36bc87585dec88facb3b123a0331774bcc6f8de4
1 /*****************************************************************************
2 * RRDtool 1.0.33 Copyright Tobias Oetiker, 1997 - 2000
3 *****************************************************************************
4 * rrd_open.c Open an RRD File
5 *****************************************************************************
6 * $Id$
7 * $Log$
8 * Revision 1.1 2001/02/25 22:25:05 oetiker
9 * Initial revision
10 *
11 *****************************************************************************/
13 #include "rrd_tool.h"
14 #define MEMBLK 8192
16 /* open a database file, return its header and a open filehandle */
17 /* positioned to the first cdp in the first rra */
19 int
20 rrd_open(char *file_name, FILE **in_file, rrd_t *rrd, int rdwr)
21 {
24 char *mode = NULL;
25 rrd_init(rrd);
26 if (rdwr == RRD_READONLY) {
27 #ifndef WIN32
28 mode = "r";
29 #else
30 mode = "rb";
31 #endif
32 } else {
33 #ifndef WIN32
34 mode = "r+";
35 #else
36 mode = "rb+";
37 #endif
38 }
40 if (((*in_file) = fopen(file_name,mode)) == NULL ){
41 rrd_set_error("opening '%s': %s",file_name, strerror(errno));
42 return (-1);
43 }
45 #define MYFREAD(MYVAR,MYVART,MYCNT) \
46 if ((MYVAR = malloc(sizeof(MYVART) * MYCNT)) == NULL) {\
47 rrd_set_error("" #MYVAR " malloc"); \
48 return (-1); } \
49 fread(MYVAR,sizeof(MYVART),MYCNT, *in_file);
52 MYFREAD(rrd->stat_head, stat_head_t, 1)
54 /* lets do some test if we are on track ... */
55 if (strncmp(rrd->stat_head->cookie,RRD_COOKIE,4) != 0){
56 rrd_set_error("'%s' is not an RRD file",file_name);
57 free(rrd->stat_head);
58 return(-1);}
60 if (strncmp(rrd->stat_head->version,RRD_VERSION,5) != 0){
61 rrd_set_error("cant handle RRD file version %s",
62 rrd->stat_head->version);
63 free(rrd->stat_head);
64 return(-1);}
66 if (rrd->stat_head->float_cookie != FLOAT_COOKIE){
67 rrd_set_error("This RRD was created on other architecture");
68 free(rrd->stat_head);
69 return(-1);}
71 MYFREAD(rrd->ds_def, ds_def_t, rrd->stat_head->ds_cnt)
72 MYFREAD(rrd->rra_def, rra_def_t, rrd->stat_head->rra_cnt)
73 MYFREAD(rrd->live_head, live_head_t, 1)
74 MYFREAD(rrd->pdp_prep, pdp_prep_t, rrd->stat_head->ds_cnt)
75 MYFREAD(rrd->cdp_prep, cdp_prep_t, (rrd->stat_head->rra_cnt
76 * rrd->stat_head->ds_cnt))
77 MYFREAD(rrd->rra_ptr, rra_ptr_t, rrd->stat_head->rra_cnt)
78 #undef MYFREAD
80 return(0);
81 }
83 void rrd_init(rrd_t *rrd)
84 {
85 rrd->stat_head = NULL;
86 rrd->ds_def = NULL;
87 rrd->rra_def = NULL;
88 rrd->live_head = NULL;
89 rrd->rra_ptr = NULL;
90 rrd->pdp_prep = NULL;
91 rrd->cdp_prep = NULL;
92 rrd->rrd_value = NULL;
93 }
95 void rrd_free(rrd_t *rrd)
96 {
97 free(rrd->stat_head);
98 free(rrd->ds_def);
99 free(rrd->rra_def);
100 free(rrd->live_head);
101 free(rrd->rra_ptr);
102 free(rrd->pdp_prep);
103 free(rrd->cdp_prep);
104 free(rrd->rrd_value);
105 }
107 int readfile(char *file_name, char **buffer, int skipfirst){
108 long writecnt=0,totalcnt = MEMBLK;
109 FILE *input=NULL;
110 char c ;
111 if ((strcmp("-",file_name) == 0)) { input = stdin; }
112 else {
113 if ((input = fopen(file_name,"rb")) == NULL ){
114 rrd_set_error("opening '%s': %s",file_name,strerror(errno));
115 return (-1);
116 }
117 }
118 if (skipfirst){
119 do { c = getc(input); } while (c != '\n' && ! feof(input));
120 }
121 if (((*buffer) = (char *) malloc((MEMBLK+4)*sizeof(char))) == NULL) {
122 perror("Allocate Buffer:");
123 exit(1);
124 };
125 do{
126 writecnt += fread((*buffer)+writecnt, 1, MEMBLK * sizeof(char) ,input);
127 if (writecnt >= totalcnt){
128 totalcnt += MEMBLK;
129 if (((*buffer)=rrd_realloc((*buffer), (totalcnt+4) * sizeof(char)))==NULL){
130 perror("Realloc Buffer:");
131 exit(1);
132 };
133 }
134 } while (! feof(input));
135 (*buffer)[writecnt] = '\0';
136 if (strcmp("-",file_name) != 0) {fclose(input);};
137 return writecnt;
138 }