Reduced memory consumption on network level.

src/base/net/tools/MemPool.h

@@ -0,0 +1,96 @@
+/* XMRig
+ * Copyright 2018-2020 SChernykh   <https://github.com/SChernykh>
+ * Copyright 2016-2020 XMRig       <https://github.com/xmrig>, <support@xmrig.com>
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef XMRIG_MEMPOOL_H
+#define XMRIG_MEMPOOL_H
+
+
+#include <map>
+#include <set>
+#include <array>
+#include <cassert>
+
+
+namespace xmrig {
+
+
+template<size_t CHUNK_SIZE, size_t INIT_SIZE>
+class MemPool
+{
+public:
+    MemPool() = default;
+
+
+    constexpr size_t chunkSize() const  { return CHUNK_SIZE; }
+    inline size_t freeSize() const      { return m_free.size() * CHUNK_SIZE; }
+    inline size_t size() const          { return m_data.size() * CHUNK_SIZE * INIT_SIZE; }
+
+
+    inline char *allocate()
+    {
+        if (m_free.empty()) {
+            resize();
+        }
+
+        const size_t i = *m_free.begin();
+        const size_t r = i / INIT_SIZE;
+
+        char *ptr = m_data[r].data() + (i - r * INIT_SIZE) * CHUNK_SIZE;
+
+        m_used.insert({ ptr, i });
+        m_free.erase(i);
+
+        return ptr;
+    }
+
+
+    inline void deallocate(const char *ptr)
+    {
+        if (ptr == nullptr) {
+            return;
+        }
+
+        assert(m_used.count(ptr));
+
+        m_free.emplace(m_used[ptr]);
+        m_used.erase(ptr);
+    }
+
+
+private:
+    inline void resize()
+    {
+        const size_t index = m_data.size();
+        m_data[index];
+
+        for (size_t i = 0; i < INIT_SIZE; ++i) {
+            m_free.emplace((index * INIT_SIZE) + i);
+        }
+    }
+
+
+    std::map<const char *, size_t> m_used;
+    std::map<size_t, std::array<char, CHUNK_SIZE * INIT_SIZE> > m_data;
+    std::set<size_t> m_free;
+};
+
+
+} /* namespace xmrig */
+
+
+#endif /* XMRIG_MEMPOOL_H */