PIP Lua Module

lib/lua/3rd/LuaBridge/RefCountedPtr.h

@@ -0,0 +1,244 @@
+//==============================================================================
+/*
+  https://github.com/vinniefalco/LuaBridge
+  
+  Copyright 2019, Dmitry Tarakanov
+  Copyright 2012, Vinnie Falco <vinnie.falco@gmail.com>
+  Copyright 2007, Nathan Reed
+
+  License: The MIT License (http://www.opensource.org/licenses/mit-license.php)
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all
+  copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+  SOFTWARE.
+*/
+//==============================================================================
+
+#pragma once
+
+#include <unordered_map>
+#include "RefCountedObject.h"
+
+namespace luabridge {
+
+//==============================================================================
+/**
+  Support for our RefCountedPtr.
+*/
+struct RefCountedPtrBase
+{
+  // Declaration of container for the refcounts
+  typedef std::unordered_map <const void *, int> RefCountsType;
+
+protected:
+  RefCountsType& getRefCounts () const
+  {
+    static RefCountsType refcounts;
+    return refcounts ;
+  }
+};
+
+//==============================================================================
+/**
+  A reference counted smart pointer.
+
+  The api is compatible with boost::RefCountedPtr and std::RefCountedPtr, in the
+  sense that it implements a strict subset of the functionality.
+
+  This implementation uses a hash table to look up the reference count
+  associated with a particular pointer.
+
+  @tparam T The class type.
+
+  @todo Decompose RefCountedPtr using a policy. At a minimum, the underlying
+        reference count should be policy based (to support atomic operations)
+        and the delete behavior should be policy based (to support custom
+        disposal methods).
+
+  @todo Provide an intrusive version of RefCountedPtr.
+*/
+template <class T>
+class RefCountedPtr : private RefCountedPtrBase
+{
+public:
+  template <typename Other>
+  struct rebind
+  {
+    typedef RefCountedPtr <Other> other;
+  };
+
+  /** Construct as nullptr or from existing pointer to T.
+
+      @param p The optional, existing pointer to assign from.
+  */
+  RefCountedPtr (T* p = 0) : m_p (p)
+  {
+    ++getRefCounts () [m_p];
+  }
+
+  /** Construct from another RefCountedPtr.
+
+      @param rhs The RefCountedPtr to assign from.
+  */
+  RefCountedPtr (RefCountedPtr <T> const& rhs) : m_p (rhs.get())
+  {
+    ++getRefCounts () [m_p];
+  }
+
+  /** Construct from a RefCountedPtr of a different type.
+
+      @invariant A pointer to U must be convertible to a pointer to T.
+
+      @param  rhs The RefCountedPtr to assign from.
+      @tparam U   The other object type.
+  */
+  template <typename U>
+  RefCountedPtr (RefCountedPtr <U> const& rhs) : m_p (static_cast <T*> (rhs.get()))
+  {
+    ++getRefCounts () [m_p];
+  }
+
+  /** Release the object.
+
+      If there are no more references then the object is deleted.
+  */
+  ~RefCountedPtr ()
+  {
+    reset();
+  }
+
+  /** Assign from another RefCountedPtr.
+
+      @param  rhs The RefCountedPtr to assign from.
+      @return     A reference to the RefCountedPtr.
+  */
+  RefCountedPtr <T>& operator= (RefCountedPtr <T> const& rhs)
+  {
+    if (m_p != rhs.m_p)
+    {
+      reset ();
+      m_p = rhs.m_p;
+      ++getRefCounts () [m_p];
+    }
+    return *this;
+  }
+
+  /** Assign from another RefCountedPtr of a different type.
+
+      @note A pointer to U must be convertible to a pointer to T.
+
+      @tparam U   The other object type.
+      @param  rhs The other RefCountedPtr to assign from.
+      @return     A reference to the RefCountedPtr.
+  */
+  template <typename U>
+  RefCountedPtr <T>& operator= (RefCountedPtr <U> const& rhs)
+  {
+    reset ();
+    m_p = static_cast <T*> (rhs.get());
+    ++getRefCounts () [m_p];
+    return *this;
+  }
+
+  /** Retrieve the raw pointer.
+
+      @return A pointer to the object.
+  */
+  T* get () const
+  {
+    return m_p;
+  }
+
+  /** Retrieve the raw pointer.
+
+      @return A pointer to the object.
+  */
+  T* operator* () const
+  {
+    return m_p;
+  }
+
+  /** Retrieve the raw pointer.
+
+      @return A pointer to the object.
+  */
+  T* operator-> () const
+  {
+    return m_p;
+  }
+
+  /** Determine the number of references.
+
+      @note This is not thread-safe.
+
+      @return The number of active references.
+  */
+  long use_count () const
+  {
+    return getRefCounts () [m_p];
+  }
+
+  /** Release the pointer.
+
+      The reference count is decremented. If the reference count reaches
+      zero, the object is deleted.
+  */
+  void reset ()
+  {
+    if (m_p != 0)
+    {
+      if (--getRefCounts () [m_p] <= 0)
+        delete m_p;
+
+      m_p = 0;
+    }
+  }
+
+private:
+  T* m_p;
+};
+
+template <class T>
+bool operator== (const RefCountedPtr <T>& lhs, const RefCountedPtr <T>& rhs)
+{
+  return lhs.get () == rhs.get ();
+}
+
+template <class T>
+bool operator!= (const RefCountedPtr <T>& lhs, const RefCountedPtr <T>& rhs)
+{
+  return lhs.get() != rhs.get();
+}
+
+//==============================================================================
+
+// forward declaration
+template <class T>
+struct ContainerTraits;
+
+template <class T>
+struct ContainerTraits <RefCountedPtr <T> >
+{
+  typedef T Type;
+
+  static T* get (RefCountedPtr <T> const& c)
+  {
+    return c.get ();
+  }
+};
+
+} // namespace luabridge