1 //
2 // Copyright (C) 2015 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 UPDATE_ENGINE_PAYLOAD_GENERATOR_EXTENT_UTILS_H_
18 #define UPDATE_ENGINE_PAYLOAD_GENERATOR_EXTENT_UTILS_H_
19
20 #include <string>
21 #include <vector>
22
23 #include "update_engine/payload_consumer/payload_constants.h"
24 #include "update_engine/update_metadata.pb.h"
25
26 // Utility functions for manipulating Extents and lists of blocks.
27
28 namespace chromeos_update_engine {
29
30 // |block| must either be the next block in the last extent or a block
31 // in the next extent. This function will not handle inserting block
32 // into an arbitrary place in the extents.
33 void AppendBlockToExtents(std::vector<Extent>* extents, uint64_t block);
34
35 // Takes a collection (vector or RepeatedPtrField) of Extent and
36 // returns a vector of the blocks referenced, in order.
37 template <typename T>
ExpandExtents(const T & extents)38 std::vector<uint64_t> ExpandExtents(const T& extents) {
39 std::vector<uint64_t> ret;
40 for (const auto& extent : extents) {
41 if (extent.start_block() == kSparseHole) {
42 ret.resize(ret.size() + extent.num_blocks(), kSparseHole);
43 } else {
44 for (uint64_t block = extent.start_block();
45 block < (extent.start_block() + extent.num_blocks());
46 block++) {
47 ret.push_back(block);
48 }
49 }
50 }
51 return ret;
52 }
53
54 // Stores all Extents in 'extents' into 'out'.
55 void StoreExtents(const std::vector<Extent>& extents,
56 google::protobuf::RepeatedPtrField<Extent>* out);
57
58 // Stores all extents in |extents| into |out_vector|.
59 void ExtentsToVector(const google::protobuf::RepeatedPtrField<Extent>& extents,
60 std::vector<Extent>* out_vector);
61
62 // Returns a string representing all extents in |extents|.
63 std::string ExtentsToString(const std::vector<Extent>& extents);
64
65 // Takes a pointer to extents |extents| and extents |extents_to_add|, and
66 // merges them by adding |extents_to_add| to |extents| and normalizing.
67 void ExtendExtents(
68 google::protobuf::RepeatedPtrField<Extent>* extents,
69 const google::protobuf::RepeatedPtrField<Extent>& extents_to_add);
70
71 // Takes a vector of extents and normalizes those extents. Expects the extents
72 // to be sorted by start block. E.g. if |extents| is [(1, 2), (3, 5), (10, 2)]
73 // then |extents| will be changed to [(1, 7), (10, 2)].
74 void NormalizeExtents(std::vector<Extent>* extents);
75
76 // Return a subsequence of the list of blocks passed. Both the passed list of
77 // blocks |extents| and the return value are expressed as a list of Extent, not
78 // blocks. The returned list skips the first |block_offset| blocks from the
79 // |extents| and cotains |block_count| blocks (or less if |extents| is shorter).
80 std::vector<Extent> ExtentsSublist(const std::vector<Extent>& extents,
81 uint64_t block_offset,
82 uint64_t block_count);
83
84 bool operator==(const Extent& a, const Extent& b);
85
86 } // namespace chromeos_update_engine
87
88 #endif // UPDATE_ENGINE_PAYLOAD_GENERATOR_EXTENT_UTILS_H_
89