Annotation of src/usr.bin/cvs/buf.c, Revision 1.1
1.1 ! jfb 1: /* $OpenBSD$ */
! 2: /*
! 3: * Copyright (c) 2003 Jean-Francois Brousseau <jfb@fugusec.net>
! 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: }
! 91: memset(b->cb_buf, 0, sizeof(b->cb_buf));
! 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);
! 344:
! 345: ret = vasprintf(&str, fmt, vap);
! 346: if (ret == -1) {
! 347: cvs_log(LP_ERRNO, "failed to format data");
! 348: return (-1);
! 349: }
! 350: va_end(vap);
! 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: }
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