1 /*****************************************************************************
2 * RRDtool 1.2.23 Copyright by Tobi Oetiker, 1997-2007
3 *****************************************************************************
4 * rrd_open.c Open an RRD File
5 *****************************************************************************
6 * $Id$
7 * $Log$
8 * Revision 1.10 2004/05/26 22:11:12 oetiker
9 * reduce compiler warnings. Many small fixes. -- Mike Slifcak <slif@bellsouth.net>
10 *
11 * Revision 1.9 2003/04/29 21:56:49 oetiker
12 * readline in rrd_open.c reads the file in 8 KB blocks, and calls realloc for
13 * each block. realloc is very slow in Mac OS X for huge blocks, e.g. when
14 * restoring databases from huge xml files. This patch finds the size of the
15 * file, and starts out with malloc'ing the full size.
16 * -- Peter Speck <speck@ruc.dk>
17 *
18 * Revision 1.8 2003/04/11 19:43:44 oetiker
19 * New special value COUNT which allows calculations based on the position of a
20 * value within a data set. Bug fix in rrd_rpncalc.c. PREV returned erroneus
21 * value for the second value. Bug fix in rrd_restore.c. Bug causing seek error
22 * when accesing an RRD restored from an xml that holds an RRD version <3.
23 * -- Ruben Justo <ruben@ainek.com>
24 *
25 * Revision 1.7 2003/03/31 21:22:12 oetiker
26 * enables RRDtool updates with microsecond or in case of windows millisecond
27 * precision. This is needed to reduce time measurement error when archive step
28 * is small. (<30s) -- Sasha Mikheev <sasha@avalon-net.co.il>
29 *
30 * Revision 1.6 2003/02/13 07:05:27 oetiker
31 * Find attached the patch I promised to send to you. Please note that there
32 * are three new source files (src/rrd_is_thread_safe.h, src/rrd_thread_safe.c
33 * and src/rrd_not_thread_safe.c) and the introduction of librrd_th. This
34 * library is identical to librrd, but it contains support code for per-thread
35 * global variables currently used for error information only. This is similar
36 * to how errno per-thread variables are implemented. librrd_th must be linked
37 * alongside of libpthred
38 *
39 * There is also a new file "THREADS", holding some documentation.
40 *
41 * -- Peter Stamfest <peter@stamfest.at>
42 *
43 * Revision 1.5 2002/06/20 00:21:03 jake
44 * More Win32 build changes; thanks to Kerry Calvert.
45 *
46 * Revision 1.4 2002/02/01 20:34:49 oetiker
47 * fixed version number and date/time
48 *
49 * Revision 1.3 2001/03/04 13:01:55 oetiker
50 * Aberrant Behavior Detection support. A brief overview added to rrdtool.pod.
51 * Major updates to rrd_update.c, rrd_create.c. Minor update to other core files.
52 * This is backwards compatible! But new files using the Aberrant stuff are not readable
53 * by old rrdtool versions. See http://cricket.sourceforge.net/aberrant/rrd_hw.htm
54 * -- Jake Brutlag <jakeb@corp.webtv.net>
55 *
56 * Revision 1.2 2001/03/04 10:29:20 oetiker
57 * fixed filedescriptor leak
58 * -- Mike Franusich <mike@franusich.com>
59 *
60 * Revision 1.1.1.1 2001/02/25 22:25:05 oetiker
61 * checkin
62 *
63 *****************************************************************************/
65 #include "rrd_tool.h"
66 #include "unused.h"
67 #define MEMBLK 8192
69 #ifdef HAVE_MMAP
70 #define __rrd_read(dst, dst_t, cnt) \
71 (dst) = (dst_t*) (data + offset); \
72 offset += sizeof(dst_t) * (cnt)
73 #else
74 #define __rrd_read(dst, dst_t, cnt) \
75 if ((dst = malloc(sizeof(dst_t)*(cnt))) == NULL) { \
76 rrd_set_error(#dst " malloc"); \
77 goto out_nullify_head; \
78 } \
79 offset += read (rrd_file->fd, dst, sizeof(dst_t)*(cnt))
80 #endif
82 /* open a database file, return its header and an open filehandle */
83 /* positioned to the first cdp in the first rra */
85 rrd_file_t *rrd_open(
86 const char *const file_name,
87 rrd_t *rrd,
88 unsigned rdwr)
89 {
90 int flags = 0;
91 mode_t mode = S_IRUSR;
92 int version;
94 #ifdef HAVE_MMAP
95 int mm_prot = PROT_READ, mm_flags = 0;
96 char *data;
97 #endif
98 off_t offset = 0;
99 struct stat statb;
100 rrd_file_t *rrd_file = malloc(sizeof(rrd_file_t));
102 if (rrd_file == NULL) {
103 rrd_set_error("allocating rrd_file descriptor for '%s'", file_name);
104 return NULL;
105 }
106 memset(rrd_file, 0, sizeof(rrd_file_t));
107 rrd_init(rrd);
108 #ifdef DEBUG
109 if ((rdwr & (RRD_READONLY | RRD_READWRITE)) ==
110 (RRD_READONLY | RRD_READWRITE)) {
111 /* Both READONLY and READWRITE were given, which is invalid. */
112 rrd_set_error("in read/write request mask");
113 exit(-1);
114 }
115 #endif
116 if (rdwr & RRD_READONLY) {
117 flags |= O_RDONLY;
118 #ifdef HAVE_MMAP
119 mm_flags = MAP_PRIVATE;
120 # ifdef MAP_NORESERVE
121 mm_flags |= MAP_NORESERVE;
122 # endif
123 mm_flags |= MAP_PRIVATE;
124 #endif
125 } else {
126 if (rdwr & RRD_READWRITE) {
127 mode |= S_IWUSR;
128 flags |= O_RDWR;
129 #ifdef HAVE_MMAP
130 mm_flags = MAP_SHARED;
131 mm_prot |= PROT_WRITE;
132 #endif
133 }
134 if (rdwr & RRD_CREAT) {
135 flags |= (O_CREAT | O_TRUNC);
136 }
137 }
138 if (rdwr & RRD_READAHEAD) {
139 #ifdef MAP_POPULATE
140 mm_flags |= MAP_POPULATE;
141 #endif
142 #if defined MAP_NONBLOCK && !defined USE_DIRECT_IO
143 mm_flags |= MAP_NONBLOCK; /* just populage ptes */
144 #endif
145 } else {
146 #ifdef USE_DIRECT_IO
147 flags |= O_DIRECT;
148 #endif
149 #if 0 //def O_NONBLOCK
150 flags |= O_NONBLOCK;
151 #endif
152 }
154 if ((rrd_file->fd = open(file_name, flags, mode)) < 0) {
155 rrd_set_error("opening '%s': %s", file_name, rrd_strerror(errno));
156 return NULL;
157 }
159 /* Better try to avoid seeks as much as possible. stat may be heavy but
160 * many concurrent seeks are even worse. */
161 if ((fstat(rrd_file->fd, &statb)) < 0) {
162 rrd_set_error("fstat '%s': %s", file_name, rrd_strerror(errno));
163 goto out_close;
164 }
165 rrd_file->file_len = statb.st_size;
167 #ifdef HAVE_POSIX_FADVISE
168 /* In general we need no read-ahead when dealing with rrd_files.
169 When we stop reading, it is highly unlikely that we start up again.
170 In this manner we actually save time and diskaccess (and buffer cache).
171 Thanks to Dave Plonka for the Idea of using POSIX_FADV_RANDOM here. */
172 if (0 != posix_fadvise(rrd_file->fd, 0, 0, POSIX_FADV_RANDOM)) {
173 rrd_set_error("setting POSIX_FADV_RANDOM on '%s': %s", file_name,
174 rrd_strerror(errno));
175 goto out_close;
176 }
177 #endif
179 /*
180 if (rdwr & RRD_READWRITE)
181 {
182 if (setvbuf((rrd_file->fd),NULL,_IONBF,2)) {
183 rrd_set_error("failed to disable the stream buffer\n");
184 return (-1);
185 }
186 }
187 */
188 #ifdef HAVE_MMAP
189 data = mmap(0, rrd_file->file_len, mm_prot, mm_flags,
190 rrd_file->fd, offset);
192 /* lets see if the first read worked */
193 if (data == MAP_FAILED) {
194 rrd_set_error("error mmaping file '%s': %s", file_name,
195 rrd_strerror(errno));
196 goto out_close;
197 }
198 rrd_file->file_start = data;
199 #else
200 #endif
201 #ifdef USE_MADVISE
202 if (rdwr & RRD_COPY) { /*XXX: currently not used! */
203 /* We will read everything in a moment (copying) */
204 madvise(data, rrd_file->file_len, MADV_WILLNEED | MADV_SEQUENTIAL);
205 goto out_done;
206 }
207 /* We do not need to read anything in for the moment */
208 madvise(data, rrd_file->file_len, MADV_DONTNEED);
209 #endif
211 #ifdef USE_MADVISE
212 /* the stat_head will be needed soonish, so hint accordingly */
213 madvise(data + offset, sizeof(stat_head_t), MADV_WILLNEED);
214 #endif
216 __rrd_read(rrd->stat_head, stat_head_t,
217 1);
219 /* lets do some test if we are on track ... */
220 if (memcmp(rrd->stat_head->cookie, RRD_COOKIE, sizeof(RRD_COOKIE)) != 0) {
221 rrd_set_error("'%s' is not an RRD file", file_name);
222 goto out_nullify_head;
223 }
225 if (rrd->stat_head->float_cookie != FLOAT_COOKIE) {
226 rrd_set_error("This RRD was created on other architecture");
227 goto out_nullify_head;
228 }
230 version = atoi(rrd->stat_head->version);
232 if (version > atoi(RRD_VERSION)) {
233 rrd_set_error("can't handle RRD file version %s",
234 rrd->stat_head->version);
235 goto out_nullify_head;
236 }
237 #ifdef USE_MADVISE
238 /* the ds_def will be needed soonish, so hint accordingly */
239 madvise(data + offset, sizeof(ds_def_t) * rrd->stat_head->ds_cnt,
240 MADV_WILLNEED);
241 #endif
242 __rrd_read(rrd->ds_def, ds_def_t,
243 rrd->stat_head->ds_cnt);
245 #ifdef USE_MADVISE
246 /* the rra_def will be needed soonish, so hint accordingly */
247 madvise(data + offset, sizeof(rra_def_t) * rrd->stat_head->rra_cnt,
248 MADV_WILLNEED);
249 #endif
250 __rrd_read(rrd->rra_def, rra_def_t,
251 rrd->stat_head->rra_cnt);
253 /* handle different format for the live_head */
254 if (version < 3) {
255 rrd->live_head = (live_head_t *) malloc(sizeof(live_head_t));
256 if (rrd->live_head == NULL) {
257 rrd_set_error("live_head_t malloc");
258 goto out_close;
259 }
260 #ifdef HAVE_MMAP
261 memmove(&rrd->live_head->last_up, data + offset, sizeof(long));
262 offset += sizeof(long);
263 #else
264 offset += read(rrd_file->fd, &rrd->live_head->last_up, sizeof(long));
265 #endif
266 rrd->live_head->last_up_usec = 0;
267 } else {
268 #ifdef USE_MADVISE
269 /* the live_head will be needed soonish, so hint accordingly */
270 madvise(data + offset, sizeof(live_head_t), MADV_WILLNEED);
271 #endif
272 __rrd_read(rrd->live_head, live_head_t,
273 1);
274 }
275 //XXX: This doesn't look like it needs madvise
276 __rrd_read(rrd->pdp_prep, pdp_prep_t,
277 rrd->stat_head->ds_cnt);
279 //XXX: This could benefit from madvise()ing
280 __rrd_read(rrd->cdp_prep, cdp_prep_t,
281 rrd->stat_head->rra_cnt * rrd->stat_head->ds_cnt);
283 //XXX: This could benefit from madvise()ing
284 __rrd_read(rrd->rra_ptr, rra_ptr_t,
285 rrd->stat_head->rra_cnt);
287 #ifdef USE_MADVISE
288 out_done:
289 #endif
290 rrd_file->header_len = offset;
291 rrd_file->pos = offset;
292 /* we could close(rrd_file->fd); here, the mapping is still valid anyway */
293 return (rrd_file);
294 out_nullify_head:
295 rrd->stat_head = NULL;
296 out_close:
297 close(rrd_file->fd);
298 return NULL;
299 }
301 /* Close a reference to an rrd_file. */
302 int rrd_close(
303 rrd_file_t *rrd_file)
304 {
305 int ret = 0;
307 #ifdef HAVE_MMAP
308 ret = munmap(rrd_file->file_start, rrd_file->file_len);
309 // if (ret != 0)
310 // rrd_set_error("munmap rrd_file");
311 #endif
312 free(rrd_file);
313 rrd_file = NULL;
314 return ret;
315 }
317 /* Set position of rrd_file. */
318 off_t rrd_seek(
319 rrd_file_t *rrd_file,
320 off_t off,
321 int whence)
322 {
323 off_t ret = 0;
325 #ifdef HAVE_MMAP
326 if (whence == SEEK_SET)
327 rrd_file->pos = off;
328 else if (whence == SEEK_CUR)
329 rrd_file->pos += off;
330 else if (whence == SEEK_END)
331 rrd_file->pos = rrd_file->file_len + off;
332 #else
333 ret = lseek(rrd_file->fd, off, whence);
334 if (ret < 0)
335 rrd_set_error("lseek: %s", rrd_strerror(errno));
336 rrd_file->pos = ret;
337 #endif
338 //XXX: mimic fseek, which returns 0 upon success
339 return ret == -1; //XXX: or just ret to mimic lseek
340 }
342 /* Get current position in rrd_file. */
343 inline off_t rrd_tell(
344 rrd_file_t *rrd_file)
345 {
346 return rrd_file->pos;
347 }
349 /* read count bytes into buffer buf, starting at rrd_file->pos.
350 * Returns the number of bytes read. */
351 ssize_t rrd_read(
352 rrd_file_t *rrd_file,
353 void *buf,
354 size_t count)
355 {
356 #ifdef HAVE_MMAP
357 char *pos = rrd_file->file_start + rrd_file->pos;
359 buf = memmove(buf, pos, count);
360 rrd_file->pos += count; /* mimmic read() semantics */
361 return count;
362 #else
363 ssize_t ret;
365 ret = read(rrd_file->fd, buf, count);
366 //XXX: eventually add generic rrd_set_error(""); here
367 rrd_file->pos += count; /* mimmic read() semantics */
368 return ret;
369 #endif
370 }
372 /* write count bytes from buffer buf to the current position
373 * rrd_file->pos of rrd_file->fd.
374 * Returns the number of bytes written. */
375 ssize_t rrd_write(
376 rrd_file_t *rrd_file,
377 const void *buf,
378 size_t count)
379 {
380 ssize_t ret = count;
382 #ifdef HAVE_MMAP
383 char *off, *new_pos;
385 off = rrd_file->file_start + rrd_file->pos;
386 new_pos = memmove(rrd_file->file_start + rrd_file->pos, buf, count);
387 ret = new_pos - off;
388 #else
389 ret = write(rrd_file->fd, buf, count);
390 #endif
391 return ret;
392 }
394 /* flush all data pending to be written to FD. */
395 inline void rrd_flush(
396 rrd_file_t *rrd_file)
397 {
398 if (fdatasync(rrd_file->fd) != 0) {
399 rrd_set_error("flushing fd %d: %s", rrd_file->fd,
400 rrd_strerror(errno));
401 }
402 }
404 void rrd_init(
405 rrd_t *rrd)
406 {
407 rrd->stat_head = NULL;
408 rrd->ds_def = NULL;
409 rrd->rra_def = NULL;
410 rrd->live_head = NULL;
411 rrd->rra_ptr = NULL;
412 rrd->pdp_prep = NULL;
413 rrd->cdp_prep = NULL;
414 rrd->rrd_value = NULL;
415 }
417 void rrd_free(
418 rrd_t UNUSED(*rrd))
419 {
420 #ifndef HAVE_MMAP
421 if (atoi(rrd->stat_head->version) < 3)
422 free(rrd->live_head);
423 free(rrd->stat_head);
424 free(rrd->ds_def);
425 free(rrd->rra_def);
426 free(rrd->rra_ptr);
427 free(rrd->pdp_prep);
428 free(rrd->cdp_prep);
429 free(rrd->rrd_value);
430 #endif
431 }
433 /* routine used by external libraries to free memory allocated by
434 * rrd library */
435 void rrd_freemem(
436 void *mem)
437 {
438 free(mem);
439 }
441 int readfile(
442 const char *file_name,
443 char **buffer,
444 int skipfirst)
445 {
446 long writecnt = 0, totalcnt = MEMBLK;
447 long offset = 0;
448 FILE *input = NULL;
449 char c;
451 if ((strcmp("-", file_name) == 0)) {
452 input = stdin;
453 } else {
454 if ((input = fopen(file_name, "rb")) == NULL) {
455 rrd_set_error("opening '%s': %s", file_name, rrd_strerror(errno));
456 return (-1);
457 }
458 }
459 if (skipfirst) {
460 do {
461 c = getc(input);
462 offset++;
463 } while (c != '\n' && !feof(input));
464 }
465 if (strcmp("-", file_name)) {
466 fseek(input, 0, SEEK_END);
467 /* have extra space for detecting EOF without realloc */
468 totalcnt = (ftell(input) + 1) / sizeof(char) - offset;
469 if (totalcnt < MEMBLK)
470 totalcnt = MEMBLK; /* sanitize */
471 fseek(input, offset * sizeof(char), SEEK_SET);
472 }
473 if (((*buffer) = (char *) malloc((totalcnt + 4) * sizeof(char))) == NULL) {
474 perror("Allocate Buffer:");
475 exit(1);
476 };
477 do {
478 writecnt +=
479 fread((*buffer) + writecnt, 1,
480 (totalcnt - writecnt) * sizeof(char), input);
481 if (writecnt >= totalcnt) {
482 totalcnt += MEMBLK;
483 if (((*buffer) =
484 rrd_realloc((*buffer),
485 (totalcnt + 4) * sizeof(char))) == NULL) {
486 perror("Realloc Buffer:");
487 exit(1);
488 };
489 }
490 } while (!feof(input));
491 (*buffer)[writecnt] = '\0';
492 if (strcmp("-", file_name) != 0) {
493 fclose(input);
494 };
495 return writecnt;
496 }