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_URL_REQUEST_URL_REQUEST_THROTTLER_ENTRY_INTERFACE_H_
6#define NET_URL_REQUEST_URL_REQUEST_THROTTLER_ENTRY_INTERFACE_H_
7
8#include <string>
9
10#include "base/basictypes.h"
11#include "base/memory/ref_counted.h"
12#include "base/time/time.h"
13#include "net/base/net_export.h"
14
15namespace net {
16
17class NetworkDelegate;
18class URLRequest;
19class URLRequestThrottlerHeaderInterface;
20
21// Interface provided on entries of the URL request throttler manager.
22class NET_EXPORT URLRequestThrottlerEntryInterface
23    : public base::RefCountedThreadSafe<URLRequestThrottlerEntryInterface> {
24 public:
25  URLRequestThrottlerEntryInterface() {}
26
27  // Returns true when we have encountered server errors and are doing
28  // exponential back-off, unless the request has load flags that mean
29  // it is likely to be user-initiated, or the NetworkDelegate returns
30  // false for |CanThrottleRequest(request)|.
31  //
32  // URLRequestHttpJob checks this method prior to every request; it
33  // cancels requests if this method returns true.
34  virtual bool ShouldRejectRequest(
35      const URLRequest& request,
36      NetworkDelegate* network_delegate) const = 0;
37
38  // Calculates a recommended sending time for the next request and reserves it.
39  // The sending time is not earlier than the current exponential back-off
40  // release time or |earliest_time|. Moreover, the previous results of
41  // the method are taken into account, in order to make sure they are spread
42  // properly over time.
43  // Returns the recommended delay before sending the next request, in
44  // milliseconds. The return value is always positive or 0.
45  // Although it is not mandatory, respecting the value returned by this method
46  // is helpful to avoid traffic overload.
47  virtual int64 ReserveSendingTimeForNextRequest(
48      const base::TimeTicks& earliest_time) = 0;
49
50  // Returns the time after which requests are allowed.
51  virtual base::TimeTicks GetExponentialBackoffReleaseTime() const = 0;
52
53  // This method needs to be called each time a response is received.
54  virtual void UpdateWithResponse(
55      const std::string& host,
56      const URLRequestThrottlerHeaderInterface* response) = 0;
57
58  // Lets higher-level modules, that know how to parse particular response
59  // bodies, notify of receiving malformed content for the given URL. This will
60  // be handled by the throttler as if an HTTP 503 response had been received to
61  // the request, i.e. it will count as a failure, unless the HTTP response code
62  // indicated is already one of those that will be counted as an error.
63  virtual void ReceivedContentWasMalformed(int response_code) = 0;
64
65 protected:
66  friend class base::RefCountedThreadSafe<URLRequestThrottlerEntryInterface>;
67  virtual ~URLRequestThrottlerEntryInterface() {}
68
69 private:
70  friend class base::RefCounted<URLRequestThrottlerEntryInterface>;
71  DISALLOW_COPY_AND_ASSIGN(URLRequestThrottlerEntryInterface);
72};
73
74}  // namespace net
75
76#endif  // NET_URL_REQUEST_URL_REQUEST_THROTTLER_ENTRY_INTERFACE_H_
77