Add memusage.h

1 files changed, 111 insertions, 0 deletions

diff --git a/src/memusage.h b/src/memusage.h
new file mode 100644
index 0000000000..9f7de9e2e1
--- /dev/null
+++ b/src/memusage.h
@@ -0,0 +1,111 @@
+// Copyright (c) 2015 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_MEMUSAGE_H
+#define BITCOIN_MEMUSAGE_H
+
+#include <stdlib.h>
+
+#include <map>
+#include <set>
+#include <vector>
+
+#include <boost/unordered_set.hpp>
+#include <boost/unordered_map.hpp>
+
+namespace memusage
+{
+
+/** Compute the total memory used by allocating alloc bytes. */
+static size_t MallocUsage(size_t alloc);
+
+/** Compute the memory used for dynamically allocated but owned data structures.
+ *  For generic data types, this is *not* recursive. DynamicUsage(vector<vector<int> >)
+ *  will compute the memory used for the vector<int>'s, but not for the ints inside.
+ *  This is for efficiency reasons, as these functions are intended to be fast. If
+ *  application data structures require more accurate inner accounting, they should
+ *  do the recursion themselves, or use more efficient caching + updating on modification.
+ */
+template<typename X> static size_t DynamicUsage(const std::vector<X>& v);
+template<typename X> static size_t DynamicUsage(const std::set<X>& s);
+template<typename X, typename Y> static size_t DynamicUsage(const std::map<X, Y>& m);
+template<typename X, typename Y> static size_t DynamicUsage(const boost::unordered_set<X, Y>& s);
+template<typename X, typename Y, typename Z> static size_t DynamicUsage(const boost::unordered_map<X, Y, Z>& s);
+template<typename X> static size_t DynamicUsage(const X& x);
+
+static inline size_t MallocUsage(size_t alloc)
+{
+    // Measured on libc6 2.19 on Linux.
+    if (sizeof(void*) == 8) {
+        return ((alloc + 31) >> 4) << 4;
+    } else if (sizeof(void*) == 4) {
+        return ((alloc + 15) >> 3) << 3;
+    } else {
+        assert(0);
+    }
+}
+
+// STL data structures
+
+template<typename X>
+struct stl_tree_node
+{
+private:
+    int color;
+    void* parent;
+    void* left;
+    void* right;
+    X x;
+};
+
+template<typename X>
+static inline size_t DynamicUsage(const std::vector<X>& v)
+{
+    return MallocUsage(v.capacity() * sizeof(X));
+}
+
+template<typename X>
+static inline size_t DynamicUsage(const std::set<X>& s)
+{
+    return MallocUsage(sizeof(stl_tree_node<X>)) * s.size();
+}
+
+template<typename X, typename Y>
+static inline size_t DynamicUsage(const std::map<X, Y>& m)
+{
+    return MallocUsage(sizeof(stl_tree_node<std::pair<const X, Y> >)) * m.size();
+}
+
+// Boost data structures
+
+template<typename X>
+struct boost_unordered_node : private X
+{
+private:
+    void* ptr;
+};
+
+template<typename X, typename Y>
+static inline size_t DynamicUsage(const boost::unordered_set<X, Y>& s)
+{
+    return MallocUsage(sizeof(boost_unordered_node<X>)) * s.size() + MallocUsage(sizeof(void*) * s.bucket_count());
+}
+
+template<typename X, typename Y, typename Z>
+static inline size_t DynamicUsage(const boost::unordered_map<X, Y, Z>& m)
+{
+    return MallocUsage(sizeof(boost_unordered_node<std::pair<const X, Y> >)) * m.size() + MallocUsage(sizeof(void*) * m.bucket_count());
+}
+
+// Dispatch to class method as fallback
+
+template<typename X>
+static inline size_t DynamicUsage(const X& x)
+{
+    return x.DynamicMemoryUsage();
+}
+
+}
+
+#endif