1 //
2 // Copyright (C) 2020 The Android Open Source Project
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 //
16
17 #ifndef __COW_OPERATION_CONVERT_H
18 #define __COW_OPERATION_CONVERT_H
19
20 #include <vector>
21
22 #include <libsnapshot/cow_format.h>
23
24 #include "update_engine/update_metadata.pb.h"
25
26 namespace chromeos_update_engine {
27 struct CowOperation {
28 enum Type {
29 CowCopy = static_cast<int>(android::snapshot::kCowCopyOp),
30 CowReplace = static_cast<int>(android::snapshot::kCowReplaceOp),
31 };
32 Type op{};
33 uint64_t src_block{};
34 uint64_t dst_block{};
35 uint64_t block_count{1};
36 };
37
38 // Convert SOURCE_COPY operations in `operations` list to a list of
39 // CowOperations according to the merge sequence. This function only converts
40 // SOURCE_COPY, other operations are ignored. If there's a merge conflict in
41 // SOURCE_COPY operations, some blocks may be converted to COW_REPLACE instead
42 // of COW_COPY.
43
44 // The list returned does not necessarily preserve the order of
45 // SOURCE_COPY in `operations`. The only guarantee about ordering in the
46 // returned list is that if operations are applied in such order, there would be
47 // no merge conflicts.
48
49 // This funnction is intended to be used by delta_performer to perform
50 // SOURCE_COPY operations on Virtual AB Compression devices.
51 std::vector<CowOperation> ConvertToCowOperations(
52 const ::google::protobuf::RepeatedPtrField<
53 ::chromeos_update_engine::InstallOperation>& operations,
54 const ::google::protobuf::RepeatedPtrField<CowMergeOperation>&
55 merge_operations);
56
IsConsecutive(const CowOperation & op1,const CowOperation & op2)57 constexpr bool IsConsecutive(const CowOperation& op1, const CowOperation& op2) {
58 return op1.op == op2.op && op1.dst_block + op1.block_count == op2.dst_block &&
59 op1.src_block + op1.block_count == op2.src_block;
60 }
61
62 void push_back(std::vector<CowOperation>* converted, const CowOperation& op);
63
64 } // namespace chromeos_update_engine
65 #endif
66