) + d = self.resolvers[0].lookupAllRecords(name, timeout) + for r in self.resolvers[1:]: + d = d.addErrback( + FailureHandler(r.lookupAllRecords, name, timeout) + ) + return d |