net/dns/address_sorter.h

   1 // Copyright (c) 2012 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 #ifndef NET_DNS_ADDRESS_SORTER_H_
   6 #define NET_DNS_ADDRESS_SORTER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/callback.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "net/base/net_export.h"
  12
  13 namespace net {
  14
  15 class AddressList;
  16
  17 // Sorts AddressList according to RFC3484, by likelihood of successful
  18 // connection. Depending on the platform, the sort could be performed
  19 // asynchronously by the OS, or synchronously by local implementation.
  20 // AddressSorter does not necessarily preserve port numbers on the sorted list.
  21 class NET_EXPORT AddressSorter {
  22  public:
  23   typedef base::Callback<void(bool success,
  24                               const AddressList& list)> CallbackType;
  25
  26   virtual ~AddressSorter() {}
  27
  28   // Sorts |list|, which must include at least one IPv6 address.
  29   // Calls |callback| upon completion. Could complete synchronously. Could
  30   // complete after this AddressSorter is destroyed.
  31   virtual void Sort(const AddressList& list,
  32                     const CallbackType& callback) const = 0;
  33
  34   // Creates platform-dependent AddressSorter.
  35   static scoped_ptr<AddressSorter> CreateAddressSorter();
  36
  37  protected:
  38   AddressSorter() {}
  39
  40  private:
  41   DISALLOW_COPY_AND_ASSIGN(AddressSorter);
  42 };
  43
  44 }  // namespace net
  45
  46 #endif  // NET_DNS_ADDRESS_SORTER_H_