net/quic/crypto/cached_network_parameters.h

   1 // Copyright (c) 2014 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_QUIC_CRYPTO_CACHED_NETWORK_PARAMETERS_H_
   6 #define NET_QUIC_CRYPTO_CACHED_NETWORK_PARAMETERS_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/strings/string_piece.h"
  12 #include "net/base/net_export.h"
  13
  14 namespace net {
  15
  16 // TODO(rtenneti): sync with server more rationally.
  17 // CachedNetworkParameters contains data that can be used to choose appropriate
  18 // connection parameters (initial RTT, initial CWND, etc.) in new connections.
  19 class NET_EXPORT_PRIVATE CachedNetworkParameters {
  20  public:
  21   // Describes the state of the connection during which the supplied network
  22   // parameters were calculated.
  23   enum PreviousConnectionState {
  24     SLOW_START = 0,
  25     CONGESTION_AVOIDANCE = 1,
  26   };
  27
  28   CachedNetworkParameters();
  29   ~CachedNetworkParameters();
  30
  31   bool operator==(const CachedNetworkParameters& other) const;
  32   bool operator!=(const CachedNetworkParameters& other) const;
  33
  34   std::string serving_region() const {
  35     return serving_region_;
  36   }
  37   void set_serving_region(base::StringPiece serving_region) {
  38     serving_region_ = serving_region.as_string();
  39   }
  40
  41   int32 bandwidth_estimate_bytes_per_second() const {
  42     return bandwidth_estimate_bytes_per_second_;
  43   }
  44   void set_bandwidth_estimate_bytes_per_second(
  45       int32 bandwidth_estimate_bytes_per_second) {
  46     bandwidth_estimate_bytes_per_second_ = bandwidth_estimate_bytes_per_second;
  47   }
  48
  49   int32 max_bandwidth_estimate_bytes_per_second() const {
  50     return max_bandwidth_estimate_bytes_per_second_;
  51   }
  52   void set_max_bandwidth_estimate_bytes_per_second(
  53       int32 max_bandwidth_estimate_bytes_per_second) {
  54     max_bandwidth_estimate_bytes_per_second_ =
  55         max_bandwidth_estimate_bytes_per_second;
  56   }
  57
  58   int64 max_bandwidth_timestamp_seconds() const {
  59     return max_bandwidth_timestamp_seconds_;
  60   }
  61   void set_max_bandwidth_timestamp_seconds(
  62       int64 max_bandwidth_timestamp_seconds) {
  63     max_bandwidth_timestamp_seconds_ = max_bandwidth_timestamp_seconds;
  64   }
  65
  66   int32 min_rtt_ms() const {
  67     return min_rtt_ms_;
  68   }
  69   void set_min_rtt_ms(int32 min_rtt_ms) {
  70     min_rtt_ms_ = min_rtt_ms;
  71     has_min_rtt_ms_ = true;
  72   }
  73   bool has_min_rtt_ms() const { return has_min_rtt_ms_; }
  74
  75   int32 previous_connection_state() const {
  76     return previous_connection_state_;
  77   }
  78   void set_previous_connection_state(int32 previous_connection_state) {
  79     previous_connection_state_ = previous_connection_state;
  80   }
  81
  82   int64 timestamp() const { return timestamp_; }
  83   void set_timestamp(int64 timestamp) { timestamp_ = timestamp; }
  84
  85  private:
  86   // serving_region_ is used to decide whether or not the bandwidth estimate and
  87   // min RTT are reasonable and if they should be used.
  88   // For example a group of geographically close servers may share the same
  89   // serving_region_ string if they are expected to have similar network
  90   // performance.
  91   std::string serving_region_;
  92   // The server can supply a bandwidth estimate (in bytes/s) which it may re-use
  93   // on receipt of a source-address token with this field set.
  94   int32 bandwidth_estimate_bytes_per_second_;
  95   // The maximum bandwidth seen by the client, not necessarily the latest.
  96   int32 max_bandwidth_estimate_bytes_per_second_;
  97   // Timestamp (seconds since UNIX epoch) that indicates when the max bandwidth
  98   // was seen by the server.
  99   int64 max_bandwidth_timestamp_seconds_;
 100   // The min RTT seen on a previous connection can be used by the server to
 101   // inform initial connection parameters for new connections.
 102   int32 min_rtt_ms_;
 103   // Whenever min_rtt_ms_ is updated, it is set to true.
 104   bool has_min_rtt_ms_;
 105   // Encodes the PreviousConnectionState enum.
 106   int32 previous_connection_state_;
 107   // UNIX timestamp when this bandwidth estimate was created.
 108   int64 timestamp_;
 109 };
 110
 111 }  // namespace net
 112
 113 #endif  // NET_QUIC_CRYPTO_CACHED_NETWORK_PARAMETERS_H_