zeda_ring.h

Go to the documentation of this file.

/* ZEDA - Elementary Data and Algorithms
 * Copyright (C) 1998 Tomomichi Sugihara (Zhidao)
 */
#ifndef __ZEDA_RING_H__
#define __ZEDA_RING_H__

#include <zeda/zeda_misc.h>

__BEGIN_DECLS

/* ********************************************************** *//* ************************************************** */

#ifdef __cplusplus
#define zRingClass(ring_t,cell_t) \
struct ring_t{\
  int size;\
  int head;\
  cell_t *buf;\
  ring_t(){ size=head=0; buf=NULL; };\
  ~ring_t(){ if( buf ) delete [] buf; };\
}
#else
#define zRingClass(ring_t,cell_t) \
typedef struct{\
  int size;\
  int head;\
  cell_t *buf;\
} ring_t
#endif /* __cplusplus */

#define zRingSize(y)     (y)->size
#define zRingBuf(y)      ( (y)->buf )

/* NOTE: do not use the following macro before allocating buffer */
#define zRingElemSize(y) sizeof(*zRingBuf(y))

#define zRingHead(y)     ( &zRingBuf(y)[(y)->head] )
#define zRingElem(y,i)   ( &zRingBuf(y)[((y)->head+(i)) % (y)->size] )
#define zRingSetElem(a,i,d) \
  memcpy( zRingElem(a,i), (d), zRingElemSize(a) )

#define zRingReset(y) ( (y)->head = 0 );
#define zRingInit(y) do{\
  zRingSize(y) = (y)->head = 0;\
  zRingBuf(y) = NULL;\
} while(0)

#define zRingAlloc(y,type,size) do{\
  zRingInit( y );\
  if( !( zRingBuf(y) = zAlloc(type,size) ) )\
    ZALLOCERROR();\
  else\
    zRingSize(y) = (size);\
} while(0)

#define zRingFree(y) do{\
  zFree( zRingBuf(y) );\
  zRingInit( y );\
} while(0)

#define zRingIncHead(y) do{\
  if( ++(y)->head >= zRingSize(y) ) (y)->head = 0;\
} while(0)
#define zRingDecHead(y) do{\
  if( --(y)->head < 0 ) (y)->head = zRingSize(y) - 1;\
} while(0)

__END_DECLS

#endif /* __ZEDA_RING_H__ */