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 28namespace 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. 33void 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. 37Extent GetElement(const std::vector<Extent>& collection, size_t index); 38Extent 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. 44template<typename T> 45uint64_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. 55template<typename T> 56std::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'. 73void StoreExtents(const std::vector<Extent>& extents, 74 google::protobuf::RepeatedPtrField<Extent>* out); 75 76// Stores all extents in |extents| into |out_vector|. 77void ExtentsToVector(const google::protobuf::RepeatedPtrField<Extent>& extents, 78 std::vector<Extent>* out_vector); 79 80// Returns a string representing all extents in |extents|. 81std::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. 85void 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)]. 92void 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). 98std::vector<Extent> ExtentsSublist(const std::vector<Extent>& extents, 99 uint64_t block_offset, uint64_t block_count); 100 101bool operator==(const Extent& a, const Extent& b); 102 103} // namespace chromeos_update_engine 104 105#endif // UPDATE_ENGINE_PAYLOAD_GENERATOR_EXTENT_UTILS_H_ 106