lbrycrd/src/memusage.h
Kaz Wesley 9805f4af7e mapNextTx: use pointer as key, simplify value
Saves about 10% of application memory usage once the mempool warms up. Since the
mempool is DynamicUsage-regulated, this will translate to a larger mempool in
the same amount of space.

Map value type: eliminate the vin index; no users of the map need to know which
input of the transaction is spending the prevout.

Map key type: replace the COutPoint with a pointer to a COutPoint. A COutPoint
is 36 bytes, but each COutPoint is accessible from the same map entry's value.
A trivial DereferencingComparator functor allows indirect map keys, but the
resulting syntax is misleading: `map.find(&outpoint)`. Implement an indirectmap
that acts as a wrapper to a map that uses a DereferencingComparator, supporting
a syntax that accurately reflect the container's semantics: inserts and
iterators use pointers since they store pointers and need them to remain
constant and dereferenceable, but lookup functions take const references.
2016-06-02 12:31:51 -07:00

148 lines
4.4 KiB
C++

// 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 "indirectmap.h"
#include <stdlib.h>
#include <map>
#include <set>
#include <vector>
#include <boost/foreach.hpp>
#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);
/** Dynamic memory usage for built-in types is zero. */
static inline size_t DynamicUsage(const int8_t& v) { return 0; }
static inline size_t DynamicUsage(const uint8_t& v) { return 0; }
static inline size_t DynamicUsage(const int16_t& v) { return 0; }
static inline size_t DynamicUsage(const uint16_t& v) { return 0; }
static inline size_t DynamicUsage(const int32_t& v) { return 0; }
static inline size_t DynamicUsage(const uint32_t& v) { return 0; }
static inline size_t DynamicUsage(const int64_t& v) { return 0; }
static inline size_t DynamicUsage(const uint64_t& v) { return 0; }
static inline size_t DynamicUsage(const float& v) { return 0; }
static inline size_t DynamicUsage(const double& v) { return 0; }
template<typename X> static inline size_t DynamicUsage(X * const &v) { return 0; }
template<typename X> static inline size_t DynamicUsage(const X * const &v) { return 0; }
/** 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
* iterate themselves, or use more efficient caching + updating on modification.
*/
static inline size_t MallocUsage(size_t alloc)
{
// Measured on libc6 2.19 on Linux.
if (alloc == 0) {
return 0;
} else 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<unsigned int N, typename X, typename S, typename D>
static inline size_t DynamicUsage(const prevector<N, X, S, D>& v)
{
return MallocUsage(v.allocated_memory());
}
template<typename X, typename Y>
static inline size_t DynamicUsage(const std::set<X, Y>& s)
{
return MallocUsage(sizeof(stl_tree_node<X>)) * s.size();
}
template<typename X, typename Y>
static inline size_t IncrementalDynamicUsage(const std::set<X, Y>& s)
{
return MallocUsage(sizeof(stl_tree_node<X>));
}
template<typename X, typename Y, typename Z>
static inline size_t DynamicUsage(const std::map<X, Y, Z>& m)
{
return MallocUsage(sizeof(stl_tree_node<std::pair<const X, Y> >)) * m.size();
}
template<typename X, typename Y, typename Z>
static inline size_t IncrementalDynamicUsage(const std::map<X, Y, Z>& m)
{
return MallocUsage(sizeof(stl_tree_node<std::pair<const X, Y> >));
}
// indirectmap has underlying map with pointer as key
template<typename X, typename Y>
static inline size_t DynamicUsage(const indirectmap<X, Y>& m)
{
return MallocUsage(sizeof(stl_tree_node<std::pair<const X*, Y> >)) * m.size();
}
template<typename X, typename Y>
static inline size_t IncrementalDynamicUsage(const indirectmap<X, Y>& m)
{
return MallocUsage(sizeof(stl_tree_node<std::pair<const X*, Y> >));
}
// 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());
}
}
#endif // BITCOIN_MEMUSAGE_H