X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=src%2Frrd_open.c;h=a01b07543a88878556e21097b4c1c6985e0f6c69;hb=271be77064640b1daa3408885d60b8bead1126ad;hp=746044edc0cadb9380b53038e29e2db43c71166e;hpb=58a8f90229ee1625e0270256683b048da1b1df24;p=rrdtool.git diff --git a/src/rrd_open.c b/src/rrd_open.c index 746044e..a01b075 100644 --- a/src/rrd_open.c +++ b/src/rrd_open.c @@ -4,62 +4,6 @@ * 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 - * - * 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 - * - * 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 - * - * 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 - * - * 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 - * - * 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 - * - * Revision 1.2 2001/03/04 10:29:20 oetiker - * fixed filedescriptor leak - * -- Mike Franusich - * - * Revision 1.1.1.1 2001/02/25 22:25:05 oetiker - * checkin - * *****************************************************************************/ #include "rrd_tool.h" @@ -143,7 +87,14 @@ rrd_file_t *rrd_open( 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) { @@ -204,12 +155,18 @@ rrd_file_t *rrd_open( /* 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. @@ -242,30 +199,34 @@ rrd_file_t *rrd_open( 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; - } + } else { # ifndef ONE_PAGE - /* We do not need to read anything in for the moment */ - _madvise(data, rrd_file->file_len, MADV_DONTNEED); + /* 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); + _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 */ - _madvise(data + PAGE_ALIGN_DOWN(offset), PAGE_ALIGN(sizeof(stat_head_t)), - MADV_WILLNEED | MADV_RANDOM); - + } #endif __rrd_read(rrd->stat_head, stat_head_t, @@ -342,12 +303,9 @@ rrd_file_t *rrd_open( __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; @@ -468,7 +426,7 @@ inline off_t rrd_tell( /* 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, @@ -476,15 +434,24 @@ inline ssize_t rrd_read( 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 } @@ -504,7 +471,8 @@ inline ssize_t rrd_write( 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; @@ -551,8 +519,7 @@ inline void rrd_free( 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);