|  | // | 
|  | // 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. | 
|  | // | 
|  |  | 
|  | syntax = "proto3"; | 
|  |  | 
|  | package chromeos_update_engine; | 
|  | option optimize_for = LITE_RUNTIME; | 
|  |  | 
|  | message CompressionAlgorithm { | 
|  | enum Type { | 
|  | UNCOMPRESSED = 0; | 
|  | LZ4 = 1; | 
|  | LZ4HC = 2; | 
|  | } | 
|  | Type type = 1; | 
|  | int32 level = 2; | 
|  | } | 
|  |  | 
|  | message CompressedBlockInfo { | 
|  | // Require fields | 
|  | uint64 uncompressed_offset = 1; | 
|  | uint64 uncompressed_length = 2; | 
|  | uint64 compressed_length = 3; | 
|  |  | 
|  | // optional SHA256 hash of re-compressed blob | 
|  | bytes sha256_hash = 4; | 
|  | // Patch to apply to re-compressed blob | 
|  | bytes postfix_bspatch = 5; | 
|  | } | 
|  |  | 
|  | enum InnerPatchType { | 
|  | BSDIFF = 0; | 
|  | PUFFDIFF = 1; | 
|  | } | 
|  |  | 
|  | message CompressionInfo { | 
|  | CompressionAlgorithm algo = 1; | 
|  | repeated CompressedBlockInfo block_info = 2; | 
|  | bool zero_padding_enabled = 3; | 
|  | } | 
|  |  | 
|  | message Lz4diffHeader { | 
|  | CompressionInfo src_info = 1; | 
|  | CompressionInfo dst_info = 2; | 
|  | InnerPatchType inner_type = 3; | 
|  | } |