1 /*****************************************************************************
2 * RRDtool 1.2.23 Copyright by Tobi Oetiker, 1997-2007
3 *****************************************************************************
4 * rrd_open.c Open an RRD File
5 *****************************************************************************
8 * Revision 1.10 2004/05/26 22:11:12 oetiker
9 * reduce compiler warnings. Many small fixes. -- Mike Slifcak <slif@bellsouth.net>
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>
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>
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>
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
39 * There is also a new file "THREADS", holding some documentation.
41 * -- Peter Stamfest <peter@stamfest.at>
43 * Revision 1.5 2002/06/20 00:21:03 jake
44 * More Win32 build changes; thanks to Kerry Calvert.
46 * Revision 1.4 2002/02/01 20:34:49 oetiker
47 * fixed version number and date/time
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>
56 * Revision 1.2 2001/03/04 10:29:20 oetiker
57 * fixed filedescriptor leak
58 * -- Mike Franusich <mike@franusich.com>
60 * Revision 1.1.1.1 2001/02/25 22:25:05 oetiker
63 *****************************************************************************/
69 /* DEBUG 2 prints information obtained via mincore(2) */
71 /* do not calculate exact madvise hints but assume 2 pages for headers and
72 * set DONTNEED for the rest, which is assumed to be data */
74 /* Avoid calling madvise on areas that were already hinted. May be benefical if
75 * your syscalls are very slow */
76 //#define CHECK_MADVISE_OVERLAPS 1
79 #define __rrd_read(dst, dst_t, cnt) \
80 (dst) = (dst_t*) (data + offset); \
81 offset += sizeof(dst_t) * (cnt)
83 #define __rrd_read(dst, dst_t, cnt) \
84 if ((dst = malloc(sizeof(dst_t)*(cnt))) == NULL) { \
85 rrd_set_error(#dst " malloc"); \
86 goto out_nullify_head; \
88 offset += read (rrd_file->fd, dst, sizeof(dst_t)*(cnt))
91 /* next page-aligned (i.e. page-align up) */
93 #define PAGE_ALIGN(addr) (((addr)+_page_size-1)&(~(_page_size-1)))
95 /* previous page-aligned (i.e. page-align down) */
96 #ifndef PAGE_ALIGN_DOWN
97 #define PAGE_ALIGN_DOWN(addr) (((addr)+_page_size-1)&(~(_page_size-1)))
101 /* vector of last madvise hint */
102 typedef struct _madvise_vec_t {
106 _madvise_vec_t _madv_vec = { NULL, 0 };
109 #if defined CHECK_MADVISE_OVERLAPS
110 #define _madvise(_start, _off, _hint) \
111 if ((_start) != _madv_vec.start && (ssize_t)(_off) != _madv_vec.length) { \
112 _madv_vec.start = (_start) ; _madv_vec.length = (_off); \
113 madvise((_start), (_off), (_hint)); \
116 #define _madvise(_start, _off, _hint) \
117 madvise((_start), (_off), (_hint))
120 /* open a database file, return its header and an open filehandle */
121 /* positioned to the first cdp in the first rra */
123 rrd_file_t *rrd_open(
124 const char *const file_name,
129 mode_t mode = S_IRUSR;
133 ssize_t _page_size = sysconf(_SC_PAGESIZE);
134 int mm_prot = PROT_READ, mm_flags = 0;
139 rrd_file_t *rrd_file = malloc(sizeof(rrd_file_t));
141 if (rrd_file == NULL) {
142 rrd_set_error("allocating rrd_file descriptor for '%s'", file_name);
145 memset(rrd_file, 0, sizeof(rrd_file_t));
148 if ((rdwr & (RRD_READONLY | RRD_READWRITE)) ==
149 (RRD_READONLY | RRD_READWRITE)) {
150 /* Both READONLY and READWRITE were given, which is invalid. */
151 rrd_set_error("in read/write request mask");
155 if (rdwr & RRD_READONLY) {
158 mm_flags = MAP_PRIVATE;
159 # ifdef MAP_NORESERVE
160 mm_flags |= MAP_NORESERVE; /* readonly, so no swap backing needed */
164 if (rdwr & RRD_READWRITE) {
168 mm_flags = MAP_SHARED;
169 mm_prot |= PROT_WRITE;
172 if (rdwr & RRD_CREAT) {
173 flags |= (O_CREAT | O_TRUNC);
176 if (rdwr & RRD_READAHEAD) {
178 mm_flags |= MAP_POPULATE; /* populate ptes and data */
180 #if defined MAP_NONBLOCK
181 mm_flags |= MAP_NONBLOCK; /* just populate ptes */
192 if ((rrd_file->fd = open(file_name, flags, mode)) < 0) {
193 rrd_set_error("opening '%s': %s", file_name, rrd_strerror(errno));
197 /* Better try to avoid seeks as much as possible. stat may be heavy but
198 * many concurrent seeks are even worse. */
199 if ((fstat(rrd_file->fd, &statb)) < 0) {
200 rrd_set_error("fstat '%s': %s", file_name, rrd_strerror(errno));
203 rrd_file->file_len = statb.st_size;
205 #ifdef HAVE_POSIX_FADVISE
206 /* In general we need no read-ahead when dealing with rrd_files.
207 When we stop reading, it is highly unlikely that we start up again.
208 In this manner we actually save time and diskaccess (and buffer cache).
209 Thanks to Dave Plonka for the Idea of using POSIX_FADV_RANDOM here. */
210 if (0 != posix_fadvise(rrd_file->fd, 0, 0, POSIX_FADV_RANDOM)) {
211 rrd_set_error("setting POSIX_FADV_RANDOM on '%s': %s", file_name,
212 rrd_strerror(errno));
218 if (rdwr & RRD_READWRITE)
220 if (setvbuf((rrd_file->fd),NULL,_IONBF,2)) {
221 rrd_set_error("failed to disable the stream buffer\n");
227 data = mmap(0, rrd_file->file_len, mm_prot, mm_flags,
228 rrd_file->fd, offset);
230 /* lets see if the first read worked */
231 if (data == MAP_FAILED) {
232 rrd_set_error("error mmaping file '%s': %s", file_name,
233 rrd_strerror(errno));
236 rrd_file->file_start = data;
239 if (rdwr & RRD_COPY) {
240 /* We will read everything in a moment (copying) */
241 _madvise(data, rrd_file->file_len, MADV_WILLNEED | MADV_SEQUENTIAL);
244 /* We do not need to read anything in for the moment */
246 _madvise(data, rrd_file->file_len, MADV_DONTNEED);
247 // _madvise(data, rrd_file->file_len, MADV_RANDOM);
249 /* alternatively: keep 2 pages worth of data, likely headers,
250 * don't need the rest. */
251 _madvise(data, _page_size * 2, MADV_WILLNEED | MADV_SEQUENTIAL);
252 _madvise(data + _page_size * 2, (rrd_file->file_len >= _page_size * 2)
253 ? rrd_file->file_len - _page_size * 2 : 0, MADV_DONTNEED);
257 #if defined USE_MADVISE && !defined TWO_PAGES
258 /* the stat_head will be needed soonish, so hint accordingly */
259 // too finegrained to calc the individual sizes, just keep 2 pages worth of hdr
260 _madvise(data + PAGE_ALIGN_DOWN(offset), PAGE_ALIGN(sizeof(stat_head_t)),
265 __rrd_read(rrd->stat_head, stat_head_t,
268 /* lets do some test if we are on track ... */
269 if (memcmp(rrd->stat_head->cookie, RRD_COOKIE, sizeof(RRD_COOKIE)) != 0) {
270 rrd_set_error("'%s' is not an RRD file", file_name);
271 goto out_nullify_head;
274 if (rrd->stat_head->float_cookie != FLOAT_COOKIE) {
275 rrd_set_error("This RRD was created on other architecture");
276 goto out_nullify_head;
279 version = atoi(rrd->stat_head->version);
281 if (version > atoi(RRD_VERSION)) {
282 rrd_set_error("can't handle RRD file version %s",
283 rrd->stat_head->version);
284 goto out_nullify_head;
286 #if defined USE_MADVISE && !defined TWO_PAGES
287 /* the ds_def will be needed soonish, so hint accordingly */
288 _madvise(data + PAGE_ALIGN_DOWN(offset),
289 PAGE_ALIGN(sizeof(ds_def_t) * rrd->stat_head->ds_cnt),
292 __rrd_read(rrd->ds_def, ds_def_t,
293 rrd->stat_head->ds_cnt);
295 #if defined USE_MADVISE && !defined TWO_PAGES
296 /* the rra_def will be needed soonish, so hint accordingly */
297 _madvise(data + PAGE_ALIGN_DOWN(offset),
298 PAGE_ALIGN(sizeof(rra_def_t) * rrd->stat_head->rra_cnt),
301 __rrd_read(rrd->rra_def, rra_def_t,
302 rrd->stat_head->rra_cnt);
304 /* handle different format for the live_head */
306 rrd->live_head = (live_head_t *) malloc(sizeof(live_head_t));
307 if (rrd->live_head == NULL) {
308 rrd_set_error("live_head_t malloc");
312 memmove(&rrd->live_head->last_up, data + offset, sizeof(long));
313 offset += sizeof(long);
315 offset += read(rrd_file->fd, &rrd->live_head->last_up, sizeof(long));
317 rrd->live_head->last_up_usec = 0;
319 #if defined USE_MADVISE && !defined TWO_PAGES
320 /* the live_head will be needed soonish, so hint accordingly */
321 _madvise(data + PAGE_ALIGN_DOWN(offset),
322 PAGE_ALIGN(sizeof(live_head_t)), MADV_WILLNEED);
324 __rrd_read(rrd->live_head, live_head_t,
327 //XXX: This doesn't look like it needs madvise
328 __rrd_read(rrd->pdp_prep, pdp_prep_t,
329 rrd->stat_head->ds_cnt);
331 //XXX: This could benefit from madvise()ing
332 __rrd_read(rrd->cdp_prep, cdp_prep_t,
333 rrd->stat_head->rra_cnt * rrd->stat_head->ds_cnt);
335 //XXX: This could benefit from madvise()ing
336 __rrd_read(rrd->rra_ptr, rra_ptr_t,
337 rrd->stat_head->rra_cnt);
342 rrd_file->header_len = offset;
343 rrd_file->pos = offset;
347 rrd->stat_head = NULL;
354 /* Close a reference to an rrd_file. */
357 rrd_file_t *rrd_file)
361 #if defined HAVE_MMAP
362 ssize_t _page_size = sysconf(_SC_PAGESIZE);
364 #if defined DEBUG && DEBUG > 1
365 /* pretty print blocks in core */
371 ((rrd_file->file_len + sysconf(_SC_PAGESIZE) -
372 1) / sysconf(_SC_PAGESIZE));
376 if (mincore(rrd_file->file_start, rrd_file->file_len, vec) == 0) {
378 unsigned is_in = 0, was_in = 0;
380 for (off = 0, prev = 0; off < rrd_file->file_len; ++off) {
381 is_in = vec[off] & 1; /* if lsb set then is core resident */
384 if (was_in != is_in) {
385 fprintf(stderr, "%sin core: %p len %ld\n",
386 was_in ? "" : "not ", vec + prev, off - prev);
392 "%sin core: %p len %ld\n",
393 was_in ? "" : "not ", vec + prev, off - prev);
395 fprintf(stderr, "mincore: %s", rrd_strerror(errno));
402 /* Keep 2 pages worth of headers around, round up to next page boundary. */
404 PAGE_ALIGN(rrd_file->header_len % _page_size + rrd_file->header_len);
405 if (rrd_file->file_len > ret)
406 _madvise(rrd_file->file_start + ret,
407 rrd_file->file_len - ret, MADV_DONTNEED);
409 /* ignoring errors from RRDs that are smaller then the file_len+rounding */
410 _madvise(rrd_file->file_start + PAGE_ALIGN_DOWN(rrd_file->header_len),
411 rrd_file->file_len - PAGE_ALIGN(rrd_file->header_len),
416 ret = munmap(rrd_file->file_start, rrd_file->file_len);
418 rrd_set_error("munmap rrd_file: %s", rrd_strerror(errno));
422 // ret = close(rrd_file->fd);
424 // rrd_set_error("closing file: %s", rrd_strerror(errno));
431 /* Set position of rrd_file. */
434 rrd_file_t *rrd_file,
441 if (whence == SEEK_SET)
443 else if (whence == SEEK_CUR)
444 rrd_file->pos += off;
445 else if (whence == SEEK_END)
446 rrd_file->pos = rrd_file->file_len + off;
448 ret = lseek(rrd_file->fd, off, whence);
450 rrd_set_error("lseek: %s", rrd_strerror(errno));
453 //XXX: mimic fseek, which returns 0 upon success
454 return ret == -1; //XXX: or just ret to mimic lseek
458 /* Get current position in rrd_file. */
460 inline off_t rrd_tell(rrd_file_t *rrd_file)
462 return rrd_file->pos;
466 /* read count bytes into buffer buf, starting at rrd_file->pos.
467 * Returns the number of bytes read. */
470 rrd_file_t *rrd_file,
475 buf = memmove(buf, rrd_file->file_start + rrd_file->pos, count);
476 rrd_file->pos += count; /* mimmic read() semantics */
481 ret = read(rrd_file->fd, buf, count);
482 //XXX: eventually add generic rrd_set_error(""); here
483 rrd_file->pos += count; /* mimmic read() semantics */
489 /* write count bytes from buffer buf to the current position
490 * rrd_file->pos of rrd_file->fd.
491 * Returns the number of bytes written. */
494 rrd_file_t *rrd_file,
499 memmove(rrd_file->file_start + rrd_file->pos, buf, count);
500 return count; /* mimmic write() semantics */
502 return write(rrd_file->fd, buf, count);
507 /* flush all data pending to be written to FD. */
509 inline void rrd_flush(
510 rrd_file_t *rrd_file)
512 if (fdatasync(rrd_file->fd) != 0) {
513 rrd_set_error("flushing fd %d: %s", rrd_file->fd,
514 rrd_strerror(errno));
519 /* Initialize RRD header. */
524 rrd->stat_head = NULL;
527 rrd->live_head = NULL;
529 rrd->pdp_prep = NULL;
530 rrd->cdp_prep = NULL;
531 rrd->rrd_value = NULL;
535 /* free RRD header data. */
541 if (atoi(rrd->stat_head->version) < 3)
542 free(rrd->live_head);
543 free(rrd->stat_head);
549 free(rrd->rrd_value);
554 /* routine used by external libraries to free memory allocated by
564 /* XXX: FIXME: missing documentation. */
565 /*XXX: FIXME should be renamed to rrd_readfile or _rrd_readfile */
567 int /*_rrd_*/ readfile(
568 const char *file_name,
572 long writecnt = 0, totalcnt = MEMBLK;
577 if ((strcmp("-", file_name) == 0)) {
580 if ((input = fopen(file_name, "rb")) == NULL) {
581 rrd_set_error("opening '%s': %s", file_name, rrd_strerror(errno));
589 } while (c != '\n' && !feof(input));
591 if (strcmp("-", file_name)) {
592 fseek(input, 0, SEEK_END);
593 /* have extra space for detecting EOF without realloc */
594 totalcnt = (ftell(input) + 1) / sizeof(char) - offset;
595 if (totalcnt < MEMBLK)
596 totalcnt = MEMBLK; /* sanitize */
597 fseek(input, offset * sizeof(char), SEEK_SET);
599 if (((*buffer) = (char *) malloc((totalcnt + 4) * sizeof(char))) == NULL) {
600 perror("Allocate Buffer:");
605 fread((*buffer) + writecnt, 1,
606 (totalcnt - writecnt) * sizeof(char), input);
607 if (writecnt >= totalcnt) {
610 rrd_realloc((*buffer),
611 (totalcnt + 4) * sizeof(char))) == NULL) {
612 perror("Realloc Buffer:");
616 } while (!feof(input));
617 (*buffer)[writecnt] = '\0';
618 if (strcmp("-", file_name) != 0) {