Annotation of src/usr.bin/rcs/buf.c, Revision 1.14
1.14 ! ray 1: /* $OpenBSD: buf.c,v 1.13 2007/05/29 00:19:10 ray Exp $ */
1.1 joris 2: /*
3: * Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
4: * All rights reserved.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: *
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. The name of the author may not be used to endorse or promote products
13: * derived from this software without specific prior written permission.
14: *
15: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16: * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17: * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18: * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21: * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22: * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23: * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24: * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
1.12 xsa 27: #include <sys/queue.h>
28: #include <sys/stat.h>
29:
30: #include <err.h>
31: #include <errno.h>
32: #include <fcntl.h>
33: #include <stdarg.h>
34: #include <stdio.h>
35: #include <string.h>
36: #include <unistd.h>
1.1 joris 37:
38: #include "buf.h"
39: #include "xmalloc.h"
40: #include "worklist.h"
41:
42: #define BUF_INCR 128
43:
44: struct rcs_buf {
45: u_int cb_flags;
46:
1.10 ray 47: /* buffer handle, buffer size, and data length */
1.1 joris 48: u_char *cb_buf;
49: size_t cb_size;
50: size_t cb_len;
51: };
52:
1.10 ray 53: #define SIZE_LEFT(b) (b->cb_size - b->cb_len)
1.1 joris 54:
55: static void rcs_buf_grow(BUF *, size_t);
56:
57: /*
58: * rcs_buf_alloc()
59: *
60: * Create a new buffer structure and return a pointer to it. This structure
61: * uses dynamically-allocated memory and must be freed with rcs_buf_free(),
62: * once the buffer is no longer needed.
63: */
64: BUF *
65: rcs_buf_alloc(size_t len, u_int flags)
66: {
67: BUF *b;
68:
69: b = xmalloc(sizeof(*b));
70: /* Postpone creation of zero-sized buffers */
71: if (len > 0)
72: b->cb_buf = xcalloc(1, len);
73: else
74: b->cb_buf = NULL;
75:
76: b->cb_flags = flags;
77: b->cb_size = len;
78: b->cb_len = 0;
79:
80: return (b);
81: }
82:
83: /*
84: * rcs_buf_load()
85: *
86: * Open the file specified by <path> and load all of its contents into a
87: * buffer.
1.8 ray 88: * Returns the loaded buffer on success or NULL on failure.
89: * Sets errno on error.
1.1 joris 90: */
91: BUF *
92: rcs_buf_load(const char *path, u_int flags)
93: {
94: int fd;
95: ssize_t ret;
96: size_t len;
97: u_char *bp;
98: struct stat st;
99: BUF *buf;
100:
1.8 ray 101: buf = NULL;
102:
103: if ((fd = open(path, O_RDONLY, 0600)) == -1)
104: goto out;
1.1 joris 105:
106: if (fstat(fd, &st) == -1)
1.8 ray 107: goto out;
1.1 joris 108:
1.8 ray 109: if (st.st_size > SIZE_MAX) {
110: errno = EFBIG;
111: goto out;
112: }
113: buf = rcs_buf_alloc(st.st_size, flags);
1.10 ray 114: for (bp = buf->cb_buf; ; bp += (size_t)ret) {
1.1 joris 115: len = SIZE_LEFT(buf);
116: ret = read(fd, bp, len);
117: if (ret == -1) {
1.8 ray 118: int saved_errno;
119:
120: saved_errno = errno;
1.1 joris 121: rcs_buf_free(buf);
1.8 ray 122: buf = NULL;
123: errno = saved_errno;
124: goto out;
1.1 joris 125: } else if (ret == 0)
126: break;
127:
128: buf->cb_len += (size_t)ret;
129: }
130:
1.8 ray 131: out:
132: if (fd != -1) {
133: int saved_errno;
134:
135: /* We may want to preserve errno here. */
136: saved_errno = errno;
137: (void)close(fd);
138: errno = saved_errno;
139: }
1.1 joris 140:
141: return (buf);
142: }
143:
144: /*
145: * rcs_buf_free()
146: *
147: * Free the buffer <b> and all associated data.
148: */
149: void
150: rcs_buf_free(BUF *b)
151: {
152: if (b->cb_buf != NULL)
153: xfree(b->cb_buf);
154: xfree(b);
155: }
156:
157: /*
158: * rcs_buf_release()
159: *
160: * Free the buffer <b>'s structural information but do not free the contents
161: * of the buffer. Instead, they are returned and should be freed later using
162: * free().
163: */
164: void *
165: rcs_buf_release(BUF *b)
166: {
1.4 niallo 167: void *tmp;
1.1 joris 168:
169: tmp = b->cb_buf;
170: xfree(b);
171: return (tmp);
1.5 niallo 172: }
173:
174: /*
175: * rcs_buf_get()
176: */
1.11 xsa 177: u_char *
1.5 niallo 178: rcs_buf_get(BUF *b)
179: {
180: return (b->cb_buf);
1.1 joris 181: }
182:
183: /*
184: * rcs_buf_empty()
185: *
186: * Empty the contents of the buffer <b> and reset pointers.
187: */
188: void
189: rcs_buf_empty(BUF *b)
190: {
191: memset(b->cb_buf, 0, b->cb_size);
192: b->cb_len = 0;
193: }
194:
195: /*
196: * rcs_buf_putc()
197: *
198: * Append a single character <c> to the end of the buffer <b>.
199: */
200: void
201: rcs_buf_putc(BUF *b, int c)
202: {
203: u_char *bp;
204:
1.10 ray 205: bp = b->cb_buf + b->cb_len;
1.1 joris 206: if (bp == (b->cb_buf + b->cb_size)) {
207: /* extend */
208: if (b->cb_flags & BUF_AUTOEXT)
209: rcs_buf_grow(b, (size_t)BUF_INCR);
210: else
211: errx(1, "rcs_buf_putc failed");
212:
213: /* the buffer might have been moved */
1.10 ray 214: bp = b->cb_buf + b->cb_len;
1.1 joris 215: }
216: *bp = (u_char)c;
217: b->cb_len++;
218: }
219:
220: /*
221: * rcs_buf_getc()
222: *
223: * Return u_char at buffer position <pos>.
224: *
225: */
226: u_char
227: rcs_buf_getc(BUF *b, size_t pos)
228: {
1.10 ray 229: return (b->cb_buf[pos]);
1.1 joris 230: }
231:
232: /*
233: * rcs_buf_append()
234: *
235: * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
236: * buffer is too small to accept all data, it will attempt to append as much
237: * data as possible, or if the BUF_AUTOEXT flag is set for the buffer, it
238: * will get resized to an appropriate size to accept all data.
239: * Returns the number of bytes successfully appended to the buffer.
240: */
1.7 ray 241: size_t
1.1 joris 242: rcs_buf_append(BUF *b, const void *data, size_t len)
243: {
244: size_t left, rlen;
245: u_char *bp, *bep;
246:
1.10 ray 247: bp = b->cb_buf + b->cb_len;
1.1 joris 248: bep = b->cb_buf + b->cb_size;
249: left = bep - bp;
250: rlen = len;
251:
252: if (left < len) {
253: if (b->cb_flags & BUF_AUTOEXT) {
254: rcs_buf_grow(b, len - left);
1.10 ray 255: bp = b->cb_buf + b->cb_len;
1.1 joris 256: } else
257: rlen = bep - bp;
258: }
259:
260: memcpy(bp, data, rlen);
261: b->cb_len += rlen;
262:
263: return (rlen);
264: }
265:
266: /*
267: * rcs_buf_fappend()
268: *
269: */
1.7 ray 270: size_t
1.1 joris 271: rcs_buf_fappend(BUF *b, const char *fmt, ...)
272: {
1.7 ray 273: size_t ret;
274: int n;
1.1 joris 275: char *str;
276: va_list vap;
277:
278: va_start(vap, fmt);
1.7 ray 279: n = vasprintf(&str, fmt, vap);
1.1 joris 280: va_end(vap);
281:
1.7 ray 282: if (n == -1)
1.1 joris 283: errx(1, "rcs_buf_fappend: failed to format data");
284:
1.7 ray 285: ret = rcs_buf_append(b, str, n);
1.1 joris 286: xfree(str);
287: return (ret);
288: }
289:
290: /*
291: * rcs_buf_len()
292: *
293: * Returns the size of the buffer that is being used.
294: */
295: size_t
296: rcs_buf_len(BUF *b)
297: {
298: return (b->cb_len);
299: }
300:
301: /*
302: * rcs_buf_write_fd()
303: *
304: * Write the contents of the buffer <b> to the specified <fd>
305: */
306: int
307: rcs_buf_write_fd(BUF *b, int fd)
308: {
309: u_char *bp;
310: size_t len;
311: ssize_t ret;
312:
313: len = b->cb_len;
1.10 ray 314: bp = b->cb_buf;
1.1 joris 315:
316: do {
317: ret = write(fd, bp, len);
318: if (ret == -1) {
319: if (errno == EINTR || errno == EAGAIN)
320: continue;
321: return (-1);
322: }
323:
324: len -= (size_t)ret;
325: bp += (size_t)ret;
326: } while (len > 0);
327:
328: return (0);
329: }
330:
331: /*
332: * rcs_buf_write()
333: *
334: * Write the contents of the buffer <b> to the file whose path is given in
335: * <path>. If the file does not exist, it is created with mode <mode>.
336: */
337: int
338: rcs_buf_write(BUF *b, const char *path, mode_t mode)
339: {
340: int fd;
341: open:
342: if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
343: if (errno == EACCES && unlink(path) != -1)
344: goto open;
345: else
1.3 xsa 346: err(1, "%s", path);
1.1 joris 347: }
348:
349: if (rcs_buf_write_fd(b, fd) == -1) {
350: (void)unlink(path);
351: errx(1, "rcs_buf_write: rcs_buf_write_fd: `%s'", path);
352: }
353:
354: if (fchmod(fd, mode) < 0)
355: warn("permissions not set on file %s", path);
356:
357: (void)close(fd);
358:
359: return (0);
360: }
361:
362: /*
363: * rcs_buf_write_stmp()
364: *
365: * Write the contents of the buffer <b> to a temporary file whose path is
366: * specified using <template> (see mkstemp.3). NB. This function will modify
367: * <template>, as per mkstemp
368: */
369: void
1.6 ray 370: rcs_buf_write_stmp(BUF *b, char *template)
1.1 joris 371: {
372: int fd;
373:
374: if ((fd = mkstemp(template)) == -1)
1.3 xsa 375: err(1, "%s", template);
1.1 joris 376:
1.14 ! ray 377: worklist_add(template, &temp_files);
1.1 joris 378:
379: if (rcs_buf_write_fd(b, fd) == -1) {
380: (void)unlink(template);
381: errx(1, "rcs_buf_write_stmp: rcs_buf_write_fd: `%s'", template);
382: }
383:
384: (void)close(fd);
385: }
386:
387: /*
388: * rcs_buf_grow()
389: *
390: * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
391: * operation regardless of the result.
392: */
393: static void
394: rcs_buf_grow(BUF *b, size_t len)
395: {
1.13 ray 396: b->cb_buf = xrealloc(b->cb_buf, 1, b->cb_size + len);
1.1 joris 397: b->cb_size += len;
398: }
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