Add beast_basics module

modules/beast_basics/containers/beast_SharedTable.h

@@ -0,0 +1,226 @@
+/*============================================================================*/
+/*
+  VFLib: https://github.com/vinniefalco/VFLib
+
+  Copyright (C) 2008 by Vinnie Falco <vinnie.falco@gmail.com>
+
+  This library contains portions of other open source products covered by
+  separate licenses. Please see the corresponding source files for specific
+  terms.
+
+  VFLib is provided under the terms of The MIT License (MIT):
+
+  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.
+*/
+/*============================================================================*/
+
+#ifndef BEAST_SHAREDTABLE_BEASTHEADER
+#define BEAST_SHAREDTABLE_BEASTHEADER
+
+/** Handle to a reference counted fixed size table.
+
+    @note Currently, ElementType must be an aggregate of POD.
+
+    @tparam ElementType The type of element.
+
+    @ingroup beast_gui
+*/
+template <class ElementType>
+class SharedTable
+{
+public:
+    typedef ElementType Entry;
+
+    static SharedTable <ElementType> const null;
+
+    /** Creates a null table.
+    */
+    SharedTable ()
+    {
+    }
+
+    /** Creates a table with the specified number of entries.
+
+        The entries are uninitialized.
+
+        @param numEntries The number of entries in the table.
+
+        @todo Initialize the data if ElementType is not POD.
+    */
+    explicit SharedTable (int numEntries)
+        : m_data (new Data (numEntries))
+    {
+    }
+
+    /** Creates a shared reference to another table.
+    */
+    SharedTable (SharedTable const& other)
+        : m_data (other.m_data)
+    {
+    }
+
+    /** Makes this table refer to another table.
+    */
+    SharedTable& operator= (SharedTable const& other)
+    {
+        m_data = other.m_data;
+        return *this;
+    }
+
+#if BEAST_COMPILER_SUPPORTS_MOVE_SEMANTICS
+    SharedTable (SharedTable&& other) noexcept
+:
+    m_data (static_cast < typename Data::Ptr&& > (other.m_data))
+    {
+    }
+
+    SharedTable& operator= (SharedTable && other) noexcept
+    {
+        m_data = static_cast < typename Data::Ptr && > (other.m_data);
+        return *this;
+    }
+#endif
+
+    /** Destructor.
+    */
+    ~SharedTable ()
+    {
+    }
+
+    /** Returns true if the two tables share the same set of entries.
+    */
+    bool operator== (SharedTable const& other) const noexcept
+    {
+        return m_data == other.m_data;
+    }
+
+    /** Returns true if the two tables do not share the same set of entries.
+    */
+    bool operator!= (SharedTable const& other) const noexcept
+    {
+        return m_data != other.m_data;
+    }
+
+    /** Returns true if the table is not null.
+    */
+    inline bool isValid () const noexcept
+    {
+        return m_data != nullptr;
+    }
+
+    /** Returns true if the table is null.
+    */
+    inline bool isNull () const noexcept
+    {
+        return m_data == nullptr;
+    }
+
+    /** Returns the number of tables referring to the same shared entries.
+    */
+    int getReferenceCount () const noexcept
+    {
+        return m_data == nullptr ? 0 : m_data->getReferenceCount ();
+    }
+
+    /** Create a physical duplicate of the table.
+    */
+    SharedTable createCopy () const
+    {
+        return SharedTable (m_data != nullptr ? m_data->clone () : nullptr);
+    }
+
+    /** Makes sure no other tables share the same entries as this table.
+    */
+    void duplicateIfShared ()
+    {
+        if (m_data != nullptr && m_data->getReferenceCount () > 1)
+            m_data = m_data->clone ();
+    }
+
+    /** Return the number of entries in this table.
+    */
+    inline int getNumEntries () const noexcept
+    {
+        return m_data->getNumEntries ();
+    }
+
+    /** Retrieve a table entry.
+
+        @param index The index of the entry, from 0 to getNumEntries ().
+    */
+    inline ElementType& operator [] (int index) const noexcept
+    {
+        return m_data->getReference (index);
+    }
+
+private:
+    class Data : public ReferenceCountedObject
+    {
+    public:
+        typedef ReferenceCountedObjectPtr <Data> Ptr;
+
+        explicit Data (int numEntries)
+            : m_numEntries (numEntries)
+            , m_table (numEntries)
+        {
+        }
+
+        inline Data* clone () const
+        {
+            Data* data = new Data (m_numEntries);
+
+            memcpy (
+                data->m_table.getData (),
+                m_table.getData (),
+                m_numEntries * sizeof (ElementType));
+
+            return data;
+        }
+
+        inline int getNumEntries () const
+        {
+            return m_numEntries;
+        }
+
+        inline ElementType& getReference (int index) const
+        {
+            bassert (index >= 0 && index < m_numEntries);
+            return m_table [index];
+        }
+
+    private:
+        int const m_numEntries;
+        HeapBlock <ElementType> const m_table;
+    };
+
+    explicit SharedTable (Data* data)
+        : m_data (data)
+    {
+    }
+
+    ReferenceCountedObjectPtr <Data> m_data;
+};
+
+template <class ElementType>
+SharedTable <ElementType> const SharedTable <ElementType>::null;
+
+#endif
+
+//------------------------------------------------------------------------------
+