extensions/browser/extension_throttle_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 EXTENSIONS_BROWSER_EXTENSION_THROTTLE_ENTRY_INTERFACE_H_
   6 #define EXTENSIONS_BROWSER_EXTENSION_THROTTLE_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 class URLRequest;
  17 }  // namespace net
  18
  19 namespace extensions {
  20
  21 // Interface provided on entries of the URL request throttler manager.
  22 class ExtensionThrottleEntryInterface
  23     : public base::RefCountedThreadSafe<ExtensionThrottleEntryInterface> {
  24  public:
  25   ExtensionThrottleEntryInterface() {}
  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(const net::URLRequest& request) const = 0;
  35
  36   // Calculates a recommended sending time for the next request and reserves it.
  37   // The sending time is not earlier than the current exponential back-off
  38   // release time or |earliest_time|. Moreover, the previous results of
  39   // the method are taken into account, in order to make sure they are spread
  40   // properly over time.
  41   // Returns the recommended delay before sending the next request, in
  42   // milliseconds. The return value is always positive or 0.
  43   // Although it is not mandatory, respecting the value returned by this method
  44   // is helpful to avoid traffic overload.
  45   virtual int64 ReserveSendingTimeForNextRequest(
  46       const base::TimeTicks& earliest_time) = 0;
  47
  48   // Returns the time after which requests are allowed.
  49   virtual base::TimeTicks GetExponentialBackoffReleaseTime() const = 0;
  50
  51   // This method needs to be called each time a response is received.
  52   virtual void UpdateWithResponse(int status_code) = 0;
  53
  54   // Lets higher-level modules, that know how to parse particular response
  55   // bodies, notify of receiving malformed content for the given URL. This will
  56   // be handled by the throttler as if an HTTP 503 response had been received to
  57   // the request, i.e. it will count as a failure, unless the HTTP response code
  58   // indicated is already one of those that will be counted as an error.
  59   virtual void ReceivedContentWasMalformed(int response_code) = 0;
  60
  61   // Get the URL ID associated with his entry. Should only be used for debugging
  62   // purpose.
  63   virtual const std::string& GetURLIdForDebugging() const = 0;
  64
  65  protected:
  66   friend class base::RefCountedThreadSafe<ExtensionThrottleEntryInterface>;
  67   virtual ~ExtensionThrottleEntryInterface() {}
  68
  69  private:
  70   friend class base::RefCounted<ExtensionThrottleEntryInterface>;
  71   DISALLOW_COPY_AND_ASSIGN(ExtensionThrottleEntryInterface);
  72 };
  73
  74 }  // namespace extensions
  75
  76 #endif  // EXTENSIONS_BROWSER_EXTENSION_THROTTLE_ENTRY_INTERFACE_H_