net/url_request/url_request_throttler_entry_interface.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_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
  15 namespace net {
  16
  17 class NetworkDelegate;
  18 class URLRequest;
  19 class URLRequestThrottlerHeaderInterface;
  20
  21 // Interface provided on entries of the URL request throttler manager.
  22 class 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_