2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 2001
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
22 * @brief scalable FILE replacement
26 stdio is very convenient, but on some systems the file descriptor
27 in FILE* is 8 bits, so it fails when more than 255 files are open.
29 XFILE replaces stdio. It is less efficient, but at least it works
30 when you have lots of files open
32 The main restriction on XFILE is that it doesn't support seeking,
33 and doesn't support O_RDWR. That keeps the code simple.
37 #include "system/filesys.h"
39 #if _SAMBA_BUILD_ == 3
43 #define XBUFSIZE BUFSIZ
45 static XFILE _x_stdin = { 0, NULL, NULL, XBUFSIZE, 0, O_RDONLY, X_IOFBF, 0 };
46 static XFILE _x_stdout = { 1, NULL, NULL, XBUFSIZE, 0, O_WRONLY, X_IOLBF, 0 };
47 static XFILE _x_stderr = { 2, NULL, NULL, 0, 0, O_WRONLY, X_IONBF, 0 };
49 XFILE *x_stdin = &_x_stdin;
50 XFILE *x_stdout = &_x_stdout;
51 XFILE *x_stderr = &_x_stderr;
54 #define X_FLAG_ERROR 2
55 #define X_FLAG_EINVAL 3
57 /** simulate setvbuf() */
58 int x_setvbuf(XFILE *f, char *buf, int mode, size_t size)
61 if (f->bufused) return -1;
63 /* on files being read full buffering is the only option */
64 if ((f->open_flags & O_ACCMODE) == O_RDONLY) {
68 /* destroy any earlier buffer */
76 if (f->buftype == X_IONBF) return 0;
78 /* if buffering then we need some size */
79 if (size == 0) size = XBUFSIZE;
87 /* allocate the buffer */
88 static int x_allocate_buffer(XFILE *f)
91 if (f->bufsize == 0) return 0;
92 f->buf = (char *)malloc(f->bufsize);
93 if (!f->buf) return 0;
99 /** this looks more like open() than fopen(), but that is quite deliberate.
100 I want programmers to *think* about O_EXCL, O_CREAT etc not just
101 get them magically added
103 XFILE *x_fopen(const char *fname, int flags, mode_t mode)
107 ret = (XFILE *)malloc_p(XFILE);
108 if (!ret) return NULL;
110 memset(ret, 0, sizeof(XFILE));
112 if ((flags & O_ACCMODE) == O_RDWR) {
113 /* we don't support RDWR in XFILE - use file
114 descriptors instead */
119 ret->open_flags = flags;
121 ret->fd = open(fname, flags, mode);
127 x_setvbuf(ret, NULL, X_IOFBF, XBUFSIZE);
132 /** simulate fclose() */
133 int x_fclose(XFILE *f)
137 /* make sure we flush any buffered data */
143 /* make sure data can't leak into a later malloc */
144 memset(f->buf, 0, f->bufsize);
147 /* check the file descriptor given to the function is NOT one of the static
148 * descriptor of this libreary or we will free unallocated memory
150 if (f != x_stdin && f != x_stdout && f != x_stderr) {
156 /** simulate fwrite() */
157 size_t x_fwrite(const void *p, size_t size, size_t nmemb, XFILE *f)
162 /* we might be writing unbuffered */
163 if (f->buftype == X_IONBF ||
164 (!f->buf && !x_allocate_buffer(f))) {
165 ret = write(f->fd, p, size*nmemb);
166 if (ret == -1) return -1;
171 while (total < size*nmemb) {
172 size_t n = f->bufsize - f->bufused;
173 n = MIN(n, (size*nmemb)-total);
176 /* it's full, flush it */
181 memcpy(f->buf + f->bufused, total+(const char *)p, n);
186 /* when line buffered we need to flush at the last linefeed. This can
187 flush a bit more than necessary, but that is harmless */
188 if (f->buftype == X_IOLBF && f->bufused) {
190 for (i=(size*nmemb)-1; i>=0; i--) {
191 if (*(i+(const char *)p) == '\n') {
201 /** thank goodness for asprintf() */
202 int x_vfprintf(XFILE *f, const char *format, va_list ap)
209 len = vasprintf(&p, format, ap2);
211 if (len <= 0) return len;
212 ret = x_fwrite(p, 1, len, f);
217 int x_fprintf(XFILE *f, const char *format, ...)
222 va_start(ap, format);
223 ret = x_vfprintf(f, format, ap);
228 /* at least fileno() is simple! */
229 int x_fileno(const XFILE *f)
234 /** simulate fflush() */
235 int x_fflush(XFILE *f)
239 if (f->flags & X_FLAG_ERROR) return -1;
241 if ((f->open_flags & O_ACCMODE) != O_WRONLY) {
246 if (f->bufused == 0) return 0;
248 ret = write(f->fd, f->buf, f->bufused);
249 if (ret == -1) return -1;
252 if (f->bufused > 0) {
253 f->flags |= X_FLAG_ERROR;
254 memmove(f->buf, ret + (char *)f->buf, f->bufused);
261 /** simulate setbuffer() */
262 void x_setbuffer(XFILE *f, char *buf, size_t size)
264 x_setvbuf(f, buf, buf?X_IOFBF:X_IONBF, size);
267 /** simulate setbuf() */
268 void x_setbuf(XFILE *f, char *buf)
270 x_setvbuf(f, buf, buf?X_IOFBF:X_IONBF, XBUFSIZE);
273 /** simulate setlinebuf() */
274 void x_setlinebuf(XFILE *f)
276 x_setvbuf(f, NULL, X_IOLBF, 0);
280 /** simulate feof() */
283 if (f->flags & X_FLAG_EOF) return 1;
287 /** simulate ferror() */
288 int x_ferror(XFILE *f)
290 if (f->flags & X_FLAG_ERROR) return 1;
294 /* fill the read buffer */
295 static void x_fillbuf(XFILE *f)
299 if (f->bufused) return;
301 if (!f->buf && !x_allocate_buffer(f)) return;
303 n = read(f->fd, f->buf, f->bufsize);
309 /** simulate fgetc() */
310 int x_fgetc(XFILE *f)
314 if (f->flags & (X_FLAG_EOF | X_FLAG_ERROR)) return EOF;
316 if (f->bufused == 0) x_fillbuf(f);
318 if (f->bufused == 0) {
319 f->flags |= X_FLAG_EOF;
323 ret = *(uint8_t *)(f->next);
329 /** simulate fread */
330 size_t x_fread(void *p, size_t size, size_t nmemb, XFILE *f)
333 while (total < size*nmemb) {
336 (total+(char *)p)[0] = (char)c;
342 /** simulate fgets() */
343 char *x_fgets(char *s, int size, XFILE *stream)
348 int c = x_fgetc(stream);
352 if (c == '\n') break;
354 if (l==size || x_ferror(stream)) {
362 * trivial seek, works only for SEEK_SET and SEEK_END if SEEK_CUR is
363 * set then an error is returned */
364 off_t x_tseek(XFILE *f, off_t offset, int whence)
366 if (f->flags & X_FLAG_ERROR)
369 /* only SEEK_SET and SEEK_END are supported */
370 /* SEEK_CUR needs internal offset counter */
371 if (whence != SEEK_SET && whence != SEEK_END) {
372 f->flags |= X_FLAG_EINVAL;
377 /* empty the buffer */
378 switch (f->open_flags & O_ACCMODE) {
383 if (x_fflush(f) != 0)
391 f->flags &= ~X_FLAG_EOF;
392 return lseek(f->fd, offset, whence);
395 XFILE *x_fdup(const XFILE *f)
400 fd = dup(x_fileno(f));
405 ret = (XFILE *)malloc_p(XFILE);
410 memset(ret, 0, sizeof(XFILE));
413 ret->open_flags = f->open_flags;
414 x_setvbuf(ret, NULL, X_IOFBF, XBUFSIZE);