1 files changed, 106 insertions, 0 deletions
diff --git a/include/comphelper/IdPropArrayHelper.hxx b/include/comphelper/IdPropArrayHelper.hxx
new file mode 100644
index 0000000000..8b70db849e
--- /dev/null
+++ b/include/comphelper/IdPropArrayHelper.hxx
@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+#pragma once
+
+#include <sal/config.h>
+
+#include <mutex>
+#include <cppuhelper/propshlp.hxx>
+#include <cassert>
+#include <unordered_map>
+
+namespace comphelper
+{
+
+    typedef std::unordered_map< sal_Int32, ::cppu::IPropertyArrayHelper* > OIdPropertyArrayMap;
+    template <class TYPE>
+    class OIdPropertyArrayUsageHelper
+    {
+    public:
+        OIdPropertyArrayUsageHelper();
+        virtual ~OIdPropertyArrayUsageHelper()
+        {
+            std::unique_lock aGuard(theMutex());
+            assert(s_nRefCount > 0 && "OIdPropertyArrayUsageHelper::~OIdPropertyArrayUsageHelper : suspicious call : have a refcount of 0 !");
+            if (!--s_nRefCount)
+            {
+                // delete the element
+                for (auto const& elem : *s_pMap)
+                    delete elem.second;
+                delete s_pMap;
+                s_pMap = nullptr;
+            }
+        }
+
+        /** call this in the getInfoHelper method of your derived class. The method returns the array helper of the
+            class, which is created if necessary.
+        */
+        ::cppu::IPropertyArrayHelper* getArrayHelper(sal_Int32 nId);
+
+    protected:
+        /** used to implement the creation of the array helper which is shared amongst all instances of the class.
+            This method needs to be implemented in derived classes.
+            <BR>
+            The method gets called with Mutex acquired.
+            @return                         a pointer to the newly created array helper. Must not be NULL.
+        */
+        virtual ::cppu::IPropertyArrayHelper* createArrayHelper(sal_Int32 nId) const = 0;
+    private:
+        static sal_Int32                        s_nRefCount;
+        static OIdPropertyArrayMap*             s_pMap;
+        static std::mutex& theMutex()
+        {
+            static std::mutex SINGLETON;
+            return SINGLETON;
+        }
+    };
+
+    template<class TYPE>
+    sal_Int32                       OIdPropertyArrayUsageHelper< TYPE >::s_nRefCount    = 0;
+
+    template<class TYPE>
+    OIdPropertyArrayMap*            OIdPropertyArrayUsageHelper< TYPE >::s_pMap = nullptr;
+
+    template <class TYPE>
+    OIdPropertyArrayUsageHelper<TYPE>::OIdPropertyArrayUsageHelper()
+    {
+        std::unique_lock aGuard(theMutex());
+        // create the map if necessary
+        if (!s_pMap)
+            s_pMap = new OIdPropertyArrayMap;
+        ++s_nRefCount;
+    }
+
+    template <class TYPE>
+    ::cppu::IPropertyArrayHelper* OIdPropertyArrayUsageHelper<TYPE>::getArrayHelper(sal_Int32 nId)
+    {
+        assert(s_nRefCount && "OIdPropertyArrayUsageHelper::getArrayHelper : suspicious call : have a refcount of 0 !");
+        std::unique_lock aGuard(theMutex());
+        // do we have the array already?
+        auto& rEntry = (*s_pMap)[nId];
+        if (!rEntry)
+        {
+            rEntry = createArrayHelper(nId);
+            assert(rEntry && "OIdPropertyArrayUsageHelper::getArrayHelper : createArrayHelper returned nonsense !");
+        }
+        return (*s_pMap)[nId];
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */