Annotation of src/usr.bin/cvs/buf.c, Revision 1.7
1.7 ! djm 1: /* $OpenBSD: buf.c,v 1.6 2004/12/07 17:10:56 tedu Exp $ */
1.1 jfb 2: /*
1.2 jfb 3: * Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
1.1 jfb 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:
27: #include <sys/param.h>
28: #include <sys/stat.h>
29:
30: #include <stdio.h>
31: #include <ctype.h>
32: #include <fcntl.h>
33: #include <stdarg.h>
34: #include <unistd.h>
35: #include <string.h>
36: #include <stdlib.h>
1.7 ! djm 37: #include <errno.h>
1.1 jfb 38:
39: #include "buf.h"
40: #include "log.h"
41:
42:
43: #define BUF_INCR 128
44:
45:
46: struct cvs_buf {
47: u_int cb_flags;
48:
49: /* buffer handle and size */
50: void *cb_buf;
51: size_t cb_size;
52:
53: /* start and length of valid data in buffer */
54: u_char *cb_cur;
55: size_t cb_len;
56: };
57:
58:
59:
60: #define SIZE_LEFT(b) ((size_t)((u_char *)b->cb_buf - b->cb_cur) + b->cb_size)
61:
62:
63: static ssize_t cvs_buf_grow (BUF *, size_t);
64:
65:
66:
67: /*
68: * cvs_buf_alloc()
69: *
70: * Create a new buffer structure and return a pointer to it. This structure
71: * uses dynamically-allocated memory and must be freed with cvs_buf_free(),
72: * once the buffer is no longer needed.
73: */
74: BUF*
75: cvs_buf_alloc(size_t len, u_int flags)
76: {
77: BUF *b;
78:
79: b = (BUF *)malloc(sizeof(*b));
80: if (b == NULL) {
81: cvs_log(LP_ERRNO, "failed to allocate buffer");
82: return (NULL);
83: }
84:
85: b->cb_buf = malloc(len);
86: if (b->cb_buf == NULL) {
87: cvs_log(LP_ERRNO, "failed to allocate buffer");
88: free(b);
89: return (NULL);
90: }
1.3 joris 91: memset(b->cb_buf, 0, len);
1.1 jfb 92:
93: b->cb_flags = flags;
94: b->cb_size = len;
95: b->cb_cur = (u_char *)b->cb_buf;
96: b->cb_len = 0;
97:
98: return (b);
99: }
100:
101:
102: /*
103: * cvs_buf_load()
104: *
105: * Open the file specified by <path> and load all of its contents into a
106: * buffer.
107: * Returns the loaded buffer on success, or NULL on failure.
108: */
109: BUF*
110: cvs_buf_load(const char *path, u_int flags)
111: {
112: int fd;
113: ssize_t ret;
114: size_t len;
115: void *bp;
116: struct stat st;
117: BUF *buf;
118:
119: fd = open(path, O_RDONLY, 0600);
120: if (fd == -1) {
121: cvs_log(LP_ERRNO, "failed to open buffer source");
122: return (NULL);
123: }
124:
125: if (fstat(fd, &st) == -1) {
126: cvs_log(LP_ERRNO, "failed to stat buffer source");
127: (void)close(fd);
128: return (NULL);
129: }
130:
131: buf = cvs_buf_alloc((size_t)st.st_size, flags);
132: if (buf == NULL) {
133: (void)close(fd);
134: return (NULL);
135: }
136:
137: for (bp = buf->cb_cur; ; bp += (size_t)ret) {
138: len = MIN(SIZE_LEFT(buf), 4096);
139: ret = read(fd, bp, len);
140: if (ret == -1) {
141: cvs_log(LP_ERRNO, "read failed from buffer source");
142: (void)close(fd);
143: cvs_buf_free(bp);
144: return (NULL);
1.5 deraadt 145: } else if (ret == 0)
1.1 jfb 146: break;
147:
148: buf->cb_len += (size_t)ret;
149: }
150:
151: (void)close(fd);
152:
153: return (buf);
154: }
155:
156:
157: /*
158: * cvs_buf_free()
159: *
160: * Free the buffer <b> and all associated data.
161: */
162: void
163: cvs_buf_free(BUF *b)
164: {
165: free(b->cb_buf);
166: free(b);
167: }
168:
169:
170: /*
171: * cvs_buf_release()
172: *
173: * Free the buffer <b>'s structural information but do not free the contents
174: * of the buffer. Instead, they are returned and should be freed later using
175: * free().
176: */
177: void*
178: cvs_buf_release(BUF *b)
179: {
180: void *tmp;
1.6 tedu 181:
1.1 jfb 182: tmp = b->cb_buf;
183: free(b);
184: return (tmp);
185: }
186:
187:
188: /*
189: * cvs_buf_empty()
190: *
191: * Empty the contents of the buffer <b> and reset pointers.
192: */
193: void
194: cvs_buf_empty(BUF *b)
195: {
196: b->cb_cur = (u_char *)b->cb_buf;
197: b->cb_len = 0;
198: }
199:
200:
201: /*
202: * cvs_buf_copy()
203: *
204: * Copy the first <len> bytes of data in the buffer <b> starting at offset
205: * <off> in the destination buffer <dst>, which can accept up to <len> bytes.
206: * Returns the number of bytes successfully copied, or -1 on failure.
207: */
208: ssize_t
209: cvs_buf_copy(BUF *b, size_t off, void *dst, size_t len)
210: {
211: size_t rc;
212:
213: if (off > b->cb_len)
214: return (-1);
215:
216: rc = MIN(len, (b->cb_len - off));
217: memcpy(dst, b->cb_buf, rc);
218:
219: return (ssize_t)rc;
220: }
221:
222:
223: /*
224: * cvs_buf_set()
225: *
226: * Set the contents of the buffer <b> to the first <len> bytes of data found
227: * at <src>. If the buffer was not created with BUF_AUTOEXT, as many bytes
228: * as possible will be copied in the buffer.
229: */
230: int
231: cvs_buf_set(BUF *b, const void *src, size_t len, size_t off)
232: {
233: size_t rlen;
234:
235: if (b->cb_size < (len + off)) {
1.6 tedu 236: if ((b->cb_flags & BUF_AUTOEXT) && (cvs_buf_grow(b,
1.1 jfb 237: len + off - b->cb_size) < 0))
238: return (-1);
239: else
240: rlen = b->cb_size - off;
1.5 deraadt 241: } else
1.1 jfb 242: rlen = len;
243:
244: memcpy((b->cb_buf + off), src, rlen);
245:
246: if (b->cb_len == 0) {
247: b->cb_cur = b->cb_buf + off;
248: b->cb_len = rlen;
249: }
250:
251: return (int)rlen;
252: }
253:
254:
255: /*
256: * cvs_buf_putc()
257: *
258: * Append a single character <c> to the end of the buffer <b>.
259: * Returns 0 on success, or -1 on failure.
260: */
261: int
262: cvs_buf_putc(BUF *b, int c)
263: {
264: u_char *bp;
265:
266: bp = b->cb_cur + b->cb_len;
267: if (bp == (b->cb_buf + b->cb_size)) {
268: /* extend */
269: if (!(b->cb_flags & BUF_AUTOEXT) ||
270: (cvs_buf_grow(b, BUF_INCR) < 0))
271: return (-1);
272:
273: /* the buffer might have been moved */
274: bp = b->cb_cur + b->cb_len;
275: }
276: *bp = (u_char)c;
277: b->cb_len++;
278:
279: return (0);
280: }
281:
282:
283: /*
284: * cvs_buf_append()
285: *
286: * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
287: * buffer is too small to accept all data, it will attempt to append as much
288: * data as possible, or if the BUF_AUTOEXT flag is set for the buffer, it
289: * will get resized to an appropriate size to accept all data.
290: * Returns the number of bytes successfully appended to the buffer, or -1
291: * on failure.
292: */
293: ssize_t
294: cvs_buf_append(BUF *b, const void *data, size_t len)
295: {
296: size_t left, rlen;
297: void *bp, *bep;
298:
299: bp = b->cb_cur + b->cb_len;
300: bep = b->cb_buf + b->cb_size;
301: left = bep - bp;
302: rlen = len;
303:
304: if (left < len) {
305: if (b->cb_flags & BUF_AUTOEXT) {
306: if (cvs_buf_grow(b, len - left) < 0)
307: return (-1);
308: bp = b->cb_cur + b->cb_len;
1.5 deraadt 309: } else
1.1 jfb 310: rlen = bep - bp;
311: }
312:
313: memcpy(bp, data, rlen);
314: b->cb_len += rlen;
315:
316: return (rlen);
317: }
318:
319:
320: /*
321: * cvs_buf_fappend()
322: *
323: */
324: int
325: cvs_buf_fappend(BUF *b, const char *fmt, ...)
326: {
327: int ret;
328: char *str;
329: va_list vap;
330:
331: va_start(vap, fmt);
1.4 pat 332: ret = vasprintf(&str, fmt, vap);
333: va_end(vap);
1.1 jfb 334:
335: if (ret == -1) {
336: cvs_log(LP_ERRNO, "failed to format data");
337: return (-1);
338: }
339:
340: ret = cvs_buf_append(b, str, ret);
341: free(str);
342: return (ret);
343: }
344:
345:
346: /*
347: * cvs_buf_size()
348: *
349: * Returns the size of the buffer that is being used.
350: */
351: size_t
352: cvs_buf_size(BUF *b)
353: {
354: return (b->cb_len);
355: }
356:
357:
358: /*
359: * cvs_buf_peek()
360: *
361: * Peek at the contents of the buffer <b> at offset <off>.
362: */
363: const void*
364: cvs_buf_peek(BUF *b, size_t off)
365: {
366: if (off >= b->cb_len)
367: return (NULL);
368:
369: return (b->cb_buf + off);
370: }
371:
372:
373: /*
1.7 ! djm 374: * cvs_buf_write_fd()
1.1 jfb 375: *
1.7 ! djm 376: * Write the contents of the buffer <b> to the specified <fd>
1.1 jfb 377: */
378: int
1.7 ! djm 379: cvs_buf_write_fd(BUF *b, int fd)
1.1 jfb 380: {
381: u_char *bp;
382: size_t len;
383: ssize_t ret;
384:
385: len = b->cb_len;
386: bp = b->cb_cur;
387:
388: do {
389: ret = write(fd, bp, MIN(len, 8192));
390: if (ret == -1) {
1.7 ! djm 391: if (errno == EINTR || errno == EAGAIN)
! 392: continue;
1.1 jfb 393: return (-1);
394: }
395:
396: len -= (size_t)ret;
397: bp += (size_t)ret;
398: } while (len > 0);
399:
1.7 ! djm 400: return (0);
! 401: }
! 402:
! 403: /*
! 404: * cvs_buf_write()
! 405: *
! 406: * Write the contents of the buffer <b> to the file whose path is given in
! 407: * <path>. If the file does not exist, it is created with mode <mode>.
! 408: */
! 409:
! 410: int
! 411: cvs_buf_write(BUF *b, const char *path, mode_t mode)
! 412: {
! 413: int ret, fd;
! 414:
! 415: fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode);
! 416: if (fd == -1) {
! 417: cvs_log(LP_ERRNO, "failed to open file `%s': %s",
! 418: path, strerror(errno));
! 419: return (-1);
! 420: }
! 421:
! 422: ret = cvs_buf_write_fd(b, fd);
! 423: if (ret == -1) {
! 424: cvs_log(LP_ERRNO, "failed to write to file `%s': %s",
! 425: path, strerror(errno));
! 426: (void)unlink(path);
! 427: }
1.1 jfb 428: (void)close(fd);
429:
1.7 ! djm 430: return (ret);
1.1 jfb 431: }
432:
1.7 ! djm 433: /*
! 434: * cvs_buf_write_stmp()
! 435: *
! 436: * Write the contents of the buffer <b> to a temporary file whose path is
! 437: * specified using <template> (see mkstemp.3). NB. This function will modify
! 438: * <template>, as per mkstemp
! 439: */
! 440:
! 441: int
! 442: cvs_buf_write_stmp(BUF *b, char *template, mode_t mode)
! 443: {
! 444: int ret, fd;
! 445:
! 446: fd = mkstemp(template);
! 447: if (fd == -1) {
! 448: cvs_log(LP_ERRNO, "failed to mkstemp file `%s': %s",
! 449: template, strerror(errno));
! 450: return (-1);
! 451: }
! 452:
! 453: ret = cvs_buf_write_fd(b, fd);
! 454: if (ret == -1) {
! 455: cvs_log(LP_ERRNO, "failed to write to temp file `%s': %s",
! 456: template, strerror(errno));
! 457: (void)unlink(template);
! 458: }
! 459: (void)close(fd);
! 460:
! 461: return (ret);
! 462: }
1.1 jfb 463:
464: /*
465: * cvs_buf_grow()
466: *
467: * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
468: * operation regardless of the result.
469: * Returns the new size on success, or -1 on failure.
470: */
471: static ssize_t
472: cvs_buf_grow(BUF *b, size_t len)
473: {
474: void *tmp;
475: size_t diff;
476:
477: diff = b->cb_cur - (u_char *)b->cb_buf;
478: tmp = realloc(b->cb_buf, b->cb_size + len);
479: if (tmp == NULL) {
480: cvs_log(LP_ERRNO, "failed to grow buffer");
481: return (-1);
482: }
483: b->cb_buf = (u_char *)tmp;
484: b->cb_size += len;
485:
486: /* readjust pointers in case the buffer moved in memory */
487: b->cb_cur = b->cb_buf + diff;
488:
489: return (ssize_t)b->cb_size;
490: }