Kernel/adt.c

   1 /*
   2  */
   3 #include <acess.h>
   4 #include <adt.h>
   5
   6 // === CODE ===
   7 // --- Ring Buffers ---
   8 tRingBuffer *RingBuffer_Create(size_t Space)
   9 {
  10         tRingBuffer     *ret = malloc(sizeof(tRingBuffer)+Space);
  11         ret->Start = 0;
  12         ret->Length = 0;
  13         ret->Space = Space;
  14         return ret;
  15 }
  16
  17 size_t RingBuffer_Read(void *Dest, tRingBuffer *Buffer, size_t Length)
  18 {
  19         if(Length > Buffer->Length)     Length = Buffer->Length;
  20
  21         if( Buffer->Start + Length > Buffer->Space )
  22         {
  23                  int    endData = Buffer->Space - Buffer->Start;
  24                 memcpy(Dest, &Buffer->Data[Buffer->Start], endData);
  25                 memcpy((Uint8*)Dest + endData, &Buffer->Data, Length - endData);
  26         }
  27         else
  28         {
  29                 memcpy(Dest, &Buffer->Data[Buffer->Start], Length);
  30         }
  31         Buffer->Start += Length;
  32         Buffer->Length -= Length;
  33         return Length;
  34 }
  35
  36 size_t RingBuffer_Write(tRingBuffer *Buffer, void *Source, size_t Length)
  37 {
  38         size_t  bufEnd = Buffer->Start + Buffer->Length;
  39         size_t  endSpace = Buffer->Space - bufEnd;
  40
  41         // Force to bounds
  42         if(Length > Buffer->Space - Buffer->Length)
  43                 Length = Buffer->Space - Buffer->Length;
  44
  45         if(endSpace < Length)
  46         {
  47                 memcpy( &Buffer->Data[bufEnd], Source, endSpace );
  48                 memcpy( Buffer->Data, (Uint8*)Source + endSpace, Length - endSpace );
  49                 Buffer->Length = Length - endSpace;
  50         }
  51         else
  52         {
  53                 memcpy( &Buffer->Data[bufEnd], Source, Length );
  54                 Buffer->Length += Length;
  55         }
  56
  57         return Length;
  58 }