src/rrd_resize.c

   1 /*****************************************************************************
   2  * RRDtool 1.2.11  Copyright by Tobi Oetiker, 1997-2005
   3  *****************************************************************************
   4  * rrd_resize.c Alters size of an RRA
   5  *****************************************************************************
   6  * Initial version by Alex van den Bogaerdt
   7  *****************************************************************************/
   8
   9 #include "rrd_tool.h"
  10
  11 int
  12 rrd_resize(int argc, char **argv)
  13 {
  14     char             *infilename,outfilename[11]="resize.rrd";
  15     FILE             *infile,*outfile;
  16     rrd_t             rrdold,rrdnew;
  17     rrd_value_t       buffer;
  18     unsigned long     l,rra;
  19     long              modify;
  20     unsigned long     target_rra;
  21     int               grow=0,shrink=0;
  22     char             *endptr;
  23
  24     infilename=argv[1];
  25     if (!strcmp(infilename,"resize.rrd")) {
  26         rrd_set_error("resize.rrd is a reserved name");
  27         return(-1);
  28     }
  29     if (argc!=5) {
  30         rrd_set_error("wrong number of parameters");
  31         return(-1);
  32     }
  33
  34     target_rra=strtol(argv[2],&endptr,0);
  35
  36     if (!strcmp(argv[3],"GROW")) grow=1;
  37     else if (!strcmp(argv[3],"SHRINK")) shrink=1;
  38     else {
  39         rrd_set_error("I can only GROW or SHRINK");
  40         return(-1);
  41     }
  42
  43     modify=strtol(argv[4],&endptr,0);
  44
  45     if ((modify<1)) {
  46         rrd_set_error("Please grow or shrink with at least 1 row");
  47         return(-1);
  48     }
  49
  50     if (shrink) modify = -modify;
  51
  52
  53     if (rrd_open(infilename, &infile, &rrdold, RRD_READWRITE)==-1) {
  54         rrd_set_error("could not open RRD");
  55         return(-1);
  56     }
  57     if (LockRRD(infile) != 0) {
  58         rrd_set_error("could not lock original RRD");
  59         rrd_free(&rrdold);
  60         fclose(infile);
  61         return(-1);
  62     }
  63
  64     if (target_rra >= rrdold.stat_head->rra_cnt) {
  65         rrd_set_error("no such RRA in this RRD");
  66         rrd_free(&rrdold);
  67         fclose(infile);
  68         return(-1);
  69     }
  70
  71     if (modify < 0)
  72         if ((long)rrdold.rra_def[target_rra].row_cnt <= -modify) {
  73             rrd_set_error("This RRA is not that big");
  74             rrd_free(&rrdold);
  75             fclose(infile);
  76             return(-1);
  77         }
  78
  79     rrdnew.stat_head = rrdold.stat_head;
  80     rrdnew.ds_def    = rrdold.ds_def;
  81     rrdnew.rra_def   = rrdold.rra_def;
  82     rrdnew.live_head = rrdold.live_head;
  83     rrdnew.pdp_prep  = rrdold.pdp_prep;
  84     rrdnew.cdp_prep  = rrdold.cdp_prep;
  85     rrdnew.rra_ptr   = rrdold.rra_ptr;
  86
  87     if ((outfile=fopen(outfilename,"wb"))==NULL) {
  88         rrd_set_error("Can't create '%s'",outfilename);
  89         return(-1);
  90     }
  91     if (LockRRD(outfile) != 0) {
  92         rrd_set_error("could not lock new RRD");
  93         rrd_free(&rrdold);
  94         fclose(infile);
  95         fclose(outfile);
  96         return(-1);
  97     }
  98     fwrite(rrdnew.stat_head, sizeof(stat_head_t),1,outfile);
  99     fwrite(rrdnew.ds_def,sizeof(ds_def_t),rrdnew.stat_head->ds_cnt,outfile);
 100     fwrite(rrdnew.rra_def,sizeof(rra_def_t),rrdnew.stat_head->rra_cnt,outfile);
 101     fwrite(rrdnew.live_head,sizeof(live_head_t),1,outfile);
 102     fwrite(rrdnew.pdp_prep,sizeof(pdp_prep_t),rrdnew.stat_head->ds_cnt,outfile);
 103     fwrite(rrdnew.cdp_prep,sizeof(cdp_prep_t),rrdnew.stat_head->ds_cnt*rrdnew.stat_head->rra_cnt,outfile);
 104     fwrite(rrdnew.rra_ptr,sizeof(rra_ptr_t),rrdnew.stat_head->rra_cnt,outfile);
 105
 106     /* Move the CDPs from the old to the new database.
 107     ** This can be made (much) faster but isn't worth the effort. Clarity
 108     ** is much more important.
 109     */
 110
 111     /* Move data in unmodified RRAs
 112     */
 113     l=0;
 114     for (rra=0;rra<target_rra;rra++) {
 115         l+=rrdnew.stat_head->ds_cnt * rrdnew.rra_def[rra].row_cnt;
 116     }
 117     while (l>0) {
 118         fread(&buffer,sizeof(rrd_value_t),1,infile);
 119         fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 120         l--;
 121     }
 122     /* Move data in this RRA, either removing or adding some rows
 123     */
 124     if (modify>0) {
 125         /* Adding extra rows; insert unknown values just after the
 126         ** current row number.
 127         */
 128         l = rrdnew.stat_head->ds_cnt * (rrdnew.rra_ptr[target_rra].cur_row+1);
 129         while (l>0) {
 130             fread(&buffer,sizeof(rrd_value_t),1,infile);
 131             fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 132             l--;
 133         }
 134         buffer=DNAN;
 135         l=rrdnew.stat_head->ds_cnt * modify;
 136         while (l>0) {
 137             fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 138             l--;
 139         }
 140     } else {
 141         /* Removing rows. Normally this would be just after the cursor
 142         ** however this may also mean that we wrap to the beginning of
 143         ** the array.
 144         */
 145         signed long int remove_end=0;
 146
 147         remove_end=(rrdnew.rra_ptr[target_rra].cur_row-modify)%rrdnew.rra_def[target_rra].row_cnt;
 148         if (remove_end <= (signed long int)rrdnew.rra_ptr[target_rra].cur_row) {
 149             while (remove_end >= 0) {
 150                 fseek(infile,sizeof(rrd_value_t)*rrdnew.stat_head->ds_cnt,SEEK_CUR);
 151                 rrdnew.rra_ptr[target_rra].cur_row--;
 152                 rrdnew.rra_def[target_rra].row_cnt--;
 153                 remove_end--;
 154                 modify++;
 155             }
 156             remove_end=rrdnew.rra_def[target_rra].row_cnt-1;
 157         }
 158         for (l=0;l<=rrdnew.rra_ptr[target_rra].cur_row;l++) {
 159             unsigned int tmp;
 160             for (tmp=0;tmp<rrdnew.stat_head->ds_cnt;tmp++) {
 161                 fread(&buffer,sizeof(rrd_value_t),1,infile);
 162                 fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 163             }
 164         }
 165         while (modify<0) {
 166             fseek(infile,sizeof(rrd_value_t)*rrdnew.stat_head->ds_cnt,SEEK_CUR);
 167             rrdnew.rra_def[target_rra].row_cnt--;
 168             modify++;
 169         }
 170     }
 171     /* Move the rest of the CDPs
 172     */
 173     while (1) {
 174         fread(&buffer,sizeof(rrd_value_t),1,infile);
 175         if (feof(infile))
 176             break;
 177         fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 178     }
 179     rrdnew.rra_def[target_rra].row_cnt += modify;
 180     fseek(outfile,sizeof(stat_head_t)+sizeof(ds_def_t)*rrdnew.stat_head->ds_cnt,SEEK_SET);
 181     fwrite(rrdnew.rra_def,sizeof(rra_def_t),rrdnew.stat_head->rra_cnt, outfile);
 182     fseek(outfile,sizeof(live_head_t),SEEK_CUR);
 183     fseek(outfile,sizeof(pdp_prep_t)*rrdnew.stat_head->ds_cnt,SEEK_CUR);
 184     fseek(outfile,sizeof(cdp_prep_t)*rrdnew.stat_head->ds_cnt*rrdnew.stat_head->rra_cnt,SEEK_CUR);
 185     fwrite(rrdnew.rra_ptr,sizeof(rra_ptr_t),rrdnew.stat_head->rra_cnt, outfile);
 186
 187     fclose(outfile);
 188     rrd_free(&rrdold);
 189     fclose(infile);
 190     return(0);
 191 }