text: // Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_INTERFACE_H__
  #define CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_INTERFACE_H__
  
  #include <string>
  
  #include "update_engine/action_processor.h"
  #include "update_engine/omaha_response.h"
  
  namespace chromeos_update_engine {
  
  // Describes the methods that need to be implemented by the PayloadState class.
  // This interface has been carved out to support mocking of the PayloadState
  // object.
  class PayloadStateInterface {
   public:
    // Sets the internal payload state based on the given Omaha response. This
    // response could be the same or different from the one for which we've stored
    // the internal state. If it's different, then this method resets all the
    // internal state corresponding to the old response. Since the Omaha response
    // has a lot of fields that are not related to payload state, it uses only
    // a subset of the fields in the Omaha response to compare equality.
    virtual void SetResponse(const OmahaResponse& response) = 0;
  
    // This method should be called whenever we have completed downloading all
    // the bytes of a payload and have verified that its size and hash match the
    // expected values. We use this notificaiton to increment the payload attempt
    // number so that the throttle the next attempt to download the same payload
    // (in case there's an error in subsequent steps such as post-install)
    // appropriately.
    virtual void DownloadComplete() = 0;
  
    // This method should be called whenever we receive new bytes from the
    // network for the current payload. We use this notification to reset the
    // failure count for a given URL since receipt of some bytes means we are
    // able to make forward progress with the current URL.
    virtual void DownloadProgress(size_t count) = 0;
  
    // This method should be called whenever an update attempt fails with the
    // given error code. We use this notification to update the payload state
    // depending on the type of the error that happened.
    virtual void UpdateFailed(ActionExitCode error) = 0;
  
    // Returns true if we should backoff the current download attempt.
    // False otherwise.
    virtual bool ShouldBackoffDownload() = 0;
  
    // Returns the currently stored response "signature". The signature  is a
    // subset of fields that are of interest to the PayloadState behavior.
    virtual std::string GetResponseSignature() = 0;
  
    // Returns the payload attempt number.
    virtual uint32_t GetPayloadAttemptNumber() = 0;
  
    // Returns the current URL index.
    virtual uint32_t GetUrlIndex() = 0;
  
    // Returns the current URL's failure count.
    virtual uint32_t GetUrlFailureCount() = 0;
  
    // Returns the expiry time for the current backoff period.
    virtual base::Time GetBackoffExpiryTime() = 0;
   };
  
  }  // namespace chromeos_update_engine
  
  #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_INTERFACE_H__
  