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 // Get/SetElement are intentionally overloaded so that templated functions 36 // can accept either type of collection of Extents. 37 Extent GetElement(const std::vector<Extent>& collection, size_t index); 38 Extent GetElement( 39 const google::protobuf::RepeatedPtrField<Extent>& collection, 40 size_t index); 41 42 // Return the total number of blocks in a collection (vector or 43 // RepeatedPtrField) of Extents. 44 template<typename T> 45 uint64_t BlocksInExtents(const T& collection) { 46 uint64_t ret = 0; 47 for (size_t i = 0; i < static_cast<size_t>(collection.size()); ++i) { 48 ret += GetElement(collection, i).num_blocks(); 49 } 50 return ret; 51 } 52 53 // Takes a collection (vector or RepeatedPtrField) of Extent and 54 // returns a vector of the blocks referenced, in order. 55 template<typename T> 56 std::vector<uint64_t> ExpandExtents(const T& extents) { 57 std::vector<uint64_t> ret; 58 for (size_t i = 0, e = static_cast<size_t>(extents.size()); i != e; ++i) { 59 const Extent extent = GetElement(extents, i); 60 if (extent.start_block() == kSparseHole) { 61 ret.resize(ret.size() + extent.num_blocks(), kSparseHole); 62 } else { 63 for (uint64_t block = extent.start_block(); 64 block < (extent.start_block() + extent.num_blocks()); block++) { 65 ret.push_back(block); 66 } 67 } 68 } 69 return ret; 70 } 71 72 // Stores all Extents in 'extents' into 'out'. 73 void StoreExtents(const std::vector<Extent>& extents, 74 google::protobuf::RepeatedPtrField<Extent>* out); 75 76 // Stores all extents in |extents| into |out_vector|. 77 void ExtentsToVector(const google::protobuf::RepeatedPtrField<Extent>& extents, 78 std::vector<Extent>* out_vector); 79 80 // Returns a string representing all extents in |extents|. 81 std::string ExtentsToString(const std::vector<Extent>& extents); 82 83 // Takes a pointer to extents |extents| and extents |extents_to_add|, and 84 // merges them by adding |extents_to_add| to |extents| and normalizing. 85 void ExtendExtents( 86 google::protobuf::RepeatedPtrField<Extent>* extents, 87 const google::protobuf::RepeatedPtrField<Extent>& extents_to_add); 88 89 // Takes a vector of extents and normalizes those extents. Expects the extents 90 // to be sorted by start block. E.g. if |extents| is [(1, 2), (3, 5), (10, 2)] 91 // then |extents| will be changed to [(1, 7), (10, 2)]. 92 void NormalizeExtents(std::vector<Extent>* extents); 93 94 // Return a subsequence of the list of blocks passed. Both the passed list of 95 // blocks |extents| and the return value are expressed as a list of Extent, not 96 // blocks. The returned list skips the first |block_offset| blocks from the 97 // |extents| and cotains |block_count| blocks (or less if |extents| is shorter). 98 std::vector<Extent> ExtentsSublist(const std::vector<Extent>& extents, 99 uint64_t block_offset, uint64_t block_count); 100 101 bool operator==(const Extent& a, const Extent& b); 102 103 } // namespace chromeos_update_engine 104 105 #endif // UPDATE_ENGINE_PAYLOAD_GENERATOR_EXTENT_UTILS_H_ 106
