1 /****************************************************************************
   2  *
   3  * ftsystem.c
   4  *
   5  *   ANSI-specific FreeType low-level system interface (body).
   6  *
   7  * Copyright (C) 1996-2019 by
   8  * David Turner, Robert Wilhelm, and Werner Lemberg.
   9  *
  10  * This file is part of the FreeType project, and may only be used,
  11  * modified, and distributed under the terms of the FreeType project
  12  * license, LICENSE.TXT.  By continuing to use, modify, or distribute
  13  * this file you indicate that you have read the license and
  14  * understand and accept it fully.
  15  *
  16  */
  17 
  18   /**************************************************************************
  19    *
  20    * This file contains the default interface used by FreeType to access
  21    * low-level, i.e. memory management, i/o access as well as thread
  22    * synchronisation.  It can be replaced by user-specific routines if
  23    * necessary.
  24    *
  25    */
  26 
  27 
  28 #include <ft2build.h>
  29 #include FT_CONFIG_CONFIG_H
  30 #include FT_INTERNAL_DEBUG_H
  31 #include FT_INTERNAL_STREAM_H
  32 #include FT_SYSTEM_H
  33 #include FT_ERRORS_H
  34 #include FT_TYPES_H
  35 
  36 
  37   /**************************************************************************
  38    *
  39    *                      MEMORY MANAGEMENT INTERFACE
  40    *
  41    */
  42 
  43   /**************************************************************************
  44    *
  45    * It is not necessary to do any error checking for the
  46    * allocation-related functions.  This will be done by the higher level
  47    * routines like ft_mem_alloc() or ft_mem_realloc().
  48    *
  49    */
  50 
  51 
  52   /**************************************************************************
  53    *
  54    * @Function:
  55    *   ft_alloc
  56    *
  57    * @Description:
  58    *   The memory allocation function.
  59    *
  60    * @Input:
  61    *   memory ::
  62    *     A pointer to the memory object.
  63    *
  64    *   size ::
  65    *     The requested size in bytes.
  66    *
  67    * @Return:
  68    *   The address of newly allocated block.
  69    */
  70   FT_CALLBACK_DEF( void* )
  71   ft_alloc( FT_Memory  memory,
  72             long       size )
  73   {
  74     FT_UNUSED( memory );
  75 
  76     return ft_smalloc( (size_t)size );
  77   }
  78 
  79 
  80   /**************************************************************************
  81    *
  82    * @Function:
  83    *   ft_realloc
  84    *
  85    * @Description:
  86    *   The memory reallocation function.
  87    *
  88    * @Input:
  89    *   memory ::
  90    *     A pointer to the memory object.
  91    *
  92    *   cur_size ::
  93    *     The current size of the allocated memory block.
  94    *
  95    *   new_size ::
  96    *     The newly requested size in bytes.
  97    *
  98    *   block ::
  99    *     The current address of the block in memory.
 100    *
 101    * @Return:
 102    *   The address of the reallocated memory block.
 103    */
 104   FT_CALLBACK_DEF( void* )
 105   ft_realloc( FT_Memory  memory,
 106               long       cur_size,
 107               long       new_size,
 108               void*      block )
 109   {
 110     FT_UNUSED( memory );
 111     FT_UNUSED( cur_size );
 112 
 113     return ft_srealloc( block, (size_t)new_size );
 114   }
 115 
 116 
 117   /**************************************************************************
 118    *
 119    * @Function:
 120    *   ft_free
 121    *
 122    * @Description:
 123    *   The memory release function.
 124    *
 125    * @Input:
 126    *   memory ::
 127    *     A pointer to the memory object.
 128    *
 129    *   block ::
 130    *     The address of block in memory to be freed.
 131    */
 132   FT_CALLBACK_DEF( void )
 133   ft_free( FT_Memory  memory,
 134            void*      block )
 135   {
 136     FT_UNUSED( memory );
 137 
 138     ft_sfree( block );
 139   }
 140 
 141 
 142   /**************************************************************************
 143    *
 144    *                    RESOURCE MANAGEMENT INTERFACE
 145    *
 146    */
 147 
 148 #ifndef FT_CONFIG_OPTION_DISABLE_STREAM_SUPPORT
 149 
 150   /**************************************************************************
 151    *
 152    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
 153    * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
 154    * messages during execution.
 155    */
 156 #undef  FT_COMPONENT
 157 #define FT_COMPONENT  io
 158 
 159   /* We use the macro STREAM_FILE for convenience to extract the       */
 160   /* system-specific stream handle from a given FreeType stream object */
 161 #define STREAM_FILE( stream )  ( (FT_FILE*)stream->descriptor.pointer )
 162 
 163 
 164   /**************************************************************************
 165    *
 166    * @Function:
 167    *   ft_ansi_stream_close
 168    *
 169    * @Description:
 170    *   The function to close a stream.
 171    *
 172    * @Input:
 173    *   stream ::
 174    *     A pointer to the stream object.
 175    */
 176   FT_CALLBACK_DEF( void )
 177   ft_ansi_stream_close( FT_Stream  stream )
 178   {
 179     ft_fclose( STREAM_FILE( stream ) );
 180 
 181     stream->descriptor.pointer = NULL;
 182     stream->size               = 0;
 183     stream->base               = NULL;
 184   }
 185 
 186 
 187   /**************************************************************************
 188    *
 189    * @Function:
 190    *   ft_ansi_stream_io
 191    *
 192    * @Description:
 193    *   The function to open a stream.
 194    *
 195    * @Input:
 196    *   stream ::
 197    *     A pointer to the stream object.
 198    *
 199    *   offset ::
 200    *     The position in the data stream to start reading.
 201    *
 202    *   buffer ::
 203    *     The address of buffer to store the read data.
 204    *
 205    *   count ::
 206    *     The number of bytes to read from the stream.
 207    *
 208    * @Return:
 209    *   The number of bytes actually read.  If `count' is zero (this is,
 210    *   the function is used for seeking), a non-zero return value
 211    *   indicates an error.
 212    */
 213   FT_CALLBACK_DEF( unsigned long )
 214   ft_ansi_stream_io( FT_Stream       stream,
 215                      unsigned long   offset,
 216                      unsigned char*  buffer,
 217                      unsigned long   count )
 218   {
 219     FT_FILE*  file;
 220 
 221 
 222     if ( !count && offset > stream->size )
 223       return 1;
 224 
 225     file = STREAM_FILE( stream );
 226 
 227     if ( stream->pos != offset )
 228       ft_fseek( file, (long)offset, SEEK_SET );
 229 
 230     return (unsigned long)ft_fread( buffer, 1, count, file );
 231   }
 232 
 233 
 234   /* documentation is in ftstream.h */
 235 
 236   FT_BASE_DEF( FT_Error )
 237   FT_Stream_Open( FT_Stream    stream,
 238                   const char*  filepathname )
 239   {
 240     FT_FILE*  file;
 241 
 242 
 243     if ( !stream )
 244       return FT_THROW( Invalid_Stream_Handle );
 245 
 246     stream->descriptor.pointer = NULL;
 247     stream->pathname.pointer   = (char*)filepathname;
 248     stream->base               = NULL;
 249     stream->pos                = 0;
 250     stream->read               = NULL;
 251     stream->close              = NULL;
 252 
 253     file = ft_fopen( filepathname, "rb" );
 254     if ( !file )
 255     {
 256       FT_ERROR(( "FT_Stream_Open:"
 257                  " could not open `%s'\n", filepathname ));
 258 
 259       return FT_THROW( Cannot_Open_Resource );
 260     }
 261 
 262     ft_fseek( file, 0, SEEK_END );
 263     stream->size = (unsigned long)ft_ftell( file );
 264     if ( !stream->size )
 265     {
 266       FT_ERROR(( "FT_Stream_Open:" ));
 267       FT_ERROR(( " opened `%s' but zero-sized\n", filepathname ));
 268       ft_fclose( file );
 269       return FT_THROW( Cannot_Open_Stream );
 270     }
 271     ft_fseek( file, 0, SEEK_SET );
 272 
 273     stream->descriptor.pointer = file;
 274     stream->read  = ft_ansi_stream_io;
 275     stream->close = ft_ansi_stream_close;
 276 
 277     FT_TRACE1(( "FT_Stream_Open:" ));
 278     FT_TRACE1(( " opened `%s' (%d bytes) successfully\n",
 279                 filepathname, stream->size ));
 280 
 281     return FT_Err_Ok;
 282   }
 283 
 284 #endif /* !FT_CONFIG_OPTION_DISABLE_STREAM_SUPPORT */
 285 
 286 #ifdef FT_DEBUG_MEMORY
 287 
 288   extern FT_Int
 289   ft_mem_debug_init( FT_Memory  memory );
 290 
 291   extern void
 292   ft_mem_debug_done( FT_Memory  memory );
 293 
 294 #endif
 295 
 296 
 297   /* documentation is in ftobjs.h */
 298 
 299   FT_BASE_DEF( FT_Memory )
 300   FT_New_Memory( void )
 301   {
 302     FT_Memory  memory;
 303 
 304 
 305     memory = (FT_Memory)ft_smalloc( sizeof ( *memory ) );
 306     if ( memory )
 307     {
 308       memory->user    = NULL;
 309       memory->alloc   = ft_alloc;
 310       memory->realloc = ft_realloc;
 311       memory->free    = ft_free;
 312 #ifdef FT_DEBUG_MEMORY
 313       ft_mem_debug_init( memory );
 314 #endif
 315     }
 316 
 317     return memory;
 318   }
 319 
 320 
 321   /* documentation is in ftobjs.h */
 322 
 323   FT_BASE_DEF( void )
 324   FT_Done_Memory( FT_Memory  memory )
 325   {
 326 #ifdef FT_DEBUG_MEMORY
 327     ft_mem_debug_done( memory );
 328 #endif
 329     ft_sfree( memory );
 330   }
 331 
 332 
 333 /* END */