src/subtitles/xy_malloc.cpp

   1 /************************************************************************/
   2 /* author: xy                                                           */
   3 /* date: 20110514                                                       */
   4 /************************************************************************/
   5 #include "xy_malloc.h"
   6 #include <stdint.h>
   7 #include <malloc.h>
   8 #include <string.h>
   9
  10 //gathered from x264
  11 /****************************************************************************
  12  * xy_malloc:
  13  ****************************************************************************/
  14 void *xy_malloc( int i_size, int align_shift )
  15 {
  16     const int ALIGNMENT = 16;
  17     const int MASK = ALIGNMENT - 1;
  18     uint8_t * buf;
  19     uint8_t * align_buf;
  20     align_shift &= MASK;
  21     buf = (uint8_t *) malloc( i_size + MASK + sizeof( void ** ) +
  22               sizeof( int ) );
  23     align_buf = buf + MASK + sizeof( void ** ) + sizeof( int );
  24     align_buf -= (ALIGNMENT + ((intptr_t) align_buf & MASK) - align_shift) & MASK;
  25     *( (void **) ( align_buf - sizeof( void ** ) ) ) = buf;
  26     *( (int *) ( align_buf - sizeof( void ** ) - sizeof( int ) ) ) = i_size;
  27     return align_buf;
  28 }
  29
  30 /****************************************************************************
  31  * xy_free:
  32  ****************************************************************************/
  33 void xy_free( void *p )
  34 {
  35     if( p )
  36     {
  37         free( *( ( ( void **) p ) - 1 ) );
  38     }
  39 }
  40
  41 /****************************************************************************
  42  * xy_realloc:
  43  ****************************************************************************/
  44 void *xy_realloc( void *p, int i_size, int align_shift )
  45 {
  46     int       i_old_size = 0;
  47     uint8_t * p_new;
  48     if( p )
  49     {
  50         i_old_size = *( (int*) ( (uint8_t*) p - sizeof( void ** ) -
  51                          sizeof( int ) ) );
  52     }
  53     p_new = (uint8_t*)xy_malloc( i_size, align_shift );
  54     if( i_old_size > 0 && i_size > 0 )
  55     {
  56         memcpy( p_new, p, ( i_old_size < i_size ) ? i_old_size : i_size );
  57     }
  58     xy_free( p );
  59     return p_new;
  60 }
  61
  62