cxr/cxr_mem.h

   1 typedef struct cxr_abuffer cxr_abuffer;
   2
   3 struct cxr_abuffer
   4 {
   5    u8 *arr;
   6    u32 esize,
   7        count,
   8        capacity;
   9 };
  10
  11 #ifdef CXR_DEBUG_ALLOCATORS
  12  #define CXR_STR_PRE(x) #x
  13  #define CXR_STR(x) CXR_STR_PRE(x)
  14  #define cxr_ab_ptr(b,i) __cxr_ab_ptr(b,i, __FILE__ ":L" CXR_STR(__LINE__) )
  15 #else
  16  #define cxr_ab_ptr(b,i) __cxr_ab_ptr(b,i)
  17 #endif
  18
  19 static void *__cxr_ab_ptr( struct cxr_abuffer *buffer, u32 index
  20
  21 #ifdef CXR_DEBUG_ALLOCATORS
  22       ,const char *debug_str
  23 #endif
  24
  25 )
  26 {
  27
  28 #ifdef CXR_DEBUG_ALLOCATORS
  29    if( index >= buffer->capacity || index < 0 )
  30    {
  31       printf( "index out of capactity (%d /: [0->%d (cap)]) (%s)\n", index, buffer->capacity, debug_str );
  32       exit(1);
  33    }
  34 #endif
  35
  36    return buffer->arr + buffer->esize*index;
  37 }
  38
  39 static void cxr_ab_reserve( struct cxr_abuffer *buffer, u32 count )
  40 {
  41    if( buffer->count + count > buffer->capacity )
  42    {
  43       buffer->capacity = cxr_max(buffer->capacity*2, buffer->capacity+count);
  44       buffer->arr = realloc( buffer->arr, buffer->capacity*buffer->esize );
  45    }
  46 }
  47
  48 static void *cxr_ab_empty( struct cxr_abuffer *buffer )
  49 {
  50    cxr_ab_reserve( buffer, 1 );
  51    return cxr_ab_ptr( buffer, buffer->count ++ );
  52 }
  53
  54 static void *cxr_ab_empty_at( struct cxr_abuffer *buffer, int at )
  55 {
  56    cxr_ab_reserve( buffer, 1 );
  57
  58    if( at == buffer->count )
  59    {
  60       buffer->count ++;
  61       return cxr_ab_ptr( buffer, at );
  62    }
  63
  64    /* Shift buffer to make room */
  65    memmove
  66    (
  67       cxr_ab_ptr( buffer, at+1 ),
  68       cxr_ab_ptr( buffer, at ),
  69       (buffer->count-at)*buffer->esize
  70    );
  71
  72    buffer->count ++;
  73    return cxr_ab_ptr( buffer, at );
  74 }
  75
  76 static void cxr_ab_push( struct cxr_abuffer *buffer, void *em )
  77 {
  78    cxr_ab_reserve( buffer, 1 );
  79
  80    memcpy( buffer->arr+buffer->count*buffer->esize, em, buffer->esize );
  81    buffer->count ++;
  82 }
  83
  84 static void cxr_ab_init( struct cxr_abuffer *buffer, u32 esize, u32 cap )
  85 {
  86    buffer->esize = esize;
  87    buffer->capacity = cxr_max(1,cap);
  88    buffer->count = 0;
  89
  90    buffer->arr = malloc( buffer->esize*buffer->capacity );
  91 }
  92
  93 static void cxr_ab_clear( struct cxr_abuffer *buffer )
  94 {
  95    buffer->count = 0;
  96 }
  97
  98 static void cxr_ab_free( struct cxr_abuffer *buffer )
  99 {
 100    free( buffer->arr );
 101 }