Annotation of src/usr.bin/rcs/buf.c, Revision 1.15
1.15 ! ray 1: /* $OpenBSD: buf.c,v 1.14 2010/07/23 08:31:19 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:
1.15 ! ray 44: struct buf {
1.1 joris 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:
1.15 ! ray 55: static void buf_grow(BUF *, size_t);
1.1 joris 56:
57: /*
1.15 ! ray 58: * buf_alloc()
1.1 joris 59: *
60: * Create a new buffer structure and return a pointer to it. This structure
1.15 ! ray 61: * uses dynamically-allocated memory and must be freed with buf_free(),
1.1 joris 62: * once the buffer is no longer needed.
63: */
64: BUF *
1.15 ! ray 65: buf_alloc(size_t len, u_int flags)
1.1 joris 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: /*
1.15 ! ray 84: * buf_load()
1.1 joris 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 *
1.15 ! ray 92: buf_load(const char *path, u_int flags)
1.1 joris 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: }
1.15 ! ray 113: buf = 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;
1.15 ! ray 121: 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: void
1.15 ! ray 145: buf_free(BUF *b)
1.1 joris 146: {
147: if (b->cb_buf != NULL)
148: xfree(b->cb_buf);
149: xfree(b);
150: }
151:
152: /*
1.15 ! ray 153: * buf_release()
1.1 joris 154: *
155: * Free the buffer <b>'s structural information but do not free the contents
156: * of the buffer. Instead, they are returned and should be freed later using
157: * free().
158: */
159: void *
1.15 ! ray 160: buf_release(BUF *b)
1.1 joris 161: {
1.4 niallo 162: void *tmp;
1.1 joris 163:
164: tmp = b->cb_buf;
165: xfree(b);
166: return (tmp);
1.5 niallo 167: }
168:
169: /*
1.15 ! ray 170: * buf_get()
1.5 niallo 171: */
1.11 xsa 172: u_char *
1.15 ! ray 173: buf_get(BUF *b)
1.5 niallo 174: {
175: return (b->cb_buf);
1.1 joris 176: }
177:
178: /*
1.15 ! ray 179: * buf_empty()
1.1 joris 180: *
181: * Empty the contents of the buffer <b> and reset pointers.
182: */
183: void
1.15 ! ray 184: buf_empty(BUF *b)
1.1 joris 185: {
186: memset(b->cb_buf, 0, b->cb_size);
187: b->cb_len = 0;
188: }
189:
190: /*
1.15 ! ray 191: * buf_putc()
1.1 joris 192: *
193: * Append a single character <c> to the end of the buffer <b>.
194: */
195: void
1.15 ! ray 196: buf_putc(BUF *b, int c)
1.1 joris 197: {
198: u_char *bp;
199:
1.10 ray 200: bp = b->cb_buf + b->cb_len;
1.1 joris 201: if (bp == (b->cb_buf + b->cb_size)) {
202: /* extend */
203: if (b->cb_flags & BUF_AUTOEXT)
1.15 ! ray 204: buf_grow(b, (size_t)BUF_INCR);
1.1 joris 205: else
1.15 ! ray 206: errx(1, "buf_putc failed");
1.1 joris 207:
208: /* the buffer might have been moved */
1.10 ray 209: bp = b->cb_buf + b->cb_len;
1.1 joris 210: }
211: *bp = (u_char)c;
212: b->cb_len++;
213: }
214:
215: /*
1.15 ! ray 216: * buf_getc()
1.1 joris 217: *
218: * Return u_char at buffer position <pos>.
219: *
220: */
221: u_char
1.15 ! ray 222: buf_getc(BUF *b, size_t pos)
1.1 joris 223: {
1.10 ray 224: return (b->cb_buf[pos]);
1.1 joris 225: }
226:
227: /*
1.15 ! ray 228: * buf_append()
1.1 joris 229: *
230: * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
231: * buffer is too small to accept all data, it will attempt to append as much
232: * data as possible, or if the BUF_AUTOEXT flag is set for the buffer, it
233: * will get resized to an appropriate size to accept all data.
234: * Returns the number of bytes successfully appended to the buffer.
235: */
1.7 ray 236: size_t
1.15 ! ray 237: buf_append(BUF *b, const void *data, size_t len)
1.1 joris 238: {
239: size_t left, rlen;
240: u_char *bp, *bep;
241:
1.10 ray 242: bp = b->cb_buf + b->cb_len;
1.1 joris 243: bep = b->cb_buf + b->cb_size;
244: left = bep - bp;
245: rlen = len;
246:
247: if (left < len) {
248: if (b->cb_flags & BUF_AUTOEXT) {
1.15 ! ray 249: buf_grow(b, len - left);
1.10 ray 250: bp = b->cb_buf + b->cb_len;
1.1 joris 251: } else
252: rlen = bep - bp;
253: }
254:
255: memcpy(bp, data, rlen);
256: b->cb_len += rlen;
257:
258: return (rlen);
259: }
260:
261: /*
1.15 ! ray 262: * buf_fappend()
1.1 joris 263: *
264: */
1.7 ray 265: size_t
1.15 ! ray 266: buf_fappend(BUF *b, const char *fmt, ...)
1.1 joris 267: {
1.7 ray 268: size_t ret;
269: int n;
1.1 joris 270: char *str;
271: va_list vap;
272:
273: va_start(vap, fmt);
1.7 ray 274: n = vasprintf(&str, fmt, vap);
1.1 joris 275: va_end(vap);
276:
1.7 ray 277: if (n == -1)
1.15 ! ray 278: errx(1, "buf_fappend: failed to format data");
1.1 joris 279:
1.15 ! ray 280: ret = buf_append(b, str, n);
1.1 joris 281: xfree(str);
282: return (ret);
283: }
284:
285: /*
1.15 ! ray 286: * buf_len()
1.1 joris 287: *
288: * Returns the size of the buffer that is being used.
289: */
290: size_t
1.15 ! ray 291: buf_len(BUF *b)
1.1 joris 292: {
293: return (b->cb_len);
294: }
295:
296: /*
1.15 ! ray 297: * buf_write_fd()
1.1 joris 298: *
299: * Write the contents of the buffer <b> to the specified <fd>
300: */
301: int
1.15 ! ray 302: buf_write_fd(BUF *b, int fd)
1.1 joris 303: {
304: u_char *bp;
305: size_t len;
306: ssize_t ret;
307:
308: len = b->cb_len;
1.10 ray 309: bp = b->cb_buf;
1.1 joris 310:
311: do {
312: ret = write(fd, bp, len);
313: if (ret == -1) {
314: if (errno == EINTR || errno == EAGAIN)
315: continue;
316: return (-1);
317: }
318:
319: len -= (size_t)ret;
320: bp += (size_t)ret;
321: } while (len > 0);
322:
323: return (0);
324: }
325:
326: /*
1.15 ! ray 327: * buf_write()
1.1 joris 328: *
329: * Write the contents of the buffer <b> to the file whose path is given in
330: * <path>. If the file does not exist, it is created with mode <mode>.
331: */
332: int
1.15 ! ray 333: buf_write(BUF *b, const char *path, mode_t mode)
1.1 joris 334: {
335: int fd;
336: open:
337: if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
338: if (errno == EACCES && unlink(path) != -1)
339: goto open;
340: else
1.3 xsa 341: err(1, "%s", path);
1.1 joris 342: }
343:
1.15 ! ray 344: if (buf_write_fd(b, fd) == -1) {
1.1 joris 345: (void)unlink(path);
1.15 ! ray 346: errx(1, "buf_write: buf_write_fd: `%s'", path);
1.1 joris 347: }
348:
349: if (fchmod(fd, mode) < 0)
350: warn("permissions not set on file %s", path);
351:
352: (void)close(fd);
353:
354: return (0);
355: }
356:
357: /*
1.15 ! ray 358: * buf_write_stmp()
1.1 joris 359: *
360: * Write the contents of the buffer <b> to a temporary file whose path is
361: * specified using <template> (see mkstemp.3). NB. This function will modify
362: * <template>, as per mkstemp
363: */
364: void
1.15 ! ray 365: buf_write_stmp(BUF *b, char *template)
1.1 joris 366: {
367: int fd;
368:
369: if ((fd = mkstemp(template)) == -1)
1.3 xsa 370: err(1, "%s", template);
1.1 joris 371:
1.14 ray 372: worklist_add(template, &temp_files);
1.1 joris 373:
1.15 ! ray 374: if (buf_write_fd(b, fd) == -1) {
1.1 joris 375: (void)unlink(template);
1.15 ! ray 376: errx(1, "buf_write_stmp: buf_write_fd: `%s'", template);
1.1 joris 377: }
378:
379: (void)close(fd);
380: }
381:
382: /*
1.15 ! ray 383: * buf_grow()
1.1 joris 384: *
385: * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
386: * operation regardless of the result.
387: */
388: static void
1.15 ! ray 389: buf_grow(BUF *b, size_t len)
1.1 joris 390: {
1.13 ray 391: b->cb_buf = xrealloc(b->cb_buf, 1, b->cb_size + len);
1.1 joris 392: b->cb_size += len;
393: }
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