AU: Resume interrupted update attempts.

delta_performer.h

 // Copyright (c) 2010 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_DELTA_PERFORMER_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_PERFORMER_H__
 
 #include <inttypes.h>
 
 #include <vector>
@@ skipping 65 matching lines @@
       uint64_t block_size,
       uint64_t full_length,
       std::string* positions_string);
 
   // Returns true if a previous update attempt can be continued based on the
   // persistent preferences and the new update check response hash.
   static bool CanResumeUpdate(PrefsInterface* prefs,
                               std::string update_check_response_hash);
 
   // Resets the persistent update progress state to indicate that an update
-  // can't be resumed. Returns true on success, false otherwise.
-  static bool ResetUpdateProgress(PrefsInterface* prefs);
+  // can't be resumed. Performs a quick update-in-progress reset if |quick| is
+  // true, otherwise resets all progress-related update state. Returns true on
+  // success, false otherwise.
+  static bool ResetUpdateProgress(PrefsInterface* prefs, bool quick);
 
  private:
   // Returns true if enough of the delta file has been passed via Write()
   // to be able to perform a given install operation.
   bool CanPerformInstallOperation(
       const DeltaArchiveManifest_InstallOperation& operation);
 
   // Returns true on success.
   bool PerformInstallOperation(
       const DeltaArchiveManifest_InstallOperation& operation);
@@ skipping 15 matching lines @@
       const DeltaArchiveManifest_InstallOperation& operation);
 
   // Updates the hash calculator with |count| bytes at the head of |buffer_| and
   // then discards them.
   void DiscardBufferHeadBytes(size_t count);
 
   // Checkpoints the update progress into persistent storage to allow this
   // update attempt to be resumed after reboot.
   bool CheckpointUpdateProgress();
 
+  // Primes the required update state. Returns true if the update state was
+  // successfully initialized to a saved resume state or if the update is a new
+  // update. Returns false otherwise.
+  bool PrimeUpdateState();
+
   // Update Engine preference store.
   PrefsInterface* prefs_;
 
   // File descriptor of open device.
   int fd_;
 
   // File descriptor of the kernel device
   int kernel_fd_;
 
   std::string path_;  // Path that fd_ refers to.
@@ skipping 28 matching lines @@
 
   // Signatures message blob extracted directly from the payload.
   std::vector<char> signatures_message_data_;
 
   DISALLOW_COPY_AND_ASSIGN(DeltaPerformer);
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_PERFORMER_H__