commit 52cb1d75b6992f880058c56d43428b97bb4ed107
author Kelvin Zhang <zhangkelvin@google.com> Tue Oct 27 13:44:25 2020 -0400
committer Kelvin Zhang <zhangkelvin@google.com> Fri Nov 20 18:53:20 2020 -0500
tree 2cf4ef6ffd8ad7696ecd3af98f8af86471263606
parent dde2ef4d525af1076b9ccd1a4f736b4de961b2e6

Handle resume of VABC updates by emitting labels

To support resuming an update with Virtual AB Compression, we emit
labels in between operations. After writing all SOURCE_COPY, we
emit label 0. Each time we finished writing an InstallOp, we emit
a label incremented by 1. When resuming, we pass the label to CowWriter.

Test: treehugger
     1. update_device.py ota.zip
     --extra-headers="SWITCH_SLOT_ON_REBOOT=0"
     2. update_device.py ota.zip
     3. Verify that 2 did not re-start the entire update,
        only fs verification and postinstall may re-run.
Change-Id: I785cd04a35457181621ed7b8c0be9a46b6004b7b

payload_consumer/delta_performer.cc

diff --git a/payload_consumer/delta_performer.cc b/payload_consumer/delta_performer.cc
index ada1372..c3a321e 100644
--- a/payload_consumer/delta_performer.cc
+++ b/payload_consumer/delta_performer.cc
@@ -48,6 +48,7 @@
 #include "update_engine/common/prefs_interface.h"
 #include "update_engine/common/subprocess.h"
 #include "update_engine/common/terminator.h"
+#include "update_engine/common/utils.h"
 #include "update_engine/payload_consumer/bzip_extent_writer.h"
 #include "update_engine/payload_consumer/cached_file_descriptor.h"
 #include "update_engine/payload_consumer/certificate_parser_interface.h"
@@ -197,12 +198,9 @@
   if (op_result)
     return true;
 
-  size_t partition_first_op_num =
-      current_partition_ ? acc_num_operations_[current_partition_ - 1] : 0;
   LOG(ERROR) << "Failed to perform " << op_type_name << " operation "
              << next_operation_num_ << ", which is the operation "
-             << next_operation_num_ - partition_first_op_num
-             << " in partition \""
+             << GetPartitionOperationNum() << " in partition \""
              << partitions_[current_partition_].partition_name() << "\"";
   if (*error == ErrorCode::kSuccess)
     *error = ErrorCode::kDownloadOperationExecutionError;
@@ -253,7 +251,17 @@
   // partial update.
   bool source_may_exist = manifest_.partial_update() ||
                           payload_->type == InstallPayloadType::kDelta;
-  return partition_writer_->Init(install_plan_, source_may_exist);
+  const size_t partition_operation_num = GetPartitionOperationNum();
+
+  TEST_AND_RETURN_FALSE(partition_writer_->Init(
+      install_plan_, source_may_exist, partition_operation_num));
+  CheckpointUpdateProgress(true);
+  return true;
+}
+
+size_t DeltaPerformer::GetPartitionOperationNum() {
+  return next_operation_num_ -
+         (current_partition_ ? acc_num_operations_[current_partition_ - 1] : 0);
 }
 
 namespace {
@@ -502,12 +510,9 @@
         return false;
       }
     }
-    const size_t partition_operation_num =
-        next_operation_num_ -
-        (current_partition_ ? acc_num_operations_[current_partition_ - 1] : 0);
 
     const InstallOperation& op =
-        partitions_[current_partition_].operations(partition_operation_num);
+        partitions_[current_partition_].operations(GetPartitionOperationNum());
 
     CopyDataToBuffer(&c_bytes, &count, op.data_length());
 
@@ -1438,6 +1443,7 @@
       TEST_AND_RETURN_FALSE(
           prefs_->SetInt64(kPrefsUpdateStateNextDataLength, 0));
     }
+    partition_writer_->CheckpointUpdateProgress(GetPartitionOperationNum());
   }
   TEST_AND_RETURN_FALSE(
       prefs_->SetInt64(kPrefsUpdateStateNextOperation, next_operation_num_));