buf.c revision 1.33 1 /* $NetBSD: buf.c,v 1.33 2020/08/09 18:52:03 rillig Exp $ */
2
3 /*
4 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Adam de Boor.
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. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 /*
36 * Copyright (c) 1988, 1989 by Adam de Boor
37 * Copyright (c) 1989 by Berkeley Softworks
38 * All rights reserved.
39 *
40 * This code is derived from software contributed to Berkeley by
41 * Adam de Boor.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 * 3. All advertising materials mentioning features or use of this software
52 * must display the following acknowledgement:
53 * This product includes software developed by the University of
54 * California, Berkeley and its contributors.
55 * 4. Neither the name of the University nor the names of its contributors
56 * may be used to endorse or promote products derived from this software
57 * without specific prior written permission.
58 *
59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69 * SUCH DAMAGE.
70 */
71
72 #ifndef MAKE_NATIVE
73 static char rcsid[] = "$NetBSD: buf.c,v 1.33 2020/08/09 18:52:03 rillig Exp $";
74 #else
75 #include <sys/cdefs.h>
76 #ifndef lint
77 #if 0
78 static char sccsid[] = "@(#)buf.c 8.1 (Berkeley) 6/6/93";
79 #else
80 __RCSID("$NetBSD: buf.c,v 1.33 2020/08/09 18:52:03 rillig Exp $");
81 #endif
82 #endif /* not lint */
83 #endif
84
85 /* Functions for automatically-expanded NUL-terminated buffers. */
86
87 #include <limits.h>
88 #include "make.h"
89 #include "buf.h"
90
91 #ifndef max
92 #define max(a, b) ((a) > (b) ? (a) : (b))
93 #endif
94
95 #define BUF_DEF_SIZE 256 /* Default buffer size */
96
97 /* Extend the buffer for adding a single byte. */
98 void
99 Buf_Expand_1(Buffer *bp)
100 {
101 bp->size += max(bp->size, 16);
102 bp->buffer = bmake_realloc(bp->buffer, bp->size);
103 }
104
105 /* Add the given bytes to the buffer. */
106 void
107 Buf_AddBytes(Buffer *bp, const Byte *bytesPtr, size_t numBytes)
108 {
109 size_t count = bp->count;
110 Byte *ptr;
111
112 if (__predict_false(count + numBytes >= bp->size)) {
113 bp->size += max(bp->size, numBytes + 16);
114 bp->buffer = bmake_realloc(bp->buffer, bp->size);
115 }
116
117 ptr = bp->buffer + count;
118 bp->count = count + numBytes;
119 memcpy(ptr, bytesPtr, numBytes);
120 ptr[numBytes] = '\0';
121 }
122
123 /* Add the bytes between start and end to the buffer. */
124 void
125 Buf_AddBytesBetween(Buffer *bp, const char *start, const char *end)
126 {
127 Buf_AddBytes(bp, start, (size_t)(end - start));
128 }
129
130 /* Add the given string to the buffer. */
131 void
132 Buf_AddStr(Buffer *bp, const char *str)
133 {
134 Buf_AddBytes(bp, str, strlen(str));
135 }
136
137 /* Add the given number to the buffer. */
138 void
139 Buf_AddInt(Buffer *bp, int n)
140 {
141 /*
142 * We need enough space for the decimal representation of an int.
143 * We calculate the space needed for the octal representation, and
144 * add enough slop to cope with a '-' sign and a trailing '\0'.
145 */
146 enum {
147 bits = sizeof(int) * CHAR_BIT,
148 buf_size = 1 + (bits + 2) / 3 + 1
149 };
150 char buf[buf_size];
151
152 size_t len = (size_t)snprintf(buf, sizeof buf, "%d", n);
153 Buf_AddBytes(bp, buf, len);
154 }
155
156 /* Get the data (usually a string) from the buffer.
157 * The returned data is valid until the next modifying operation
158 * on the buffer.
159 *
160 * Returns the pointer to the data and optionally the length of the
161 * data in the buffer. */
162 Byte *
163 Buf_GetAll(Buffer *bp, size_t *numBytesPtr)
164 {
165 if (numBytesPtr != NULL)
166 *numBytesPtr = bp->count;
167 return bp->buffer;
168 }
169
170 /* Mark the buffer as empty, so it can be filled with data again. */
171 void
172 Buf_Empty(Buffer *bp)
173 {
174 bp->count = 0;
175 bp->buffer[0] = '\0';
176 }
177
178 /* Initialize a buffer.
179 * If the given initial size is 0, a reasonable default is used. */
180 void
181 Buf_Init(Buffer *bp, size_t size)
182 {
183 if (size <= 0) {
184 size = BUF_DEF_SIZE;
185 }
186 bp->size = size;
187 bp->count = 0;
188 bp->buffer = bmake_malloc(size);
189 *bp->buffer = 0;
190 }
191
192 /* Reset the buffer.
193 * If freeData is TRUE, the data from the buffer is freed as well.
194 * Otherwise it is kept and returned. */
195 Byte *
196 Buf_Destroy(Buffer *buf, Boolean freeData)
197 {
198 Byte *data = buf->buffer;
199 if (freeData) {
200 free(data);
201 data = NULL;
202 }
203
204 buf->size = 0;
205 buf->count = 0;
206 buf->buffer = NULL;
207
208 return data;
209 }
210
211 #ifndef BUF_COMPACT_LIMIT
212 # define BUF_COMPACT_LIMIT 128 /* worthwhile saving */
213 #endif
214
215 /* Reset the buffer and return its data.
216 *
217 * If the buffer size is much greater than its content,
218 * a new buffer will be allocated and the old one freed. */
219 Byte *
220 Buf_DestroyCompact(Buffer *buf)
221 {
222 #if BUF_COMPACT_LIMIT > 0
223 if (buf->size - buf->count >= BUF_COMPACT_LIMIT) {
224 /* We trust realloc to be smart */
225 Byte *data = bmake_realloc(buf->buffer, buf->count + 1);
226 data[buf->count] = 0;
227 Buf_Destroy(buf, FALSE);
228 return data;
229 }
230 #endif
231 return Buf_Destroy(buf, FALSE);
232 }
233