include/comphelper/IdPropArrayHelper.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19 #pragma once
  20
  21 #include <sal/config.h>
  22
  23 #include <mutex>
  24 #include <cppuhelper/propshlp.hxx>
  25 #include <cassert>
  26 #include <unordered_map>
  27
  28 namespace comphelper
  29 {
  30
  31     typedef std::unordered_map< sal_Int32, ::cppu::IPropertyArrayHelper* > OIdPropertyArrayMap;
  32     template <class TYPE>
  33     class OIdPropertyArrayUsageHelper
  34     {
  35     public:
  36         OIdPropertyArrayUsageHelper();
  37         virtual ~OIdPropertyArrayUsageHelper()
  38         {
  39             std::unique_lock aGuard(theMutex());
  40             assert(s_nRefCount > 0 && "OIdPropertyArrayUsageHelper::~OIdPropertyArrayUsageHelper : suspicious call : have a refcount of 0 !");
  41             if (!--s_nRefCount)
  42             {
  43                 // delete the element
  44                 for (auto const& elem : *s_pMap)
  45                     delete elem.second;
  46                 delete s_pMap;
  47                 s_pMap = nullptr;
  48             }
  49         }
  50
  51         /** call this in the getInfoHelper method of your derived class. The method returns the array helper of the
  52             class, which is created if necessary.
  53         */
  54         ::cppu::IPropertyArrayHelper* getArrayHelper(sal_Int32 nId);
  55
  56     protected:
  57         /** used to implement the creation of the array helper which is shared amongst all instances of the class.
  58             This method needs to be implemented in derived classes.
  59             <BR>
  60             The method gets called with Mutex acquired.
  61             @return                         a pointer to the newly created array helper. Must not be NULL.
  62         */
  63         virtual ::cppu::IPropertyArrayHelper* createArrayHelper(sal_Int32 nId) const = 0;
  64     private:
  65         static sal_Int32                        s_nRefCount;
  66         static OIdPropertyArrayMap*             s_pMap;
  67         static std::mutex& theMutex()
  68         {
  69             static std::mutex SINGLETON;
  70             return SINGLETON;
  71         }
  72     };
  73
  74     template<class TYPE>
  75     sal_Int32                       OIdPropertyArrayUsageHelper< TYPE >::s_nRefCount    = 0;
  76
  77     template<class TYPE>
  78     OIdPropertyArrayMap*            OIdPropertyArrayUsageHelper< TYPE >::s_pMap = nullptr;
  79
  80     template <class TYPE>
  81     OIdPropertyArrayUsageHelper<TYPE>::OIdPropertyArrayUsageHelper()
  82     {
  83         std::unique_lock aGuard(theMutex());
  84         // create the map if necessary
  85         if (!s_pMap)
  86             s_pMap = new OIdPropertyArrayMap;
  87         ++s_nRefCount;
  88     }
  89
  90     template <class TYPE>
  91     ::cppu::IPropertyArrayHelper* OIdPropertyArrayUsageHelper<TYPE>::getArrayHelper(sal_Int32 nId)
  92     {
  93         assert(s_nRefCount && "OIdPropertyArrayUsageHelper::getArrayHelper : suspicious call : have a refcount of 0 !");
  94         std::unique_lock aGuard(theMutex());
  95         // do we have the array already?
  96         auto& rEntry = (*s_pMap)[nId];
  97         if (!rEntry)
  98         {
  99             rEntry = createArrayHelper(nId);
 100             assert(rEntry && "OIdPropertyArrayUsageHelper::getArrayHelper : createArrayHelper returned nonsense !");
 101         }
 102         return (*s_pMap)[nId];
 103     }
 104 }
 105
 106 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */