| // 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_H__ |
| #define CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_H__ |
| |
| #include "base/file_path.h" |
| |
| #include "update_engine/action_processor.h" |
| #include "update_engine/prefs_interface.h" |
| |
| namespace chromeos_update_engine { |
| |
| // Forward declaration here because we get a circular dependency if |
| // we include omaha_request_action.h directly. |
| struct OmahaResponse; |
| |
| // Encapsulates all the payload state required for download. This includes the |
| // state necessary for handling multiple URLs in Omaha response, the back-off |
| // state, etc. All state is persisted so that we use the most recently saved |
| // value when resuming the update_engine process. All state is also cached in |
| // memory so that we ensure we always make progress based on last known good |
| // state even when there's any issue in reading/writing from the file system. |
| class PayloadState { |
| public: |
| |
| PayloadState() : prefs_(NULL), num_urls_(0), url_index_(0) {} |
| |
| // Initializes a payload state object using |prefs| for storing the |
| // persisted state. It also performs the initial loading of all persisted |
| // state into memory and dumps the initial state for debugging purposes. |
| // Note: the other methods should be called only after calling Initialize |
| // on this object. |
| bool Initialize(PrefsInterface* prefs); |
| |
| // Logs the current payload state. |
| void LogPayloadState(); |
| |
| // 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. |
| void SetResponse(const OmahaResponse& response); |
| |
| // Updates the payload state when the current update attempt has failed. |
| void UpdateFailed(ActionExitCode error); |
| |
| // Returns the internally stored subset of the response state as a string. |
| // This is logically a private method, but exposed here for unit tests. |
| std::string GetResponse() { |
| return response_; |
| } |
| |
| // Returns the current URL index. |
| uint32_t GetUrlIndex() { |
| return url_index_; |
| } |
| |
| private: |
| // Sets the stored response_ value from the currently persisted value for |
| // the response. Returns the same value. |
| std::string LoadResponse(); |
| |
| // Sets the url_index_ value from the currently persisted value for |
| // URL index. Returns the same value. |
| uint32_t LoadUrlIndex(); |
| |
| // Sets the current URL index. |
| void SetUrlIndex(uint32_t url_index); |
| |
| // Interface object with which we read/write persisted state. This must |
| // be set by calling the Initialize method before calling any other method. |
| PrefsInterface* prefs_; |
| |
| // Cached value of the latest subset of the Omaha response with which we're |
| // working off currently. This value is persisted so we load it off the next |
| // time when update_engine restarts. The rest of the state in this class will |
| // be cleared when we set a new response. |
| std::string response_; |
| |
| // The number of urls in the current response. Not persisted. |
| uint32_t num_urls_; |
| |
| // Cached value of the index of the current URL, to be used in case we are |
| // unable to read from the persisted store for any reason. This type is |
| // different from the one in the accessor methods because PrefsInterface |
| // supports only int64_t but we want to provide a stronger abstraction of |
| // uint32_t. |
| int64_t url_index_; |
| |
| DISALLOW_COPY_AND_ASSIGN(PayloadState); |
| }; |
| |
| } // namespace chromeos_update_engine |
| |
| #endif // CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_H__ |