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1/* $OpenBSD: buf.c,v 1.31 2024/06/18 02:11:03 millert Exp $ */
2/* $NetBSD: buf.c,v 1.9 1996/12/31 17:53:21 christos Exp $ */
3
4/*
5 * Copyright (c) 1999 Marc Espie.
6 *
7 * Extensive code changes for the OpenBSD project.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBSD
22 * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30/*
31 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
32 * Copyright (c) 1988, 1989 by Adam de Boor
33 * Copyright (c) 1989 by Berkeley Softworks
34 * All rights reserved.
35 *
36 * This code is derived from software contributed to Berkeley by
37 * Adam de Boor.
38 *
39 * Redistribution and use in source and binary forms, with or without
40 * modification, are permitted provided that the following conditions
41 * are met:
42 * 1. Redistributions of source code must retain the above copyright
43 * notice, this list of conditions and the following disclaimer.
44 * 2. Redistributions in binary form must reproduce the above copyright
45 * notice, this list of conditions and the following disclaimer in the
46 * documentation and/or other materials provided with the distribution.
47 * 3. Neither the name of the University nor the names of its contributors
48 * may be used to endorse or promote products derived from this software
49 * without specific prior written permission.
50 *
51 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61 * SUCH DAMAGE.
62 */
63
64/*-
65 * buf.c --
66 * Functions for automatically expanded buffers.
67 */
68
69#include <assert.h>
70#include <ctype.h>
71#include <limits.h>
72#include <stddef.h>
73#include <stdint.h>
74#include <stdlib.h>
75#include <string.h>
76#include <stdio.h>
77#include <stdarg.h>
78#include "defines.h"
79#include "buf.h"
80#include "stats.h"
81#include "memory.h"
82
83#ifdef STATS_BUF
84#define DO_STAT_BUF(bp, nb) \
85 STAT_BUFS_EXPANSION++; \
86 if ((bp)->endPtr - (bp)->buffer == 1) \
87 STAT_WEIRD_INEFFICIENT++;
88#else
89#define DO_STAT_BUF(a, b)
90#endif
91
92static void
93fatal_overflow(void)
94{
95 fprintf(stderr, "buffer size overflow\n");
96 exit(2);
97}
98
99#define BUF_DEF_SIZE 256U /* Default buffer size */
100#define BUF_MARGIN 256U /* Make sure we are comfortable */
101
102/* BufExpand(bp, nb)
103 * Expand buffer bp to hold up to nb additional
104 * chars. Makes sure there's always room for an extra '\0' char
105 * at the end of the buffer for Buf_Retrieve. */
106void
107BufExpand(Buffer bp, size_t nb)
108{
109 size_t occupied = bp->inPtr - bp->buffer;
110 size_t size = bp->endPtr - bp->buffer;
111 DO_STAT_BUF(bp, nb);
112
113 do {
114 if (size <= SIZE_MAX/2) {
115 size *= 2 ;
116 } else {
117 fatal_overflow();
118 }
119 assert(size >= occupied);
120 } while (size - occupied < nb+1+BUF_MARGIN);
121 bp->buffer = erealloc(bp->buffer, size);
122 bp->inPtr = bp->buffer +occupied;
123 bp->endPtr = bp->buffer + size;
124}
125
126void
127Buf_AddChars(Buffer bp, size_t numBytes, const char *bytesPtr)
128{
129 assert(bp->endPtr >= bp->inPtr);
130 if ((size_t)(bp->endPtr - bp->inPtr) < numBytes+1)
131 BufExpand(bp, numBytes);
132
133 memcpy(bp->inPtr, bytesPtr, numBytes);
134 bp->inPtr += numBytes;
135}
136
137void
138Buf_printf(Buffer bp, const char *fmt, ...)
139{
140 va_list va;
141 int n;
142 va_start(va, fmt);
143 n = vsnprintf(bp->inPtr, bp->endPtr - bp->inPtr, fmt, va);
144 va_end(va);
145 if (n+1 > bp->endPtr - bp->inPtr) {
146 va_list vb;
147 BufExpand(bp, n);
148 va_start(vb, fmt);
149 (void)vsnprintf(bp->inPtr, bp->endPtr - bp->inPtr, fmt, vb);
150 va_end(vb);
151 }
152 bp->inPtr += n;
153}
154
155void
156Buf_Reinit(Buffer bp, size_t size)
157{
158 if (bp->buffer == NULL)
159 Buf_Init(bp, size);
160 else
161 Buf_Reset(bp);
162}
163
164void
165Buf_Init(Buffer bp, size_t size)
166{
167#ifdef STATS_BUF
168 STAT_TOTAL_BUFS++;
169 if (size == 0)
170 STAT_DEFAULT_BUFS++;
171 if (size == 1)
172 STAT_WEIRD_BUFS++;
173#endif
174 if (size == 0)
175 size = BUF_DEF_SIZE;
176 bp->inPtr = bp->endPtr = bp->buffer = emalloc(size);
177 bp->endPtr += size;
178}