xref: /freebsd/contrib/bmake/buf.c (revision 3f0164abf32b9b761e0a2cb4bdca3a8b84f156d4)
1 /*	$NetBSD: buf.c,v 1.25 2012/04/24 20:26:58 sjg 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 1.25 2012/04/24 20:26:58 sjg 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 1.25 2012/04/24 20:26:58 sjg Exp $");
81 #endif
82 #endif /* not lint */
83 #endif
84 
85 /*-
86  * buf.c --
87  *	Functions for automatically-expanded buffers.
88  */
89 
90 #include    "make.h"
91 #include    "buf.h"
92 
93 #ifndef max
94 #define max(a,b)  ((a) > (b) ? (a) : (b))
95 #endif
96 
97 #define BUF_DEF_SIZE	256 	/* Default buffer size */
98 
99 /*-
100  *-----------------------------------------------------------------------
101  * Buf_Expand_1 --
102  *	Extend buffer for single byte add.
103  *
104  *-----------------------------------------------------------------------
105  */
106 void
107 Buf_Expand_1(Buffer *bp)
108 {
109     bp->size += max(bp->size, 16);
110     bp->buffer = bmake_realloc(bp->buffer, bp->size);
111 }
112 
113 /*-
114  *-----------------------------------------------------------------------
115  * Buf_AddBytes --
116  *	Add a number of bytes to the buffer.
117  *
118  * Results:
119  *	None.
120  *
121  * Side Effects:
122  *	Guess what?
123  *
124  *-----------------------------------------------------------------------
125  */
126 void
127 Buf_AddBytes(Buffer *bp, int numBytes, const Byte *bytesPtr)
128 {
129     int count = bp->count;
130     Byte *ptr;
131 
132     if (__predict_false(count + numBytes >= bp->size)) {
133 	bp->size += max(bp->size, numBytes + 16);
134 	bp->buffer = bmake_realloc(bp->buffer, bp->size);
135     }
136 
137     ptr = bp->buffer + count;
138     bp->count = count + numBytes;
139     ptr[numBytes] = 0;
140     memcpy(ptr, bytesPtr, numBytes);
141 }
142 
143 /*-
144  *-----------------------------------------------------------------------
145  * Buf_GetAll --
146  *	Get all the available data at once.
147  *
148  * Results:
149  *	A pointer to the data and the number of bytes available.
150  *
151  * Side Effects:
152  *	None.
153  *
154  *-----------------------------------------------------------------------
155  */
156 Byte *
157 Buf_GetAll(Buffer *bp, int *numBytesPtr)
158 {
159 
160     if (numBytesPtr != NULL)
161 	*numBytesPtr = bp->count;
162 
163     return (bp->buffer);
164 }
165 
166 /*-
167  *-----------------------------------------------------------------------
168  * Buf_Empty --
169  *	Throw away bytes in a buffer.
170  *
171  * Results:
172  *	None.
173  *
174  * Side Effects:
175  *	The bytes are discarded.
176  *
177  *-----------------------------------------------------------------------
178  */
179 void
180 Buf_Empty(Buffer *bp)
181 {
182 
183     bp->count = 0;
184     *bp->buffer = 0;
185 }
186 
187 /*-
188  *-----------------------------------------------------------------------
189  * Buf_Init --
190  *	Initialize a buffer. If no initial size is given, a reasonable
191  *	default is used.
192  *
193  * Input:
194  *	size		Initial size for the buffer
195  *
196  * Results:
197  *	A buffer to be given to other functions in this library.
198  *
199  * Side Effects:
200  *	The buffer is created, the space allocated and pointers
201  *	initialized.
202  *
203  *-----------------------------------------------------------------------
204  */
205 void
206 Buf_Init(Buffer *bp, int size)
207 {
208     if (size <= 0) {
209 	size = BUF_DEF_SIZE;
210     }
211     bp->size = size;
212     bp->count = 0;
213     bp->buffer = bmake_malloc(size);
214     *bp->buffer = 0;
215 }
216 
217 /*-
218  *-----------------------------------------------------------------------
219  * Buf_Destroy --
220  *	Nuke a buffer and all its resources.
221  *
222  * Input:
223  *	buf		Buffer to destroy
224  *	freeData	TRUE if the data should be destroyed
225  *
226  * Results:
227  *	Data buffer, NULL if freed
228  *
229  * Side Effects:
230  *	The buffer is freed.
231  *
232  *-----------------------------------------------------------------------
233  */
234 Byte *
235 Buf_Destroy(Buffer *buf, Boolean freeData)
236 {
237     Byte *data;
238 
239     data = buf->buffer;
240     if (freeData) {
241 	free(data);
242 	data = NULL;
243     }
244 
245     buf->size = 0;
246     buf->count = 0;
247     buf->buffer = NULL;
248 
249     return data;
250 }
251 
252 
253 /*-
254  *-----------------------------------------------------------------------
255  * Buf_DestroyCompact --
256  *	Nuke a buffer and return its data.
257  *
258  * Input:
259  *	buf		Buffer to destroy
260  *
261  * Results:
262  *	Data buffer
263  *
264  * Side Effects:
265  *	If the buffer size is much greater than its content,
266  *	a new buffer will be allocated and the old one freed.
267  *
268  *-----------------------------------------------------------------------
269  */
270 #ifndef BUF_COMPACT_LIMIT
271 # define BUF_COMPACT_LIMIT 128          /* worthwhile saving */
272 #endif
273 
274 Byte *
275 Buf_DestroyCompact(Buffer *buf)
276 {
277 #if BUF_COMPACT_LIMIT > 0
278     Byte *data;
279 
280     if (buf->size - buf->count >= BUF_COMPACT_LIMIT) {
281 	/* We trust realloc to be smart */
282 	data = bmake_realloc(buf->buffer, buf->count + 1);
283 	if (data) {
284 	    data[buf->count] = 0;
285 	    Buf_Destroy(buf, FALSE);
286 	    return data;
287 	}
288     }
289 #endif
290     return Buf_Destroy(buf, FALSE);
291 }
292