1 /* Copyright (c) 2014-2022. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #ifndef SIMGRID_MC_CHUNKED_DATA_HPP
7 #define SIMGRID_MC_CHUNKED_DATA_HPP
11 #include "src/mc/mc_forward.hpp"
12 #include "src/mc/remote/RemotePtr.hpp"
13 #include "src/mc/sosp/PageStore.hpp"
18 /** A byte-string represented as a sequence of chunks from a PageStore
20 * In order to save memory when taking memory snapshots, a given byte-string
21 * is split in fixed-size chunks. Identical chunks (either from the same
22 * snapshot or more probably from different snapshots) share the same memory
25 * Thus a chunked is represented as a sequence of indices of each chunk.
28 /** This is where we store the chunks */
29 PageStore* store_ = nullptr;
30 /** Indices of the chunks in the `PageStore` */
31 std::vector<std::size_t> pagenos_;
34 ChunkedData() = default;
37 for (std::size_t const& pageno : pagenos_)
38 store_->unref_page(pageno);
41 ~ChunkedData() { clear(); }
44 ChunkedData(ChunkedData const& that) : store_(that.store_), pagenos_(that.pagenos_)
46 for (std::size_t const& pageno : pagenos_)
47 store_->ref_page(pageno);
49 ChunkedData(ChunkedData&& that) noexcept : pagenos_(std::move(that.pagenos_))
51 std::swap(store_, that.store_);
52 that.pagenos_.clear();
54 ChunkedData& operator=(ChunkedData const& that)
59 pagenos_ = that.pagenos_;
60 for (std::size_t const& pageno : pagenos_)
61 store_->ref_page(pageno);
65 ChunkedData& operator=(ChunkedData&& that) noexcept
70 that.store_ = nullptr;
71 pagenos_ = std::move(that.pagenos_);
72 that.pagenos_.clear();
77 /** How many pages are used */
78 std::size_t page_count() const { return pagenos_.size(); }
80 /** Get a chunk index */
81 std::size_t pageno(std::size_t i) const { return pagenos_[i]; }
83 /** Get a view of the chunk indices */
84 const std::size_t* pagenos() const { return pagenos_.data(); }
86 /** Get a pointer to a chunk */
87 void* page(std::size_t i) const { return store_->get_page(pagenos_[i]); }
89 ChunkedData(PageStore& store, const AddressSpace& as, RemotePtr<void> addr, std::size_t page_count);
93 } // namespace simgrid