1 /* $NetBSD: buffer.h,v 1.5 2017/10/13 00:11:56 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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <stddef.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <wchar.h>
36 #include <err.h>
37
38 #define BUF_SIZE BUFSIZ
39 struct buffer {
40 wchar_t *ptr;
41 wchar_t *bptr;
42 wchar_t *eptr;
43 };
44
45 static void
buf_init(struct buffer * buf)46 buf_init(struct buffer *buf)
47 {
48 buf->ptr = buf->bptr = calloc(BUF_SIZE, sizeof(*buf->ptr));
49 if (buf->ptr == NULL)
50 err(1, "Cannot allocate buffer");
51 buf->eptr = buf->ptr + BUF_SIZE;
52 }
53
54 static void
buf_end(struct buffer * buf)55 buf_end(struct buffer *buf)
56 {
57 free(buf->bptr);
58 }
59
60 static void
buf_grow(struct buffer * buf,size_t minsize)61 buf_grow(struct buffer *buf, size_t minsize)
62 {
63 ptrdiff_t diff;
64 size_t len = (buf->eptr - buf->bptr) +
65 (minsize > BUF_SIZE ? minsize : BUF_SIZE);
66 wchar_t *nptr = realloc(buf->bptr, len * sizeof(*buf->ptr));
67
68 if (nptr == NULL)
69 err(1, "Cannot grow buffer");
70
71 if (nptr == buf->bptr) {
72 buf->eptr = buf->bptr + len;
73 return;
74 }
75
76 diff = nptr - buf->bptr;
77 buf->bptr += diff;
78 buf->eptr = buf->bptr + len;
79 buf->ptr += diff;
80 }
81
82 static inline void
buf_putc(struct buffer * buf,wchar_t c)83 buf_putc(struct buffer *buf, wchar_t c)
84 {
85 if (buf->ptr >= buf->eptr)
86 buf_grow(buf, 1);
87 *buf->ptr++ = c;
88 }
89
90 static inline void
buf_reset(struct buffer * buf)91 buf_reset(struct buffer *buf)
92 {
93 buf->ptr = buf->bptr;
94 }
95
96 static inline wchar_t
buf_unputc(struct buffer * buf)97 buf_unputc(struct buffer *buf)
98 {
99 return buf->ptr > buf->bptr ? *--buf->ptr : '\0';
100 }
101