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