X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/9ae3c710a6a8ac04570f77d88eb8e0c7a13f101c..4b0aa1525597fd0800c4d00c6df3f3c49d53ee2c:/src/mc/sosp/ChunkedData.hpp

diff --git a/src/mc/sosp/ChunkedData.hpp b/src/mc/sosp/ChunkedData.hpp
new file mode 100644
index 0000000000..c904a29f97
--- /dev/null
+++ b/src/mc/sosp/ChunkedData.hpp
@@ -0,0 +1,94 @@
+/* Copyright (c) 2014-2018. The SimGrid Team. All rights reserved.          */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+#ifndef SIMGRID_MC_CHUNKED_DATA_HPP
+#define SIMGRID_MC_CHUNKED_DATA_HPP
+
+#include <cstddef>
+#include <cstdint>
+
+#include <utility>
+#include <vector>
+
+#include "src/mc/mc_forward.hpp"
+#include "src/mc/sosp/PageStore.hpp"
+
+namespace simgrid {
+namespace mc {
+
+/** A byte-string represented as a sequence of chunks from a PageStore
+ *
+ *  In order to save memory when taking memory snapshots, a given byte-string
+ *  is split in fixed-size chunks. Identical chunks (either from the same
+ *  snapshot or more probably from different snpashots) share the same memory
+ *  storage.
+ *
+ *  Thus a chunked is represented as a sequence of indices of each chunk.
+ */
+class ChunkedData {
+  /** This is where we store the chunks */
+  PageStore* store_ = nullptr;
+  /** Indices of the chunks in the `PageStore` */
+  std::vector<std::size_t> pagenos_;
+
+public:
+  ChunkedData() = default;
+  void clear()
+  {
+    for (std::size_t const& pageno : pagenos_)
+      store_->unref_page(pageno);
+    pagenos_.clear();
+  }
+  ~ChunkedData() { clear(); }
+
+  // Copy and move
+  ChunkedData(ChunkedData const& that) : store_(that.store_), pagenos_(that.pagenos_)
+  {
+    for (std::size_t const& pageno : pagenos_)
+      store_->ref_page(pageno);
+  }
+  ChunkedData(ChunkedData&& that) : store_(that.store_), pagenos_(std::move(that.pagenos_))
+  {
+    that.store_ = nullptr;
+    that.pagenos_.clear();
+  }
+  ChunkedData& operator=(ChunkedData const& that)
+  {
+    this->clear();
+    store_   = that.store_;
+    pagenos_ = that.pagenos_;
+    for (std::size_t const& pageno : pagenos_)
+      store_->ref_page(pageno);
+    return *this;
+  }
+  ChunkedData& operator=(ChunkedData&& that)
+  {
+    this->clear();
+    store_      = that.store_;
+    that.store_ = nullptr;
+    pagenos_    = std::move(that.pagenos_);
+    that.pagenos_.clear();
+    return *this;
+  }
+
+  /** How many pages are used */
+  std::size_t page_count() const { return pagenos_.size(); }
+
+  /** Get a chunk index */
+  std::size_t pageno(std::size_t i) const { return pagenos_[i]; }
+
+  /** Get a view of the chunk indices */
+  const std::size_t* pagenos() const { return pagenos_.data(); }
+
+  /** Get a a pointer to a chunk */
+  const void* page(std::size_t i) const { return store_->get_page(pagenos_[i]); }
+
+  ChunkedData(PageStore& store, AddressSpace& as, RemotePtr<void> addr, std::size_t page_count);
+};
+
+} // namespace mc
+} // namespace simgrid
+
+#endif