1 /*****************************************************************************
2 * RRDtool 1.2.12 Copyright by Tobi Oetiker, 1997-2005
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 }
90 /*
91 if (rdwr == RRD_READWRITE)
92 {
93 if (setvbuf((*in_file),NULL,_IONBF,2)) {
94 rrd_set_error("failed to disable the stream buffer\n");
95 return (-1);
96 }
97 }
98 */
100 #define MYFREAD(MYVAR,MYVART,MYCNT) \
101 if ((MYVAR = malloc(sizeof(MYVART) * MYCNT)) == NULL) {\
102 rrd_set_error("" #MYVAR " malloc"); \
103 fclose(*in_file); \
104 return (-1); } \
105 fread(MYVAR,sizeof(MYVART),MYCNT, *in_file);
108 MYFREAD(rrd->stat_head, stat_head_t, 1)
109 /* lets see if the first read worked */
110 if (ferror( *in_file ) || feof(*in_file)) {
111 rrd_set_error("reading the cookie off %s faild",file_name);
112 fclose(*in_file);
113 return(-1);
114 }
116 /* lets do some test if we are on track ... */
117 if (strncmp(rrd->stat_head->cookie,RRD_COOKIE,4) != 0){
118 rrd_set_error("'%s' is not an RRD file",file_name);
119 free(rrd->stat_head);
120 rrd->stat_head = NULL;
121 fclose(*in_file);
122 return(-1);}
124 if (rrd->stat_head->float_cookie != FLOAT_COOKIE){
125 rrd_set_error("This RRD was created on other architecture");
126 free(rrd->stat_head);
127 rrd->stat_head = NULL;
128 fclose(*in_file);
129 return(-1);}
131 version = atoi(rrd->stat_head->version);
133 if (version > atoi(RRD_VERSION)){
134 rrd_set_error("can't handle RRD file version %s",
135 rrd->stat_head->version);
136 free(rrd->stat_head);
137 rrd->stat_head = NULL;
138 fclose(*in_file);
139 return(-1);}
142 MYFREAD(rrd->ds_def, ds_def_t, rrd->stat_head->ds_cnt)
143 MYFREAD(rrd->rra_def, rra_def_t, rrd->stat_head->rra_cnt)
144 /* handle different format for the live_head */
145 if(version < 3) {
146 rrd->live_head = (live_head_t *)malloc(sizeof(live_head_t));
147 if(rrd->live_head == NULL) {
148 rrd_set_error("live_head_t malloc");
149 fclose(*in_file);
150 return (-1);
151 }
152 fread(&rrd->live_head->last_up, sizeof(long), 1, *in_file);
153 rrd->live_head->last_up_usec = 0;
154 }
155 else {
156 MYFREAD(rrd->live_head, live_head_t, 1)
157 }
158 MYFREAD(rrd->pdp_prep, pdp_prep_t, rrd->stat_head->ds_cnt)
159 MYFREAD(rrd->cdp_prep, cdp_prep_t, (rrd->stat_head->rra_cnt
160 * rrd->stat_head->ds_cnt))
161 MYFREAD(rrd->rra_ptr, rra_ptr_t, rrd->stat_head->rra_cnt)
162 #undef MYFREAD
164 return(0);
165 }
167 void rrd_init(rrd_t *rrd)
168 {
169 rrd->stat_head = NULL;
170 rrd->ds_def = NULL;
171 rrd->rra_def = NULL;
172 rrd->live_head = NULL;
173 rrd->rra_ptr = NULL;
174 rrd->pdp_prep = NULL;
175 rrd->cdp_prep = NULL;
176 rrd->rrd_value = NULL;
177 }
179 void rrd_free(rrd_t *rrd)
180 {
181 if (rrd->stat_head) free(rrd->stat_head);
182 if (rrd->ds_def) free(rrd->ds_def);
183 if (rrd->rra_def) free(rrd->rra_def);
184 if (rrd->live_head) free(rrd->live_head);
185 if (rrd->rra_ptr) free(rrd->rra_ptr);
186 if (rrd->pdp_prep) free(rrd->pdp_prep);
187 if (rrd->cdp_prep) free(rrd->cdp_prep);
188 if (rrd->rrd_value) free(rrd->rrd_value);
189 }
191 /* routine used by external libraries to free memory allocated by
192 * rrd library */
193 void rrd_freemem(void *mem)
194 {
196 if (mem) free(mem);
197 }
199 int readfile(const char *file_name, char **buffer, int skipfirst){
200 long writecnt=0,totalcnt = MEMBLK;
201 long offset = 0;
202 FILE *input=NULL;
203 char c ;
204 if ((strcmp("-",file_name) == 0)) { input = stdin; }
205 else {
206 if ((input = fopen(file_name,"rb")) == NULL ){
207 rrd_set_error("opening '%s': %s",file_name,rrd_strerror(errno));
208 return (-1);
209 }
210 }
211 if (skipfirst){
212 do { c = getc(input); offset++; } while (c != '\n' && ! feof(input));
213 }
214 if (strcmp("-",file_name)) {
215 fseek(input, 0, SEEK_END);
216 /* have extra space for detecting EOF without realloc */
217 totalcnt = (ftell(input) + 1) / sizeof(char) - offset;
218 if (totalcnt < MEMBLK)
219 totalcnt = MEMBLK; /* sanitize */
220 fseek(input, offset * sizeof(char), SEEK_SET);
221 }
222 if (((*buffer) = (char *) malloc((totalcnt+4) * sizeof(char))) == NULL) {
223 perror("Allocate Buffer:");
224 exit(1);
225 };
226 do{
227 writecnt += fread((*buffer)+writecnt, 1, (totalcnt - writecnt) * sizeof(char),input);
228 if (writecnt >= totalcnt){
229 totalcnt += MEMBLK;
230 if (((*buffer)=rrd_realloc((*buffer), (totalcnt+4) * sizeof(char)))==NULL){
231 perror("Realloc Buffer:");
232 exit(1);
233 };
234 }
235 } while (! feof(input));
236 (*buffer)[writecnt] = '\0';
237 if (strcmp("-",file_name) != 0) {fclose(input);};
238 return writecnt;
239 }