Annotation of src/usr.bin/rcs/buf.c, Revision 1.22
1.22 ! nicm 1: /* $OpenBSD: buf.c,v 1.21 2011/04/20 19:34:16 nicm 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 <stdio.h>
34: #include <string.h>
35: #include <unistd.h>
1.1 joris 36:
37: #include "buf.h"
38: #include "xmalloc.h"
39: #include "worklist.h"
40:
41: #define BUF_INCR 128
42:
1.15 ray 43: struct buf {
1.10 ray 44: /* buffer handle, buffer size, and data length */
1.1 joris 45: u_char *cb_buf;
46: size_t cb_size;
47: size_t cb_len;
48: };
49:
1.10 ray 50: #define SIZE_LEFT(b) (b->cb_size - b->cb_len)
1.1 joris 51:
1.15 ray 52: static void buf_grow(BUF *, size_t);
1.1 joris 53:
54: /*
55: * Create a new buffer structure and return a pointer to it. This structure
1.18 nicm 56: * uses dynamically-allocated memory and must be freed with buf_free(), once
57: * the buffer is no longer needed.
1.1 joris 58: */
59: BUF *
1.16 ray 60: buf_alloc(size_t len)
1.1 joris 61: {
62: BUF *b;
63:
64: b = xmalloc(sizeof(*b));
65: /* Postpone creation of zero-sized buffers */
66: if (len > 0)
67: b->cb_buf = xcalloc(1, len);
68: else
69: b->cb_buf = NULL;
70:
71: b->cb_size = len;
72: b->cb_len = 0;
73:
74: return (b);
75: }
76:
77: /*
78: * Open the file specified by <path> and load all of its contents into a
79: * buffer.
1.8 ray 80: * Returns the loaded buffer on success or NULL on failure.
81: * Sets errno on error.
1.1 joris 82: */
83: BUF *
1.16 ray 84: buf_load(const char *path)
1.1 joris 85: {
86: int fd;
87: ssize_t ret;
88: size_t len;
89: u_char *bp;
90: struct stat st;
91: BUF *buf;
92:
1.8 ray 93: buf = NULL;
94:
95: if ((fd = open(path, O_RDONLY, 0600)) == -1)
96: goto out;
1.1 joris 97:
98: if (fstat(fd, &st) == -1)
1.8 ray 99: goto out;
1.1 joris 100:
1.8 ray 101: if (st.st_size > SIZE_MAX) {
102: errno = EFBIG;
103: goto out;
104: }
1.16 ray 105: buf = buf_alloc(st.st_size);
1.10 ray 106: for (bp = buf->cb_buf; ; bp += (size_t)ret) {
1.1 joris 107: len = SIZE_LEFT(buf);
108: ret = read(fd, bp, len);
109: if (ret == -1) {
1.8 ray 110: int saved_errno;
111:
112: saved_errno = errno;
1.15 ray 113: buf_free(buf);
1.8 ray 114: buf = NULL;
115: errno = saved_errno;
116: goto out;
1.1 joris 117: } else if (ret == 0)
118: break;
119:
120: buf->cb_len += (size_t)ret;
121: }
122:
1.8 ray 123: out:
124: if (fd != -1) {
125: int saved_errno;
126:
127: /* We may want to preserve errno here. */
128: saved_errno = errno;
129: (void)close(fd);
130: errno = saved_errno;
131: }
1.1 joris 132:
133: return (buf);
134: }
135:
136: void
1.15 ray 137: buf_free(BUF *b)
1.1 joris 138: {
139: if (b->cb_buf != NULL)
140: xfree(b->cb_buf);
141: xfree(b);
142: }
143:
144: /*
145: * Free the buffer <b>'s structural information but do not free the contents
146: * of the buffer. Instead, they are returned and should be freed later using
1.18 nicm 147: * xfree().
1.1 joris 148: */
149: void *
1.15 ray 150: buf_release(BUF *b)
1.1 joris 151: {
1.4 niallo 152: void *tmp;
1.1 joris 153:
154: tmp = b->cb_buf;
155: xfree(b);
156: return (tmp);
1.5 niallo 157: }
158:
1.11 xsa 159: u_char *
1.15 ray 160: buf_get(BUF *b)
1.5 niallo 161: {
162: return (b->cb_buf);
1.1 joris 163: }
164:
165: /*
166: * Empty the contents of the buffer <b> and reset pointers.
167: */
168: void
1.15 ray 169: buf_empty(BUF *b)
1.1 joris 170: {
171: memset(b->cb_buf, 0, b->cb_size);
172: b->cb_len = 0;
173: }
174:
175: /*
176: * Append a single character <c> to the end of the buffer <b>.
177: */
178: void
1.15 ray 179: buf_putc(BUF *b, int c)
1.1 joris 180: {
181: u_char *bp;
182:
1.17 tobias 183: if (SIZE_LEFT(b) == 0)
184: buf_grow(b, BUF_INCR);
1.10 ray 185: bp = b->cb_buf + b->cb_len;
1.1 joris 186: *bp = (u_char)c;
187: b->cb_len++;
1.22 ! nicm 188: }
! 189:
! 190: /*
! 191: * Append a string <s> to the end of buffer <b>.
! 192: */
! 193: void
! 194: buf_puts(BUF *b, const char *str)
! 195: {
! 196: buf_append(b, str, strlen(str));
1.1 joris 197: }
198:
199: /*
200: * Return u_char at buffer position <pos>.
201: */
202: u_char
1.15 ray 203: buf_getc(BUF *b, size_t pos)
1.1 joris 204: {
1.10 ray 205: return (b->cb_buf[pos]);
1.1 joris 206: }
207:
208: /*
209: * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
1.18 nicm 210: * buffer is too small to accept all data, it will get resized to an
211: * appropriate size to accept all data.
1.1 joris 212: * Returns the number of bytes successfully appended to the buffer.
213: */
1.7 ray 214: size_t
1.15 ray 215: buf_append(BUF *b, const void *data, size_t len)
1.1 joris 216: {
217: size_t left, rlen;
1.17 tobias 218: u_char *bp;
1.1 joris 219:
1.17 tobias 220: left = SIZE_LEFT(b);
1.1 joris 221: rlen = len;
222:
1.17 tobias 223: if (left < len)
1.16 ray 224: buf_grow(b, len - left);
1.17 tobias 225: bp = b->cb_buf + b->cb_len;
1.1 joris 226: memcpy(bp, data, rlen);
227: b->cb_len += rlen;
228:
229: return (rlen);
230: }
231:
232: /*
233: * Returns the size of the buffer that is being used.
234: */
235: size_t
1.15 ray 236: buf_len(BUF *b)
1.1 joris 237: {
238: return (b->cb_len);
239: }
240:
241: /*
242: * Write the contents of the buffer <b> to the specified <fd>
243: */
244: int
1.15 ray 245: buf_write_fd(BUF *b, int fd)
1.1 joris 246: {
247: u_char *bp;
248: size_t len;
249: ssize_t ret;
250:
251: len = b->cb_len;
1.10 ray 252: bp = b->cb_buf;
1.1 joris 253:
254: do {
255: ret = write(fd, bp, len);
256: if (ret == -1) {
257: if (errno == EINTR || errno == EAGAIN)
258: continue;
259: return (-1);
260: }
261:
262: len -= (size_t)ret;
263: bp += (size_t)ret;
264: } while (len > 0);
265:
266: return (0);
267: }
268:
269: /*
270: * Write the contents of the buffer <b> to the file whose path is given in
271: * <path>. If the file does not exist, it is created with mode <mode>.
272: */
273: int
1.15 ray 274: buf_write(BUF *b, const char *path, mode_t mode)
1.1 joris 275: {
276: int fd;
277: open:
278: if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
279: if (errno == EACCES && unlink(path) != -1)
280: goto open;
281: else
1.3 xsa 282: err(1, "%s", path);
1.1 joris 283: }
284:
1.15 ray 285: if (buf_write_fd(b, fd) == -1) {
1.1 joris 286: (void)unlink(path);
1.15 ray 287: errx(1, "buf_write: buf_write_fd: `%s'", path);
1.1 joris 288: }
289:
290: if (fchmod(fd, mode) < 0)
291: warn("permissions not set on file %s", path);
292:
293: (void)close(fd);
294:
295: return (0);
296: }
297:
298: /*
299: * Write the contents of the buffer <b> to a temporary file whose path is
1.18 nicm 300: * specified using <template> (see mkstemp.3).
301: * NB. This function will modify <template>, as per mkstemp
1.1 joris 302: */
303: void
1.15 ray 304: buf_write_stmp(BUF *b, char *template)
1.1 joris 305: {
306: int fd;
307:
308: if ((fd = mkstemp(template)) == -1)
1.3 xsa 309: err(1, "%s", template);
1.1 joris 310:
1.14 ray 311: worklist_add(template, &temp_files);
1.1 joris 312:
1.15 ray 313: if (buf_write_fd(b, fd) == -1) {
1.1 joris 314: (void)unlink(template);
1.15 ray 315: errx(1, "buf_write_stmp: buf_write_fd: `%s'", template);
1.1 joris 316: }
317:
318: (void)close(fd);
319: }
320:
321: /*
322: * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
323: * operation regardless of the result.
324: */
325: static void
1.15 ray 326: buf_grow(BUF *b, size_t len)
1.1 joris 327: {
1.13 ray 328: b->cb_buf = xrealloc(b->cb_buf, 1, b->cb_size + len);
1.1 joris 329: b->cb_size += len;
330: }
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