cxr/cxr_mem.h

   1 #ifndef CXR_MEM_H
   2 #define CXR_MEM_H
   3
   4 #include <string.h>
   5 #include <stdlib.h>
   6
   7 #include "cxr_types.h"
   8 #include "cxr_math.h"
   9
  10 typedef struct cxr_abuffer cxr_abuffer;
  11
  12 struct cxr_abuffer
  13 {
  14    u8 *arr;
  15    u32 esize,
  16        count,
  17        capacity;
  18 };
  19
  20 #ifdef CXR_DEBUG_ALLOCATORS
  21  #define CXR_STR_PRE(x) #x
  22  #define CXR_STR(x) CXR_STR_PRE(x)
  23  #define cxr_ab_ptr(b,i) __cxr_ab_ptr(b,i, __FILE__ ":L" CXR_STR(__LINE__) )
  24 #else
  25  #define cxr_ab_ptr(b,i) __cxr_ab_ptr(b,i)
  26 #endif
  27
  28 static void *__cxr_ab_ptr( struct cxr_abuffer *buffer, u32 index
  29
  30 #ifdef CXR_DEBUG_ALLOCATORS
  31       ,const char *debug_str
  32 #endif
  33
  34 )
  35 {
  36
  37 #ifdef CXR_DEBUG_ALLOCATORS
  38    if( index >= buffer->capacity || index < 0 )
  39    {
  40       printf( "index out of capactity (%d /: [0->%d (cap)]) (%s)\n", index,
  41             buffer->capacity, debug_str );
  42       exit(1);
  43    }
  44 #endif
  45
  46    return buffer->arr + buffer->esize*index;
  47 }
  48
  49 static void cxr_ab_reserve( struct cxr_abuffer *buffer, u32 count )
  50 {
  51    if( buffer->count + count > buffer->capacity )
  52    {
  53       buffer->capacity = cxr_max(buffer->capacity*2, buffer->capacity+count);
  54       buffer->arr = realloc( buffer->arr, buffer->capacity*buffer->esize );
  55    }
  56 }
  57
  58 static void *cxr_ab_empty( struct cxr_abuffer *buffer )
  59 {
  60    cxr_ab_reserve( buffer, 1 );
  61    return cxr_ab_ptr( buffer, buffer->count ++ );
  62 }
  63
  64 static void *cxr_ab_empty_at( struct cxr_abuffer *buffer, int at )
  65 {
  66    cxr_ab_reserve( buffer, 1 );
  67
  68    if( at == buffer->count )
  69    {
  70       buffer->count ++;
  71       return cxr_ab_ptr( buffer, at );
  72    }
  73
  74    /* Shift buffer to make room */
  75    memmove
  76    (
  77       cxr_ab_ptr( buffer, at+1 ),
  78       cxr_ab_ptr( buffer, at ),
  79       (buffer->count-at)*buffer->esize
  80    );
  81
  82    buffer->count ++;
  83    return cxr_ab_ptr( buffer, at );
  84 }
  85
  86 static void cxr_ab_push( struct cxr_abuffer *buffer, void *em )
  87 {
  88    cxr_ab_reserve( buffer, 1 );
  89
  90    memcpy( buffer->arr+buffer->count*buffer->esize, em, buffer->esize );
  91    buffer->count ++;
  92 }
  93
  94 static void cxr_ab_init( struct cxr_abuffer *buffer, u32 esize, u32 cap )
  95 {
  96    buffer->esize = esize;
  97    buffer->capacity = cap;
  98    buffer->count = 0;
  99
 100    if( cap )
 101       buffer->arr = malloc( buffer->esize*buffer->capacity );
 102    else
 103       buffer->arr = NULL;
 104 }
 105
 106 static void cxr_ab_clear( struct cxr_abuffer *buffer )
 107 {
 108    buffer->count = 0;
 109 }
 110
 111 static void cxr_ab_free( struct cxr_abuffer *buffer )
 112 {
 113    free( buffer->arr );
 114 }
 115
 116 #endif /* CXR_TYPES_H */