1 /* $NetBSD: buffer.h,v 1.3 2006/01/04 22:05:26 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2005 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <stddef.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <err.h> 43 44 #define BUF_SIZE BUFSIZ 45 struct buffer { 46 char *ptr; 47 char *bptr; 48 char *eptr; 49 }; 50 51 static void 52 buf_init(struct buffer *buf) 53 { 54 buf->ptr = buf->bptr = malloc(BUF_SIZE); 55 if (buf->ptr == NULL) 56 err(1, "Cannot allocate buffer"); 57 buf->eptr = buf->ptr + BUF_SIZE; 58 } 59 60 static void 61 buf_end(struct buffer *buf) 62 { 63 free(buf->bptr); 64 } 65 66 static void 67 buf_grow(struct buffer *buf, size_t minsize) 68 { 69 ptrdiff_t diff; 70 size_t len = (buf->eptr - buf->bptr) + 71 (minsize > BUF_SIZE ? minsize : BUF_SIZE); 72 char *nptr = realloc(buf->bptr, len); 73 74 if (nptr == NULL) 75 err(1, "Cannot grow buffer"); 76 77 if (nptr == buf->bptr) { 78 buf->eptr = buf->bptr + len; 79 return; 80 } 81 82 diff = nptr - buf->bptr; 83 buf->bptr += diff; 84 buf->eptr = buf->bptr + len; 85 buf->ptr += diff; 86 } 87 88 static inline void 89 buf_putc(struct buffer *buf, char c) 90 { 91 if (buf->ptr >= buf->eptr) 92 buf_grow(buf, 1); 93 *buf->ptr++ = c; 94 } 95 96 static inline void 97 buf_reset(struct buffer *buf) 98 { 99 buf->ptr = buf->bptr; 100 } 101 102 static inline char 103 buf_unputc(struct buffer *buf) 104 { 105 return buf->ptr > buf->bptr ? *--buf->ptr : '\0'; 106 } 107