workbench/fs/pipe/pipebuf.h

   1 /****************************************************************************
   2 **  File:       pipebuf.h
   3 **  Program:    pipe-handler - an AmigaDOS handler for named pipes
   4 **  Version:    1.1
   5 **  Author:     Ed Puckett      qix@mit-oz
   6 **
   7 **  Copyright 1987 by EpAc Software.  All Rights Reserved.
   8 **
   9 **  History:    05-Jan-87       Original Version (1.0)
  10 */
  11
  12
  13
  14 #define   MAX_PIPELEN   (1L << 24)
  15
  16
  17
  18 typedef struct pipebuf
  19   { ULONG  head,       /* index of first character */
  20            tail;       /* index of last character */
  21     BYTE   full;       /* flag - takes care of full/empty ambiguity */
  22     ULONG  len;        /* length of buffer */
  23     BYTE   buf[1];     /* buffer proceeds from here */
  24   }
  25 PIPEBUF;
  26
  27
  28
  29 #define   PipebufEmpty(pb)   (((pb)->head == (pb)->tail) && (! (pb)->full))
  30 #define   PipebufFull(pb)    (((pb)->head == (pb)->tail) && ((pb)->full))
  31 #define   FreePipebuf(pb)    (FreeMem ((pb), sizeof (PIPEBUF) - 1 + (pb)->len))
  32
  33
  34
  35 extern PIPEBUF  *AllocPipebuf   ( /* len */ );
  36 extern ULONG    MoveFromPipebuf ( /* pb, dest, amt */ );
  37 extern ULONG    MoveToPipebuf   ( /* pb, src, amt */ );