1"""High-level interface to adns."""
2
3import adns
4
5class Error(Exception): pass
6
7class QueryEngine:
8
9    callback_submit = None
10    callback_submit_reverse = None
11    callback_submit_reverse_any = None
12
13    def __init__(self, s=None):
14        self._s = s or adns.init(adns.iflags.noautosys)
15        self._queries = {}
16
17    def synchronous(self, qname, rr, flags=0):
18        return self._s.synchronous(qname, rr, flags)
19
20    def submit(self, qname, rr, flags=0, callback=None, extra=None):
21        callback = callback or self.callback_submit
22        if not callback: raise Error("callback required")
23        q = self._s.submit(qname, rr, flags)
24        self._queries[q] = qname, rr, flags, callback, extra
25
26    def submit_reverse(self, qname, rr, flags=0, callback=None, extra=None):
27        callback = callback or self.callback_submit_reverse
28        if not callback: raise Error("callback required")
29        q = self._s.submit_reverse(qname, rr, flags)
30        self._queries[q] = qname, rr, flags, callback, extra
31
32    def submit_reverse_any(self, qname, rr, flags=0,
33                           callback=None, extra=None):
34        callback = callback or self.callback_submit_reverse_any
35        if not callback: raise Error("callback required")
36        q = self._s.submit_reverse_any(qname, rr, flags)
37        self._queries[q] = qname, rr, flags, callback, extra
38
39    def cancel(self, query):
40        query.cancel()
41        try: del self._queries[query]
42        except KeyError: pass
43
44    def run(self, timeout=0):
45        for q in self._s.completed(timeout):
46            answer = q.check()
47            qname, rr, flags, callback, extra = self._queries[q]
48            del self._queries[q]
49            callback(*(answer, qname, rr, flags, extra))
50
51    def finished(self):
52        return not len(self._queries)
53
54    def finish(self):
55        while not self.finished():
56            self.run(1)
57
58    def run_max(self, max):
59        from time import time
60        quittime = time()+max
61        while not self.finished() and time()<=quittime:
62            self.run(1)
63
64    def globalsystemfailure(self):
65        self._s.globalsystemfailure()
66        self._queries.clear()
67
68init = QueryEngine
69