Add block extent writer
Add a utility class for writing block aligned data. Writes will always
happen at block boundary, and write size will always be a multiple of
block size. This is handy for upcomming XOR writers.
Test: th
Bug: 177104308
Change-Id: I11b4d9b79e20ba48f30b55243188a47c60c65552
diff --git a/payload_consumer/snapshot_extent_writer.cc b/payload_consumer/snapshot_extent_writer.cc
index 242e726..88f394a 100644
--- a/payload_consumer/snapshot_extent_writer.cc
+++ b/payload_consumer/snapshot_extent_writer.cc
@@ -25,99 +25,11 @@
namespace chromeos_update_engine {
-SnapshotExtentWriter::SnapshotExtentWriter(
- android::snapshot::ICowWriter* cow_writer)
- : cow_writer_(cow_writer) {
- CHECK_NE(cow_writer, nullptr);
+bool SnapshotExtentWriter::WriteExtent(const void* bytes,
+ const Extent& extent,
+ size_t block_size) {
+ return cow_writer_->AddRawBlocks(
+ extent.start_block(), bytes, extent.num_blocks() * block_size);
}
-SnapshotExtentWriter::~SnapshotExtentWriter() {
- CHECK(buffer_.empty()) << buffer_.size();
-}
-
-bool SnapshotExtentWriter::Init(
- const google::protobuf::RepeatedPtrField<Extent>& extents,
- uint32_t block_size) {
- extents_ = extents;
- cur_extent_idx_ = 0;
- buffer_.clear();
- buffer_.reserve(block_size);
- block_size_ = block_size;
- return true;
-}
-
-size_t SnapshotExtentWriter::ConsumeWithBuffer(const uint8_t* data,
- size_t count) {
- CHECK_LT(cur_extent_idx_, static_cast<size_t>(extents_.size()));
- const auto& cur_extent = extents_[cur_extent_idx_];
- const auto cur_extent_size = cur_extent.num_blocks() * block_size_;
-
- if (buffer_.empty() && count >= cur_extent_size) {
- if (!cow_writer_->AddRawBlocks(
- cur_extent.start_block(), data, cur_extent_size)) {
- LOG(ERROR) << "AddRawBlocks(" << cur_extent.start_block() << ", " << data
- << ", " << cur_extent_size << ") failed.";
- // return value is expected to be greater than 0. Return 0 to signal error
- // condition
- return 0;
- }
- if (!next_extent()) {
- CHECK_EQ(count, cur_extent_size)
- << "Exhausted all blocks, but still have " << count - cur_extent_size
- << " bytes left";
- }
- return cur_extent_size;
- }
- CHECK_LT(buffer_.size(), cur_extent_size)
- << "Data left in buffer should never be >= cur_extent_size, otherwise "
- "we should have send that data to CowWriter. Buffer size: "
- << buffer_.size() << " current extent size: " << cur_extent_size;
- size_t bytes_to_copy =
- std::min<size_t>(count, cur_extent_size - buffer_.size());
- CHECK_GT(bytes_to_copy, 0U);
-
- buffer_.insert(buffer_.end(), data, data + bytes_to_copy);
- CHECK_LE(buffer_.size(), cur_extent_size);
-
- if (buffer_.size() == cur_extent_size) {
- if (!cow_writer_->AddRawBlocks(
- cur_extent.start_block(), buffer_.data(), buffer_.size())) {
- LOG(ERROR) << "AddRawBlocks(" << cur_extent.start_block() << ", "
- << buffer_.data() << ", " << buffer_.size() << ") failed.";
- return 0;
- }
- buffer_.clear();
- if (!next_extent()) {
- CHECK_EQ(count, bytes_to_copy) << "Exhausted all blocks, but still have "
- << count - bytes_to_copy << " bytes left";
- }
- }
- return bytes_to_copy;
-}
-
-// Returns true on success.
-// This will construct a COW_REPLACE operation and forward it to CowWriter. It
-// is important that caller does not perform SOURCE_COPY operation on this
-// class, otherwise raw data will be stored. Caller should find ways to use
-// COW_COPY whenever possible.
-bool SnapshotExtentWriter::Write(const void* bytes, size_t count) {
- if (count == 0) {
- return true;
- }
- CHECK_NE(extents_.size(), 0);
-
- auto data = static_cast<const uint8_t*>(bytes);
- while (count > 0) {
- auto bytes_written = ConsumeWithBuffer(data, count);
- TEST_AND_RETURN_FALSE(bytes_written > 0);
- data += bytes_written;
- count -= bytes_written;
- }
- return true;
-}
-
-bool SnapshotExtentWriter::next_extent() {
- cur_extent_idx_++;
- return cur_extent_idx_ < static_cast<size_t>(extents_.size());
-}
} // namespace chromeos_update_engine