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 #define MEMBLK 8192
68 /* open a database file, return its header and a open filehandle */
69 /* positioned to the first cdp in the first rra */
71 int
72 rrd_open(const char *file_name, FILE **in_file, rrd_t *rrd, int rdwr)
73 {
76 char *mode = NULL;
77 int version;
79 rrd_init(rrd);
80 if (rdwr == RRD_READONLY) {
81 mode = "rb";
82 } else {
83 mode = "rb+";
84 }
86 if (((*in_file) = fopen(file_name,mode)) == NULL ){
87 rrd_set_error("opening '%s': %s",file_name, rrd_strerror(errno));
88 return (-1);
89 }
91 #ifdef HAVE_POSIX_FADVISE
92 /* In general we need no read-ahead when dealing with rrd_files.
93 When we stop reading, it is highly unlikely that we start up again.
94 In this manner we actually save time and diskaccess (and buffer cache).
95 Thanks to Dave Plonka for the Idea of using POSIX_FADV_RANDOM here. */
96 if (0 != posix_fadvise(fileno(*in_file), 0, 0, POSIX_FADV_RANDOM)) {
97 rrd_set_error("setting POSIX_FADV_RANDOM on '%s': %s",file_name, rrd_strerror(errno));
98 fclose(*in_file);
99 return(-1);
100 }
101 #endif
103 /*
104 if (rdwr == RRD_READWRITE)
105 {
106 if (setvbuf((*in_file),NULL,_IONBF,2)) {
107 rrd_set_error("failed to disable the stream buffer\n");
108 return (-1);
109 }
110 }
111 */
113 #define MYFREAD(MYVAR,MYVART,MYCNT) \
114 if ((MYVAR = malloc(sizeof(MYVART) * MYCNT)) == NULL) {\
115 rrd_set_error("" #MYVAR " malloc"); \
116 fclose(*in_file); \
117 return (-1); } \
118 fread(MYVAR,sizeof(MYVART),MYCNT, *in_file);
121 MYFREAD(rrd->stat_head, stat_head_t, 1)
122 /* lets see if the first read worked */
123 if (ferror( *in_file ) || feof(*in_file)) {
124 rrd_set_error("reading the cookie off %s faild",file_name);
125 fclose(*in_file);
126 return(-1);
127 }
129 /* lets do some test if we are on track ... */
130 if (strncmp(rrd->stat_head->cookie,RRD_COOKIE,4) != 0){
131 rrd_set_error("'%s' is not an RRD file",file_name);
132 free(rrd->stat_head);
133 rrd->stat_head = NULL;
134 fclose(*in_file);
135 return(-1);}
137 if (rrd->stat_head->float_cookie != FLOAT_COOKIE){
138 rrd_set_error("This RRD was created on other architecture");
139 free(rrd->stat_head);
140 rrd->stat_head = NULL;
141 fclose(*in_file);
142 return(-1);}
144 version = atoi(rrd->stat_head->version);
146 if (version > atoi(RRD_VERSION)){
147 rrd_set_error("can't handle RRD file version %s",
148 rrd->stat_head->version);
149 free(rrd->stat_head);
150 rrd->stat_head = NULL;
151 fclose(*in_file);
152 return(-1);}
155 MYFREAD(rrd->ds_def, ds_def_t, rrd->stat_head->ds_cnt)
156 MYFREAD(rrd->rra_def, rra_def_t, rrd->stat_head->rra_cnt)
157 /* handle different format for the live_head */
158 if(version < 3) {
159 rrd->live_head = (live_head_t *)malloc(sizeof(live_head_t));
160 if(rrd->live_head == NULL) {
161 rrd_set_error("live_head_t malloc");
162 fclose(*in_file);
163 return (-1);
164 }
165 fread(&rrd->live_head->last_up, sizeof(long), 1, *in_file);
166 rrd->live_head->last_up_usec = 0;
167 }
168 else {
169 MYFREAD(rrd->live_head, live_head_t, 1)
170 }
171 MYFREAD(rrd->pdp_prep, pdp_prep_t, rrd->stat_head->ds_cnt)
172 MYFREAD(rrd->cdp_prep, cdp_prep_t, (rrd->stat_head->rra_cnt
173 * rrd->stat_head->ds_cnt))
174 MYFREAD(rrd->rra_ptr, rra_ptr_t, rrd->stat_head->rra_cnt)
175 #undef MYFREAD
177 return(0);
178 }
180 void rrd_init(rrd_t *rrd)
181 {
182 rrd->stat_head = NULL;
183 rrd->ds_def = NULL;
184 rrd->rra_def = NULL;
185 rrd->live_head = NULL;
186 rrd->rra_ptr = NULL;
187 rrd->pdp_prep = NULL;
188 rrd->cdp_prep = NULL;
189 rrd->rrd_value = NULL;
190 }
192 void rrd_free(rrd_t *rrd)
193 {
194 if (rrd->stat_head) free(rrd->stat_head);
195 if (rrd->ds_def) free(rrd->ds_def);
196 if (rrd->rra_def) free(rrd->rra_def);
197 if (rrd->live_head) free(rrd->live_head);
198 if (rrd->rra_ptr) free(rrd->rra_ptr);
199 if (rrd->pdp_prep) free(rrd->pdp_prep);
200 if (rrd->cdp_prep) free(rrd->cdp_prep);
201 if (rrd->rrd_value) free(rrd->rrd_value);
202 }
204 /* routine used by external libraries to free memory allocated by
205 * rrd library */
206 void rrd_freemem(void *mem)
207 {
209 if (mem) free(mem);
210 }
212 int readfile(const char *file_name, char **buffer, int skipfirst){
213 long writecnt=0,totalcnt = MEMBLK;
214 long offset = 0;
215 FILE *input=NULL;
216 char c ;
217 if ((strcmp("-",file_name) == 0)) { input = stdin; }
218 else {
219 if ((input = fopen(file_name,"rb")) == NULL ){
220 rrd_set_error("opening '%s': %s",file_name,rrd_strerror(errno));
221 return (-1);
222 }
223 }
224 if (skipfirst){
225 do { c = getc(input); offset++; } while (c != '\n' && ! feof(input));
226 }
227 if (strcmp("-",file_name)) {
228 fseek(input, 0, SEEK_END);
229 /* have extra space for detecting EOF without realloc */
230 totalcnt = (ftell(input) + 1) / sizeof(char) - offset;
231 if (totalcnt < MEMBLK)
232 totalcnt = MEMBLK; /* sanitize */
233 fseek(input, offset * sizeof(char), SEEK_SET);
234 }
235 if (((*buffer) = (char *) malloc((totalcnt+4) * sizeof(char))) == NULL) {
236 perror("Allocate Buffer:");
237 exit(1);
238 };
239 do{
240 writecnt += fread((*buffer)+writecnt, 1, (totalcnt - writecnt) * sizeof(char),input);
241 if (writecnt >= totalcnt){
242 totalcnt += MEMBLK;
243 if (((*buffer)=rrd_realloc((*buffer), (totalcnt+4) * sizeof(char)))==NULL){
244 perror("Realloc Buffer:");
245 exit(1);
246 };
247 }
248 } while (! feof(input));
249 (*buffer)[writecnt] = '\0';
250 if (strcmp("-",file_name) != 0) {fclose(input);};
251 return writecnt;
252 }