v/thirdparty/libgc/include/gc/ec.h

90 lines
2.7 KiB
C

/*
* Copyright (c) 1993-1994 by Xerox Corporation. All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*/
#ifndef EC_H
#define EC_H
# ifndef CORD_H
# include "cord.h"
# endif
#ifdef __cplusplus
extern "C" {
#endif
/* Extensible cords are strings that may be destructively appended to. */
/* They allow fast construction of cords from characters that are */
/* being read from a stream. */
/*
* A client might look like:
*
* {
* CORD_ec x;
* CORD result;
* char c;
* FILE *f;
*
* ...
* CORD_ec_init(x);
* while(...) {
* c = getc(f);
* ...
* CORD_ec_append(x, c);
* }
* result = CORD_balance(CORD_ec_to_cord(x));
*
* If a C string is desired as the final result, the call to CORD_balance
* may be replaced by a call to CORD_to_char_star.
*/
# ifndef CORD_BUFSZ
# define CORD_BUFSZ 128
# endif
typedef struct CORD_ec_struct {
CORD ec_cord;
char * ec_bufptr;
char ec_buf[CORD_BUFSZ+1];
} CORD_ec[1];
/* This structure represents the concatenation of ec_cord with */
/* ec_buf[0 ... (ec_bufptr-ec_buf-1)] */
/* Flush the buffer part of the extended cord into ec_cord. */
/* Note that this is almost the only real function, and it is */
/* implemented in 6 lines in cordxtra.c */
void CORD_ec_flush_buf(CORD_ec x);
/* Convert an extensible cord to a cord. */
# define CORD_ec_to_cord(x) (CORD_ec_flush_buf(x), (x)[0].ec_cord)
/* Initialize an extensible cord. */
#define CORD_ec_init(x) \
((x)[0].ec_cord = 0, (void)((x)[0].ec_bufptr = (x)[0].ec_buf))
/* Append a character to an extensible cord. */
#define CORD_ec_append(x, c) \
((void)((x)[0].ec_bufptr == (x)[0].ec_buf + CORD_BUFSZ \
? (CORD_ec_flush_buf(x), 0) : 0), \
(void)(*(x)[0].ec_bufptr++ = (c)))
/* Append a cord to an extensible cord. Structure remains shared with */
/* original. */
void CORD_ec_append_cord(CORD_ec x, CORD s);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* EC_H */