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/Android.bp b/Android.bp
index 90e7698..51105eb 100644
--- a/Android.bp
+++ b/Android.bp
@@ -242,6 +242,7 @@
"payload_consumer/partition_writer.cc",
"payload_consumer/partition_writer_factory_android.cc",
"payload_consumer/vabc_partition_writer.cc",
+ "payload_consumer/block_extent_writer.cc",
"payload_consumer/snapshot_extent_writer.cc",
"payload_consumer/postinstall_runner_action.cc",
"payload_consumer/verified_source_fd.cc",
diff --git a/payload_consumer/block_extent_writer.cc b/payload_consumer/block_extent_writer.cc
new file mode 100644
index 0000000..a5c990c
--- /dev/null
+++ b/payload_consumer/block_extent_writer.cc
@@ -0,0 +1,113 @@
+//
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include "update_engine/payload_consumer/block_extent_writer.h"
+
+#include <algorithm>
+#include <cstdint>
+
+#include "update_engine/update_metadata.pb.h"
+
+namespace chromeos_update_engine {
+
+BlockExtentWriter::~BlockExtentWriter() {
+ CHECK(buffer_.empty()) << buffer_.size();
+}
+
+bool BlockExtentWriter::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 BlockExtentWriter::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 (!WriteExtent(data, cur_extent, block_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 (!NextExtent()) {
+ 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 (!WriteExtent(buffer_.data(), cur_extent, block_size_)) {
+ LOG(ERROR) << "WriteExtent(" << buffer_.data() << ", "
+ << cur_extent.start_block() << ", " << cur_extent.num_blocks()
+ << ") failed.";
+ return 0;
+ }
+ buffer_.clear();
+ if (!NextExtent()) {
+ 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 BlockExtentWriter::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 BlockExtentWriter::NextExtent() {
+ cur_extent_idx_++;
+ return cur_extent_idx_ < static_cast<size_t>(extents_.size());
+}
+} // namespace chromeos_update_engine
diff --git a/payload_consumer/block_extent_writer.h b/payload_consumer/block_extent_writer.h
new file mode 100644
index 0000000..7c90459
--- /dev/null
+++ b/payload_consumer/block_extent_writer.h
@@ -0,0 +1,59 @@
+//
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef UPDATE_ENGINE_BLOCK_EXTENT_WRITER_H_
+#define UPDATE_ENGINE_BLOCK_EXTENT_WRITER_H_
+
+#include <cstdint>
+#include <vector>
+
+#include "update_engine/payload_consumer/extent_writer.h"
+#include "update_engine/update_metadata.pb.h"
+
+namespace chromeos_update_engine {
+
+// Cache data upto size of one extent before writing.
+class BlockExtentWriter : public chromeos_update_engine::ExtentWriter {
+ public:
+ BlockExtentWriter() = default;
+ ~BlockExtentWriter();
+ // Returns true on success.
+ bool Init(const google::protobuf::RepeatedPtrField<Extent>& extents,
+ uint32_t block_size) override;
+ // Returns true on success.
+ bool Write(const void* bytes, size_t count) final;
+ // Write data for 1 extent. |bytes| will be a pointer which points to data of
+ // size |extent.num_blocks()*block_size|. |extent| is the current extent we
+ // are writing to.
+ virtual bool WriteExtent(const void* bytes,
+ const Extent& extent,
+ size_t block_size) = 0;
+
+ private:
+ bool NextExtent();
+ [[nodiscard]] size_t ConsumeWithBuffer(const uint8_t* bytes, size_t count);
+ // It's a non-owning pointer, because PartitionWriter owns the CowWruter. This
+ // allows us to use a single instance of CowWriter for all operations applied
+ // to the same partition.
+ google::protobuf::RepeatedPtrField<Extent> extents_;
+ size_t cur_extent_idx_;
+ std::vector<uint8_t> buffer_;
+ size_t block_size_;
+};
+
+} // namespace chromeos_update_engine
+
+#endif
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
diff --git a/payload_consumer/snapshot_extent_writer.h b/payload_consumer/snapshot_extent_writer.h
index c3a948e..c2e5446 100644
--- a/payload_consumer/snapshot_extent_writer.h
+++ b/payload_consumer/snapshot_extent_writer.h
@@ -22,36 +22,21 @@
#include <libsnapshot/cow_writer.h>
-#include "update_engine/payload_consumer/extent_writer.h"
+#include "update_engine/payload_consumer/block_extent_writer.h"
#include "update_engine/update_metadata.pb.h"
namespace chromeos_update_engine {
-class SnapshotExtentWriter : public chromeos_update_engine::ExtentWriter {
+class SnapshotExtentWriter final : public BlockExtentWriter {
public:
- explicit SnapshotExtentWriter(android::snapshot::ICowWriter* cow_writer);
- ~SnapshotExtentWriter();
- // Returns true on success.
- bool Init(const google::protobuf::RepeatedPtrField<Extent>& extents,
- uint32_t block_size) override;
- // 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 Write(const void* bytes, size_t count) override;
+ explicit SnapshotExtentWriter(android::snapshot::ICowWriter* cow_writer)
+ : cow_writer_(cow_writer) {}
+ bool WriteExtent(const void* bytes,
+ const Extent& extent,
+ size_t block_size) override;
private:
- bool next_extent();
- [[nodiscard]] size_t ConsumeWithBuffer(const uint8_t* bytes, size_t count);
- // It's a non-owning pointer, because PartitionWriter owns the CowWruter. This
- // allows us to use a single instance of CowWriter for all operations applied
- // to the same partition.
android::snapshot::ICowWriter* cow_writer_;
- google::protobuf::RepeatedPtrField<Extent> extents_;
- size_t cur_extent_idx_;
- std::vector<uint8_t> buffer_;
- size_t block_size_;
};
} // namespace chromeos_update_engine