Branch data Line data Source code
1 : : // Copyright (C) 2010 Internet Systems Consortium, Inc. ("ISC")
2 : : //
3 : : // Permission to use, copy, modify, and/or distribute this software for any
4 : : // purpose with or without fee is hereby granted, provided that the above
5 : : // copyright notice and this permission notice appear in all copies.
6 : : //
7 : : // THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
8 : : // REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
9 : : // AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
10 : : // INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
11 : : // LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
12 : : // OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
13 : : // PERFORMANCE OF THIS SOFTWARE.
14 : :
15 : : #ifndef __RESOLVER_INTERFACE_H
16 : : #define __RESOLVER_INTERFACE_H
17 : :
18 : : #include <dns/message.h>
19 : :
20 : : ///
21 : : /// \file resolver_interface.h
22 : : /// \short Interface to resolver.
23 : : ///
24 : : /// This file contains an interface for the resolver. By subclassing
25 : : /// this abstract interface, other parts of the system can ask the
26 : : /// resolver to do some resolving too.
27 : : ///
28 : : /// This is done by creating a subclass of ResolverInterface::Callback,
29 : : /// which defines what to do with the result, and then calling resolve()
30 : : /// on the ResolverInterface implementation.
31 : : ///
32 : : /// One default Callback subclass is provided right now, in
33 : : /// resolver_callback.[h|cc], which calls resumse() on a given DNSServer
34 : : ///
35 : :
36 : : namespace isc {
37 : : namespace resolve {
38 : :
39 : : ///
40 : : /// \short Abstract interface to the resolver.
41 : : ///
42 : : /// Abstract interface to the resolver. The NameserverAddressStore uses this
43 : : /// to ask for addresses. It is here because resolver does not yet exist.
44 : : ///
45 : : /// It is abstract to allow tests pass dummy resolvers.
46 : : ///
47 : 92 : class ResolverInterface {
48 : : public:
49 : : /// \short An abstract callback for when the resolver is done.
50 : : ///
51 : : /// You can pass an instance of a subclass of this (as a
52 : : /// CallbackPtr) to RecursiveQuery::sendQuery(), and when it
53 : : /// is done, it will either call success() if there is an
54 : : /// answer MessagePtr, or failure(), if the resolver was not
55 : : /// able to find anything.
56 : : ///
57 : : /// Note that a result Message does not necessarily contain
58 : : /// the actual answer (it could be a noerror/nodata response).
59 : 128 : class Callback {
60 : : public:
61 : : /// \short Some data arrived.
62 : : virtual void success(const isc::dns::MessagePtr response) = 0;
63 : :
64 : : ///
65 : : ///\short No data available.
66 : : ///
67 : : ///\todo Provide error reason (result of the
68 : : /// classification call, for instance? We'd also
69 : : /// need some way to say 'everything times out')
70 : : ///
71 : : virtual void failure() = 0;
72 : :
73 : : /// \short Virtual destructor, so descendants are cleaned up
74 : 120 : virtual ~Callback() {};
75 : : };
76 : :
77 : : typedef boost::shared_ptr<Callback> CallbackPtr;
78 : :
79 : : ///
80 : : ///\short Ask a question.
81 : : ///
82 : : /// Asks the resolver a question. Once the answer is ready
83 : : /// the callback is called.
84 : : ///
85 : : /// \param question What to ask. The resolver will decide who.
86 : : /// \param callback What should happen when the answer is ready.
87 : : ///
88 : : virtual void resolve(const isc::dns::QuestionPtr& question,
89 : : const CallbackPtr& callback) = 0;
90 : :
91 : : /// \short Virtual destructor, so descendants are properly cleaned up
92 : 92 : virtual ~ ResolverInterface() {}
93 : : };
94 : :
95 : : } // namespace nsas
96 : : } // namespace isc
97 : :
98 : : #endif //__RESOLVER_INTERFACE_H
|
