Add parser for EROFS file data
This CL parses file names and compression info from input EROFS image,
so that OTA generation can use it later.
Test: th
Test: Generate an incremental OTA with erofs images, make sure we see
file lists.
Bug: 206729162
Change-Id: I70536d7762acc19a6977460738065d5557338532
diff --git a/payload_generator/erofs_filesystem.h b/payload_generator/erofs_filesystem.h
new file mode 100644
index 0000000..473c609
--- /dev/null
+++ b/payload_generator/erofs_filesystem.h
@@ -0,0 +1,69 @@
+//
+// 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_PAYLOAD_GENERATOR_EROFS_FILESYSTEM_H_
+#define UPDATE_ENGINE_PAYLOAD_GENERATOR_EROFS_FILESYSTEM_H_
+
+#include "update_engine/payload_generator/filesystem_interface.h"
+#include "update_engine/payload_generator/delta_diff_generator.h"
+
+namespace chromeos_update_engine {
+
+class ErofsFilesystem final : public FilesystemInterface {
+ public:
+ // Creates an Ext2Filesystem from a ext2 formatted filesystem stored in a
+ // file. The file doesn't need to be loop-back mounted.
+ static std::unique_ptr<ErofsFilesystem> CreateFromFile(
+ const std::string& filename);
+ virtual ~ErofsFilesystem() = default;
+
+ // FilesystemInterface overrides.
+ size_t GetBlockSize() const override { return kBlockSize; }
+ size_t GetBlockCount() const override { return fs_size_ / kBlockSize; }
+
+ // GetFiles will return one FilesystemInterface::File for every file and every
+ // directory in the filesystem. Hard-linked files will appear in the list
+ // several times with the same list of blocks.
+ // On addition to actual files, it also returns these pseudo-files:
+ // <free-space>: With all the unallocated data-blocks.
+ // <inode-blocks>: Will all the data-blocks for second and third level inodes
+ // of all the files.
+ // <group-descriptors>: With the block group descriptor and their reserved
+ // space.
+ // <metadata>: With the rest of ext2 metadata blocks, such as superblocks
+ // and bitmap tables.
+ static bool GetFiles(const std::string& filename, std::vector<File>* files);
+
+ bool GetFiles(std::vector<File>* files) const override;
+
+ bool LoadSettings(
+ [[maybe_unused]] brillo::KeyValueStore* store) const override {
+ return true;
+ }
+
+ private:
+ ErofsFilesystem(std::string filename, size_t fs_size, std::vector<File> files)
+ : filename_(filename), fs_size_(fs_size), files_(std::move(files)) {}
+
+ // The file where the filesystem is stored.
+ const std::string filename_;
+ const size_t fs_size_;
+ const std::vector<File> files_;
+}; // namespace chromeos_update_engine
+
+} // namespace chromeos_update_engine
+
+#endif
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