usr/src/usr.bin/make/buf.h

/*
 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
 * Copyright (c) 1988, 1989 by Adam de Boor
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)buf.h       5.4 (Berkeley) %G%
 */

/*-
 * buf.h --
 *      Header for users of the buf library.
 */

#ifndef _BUF_H
#define _BUF_H

#include    "sprite.h"

typedef unsigned char Byte;

typedef struct Buffer {
    int     size;       /* Current size of the buffer */
    int     left;       /* Space left (== size - (inPtr - buffer)) */
    Byte    *buffer;    /* The buffer itself */
    Byte    *inPtr;     /* Place to write to */
    Byte    *outPtr;    /* Place to read from */
} *Buffer;

Buffer            Buf_Init();       /* Initialize a buffer */
void              Buf_Destroy();    /* Destroy a buffer */
void              Buf_AddBytes();   /* Add a range of bytes to a buffer */
int               Buf_GetByte();    /* Get a byte from a buffer */
int               Buf_GetBytes();   /* Get multiple bytes */
void              Buf_UngetByte();  /* Push a byte back into the buffer */
void              Buf_UngetBytes(); /* Push many bytes back into the buf */
Byte              *Buf_GetAll();    /* Get them all */
void              Buf_Discard();    /* Throw away some of the bytes */
int               Buf_Size();       /* See how many are there */

/* Buf_AddByte adds a single byte to a buffer. */
#define Buf_AddByte(bp, byte) \
        (--(bp)->left <= 0 ? Buf_OvAddByte(bp, byte) : \
                (void)(*(bp)->inPtr++ = (byte), *(bp)->inPtr = 0))

void    Buf_OvAddByte();                /* adds a byte when buffer overflows */

#define BUF_ERROR 256

#endif _BUF_H