def __init__(self, loop):
self._loop = loop
self._hosts = load_hosts_conf()
self._servers = load_resolv_conf()
self._callbacks = {}
self._cache = LRUCache(timeout=300, **self._hosts)
self._sock = None
# TODO monitor hosts change and reload hosts
# TODO parse /etc/gai.conf and follow its rules
self._register_to_loop()
def __init__(self, loop):
self._loop = loop
self._hosts = load_hosts_conf()
self._servers = load_resolv_conf()
self._callbacks = {}
self._cache = LRUCache(timeout=300, **self._hosts)
self._sock = None
# TODO monitor hosts change and reload hosts
# TODO parse /etc/gai.conf and follow its rules
self._register_to_loop()
class DNSResolver(object):
def __init__(self, loop):
self._loop = loop
self._hosts = load_hosts_conf()
self._servers = load_resolv_conf()
self._callbacks = {}
self._cache = LRUCache(timeout=300, **self._hosts)
self._sock = None
# TODO monitor hosts change and reload hosts
# TODO parse /etc/gai.conf and follow its rules
self._register_to_loop()
def _register_to_loop(self):
self._sock = Socket(self._servers)
self._sock.setblocking(False)
self._loop.register(self._sock, MainLoop.EVENT_READ, self.handle_event)
self._loop.add_timeout(self._handle_timeout, 20)
def _call_callback(self, hostname, ipaddr, error=None):
"""domain resolved, execute the callbacks"""
DEBUG('DNS callback %s:%s' % (hostname, ipaddr))
for callback in self._callbacks.get(hostname, []):
if ipaddr or error:
callback((hostname, ipaddr), error)
else:
callback((hostname, None),
Exception('unknown hostname %s' % hostname))
if hostname in self._callbacks:
del self._callbacks[hostname]
def _send_request(self, hostname):
DEBUG('query DNS %s' % hostname)
self._sock.send_dns_request(hostname)
def _handle_response(self, response):
if response is None:
"""wait another response"""
return
if response.is_valid():
self._cache[response.hostname] = response.answer
self._call_callback(response.hostname, response.answer)
def handle_event(self, sock, event):
if sock != self._sock:
return
if event & MainLoop.EVENT_ERROR:
ERROR('dns socket error')
self._loop.remove(self._sock)
self._sock.close()
self._refresh()
elif event & MainLoop.EVENT_READ:
response = sock.recv_dns_response()
self._handle_response(response)
def _handle_timeout(self):
self._cache.sweep()
def resolve(self, host, callback):
"""resolve a domain names"""
hostname = tobytes(host)
if not hostname or not check_hostname(hostname):
callback(None, Exception('invalid hostname: %s' % hostname))
elif ip_address(hostname):
callback((hostname, hostname), None)
elif hostname in self._cache:
DEBUG('hit cache: %s' % host)
ip = self._cache[hostname]
callback((hostname, ip), None)
else:
arr = self._callbacks.get(hostname, None)
if not arr:
self._callbacks[hostname] = [callback]
self._send_request(hostname)
else:
arr.append(callback)
# TODO send again only if waited too long
self._send_request(hostname)
def close(self):
if self._sock:
if self._loop:
self._loop.remove_timeout(self._handle_timeout)
self._loop.unregister(self._sock)
self._sock.close()
self._sock = None
class DNSResolver(object):
def __init__(self, loop):
self._loop = loop
self._hosts = load_hosts_conf()
self._servers = load_resolv_conf()
self._callbacks = {}
self._cache = LRUCache(timeout=300, **self._hosts)
self._sock = None
# TODO monitor hosts change and reload hosts
# TODO parse /etc/gai.conf and follow its rules
self._register_to_loop()
def _register_to_loop(self):
self._sock = Socket(self._servers)
self._sock.setblocking(False)
self._loop.register(self._sock, MainLoop.EVENT_READ, self.handle_event)
self._loop.add_timeout(self._handle_timeout, 20)
def _call_callback(self, hostname, ipaddr, error=None):
"""domain resolved, execute the callbacks"""
DEBUG('DNS callback %s:%s' % (hostname, ipaddr))
for callback in self._callbacks.get(hostname, []):
if ipaddr or error:
callback((hostname, ipaddr), error)
else:
callback((hostname, None),
Exception('unknown hostname %s' % hostname))
if hostname in self._callbacks:
del self._callbacks[hostname]
def _send_request(self, hostname):
DEBUG('query DNS %s' % hostname)
self._sock.send_dns_request(hostname)
def _handle_response(self, response):
if response is None:
"""wait another response"""
return
if response.is_valid():
self._cache[response.hostname] = response.answer
self._call_callback(response.hostname, response.answer)
def handle_event(self, sock, event):
if sock != self._sock:
return
if event & MainLoop.EVENT_ERROR:
ERROR('dns socket error')
self._loop.remove(self._sock)
self._sock.close()
self._refresh()
elif event & MainLoop.EVENT_READ:
response = sock.recv_dns_response()
self._handle_response(response)
def _handle_timeout(self):
self._cache.sweep()
def resolve(self, host, callback):
"""resolve a domain names"""
hostname = tobytes(host)
if not hostname or not check_hostname(hostname):
callback(None, Exception('invalid hostname: %s' % hostname))
elif ip_address(hostname):
callback((hostname, hostname), None)
elif hostname in self._cache:
DEBUG('hit cache: %s' % host)
ip = self._cache[hostname]
callback((hostname, ip), None)
else:
arr = self._callbacks.get(hostname, None)
if not arr:
self._callbacks[hostname] = [callback]
self._send_request(hostname)
else:
arr.append(callback)
# TODO send again only if waited too long
self._send_request(hostname)
def close(self):
if self._sock:
if self._loop:
self._loop.remove_timeout(self._handle_timeout)
self._loop.unregister(self._sock)
self._sock.close()
self._sock = None
