Annotation of src/usr.bin/rcs/buf.c, Revision 1.18
1.18 ! nicm 1: /* $OpenBSD: buf.c,v 1.17 2010/09/08 15:13:39 tobias 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 {
1.10 ray 45: /* buffer handle, buffer size, and data length */
1.1 joris 46: u_char *cb_buf;
47: size_t cb_size;
48: size_t cb_len;
49: };
50:
1.10 ray 51: #define SIZE_LEFT(b) (b->cb_size - b->cb_len)
1.1 joris 52:
1.15 ray 53: static void buf_grow(BUF *, size_t);
1.1 joris 54:
55: /*
56: * Create a new buffer structure and return a pointer to it. This structure
1.18 ! nicm 57: * uses dynamically-allocated memory and must be freed with buf_free(), once
! 58: * the buffer is no longer needed.
1.1 joris 59: */
60: BUF *
1.16 ray 61: buf_alloc(size_t len)
1.1 joris 62: {
63: BUF *b;
64:
65: b = xmalloc(sizeof(*b));
66: /* Postpone creation of zero-sized buffers */
67: if (len > 0)
68: b->cb_buf = xcalloc(1, len);
69: else
70: b->cb_buf = NULL;
71:
72: b->cb_size = len;
73: b->cb_len = 0;
74:
75: return (b);
76: }
77:
78: /*
79: * Open the file specified by <path> and load all of its contents into a
80: * buffer.
1.8 ray 81: * Returns the loaded buffer on success or NULL on failure.
82: * Sets errno on error.
1.1 joris 83: */
84: BUF *
1.16 ray 85: buf_load(const char *path)
1.1 joris 86: {
87: int fd;
88: ssize_t ret;
89: size_t len;
90: u_char *bp;
91: struct stat st;
92: BUF *buf;
93:
1.8 ray 94: buf = NULL;
95:
96: if ((fd = open(path, O_RDONLY, 0600)) == -1)
97: goto out;
1.1 joris 98:
99: if (fstat(fd, &st) == -1)
1.8 ray 100: goto out;
1.1 joris 101:
1.8 ray 102: if (st.st_size > SIZE_MAX) {
103: errno = EFBIG;
104: goto out;
105: }
1.16 ray 106: buf = buf_alloc(st.st_size);
1.10 ray 107: for (bp = buf->cb_buf; ; bp += (size_t)ret) {
1.1 joris 108: len = SIZE_LEFT(buf);
109: ret = read(fd, bp, len);
110: if (ret == -1) {
1.8 ray 111: int saved_errno;
112:
113: saved_errno = errno;
1.15 ray 114: buf_free(buf);
1.8 ray 115: buf = NULL;
116: errno = saved_errno;
117: goto out;
1.1 joris 118: } else if (ret == 0)
119: break;
120:
121: buf->cb_len += (size_t)ret;
122: }
123:
1.8 ray 124: out:
125: if (fd != -1) {
126: int saved_errno;
127:
128: /* We may want to preserve errno here. */
129: saved_errno = errno;
130: (void)close(fd);
131: errno = saved_errno;
132: }
1.1 joris 133:
134: return (buf);
135: }
136:
137: void
1.15 ray 138: buf_free(BUF *b)
1.1 joris 139: {
140: if (b->cb_buf != NULL)
141: xfree(b->cb_buf);
142: xfree(b);
143: }
144:
145: /*
146: * Free the buffer <b>'s structural information but do not free the contents
147: * of the buffer. Instead, they are returned and should be freed later using
1.18 ! nicm 148: * xfree().
1.1 joris 149: */
150: void *
1.15 ray 151: buf_release(BUF *b)
1.1 joris 152: {
1.4 niallo 153: void *tmp;
1.1 joris 154:
155: tmp = b->cb_buf;
156: xfree(b);
157: return (tmp);
1.5 niallo 158: }
159:
1.11 xsa 160: u_char *
1.15 ray 161: buf_get(BUF *b)
1.5 niallo 162: {
163: return (b->cb_buf);
1.1 joris 164: }
165:
166: /*
167: * Empty the contents of the buffer <b> and reset pointers.
168: */
169: void
1.15 ray 170: buf_empty(BUF *b)
1.1 joris 171: {
172: memset(b->cb_buf, 0, b->cb_size);
173: b->cb_len = 0;
174: }
175:
176: /*
177: * Append a single character <c> to the end of the buffer <b>.
178: */
179: void
1.15 ray 180: buf_putc(BUF *b, int c)
1.1 joris 181: {
182: u_char *bp;
183:
1.17 tobias 184: if (SIZE_LEFT(b) == 0)
185: buf_grow(b, BUF_INCR);
1.10 ray 186: bp = b->cb_buf + b->cb_len;
1.1 joris 187: *bp = (u_char)c;
188: b->cb_len++;
189: }
190:
191: /*
192: * Return u_char at buffer position <pos>.
193: */
194: u_char
1.15 ray 195: buf_getc(BUF *b, size_t pos)
1.1 joris 196: {
1.10 ray 197: return (b->cb_buf[pos]);
1.1 joris 198: }
199:
200: /*
201: * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
1.18 ! nicm 202: * buffer is too small to accept all data, it will get resized to an
! 203: * appropriate size to accept all data.
1.1 joris 204: * Returns the number of bytes successfully appended to the buffer.
205: */
1.7 ray 206: size_t
1.15 ray 207: buf_append(BUF *b, const void *data, size_t len)
1.1 joris 208: {
209: size_t left, rlen;
1.17 tobias 210: u_char *bp;
1.1 joris 211:
1.17 tobias 212: left = SIZE_LEFT(b);
1.1 joris 213: rlen = len;
214:
1.17 tobias 215: if (left < len)
1.16 ray 216: buf_grow(b, len - left);
1.17 tobias 217: bp = b->cb_buf + b->cb_len;
1.1 joris 218: memcpy(bp, data, rlen);
219: b->cb_len += rlen;
220:
221: return (rlen);
222: }
223:
1.7 ray 224: size_t
1.15 ray 225: buf_fappend(BUF *b, const char *fmt, ...)
1.1 joris 226: {
1.7 ray 227: size_t ret;
228: int n;
1.1 joris 229: char *str;
230: va_list vap;
231:
232: va_start(vap, fmt);
1.7 ray 233: n = vasprintf(&str, fmt, vap);
1.1 joris 234: va_end(vap);
235:
1.7 ray 236: if (n == -1)
1.15 ray 237: errx(1, "buf_fappend: failed to format data");
1.1 joris 238:
1.15 ray 239: ret = buf_append(b, str, n);
1.1 joris 240: xfree(str);
241: return (ret);
242: }
243:
244: /*
245: * Returns the size of the buffer that is being used.
246: */
247: size_t
1.15 ray 248: buf_len(BUF *b)
1.1 joris 249: {
250: return (b->cb_len);
251: }
252:
253: /*
254: * Write the contents of the buffer <b> to the specified <fd>
255: */
256: int
1.15 ray 257: buf_write_fd(BUF *b, int fd)
1.1 joris 258: {
259: u_char *bp;
260: size_t len;
261: ssize_t ret;
262:
263: len = b->cb_len;
1.10 ray 264: bp = b->cb_buf;
1.1 joris 265:
266: do {
267: ret = write(fd, bp, len);
268: if (ret == -1) {
269: if (errno == EINTR || errno == EAGAIN)
270: continue;
271: return (-1);
272: }
273:
274: len -= (size_t)ret;
275: bp += (size_t)ret;
276: } while (len > 0);
277:
278: return (0);
279: }
280:
281: /*
282: * Write the contents of the buffer <b> to the file whose path is given in
283: * <path>. If the file does not exist, it is created with mode <mode>.
284: */
285: int
1.15 ray 286: buf_write(BUF *b, const char *path, mode_t mode)
1.1 joris 287: {
288: int fd;
289: open:
290: if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
291: if (errno == EACCES && unlink(path) != -1)
292: goto open;
293: else
1.3 xsa 294: err(1, "%s", path);
1.1 joris 295: }
296:
1.15 ray 297: if (buf_write_fd(b, fd) == -1) {
1.1 joris 298: (void)unlink(path);
1.15 ray 299: errx(1, "buf_write: buf_write_fd: `%s'", path);
1.1 joris 300: }
301:
302: if (fchmod(fd, mode) < 0)
303: warn("permissions not set on file %s", path);
304:
305: (void)close(fd);
306:
307: return (0);
308: }
309:
310: /*
311: * Write the contents of the buffer <b> to a temporary file whose path is
1.18 ! nicm 312: * specified using <template> (see mkstemp.3).
! 313: * NB. This function will modify <template>, as per mkstemp
1.1 joris 314: */
315: void
1.15 ray 316: buf_write_stmp(BUF *b, char *template)
1.1 joris 317: {
318: int fd;
319:
320: if ((fd = mkstemp(template)) == -1)
1.3 xsa 321: err(1, "%s", template);
1.1 joris 322:
1.14 ray 323: worklist_add(template, &temp_files);
1.1 joris 324:
1.15 ray 325: if (buf_write_fd(b, fd) == -1) {
1.1 joris 326: (void)unlink(template);
1.15 ray 327: errx(1, "buf_write_stmp: buf_write_fd: `%s'", template);
1.1 joris 328: }
329:
330: (void)close(fd);
331: }
332:
333: /*
334: * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
335: * operation regardless of the result.
336: */
337: static void
1.15 ray 338: buf_grow(BUF *b, size_t len)
1.1 joris 339: {
1.13 ray 340: b->cb_buf = xrealloc(b->cb_buf, 1, b->cb_size + len);
1.1 joris 341: b->cb_size += len;
342: }
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