Repo created

libs/drape/object_pool.hpp

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+#pragma once
+
+#include "base/assert.hpp"
+#include "base/logging.hpp"
+
+#include <list>
+#include <mutex>
+#include <set>
+#include <string>
+
+#define LOG_OBJECT_POOL
+
+namespace dp
+{
+template <typename T, typename Factory>
+class ObjectPool final
+{
+public:
+  ObjectPool(int count, Factory const & f) : m_factory(f)
+  {
+    for (int i = 0; i < count; ++i)
+    {
+      T * novice = m_factory.GetNew();
+#if defined(DEBUG) || defined(LOG_OBJECT_POOL)
+      m_checkerSet.insert(novice);
+#endif
+      m_pool.push_back(novice);
+    }
+  }
+
+  ~ObjectPool()
+  {
+    for (auto it = m_pool.begin(); it != m_pool.end(); it++)
+    {
+      T * cur = *it;
+#if defined(DEBUG) || defined(LOG_OBJECT_POOL)
+      auto its = m_checkerSet.find(cur);
+      static std::string const kMessage = "The same element has been returned twice or more!";
+      ASSERT(its != m_checkerSet.end(), (kMessage));
+      if (its == m_checkerSet.end())
+        LOG(LWARNING, (kMessage));
+      m_checkerSet.erase(its);
+#endif
+      delete cur;
+    }
+#if defined(DEBUG) || defined(LOG_OBJECT_POOL)
+    static std::string const kMessage2 = "Not all elements were returned to pool!";
+    ASSERT(m_checkerSet.empty(), (kMessage2));
+    if (!m_checkerSet.empty())
+      LOG(LWARNING, (kMessage2));
+#endif
+  }
+
+  T * Get()
+  {
+    std::lock_guard<std::mutex> lock(m_lock);
+    if (m_pool.empty())
+    {
+      T * novice = m_factory.GetNew();
+#if defined(DEBUG) || defined(LOG_OBJECT_POOL)
+      m_checkerSet.insert(novice);
+#endif
+      return novice;
+    }
+    else
+    {
+      T * pt = m_pool.front();
+      m_pool.pop_front();
+      return pt;
+    }
+  }
+
+  void Return(T * object)
+  {
+    std::lock_guard<std::mutex> lock(m_lock);
+    m_pool.push_back(object);
+  }
+
+private:
+#if defined(DEBUG) || defined(LOG_OBJECT_POOL)
+  std::set<T *> m_checkerSet;
+#endif
+  std::list<T *> m_pool;
+  Factory m_factory;
+  std::mutex m_lock;
+};
+}  // namespace dp