src/util/pointer.h

   1 /*
   2 Minetest
   3 Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #pragma once
  21
  22 #include "irrlichttypes.h"
  23 #include "debug.h" // For assert()
  24 #include <cstring>
  25
  26 template <typename T>
  27 class Buffer
  28 {
  29 public:
  30         Buffer()
  31         {
  32                 m_size = 0;
  33                 data = NULL;
  34         }
  35         Buffer(unsigned int size)
  36         {
  37                 m_size = size;
  38                 if(size != 0)
  39                         data = new T[size];
  40                 else
  41                         data = NULL;
  42         }
  43         Buffer(const Buffer &buffer)
  44         {
  45                 m_size = buffer.m_size;
  46                 if(m_size != 0)
  47                 {
  48                         data = new T[buffer.m_size];
  49                         memcpy(data, buffer.data, buffer.m_size);
  50                 }
  51                 else
  52                         data = NULL;
  53         }
  54         Buffer(const T *t, unsigned int size)
  55         {
  56                 m_size = size;
  57                 if(size != 0)
  58                 {
  59                         data = new T[size];
  60                         memcpy(data, t, size);
  61                 }
  62                 else
  63                         data = NULL;
  64         }
  65         ~Buffer()
  66         {
  67                 drop();
  68         }
  69         Buffer& operator=(const Buffer &buffer)
  70         {
  71                 if(this == &buffer)
  72                         return *this;
  73                 drop();
  74                 m_size = buffer.m_size;
  75                 if(m_size != 0)
  76                 {
  77                         data = new T[buffer.m_size];
  78                         memcpy(data, buffer.data, buffer.m_size);
  79                 }
  80                 else
  81                         data = NULL;
  82                 return *this;
  83         }
  84         T & operator[](unsigned int i) const
  85         {
  86                 return data[i];
  87         }
  88         T * operator*() const
  89         {
  90                 return data;
  91         }
  92         unsigned int getSize() const
  93         {
  94                 return m_size;
  95         }
  96 private:
  97         void drop()
  98         {
  99                 delete[] data;
 100         }
 101         T *data;
 102         unsigned int m_size;
 103 };
 104
 105 /************************************************
 106  *           !!!  W A R N I N G  !!!            *
 107  *                                              *
 108  * This smart pointer class is NOT thread safe. *
 109  * ONLY use in a single-threaded context!       *
 110  *                                              *
 111  ************************************************/
 112 template <typename T>
 113 class SharedBuffer
 114 {
 115 public:
 116         SharedBuffer()
 117         {
 118                 m_size = 0;
 119                 data = NULL;
 120                 refcount = new unsigned int;
 121                 (*refcount) = 1;
 122         }
 123         SharedBuffer(unsigned int size)
 124         {
 125                 m_size = size;
 126                 if(m_size != 0)
 127                         data = new T[m_size];
 128                 else
 129                         data = NULL;
 130                 refcount = new unsigned int;
 131                 memset(data,0,sizeof(T)*m_size);
 132                 (*refcount) = 1;
 133         }
 134         SharedBuffer(const SharedBuffer &buffer)
 135         {
 136                 m_size = buffer.m_size;
 137                 data = buffer.data;
 138                 refcount = buffer.refcount;
 139                 (*refcount)++;
 140         }
 141         SharedBuffer & operator=(const SharedBuffer & buffer)
 142         {
 143                 if(this == &buffer)
 144                         return *this;
 145                 drop();
 146                 m_size = buffer.m_size;
 147                 data = buffer.data;
 148                 refcount = buffer.refcount;
 149                 (*refcount)++;
 150                 return *this;
 151         }
 152         /*
 153                 Copies whole buffer
 154         */
 155         SharedBuffer(const T *t, unsigned int size)
 156         {
 157                 m_size = size;
 158                 if(m_size != 0)
 159                 {
 160                         data = new T[m_size];
 161                         memcpy(data, t, m_size);
 162                 }
 163                 else
 164                         data = NULL;
 165                 refcount = new unsigned int;
 166                 (*refcount) = 1;
 167         }
 168         /*
 169                 Copies whole buffer
 170         */
 171         SharedBuffer(const Buffer<T> &buffer)
 172         {
 173                 m_size = buffer.getSize();
 174                 if (m_size != 0) {
 175                                 data = new T[m_size];
 176                                 memcpy(data, *buffer, buffer.getSize());
 177                 }
 178                 else
 179                         data = NULL;
 180                 refcount = new unsigned int;
 181                 (*refcount) = 1;
 182         }
 183         ~SharedBuffer()
 184         {
 185                 drop();
 186         }
 187         T & operator[](unsigned int i) const
 188         {
 189                 assert(i < m_size);
 190                 return data[i];
 191         }
 192         T * operator*() const
 193         {
 194                 return data;
 195         }
 196         unsigned int getSize() const
 197         {
 198                 return m_size;
 199         }
 200         operator Buffer<T>() const
 201         {
 202                 return Buffer<T>(data, m_size);
 203         }
 204 private:
 205         void drop()
 206         {
 207                 assert((*refcount) > 0);
 208                 (*refcount)--;
 209                 if(*refcount == 0)
 210                 {
 211                         delete[] data;
 212                         delete refcount;
 213                 }
 214         }
 215         T *data;
 216         unsigned int m_size;
 217         unsigned int *refcount;
 218 };