1 /* Copyright (c) 2014-2019. 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 snpashots) 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) : store_(that.store_), pagenos_(std::move(that.pagenos_))
51 that.store_ = nullptr;
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)
69 that.store_ = nullptr;
70 pagenos_ = std::move(that.pagenos_);
71 that.pagenos_.clear();
75 /** How many pages are used */
76 std::size_t page_count() const { return pagenos_.size(); }
78 /** Get a chunk index */
79 std::size_t pageno(std::size_t i) const { return pagenos_[i]; }
81 /** Get a view of the chunk indices */
82 const std::size_t* pagenos() const { return pagenos_.data(); }
84 /** Get a a pointer to a chunk */
85 const void* page(std::size_t i) const { return store_->get_page(pagenos_[i]); }
87 ChunkedData(PageStore& store, AddressSpace& as, RemotePtr<void> addr, std::size_t page_count);
91 } // namespace simgrid