Split payload application code into a subdirectory.
This patch splits from the main libupdate_engine code the part that
is strictly used to download and apply a payload into a new static
library, moving the code to subdirectories. The new library is divided
in two subdirectories: common/ and payload_consumer/, and should not
depend on other update_engine files outside those two subdirectories.
The main difference between those two is that the common/ tools are more
generic and not tied to the payload consumer process, but otherwise they
are both compiled together.
There are still dependencies from the new libpayload_consumer library
into the main directory files and DBus generated files. Those will be
addressed in follow up CLs.
Bug: 25197634
Test: FEATURES=test emerge-link update_engine; `mm` on Brillo.
Change-Id: Id8d0204ea573627e6e26ca9ea17b9592ca95bc23
diff --git a/payload_consumer/extent_writer.h b/payload_consumer/extent_writer.h
new file mode 100644
index 0000000..6484ebf
--- /dev/null
+++ b/payload_consumer/extent_writer.h
@@ -0,0 +1,134 @@
+//
+// Copyright (C) 2009 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_PAYLOAD_CONSUMER_EXTENT_WRITER_H_
+#define UPDATE_ENGINE_PAYLOAD_CONSUMER_EXTENT_WRITER_H_
+
+#include <vector>
+
+#include <base/logging.h>
+#include <brillo/secure_blob.h>
+
+#include "update_engine/common/utils.h"
+#include "update_engine/payload_consumer/file_descriptor.h"
+#include "update_engine/update_metadata.pb.h"
+
+// ExtentWriter is an abstract class which synchronously writes to a given
+// file descriptor at the extents given.
+
+namespace chromeos_update_engine {
+
+class ExtentWriter {
+ public:
+ ExtentWriter() = default;
+ virtual ~ExtentWriter() {
+ LOG_IF(ERROR, !end_called_) << "End() not called on ExtentWriter.";
+ }
+
+ // Returns true on success.
+ virtual bool Init(FileDescriptorPtr fd,
+ const std::vector<Extent>& extents,
+ uint32_t block_size) = 0;
+
+ // Returns true on success.
+ virtual bool Write(const void* bytes, size_t count) = 0;
+
+ // Should be called when all writing is complete. Returns true on success.
+ // The fd is not closed. Caller is responsible for closing it.
+ bool End() {
+ end_called_ = true;
+ return EndImpl();
+ }
+ virtual bool EndImpl() = 0;
+ private:
+ bool end_called_{false};
+};
+
+// DirectExtentWriter is probably the simplest ExtentWriter implementation.
+// It writes the data directly into the extents.
+
+class DirectExtentWriter : public ExtentWriter {
+ public:
+ DirectExtentWriter() = default;
+ ~DirectExtentWriter() override = default;
+
+ bool Init(FileDescriptorPtr fd,
+ const std::vector<Extent>& extents,
+ uint32_t block_size) override {
+ fd_ = fd;
+ block_size_ = block_size;
+ extents_ = extents;
+ return true;
+ }
+ bool Write(const void* bytes, size_t count) override;
+ bool EndImpl() override { return true; }
+
+ private:
+ FileDescriptorPtr fd_{nullptr};
+
+ size_t block_size_{0};
+ // Bytes written into next_extent_index_ thus far
+ uint64_t extent_bytes_written_{0};
+ std::vector<Extent> extents_;
+ // The next call to write should correspond to extents_[next_extent_index_]
+ std::vector<Extent>::size_type next_extent_index_{0};
+};
+
+// Takes an underlying ExtentWriter to which all operations are delegated.
+// When End() is called, ZeroPadExtentWriter ensures that the total number
+// of bytes written is a multiple of block_size_. If not, it writes zeros
+// to pad as needed.
+
+class ZeroPadExtentWriter : public ExtentWriter {
+ public:
+ explicit ZeroPadExtentWriter(
+ std::unique_ptr<ExtentWriter> underlying_extent_writer)
+ : underlying_extent_writer_(std::move(underlying_extent_writer)) {}
+ ~ZeroPadExtentWriter() override = default;
+
+ bool Init(FileDescriptorPtr fd,
+ const std::vector<Extent>& extents,
+ uint32_t block_size) override {
+ block_size_ = block_size;
+ return underlying_extent_writer_->Init(fd, extents, block_size);
+ }
+ bool Write(const void* bytes, size_t count) override {
+ if (underlying_extent_writer_->Write(bytes, count)) {
+ bytes_written_mod_block_size_ += count;
+ bytes_written_mod_block_size_ %= block_size_;
+ return true;
+ }
+ return false;
+ }
+ bool EndImpl() override {
+ if (bytes_written_mod_block_size_) {
+ const size_t write_size = block_size_ - bytes_written_mod_block_size_;
+ brillo::Blob zeros(write_size, 0);
+ TEST_AND_RETURN_FALSE(underlying_extent_writer_->Write(zeros.data(),
+ write_size));
+ }
+ return underlying_extent_writer_->End();
+ }
+
+ private:
+ std::unique_ptr<ExtentWriter> underlying_extent_writer_;
+ size_t block_size_{0};
+ size_t bytes_written_mod_block_size_{0};
+};
+
+} // namespace chromeos_update_engine
+
+#endif // UPDATE_ENGINE_PAYLOAD_CONSUMER_EXTENT_WRITER_H_