apdf/freetype2/include/freetype/ftsysmem.h

   1 #ifndef __FT_SYSTEM_MEMORY_H__
   2 #define __FT_SYSTEM_MEMORY_H__
   3
   4 #include <ft2build.h>
   5
   6 FT_BEGIN_HEADER
   7
   8  /***********************************************************************
   9   *
  10   * @type: FT_Memory
  11   *
  12   * @description:
  13   *   opaque handle to a memory manager handle. Note that since FreeType
  14   *   2.2, the memory manager structure FT_MemoryRec is hidden to client
  15   *   applications.
  16   *
  17   *   however, you can still define custom allocators easily using the
  18   *   @ft_memory_new API
  19   */
  20   typedef struct FT_MemoryRec_*   FT_Memory;
  21
  22
  23  /***********************************************************************
  24   *
  25   * @functype: FT_Memory_AllocFunc
  26   *
  27   * @description:
  28   *   a function used to allocate a block of memory.
  29   *
  30   * @input:
  31   *   size     :: size of blocks in bytes. Always > 0 !!
  32   *   mem_data :: memory-manager specific optional argument
  33   *               (see @ft_memory_new)
  34   *
  35   * @return:
  36   *   address of new block. NULL in case of memory exhaustion
  37   */
  38   typedef FT_Pointer  (*FT_Memory_AllocFunc)( FT_ULong   size,
  39                                               FT_Pointer mem_data );
  40
  41
  42  /***********************************************************************
  43   *
  44   * @functype: FT_Memory_FreeFunc
  45   *
  46   * @description:
  47   *   a function used to release a block of memory created through
  48   *   @FT_Memory_AllocFunc or @FT_Memory_ReallocFunc
  49   *
  50   * @input:
  51   *   block    :: address of target memory block. cannot be NULL !!
  52   *   mem_data :: memory-manager specific optional argument
  53   *               (see @ft_memory_new)
  54   */
  55   typedef void        (*FT_Memory_FreeFunc) ( FT_Pointer  block,
  56                                               FT_Pointer  mem_data );
  57
  58
  59  /***********************************************************************
  60   *
  61   * @functype: FT_Memory_ReallocFunc
  62   *
  63   * @description:
  64   *   a function used to reallocate a memory block.
  65   *
  66   * @input:
  67   *   block    :: address of target memory block. cannot be NULL !!
  68   *   new_size :: new requested size in bytes
  69   *   cur_size :: current block size in bytes
  70   *   mem_data :: memory-manager specific optional argument
  71   *               (see @ft_memory_new)
  72   */
  73   typedef FT_Pointer  (*FT_Memory_ReallocFunc)( FT_Pointer   block,
  74                                                 FT_ULong     new_size,
  75                                                 FT_ULong     cur_size,
  76                                                 FT_Pointer   mem_data );
  77
  78
  79  /***********************************************************************
  80   *
  81   * @functype: FT_Memory_CreateFunc
  82   *
  83   * @description:
  84   *   a function used to create a @FT_Memory object to model a
  85   *   memory manager
  86   *
  87   * @input:
  88   *   size      :: size of memory manager structure in bytes
  89   *   init_data :: optional initialisation argument
  90   *
  91   * @output:
  92   *   amem_data :: memory-manager specific argument to block management
  93   *                routines.
  94   *
  95   * @return:
  96   *   handle to new memory manager object. NULL in case of failure
  97   */
  98   typedef FT_Pointer  (*FT_Memory_CreateFunc)( FT_UInt     size,
  99                                                FT_Pointer  init_data,
 100                                                FT_Pointer *amem_data );
 101
 102
 103  /***********************************************************************
 104   *
 105   * @functype: FT_Memory_DestroyFunc
 106   *
 107   * @description:
 108   *   a function used to destroy a given @FT_Memory manager
 109   *
 110   * @input:
 111   *   memory   :: target memory manager handle
 112   *   mem_data :: option manager-specific argument
 113   */
 114   typedef void        (*FT_Memory_DestroyFunc)( FT_Memory  memory,
 115                                                 FT_Pointer mem_data );
 116
 117
 118  /***********************************************************************
 119   *
 120   * @struct: FT_Memory_FuncsRec
 121   *
 122   * @description:
 123   *   a function used to hold all methods of a given memory manager
 124   *   implementation.
 125   *
 126   * @fields:
 127   *   mem_alloc   :: block allocation routine
 128   *   mem_free    :: block release routine
 129   *   mem_realloc :: block re-allocation routine
 130   *   mem_create  :: manager creation routine
 131   *   mem_destroy :: manager destruction routine
 132   */
 133   typedef struct FT_Memory_FuncsRec_
 134   {
 135     FT_Memory_AllocFunc     mem_alloc;
 136     FT_Memory_FreeFunc      mem_free;
 137     FT_Memory_ReallocFunc   mem_realloc;
 138     FT_Memory_CreateFunc    mem_create;
 139     FT_Memory_DestroyFunc   mem_destroy;
 140
 141   } FT_Memory_FuncsRec, *FT_Memory_Funcs;
 142
 143
 144  /***********************************************************************
 145   *
 146   * @type: FT_Memory_Funcs
 147   *
 148   * @description:
 149   *   a pointer to a constant @FT_Memory_FuncsRec structure used to
 150   *   describe a given memory manager implementation.
 151   */
 152   typedef const FT_Memory_FuncsRec*  FT_Memory_Funcs;
 153
 154
 155  /***********************************************************************
 156   *
 157   * @function: ft_memory_new
 158   *
 159   * @description:
 160   *   create a new memory manager, given a set of memory methods
 161   *
 162   * @input:
 163   *   mem_funcs     :: handle to memory manager implementation descriptor
 164   *   mem_init_data :: optional initialisation argument, passed to
 165   *                    @FT_Memory_CreateFunc
 166   *
 167   * @return:
 168   *   new memory manager handle. NULL in case of failure
 169   */
 170   FT_BASE( FT_Memory )
 171   ft_memory_new( FT_Memory_Funcs  mem_funcs,
 172                  FT_Pointer       mem_init_data );
 173
 174
 175  /***********************************************************************
 176   *
 177   * @function: ft_memory_destroy
 178   *
 179   * @description:
 180   *   destroy a given memory manager
 181   *
 182   * @input:
 183   *   memory :: handle to target memory manager
 184   */
 185   FT_BASE( void )
 186   ft_memory_destroy( FT_Memory  memory );
 187
 188 /* */
 189
 190 FT_END_HEADER
 191
 192 #endif /* __FT_SYSTEM_MEMORY_H__ */