host_resolver.cc revision dc0f95d653279beabeb9817299e2902918ba123e 
1// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "net/base/host_resolver.h"
6
7#include "base/compiler_specific.h"
8#include "base/logging.h"
9#include "net/base/net_errors.h"
10
11namespace net {
12
13HostResolver::RequestInfo::RequestInfo(const HostPortPair& host_port_pair)
14    : host_port_pair_(host_port_pair),
15      address_family_(ADDRESS_FAMILY_UNSPECIFIED),
16      host_resolver_flags_(0),
17      allow_cached_response_(true),
18      only_use_cached_response_(false),
19      is_speculative_(false),
20      priority_(MEDIUM) {
21}
22
23HostResolver::~HostResolver() {
24}
25
26AddressFamily HostResolver::GetDefaultAddressFamily() const {
27  return net::ADDRESS_FAMILY_UNSPECIFIED;
28}
29
30HostResolverImpl* HostResolver::GetAsHostResolverImpl() {
31  return NULL;
32}
33
34HostResolver::HostResolver() {
35}
36
37SingleRequestHostResolver::SingleRequestHostResolver(HostResolver* resolver)
38    : resolver_(resolver),
39      cur_request_(NULL),
40      cur_request_callback_(NULL),
41      ALLOW_THIS_IN_INITIALIZER_LIST(
42          callback_(this, &SingleRequestHostResolver::OnResolveCompletion)) {
43  DCHECK(resolver_ != NULL);
44}
45
46SingleRequestHostResolver::~SingleRequestHostResolver() {
47  Cancel();
48}
49
50int SingleRequestHostResolver::Resolve(const HostResolver::RequestInfo& info,
51                                       AddressList* addresses,
52                                       CompletionCallback* callback,
53                                       const BoundNetLog& net_log) {
54  DCHECK(!cur_request_ && !cur_request_callback_) << "resolver already in use";
55
56  HostResolver::RequestHandle request = NULL;
57
58  // We need to be notified of completion before |callback| is called, so that
59  // we can clear out |cur_request_*|.
60  CompletionCallback* transient_callback = callback ? &callback_ : NULL;
61
62  int rv = resolver_->Resolve(
63      info, addresses, transient_callback, &request, net_log);
64
65  if (rv == ERR_IO_PENDING) {
66    // Cleared in OnResolveCompletion().
67    cur_request_ = request;
68    cur_request_callback_ = callback;
69  }
70
71  return rv;
72}
73
74void SingleRequestHostResolver::Cancel() {
75  if (cur_request_) {
76    resolver_->CancelRequest(cur_request_);
77    cur_request_ = NULL;
78  }
79}
80
81void SingleRequestHostResolver::OnResolveCompletion(int result) {
82  DCHECK(cur_request_ && cur_request_callback_);
83
84  CompletionCallback* callback = cur_request_callback_;
85
86  // Clear the outstanding request information.
87  cur_request_ = NULL;
88  cur_request_callback_ = NULL;
89
90  // Call the user's original callback.
91  callback->Run(result);
92}
93
94}  // namespace net
95