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/partition_writer.cc

diff --git a/payload_consumer/partition_writer.cc b/payload_consumer/partition_writer.cc
index bec2594..6f06dd2 100644
--- a/payload_consumer/partition_writer.cc
+++ b/payload_consumer/partition_writer.cc
@@ -274,7 +274,8 @@
 }
 
 bool PartitionWriter::Init(const InstallPlan* install_plan,
-                           bool source_may_exist) {
+                           bool source_may_exist,
+                           size_t next_op_index) {
   const PartitionUpdate& partition = partition_update_;
   uint32_t source_slot = install_plan->source_slot;
   uint32_t target_slot = install_plan->target_slot;
@@ -329,7 +330,7 @@
       writer->Init(target_fd_, operation.dst_extents(), block_size_));
   TEST_AND_RETURN_FALSE(writer->Write(data, operation.data_length()));
 
-  return Flush();
+  return true;
 }
 
 bool PartitionWriter::PerformZeroOrDiscardOperation(
@@ -362,7 +363,7 @@
           target_fd_, zeros.data(), chunk_length, start + offset));
     }
   }
-  return Flush();
+  return true;
 }
 
 bool PartitionWriter::PerformSourceCopyOperation(
@@ -473,7 +474,7 @@
                                                        block_size_,
                                                        nullptr));
   }
-  return Flush();
+  return true;
 }
 
 bool PartitionWriter::PerformSourceBsdiffOperation(
@@ -502,7 +503,7 @@
                                         std::move(dst_file),
                                         reinterpret_cast<const uint8_t*>(data),
                                         count) == 0);
-  return Flush();
+  return true;
 }
 
 bool PartitionWriter::PerformPuffDiffOperation(
@@ -534,7 +535,7 @@
                         reinterpret_cast<const uint8_t*>(data),
                         count,
                         kMaxCacheSize));
-  return Flush();
+  return true;
 }
 
 FileDescriptorPtr PartitionWriter::ChooseSourceFD(
@@ -652,12 +653,12 @@
   return -err;
 }
 
-std::unique_ptr<ExtentWriter> PartitionWriter::CreateBaseExtentWriter() {
-  return std::make_unique<DirectExtentWriter>();
+void PartitionWriter::CheckpointUpdateProgress(size_t next_op_index) {
+  target_fd_->Flush();
 }
 
-bool PartitionWriter::Flush() {
-  return target_fd_->Flush();
+std::unique_ptr<ExtentWriter> PartitionWriter::CreateBaseExtentWriter() {
+  return std::make_unique<DirectExtentWriter>();
 }
 
 }  // namespace chromeos_update_engine