AU: Optimize checkpointing a bit and decide on new update vs. resume.

omaha_response_handler_action.cc

 // 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.
 
 #include "update_engine/omaha_response_handler_action.h"
 
 #include <string>
 
 #include <base/logging.h>
 
+#include "update_engine/delta_performer.h"
 #include "update_engine/prefs_interface.h"
 #include "update_engine/utils.h"
 
 using std::string;
 
 namespace chromeos_update_engine {
 
 void OmahaResponseHandlerAction::PerformAction() {
   CHECK(HasInputObject());
   ScopedActionCompleter completer(processor_, this);
   const OmahaResponse& response = GetInputObject();
   if (!response.update_exists) {
     got_no_update_response_ = true;
     LOG(INFO) << "There are no updates. Aborting.";
     return;
   }
   install_plan_.download_url = response.codebase;
   install_plan_.size = response.size;
   install_plan_.download_hash = response.hash;
-  // TODO(petkov): Decide here if this is going to be a regular update or
-  // resume-after-boot. This should also set the number of ops performed so far
-  // to invalid if no need to resume.
-  LOG_IF(WARNING, !prefs_->SetString(kPrefsUpdateCheckResponseHash,
-                                     response.hash))
-      << "Unable to save the update check response hash.";
+
+  install_plan_.is_resume =
+      DeltaPerformer::CanResumeUpdate(prefs_, response.hash);
+  if (!install_plan_.is_resume) {
+    LOG_IF(WARNING, !DeltaPerformer::ResetUpdateProgress(prefs_))
+        << "Unable to reset the update progress.";
+    LOG_IF(WARNING, !prefs_->SetString(kPrefsUpdateCheckResponseHash,
+                                       response.hash))
+        << "Unable to save the update check response hash.";
+  }
+
   TEST_AND_RETURN(GetInstallDev(
       (!boot_device_.empty() ? boot_device_ : utils::BootDevice()),
       &install_plan_.install_path));
   install_plan_.kernel_install_path =
       utils::BootKernelDevice(install_plan_.install_path);
 
   install_plan_.is_full_update = !response.is_delta;
 
   TEST_AND_RETURN(HasOutputPipe());
   if (HasOutputPipe())
@@ skipping 10 matching lines @@
   string ret(boot_dev);
   string::reverse_iterator it = ret.rbegin();  // last character in string
   // Right now, we just switch '3' and '5' partition numbers.
   TEST_AND_RETURN_FALSE((*it == '3') || (*it == '5'));
   *it = (*it == '3') ? '5' : '3';
   *install_dev = ret;
   return true;
 }
 
 }  // namespace chromeos_update_engine