* rrd_open.c Open an RRD File
*****************************************************************************
* $Id$
- * $Log$
- * Revision 1.10 2004/05/26 22:11:12 oetiker
- * reduce compiler warnings. Many small fixes. -- Mike Slifcak <slif@bellsouth.net>
- *
- * Revision 1.9 2003/04/29 21:56:49 oetiker
- * readline in rrd_open.c reads the file in 8 KB blocks, and calls realloc for
- * each block. realloc is very slow in Mac OS X for huge blocks, e.g. when
- * restoring databases from huge xml files. This patch finds the size of the
- * file, and starts out with malloc'ing the full size.
- * -- Peter Speck <speck@ruc.dk>
- *
- * Revision 1.8 2003/04/11 19:43:44 oetiker
- * New special value COUNT which allows calculations based on the position of a
- * value within a data set. Bug fix in rrd_rpncalc.c. PREV returned erroneus
- * value for the second value. Bug fix in rrd_restore.c. Bug causing seek error
- * when accesing an RRD restored from an xml that holds an RRD version <3.
- * -- Ruben Justo <ruben@ainek.com>
- *
- * Revision 1.7 2003/03/31 21:22:12 oetiker
- * enables RRDtool updates with microsecond or in case of windows millisecond
- * precision. This is needed to reduce time measurement error when archive step
- * is small. (<30s) -- Sasha Mikheev <sasha@avalon-net.co.il>
- *
- * Revision 1.6 2003/02/13 07:05:27 oetiker
- * Find attached the patch I promised to send to you. Please note that there
- * are three new source files (src/rrd_is_thread_safe.h, src/rrd_thread_safe.c
- * and src/rrd_not_thread_safe.c) and the introduction of librrd_th. This
- * library is identical to librrd, but it contains support code for per-thread
- * global variables currently used for error information only. This is similar
- * to how errno per-thread variables are implemented. librrd_th must be linked
- * alongside of libpthred
- *
- * There is also a new file "THREADS", holding some documentation.
- *
- * -- Peter Stamfest <peter@stamfest.at>
- *
- * Revision 1.5 2002/06/20 00:21:03 jake
- * More Win32 build changes; thanks to Kerry Calvert.
- *
- * Revision 1.4 2002/02/01 20:34:49 oetiker
- * fixed version number and date/time
- *
- * Revision 1.3 2001/03/04 13:01:55 oetiker
- * Aberrant Behavior Detection support. A brief overview added to rrdtool.pod.
- * Major updates to rrd_update.c, rrd_create.c. Minor update to other core files.
- * This is backwards compatible! But new files using the Aberrant stuff are not readable
- * by old rrdtool versions. See http://cricket.sourceforge.net/aberrant/rrd_hw.htm
- * -- Jake Brutlag <jakeb@corp.webtv.net>
- *
- * Revision 1.2 2001/03/04 10:29:20 oetiker
- * fixed filedescriptor leak
- * -- Mike Franusich <mike@franusich.com>
- *
- * Revision 1.1.1.1 2001/02/25 22:25:05 oetiker
- * checkin
- *
*****************************************************************************/
#include "rrd_tool.h"
#define CHECK_MADVISE_OVERLAPS 1
#ifdef HAVE_MMAP
+/* the cast to void* is there to avoid this warning seen on ia64 with certain
+ versions of gcc: 'cast increases required alignment of target type'
+*/
#define __rrd_read(dst, dst_t, cnt) \
- (dst) = (dst_t*) (data + offset); \
+ (dst) = (dst_t*)(void*) (data + offset); \
offset += sizeof(dst_t) * (cnt)
#else
#define __rrd_read(dst, dst_t, cnt) \
off_t offset = 0;
struct stat statb;
rrd_file_t *rrd_file = NULL;
+ off_t newfile_size = 0;
+ if (rdwr & RRD_CREAT) {
+ /* yes bad inline signaling alert, we are using the
+ floatcookie to pass the size in ... only used in resize */
+ newfile_size = (off_t) rrd->stat_head->float_cookie;
+ free(rrd->stat_head);
+ }
rrd_init(rrd);
rrd_file = malloc(sizeof(rrd_file_t));
if (rrd_file == NULL) {
/* Better try to avoid seeks as much as possible. stat may be heavy but
* many concurrent seeks are even worse. */
- if ((fstat(rrd_file->fd, &statb)) < 0) {
+ if (newfile_size == 0 && ((fstat(rrd_file->fd, &statb)) < 0)) {
rrd_set_error("fstat '%s': %s", file_name, rrd_strerror(errno));
goto out_close;
}
- rrd_file->file_len = statb.st_size;
-
+ if (newfile_size == 0) {
+ rrd_file->file_len = statb.st_size;
+ } else {
+ rrd_file->file_len = newfile_size;
+ lseek(rrd_file->fd, newfile_size - 1, SEEK_SET);
+ write(rrd_file->fd, "\0", 1); /* poke */
+ lseek(rrd_file->fd, 0, SEEK_SET);
+ }
#ifdef HAVE_POSIX_FADVISE
/* In general we need no read-ahead when dealing with rrd_files.
When we stop reading, it is highly unlikely that we start up again.
goto out_close;
}
rrd_file->file_start = data;
+ if (rdwr & RRD_CREAT) {
+ memset(data, DNAN, newfile_size - 1);
+ goto out_done;
+ }
#endif
+ if (rdwr & RRD_CREAT)
+ goto out_done;
#ifdef USE_MADVISE
if (rdwr & RRD_COPY) {
/* We will read everything in a moment (copying) */
_madvise(data, rrd_file->file_len, MADV_WILLNEED | MADV_SEQUENTIAL);
- goto out_done;
- }
- /* We do not need to read anything in for the moment */
-#ifndef ONE_PAGE
- _madvise(data, rrd_file->file_len, MADV_DONTNEED);
-// _madvise(data, rrd_file->file_len, MADV_RANDOM);
-#else
-/* alternatively: keep 2 pages worth of data, likely headers,
- * don't need the rest. */
- _madvise(data, _page_size, MADV_WILLNEED | MADV_SEQUENTIAL);
- _madvise(data + _page_size, (rrd_file->file_len >= _page_size)
- ? rrd_file->file_len - _page_size : 0, MADV_DONTNEED);
-#endif
-#endif
-
-#if defined USE_MADVISE && !defined ONE_PAGE
- /* the stat_head will be needed soonish, so hint accordingly */
-// too finegrained to calc the individual sizes, just keep 2 pages worth of hdr
- _madvise(data + PAGE_ALIGN_DOWN(offset), PAGE_ALIGN(sizeof(stat_head_t)),
- MADV_WILLNEED);
+ } else {
+# ifndef ONE_PAGE
+ /* We do not need to read anything in for the moment */
+ _madvise(data, rrd_file->file_len, MADV_DONTNEED);
+ /* the stat_head will be needed soonish, so hint accordingly */
+ _madvise(data + PAGE_ALIGN_DOWN(offset),
+ PAGE_ALIGN(sizeof(stat_head_t)),
+ MADV_WILLNEED | MADV_RANDOM);
+# else
+/* alternatively: keep 1 page worth of data, likely headers,
+ * don't need the rest. */
+ _madvise(data, _page_size, MADV_WILLNEED | MADV_SEQUENTIAL);
+ _madvise(data + _page_size, (rrd_file->file_len >= _page_size)
+ ? rrd_file->file_len - _page_size : 0, MADV_DONTNEED);
+# endif
+ }
#endif
__rrd_read(rrd->stat_head, stat_head_t,
__rrd_read(rrd->rra_ptr, rra_ptr_t,
rrd->stat_head->rra_cnt);
-#ifdef USE_MADVISE
- out_done:
-#endif
rrd_file->header_len = offset;
rrd_file->pos = offset;
-
+ out_done:
return (rrd_file);
out_nullify_head:
rrd->stat_head = NULL;
/* read count bytes into buffer buf, starting at rrd_file->pos.
- * Returns the number of bytes read. */
+ * Returns the number of bytes read or <0 on error. */
inline ssize_t rrd_read(
rrd_file_t *rrd_file,
size_t count)
{
#ifdef HAVE_MMAP
- buf = memcpy(buf, rrd_file->file_start + rrd_file->pos, count);
- rrd_file->pos += count; /* mimmic read() semantics */
- return count;
+ size_t _cnt = count;
+ ssize_t _surplus = rrd_file->pos + _cnt - rrd_file->file_len;
+
+ if (_surplus > 0) { /* short read */
+ _cnt -= _surplus;
+ }
+ if (_cnt == 0)
+ return 0; /* EOF */
+ buf = memcpy(buf, rrd_file->file_start + rrd_file->pos, _cnt);
+
+ rrd_file->pos += _cnt; /* mimmic read() semantics */
+ return _cnt;
#else
ssize_t ret;
ret = read(rrd_file->fd, buf, count);
- //XXX: eventually add generic rrd_set_error(""); here
- rrd_file->pos += count; /* mimmic read() semantics */
+ if (ret > 0)
+ rrd_file->pos += ret; /* mimmic read() semantics */
return ret;
#endif
}
rrd_file->pos += count;
return count; /* mimmic write() semantics */
#else
- ssize_t _sz = write(rrd_file->fd, buf, count);
+ ssize_t _sz = write(rrd_file->fd, buf, count);
+
if (_sz > 0)
rrd_file->pos += _sz;
return _sz;
void rrd_free(
rrd_t *rrd)
{
- if (atoi(rrd->stat_head->version) < 3)
- free(rrd->live_head);
+ free(rrd->live_head);
free(rrd->stat_head);
free(rrd->ds_def);
free(rrd->rra_def);
projects / rrdtool.git / blobdiff