src/rrd_resize.c

   1 /*****************************************************************************
   2  * RRDtool 1.2.16  Copyright by Tobi Oetiker, 1997-2006
   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     int                 version;
  19     unsigned long       l,rra;
  20     long                modify;
  21     unsigned long       target_rra;
  22     int                 grow=0,shrink=0;
  23     char                *endptr;
  24
  25     infilename=argv[1];
  26     if (!strcmp(infilename,"resize.rrd")) {
  27         rrd_set_error("resize.rrd is a reserved name");
  28         return(-1);
  29     }
  30     if (argc!=5) {
  31         rrd_set_error("wrong number of parameters");
  32         return(-1);
  33     }
  34
  35     target_rra=strtol(argv[2],&endptr,0);
  36
  37     if (!strcmp(argv[3],"GROW")) grow=1;
  38     else if (!strcmp(argv[3],"SHRINK")) shrink=1;
  39     else {
  40         rrd_set_error("I can only GROW or SHRINK");
  41         return(-1);
  42     }
  43
  44     modify=strtol(argv[4],&endptr,0);
  45
  46     if ((modify<1)) {
  47         rrd_set_error("Please grow or shrink with at least 1 row");
  48         return(-1);
  49     }
  50
  51     if (shrink) modify = -modify;
  52
  53
  54     if (rrd_open(infilename, &infile, &rrdold, RRD_READWRITE)==-1) {
  55         rrd_set_error("could not open RRD");
  56         return(-1);
  57     }
  58     if (LockRRD(infile) != 0) {
  59         rrd_set_error("could not lock original RRD");
  60         rrd_free(&rrdold);
  61         fclose(infile);
  62         return(-1);
  63     }
  64
  65     if (target_rra >= rrdold.stat_head->rra_cnt) {
  66         rrd_set_error("no such RRA in this RRD");
  67         rrd_free(&rrdold);
  68         fclose(infile);
  69         return(-1);
  70     }
  71
  72     if (modify < 0)
  73         if ((long)rrdold.rra_def[target_rra].row_cnt <= -modify) {
  74             rrd_set_error("This RRA is not that big");
  75             rrd_free(&rrdold);
  76             fclose(infile);
  77             return(-1);
  78         }
  79
  80     rrdnew.stat_head = rrdold.stat_head;
  81     rrdnew.ds_def    = rrdold.ds_def;
  82     rrdnew.rra_def   = rrdold.rra_def;
  83     rrdnew.live_head = rrdold.live_head;
  84     rrdnew.pdp_prep  = rrdold.pdp_prep;
  85     rrdnew.cdp_prep  = rrdold.cdp_prep;
  86     rrdnew.rra_ptr   = rrdold.rra_ptr;
  87
  88     version = atoi(rrdold.stat_head->version);
  89     switch (version) {
  90         case 3: break;
  91         case 1: rrdold.stat_head->version[3]='3';
  92                 break;
  93         default: {
  94                 rrd_set_error("Do not know how to handle RRD version %s",rrdold.stat_head->version);
  95                 rrd_free(&rrdold);
  96                 fclose(infile);
  97                 return(-1);
  98                 }
  99     }
 100
 101     if ((outfile=fopen(outfilename,"wb"))==NULL) {
 102         rrd_set_error("Can't create '%s'",outfilename);
 103         return(-1);
 104     }
 105     if (LockRRD(outfile) != 0) {
 106         rrd_set_error("could not lock new RRD");
 107         rrd_free(&rrdold);
 108         fclose(infile);
 109         fclose(outfile);
 110         return(-1);
 111     }
 112     fwrite(rrdnew.stat_head, sizeof(stat_head_t),1,outfile);
 113     fwrite(rrdnew.ds_def,sizeof(ds_def_t),rrdnew.stat_head->ds_cnt,outfile);
 114     fwrite(rrdnew.rra_def,sizeof(rra_def_t),rrdnew.stat_head->rra_cnt,outfile);
 115     fwrite(rrdnew.live_head,sizeof(live_head_t),1,outfile);
 116     fwrite(rrdnew.pdp_prep,sizeof(pdp_prep_t),rrdnew.stat_head->ds_cnt,outfile);
 117     fwrite(rrdnew.cdp_prep,sizeof(cdp_prep_t),rrdnew.stat_head->ds_cnt*rrdnew.stat_head->rra_cnt,outfile);
 118     fwrite(rrdnew.rra_ptr,sizeof(rra_ptr_t),rrdnew.stat_head->rra_cnt,outfile);
 119
 120     /* Move the CDPs from the old to the new database.
 121     ** This can be made (much) faster but isn't worth the effort. Clarity
 122     ** is much more important.
 123     */
 124
 125     /* Move data in unmodified RRAs
 126     */
 127     l=0;
 128     for (rra=0;rra<target_rra;rra++) {
 129         l+=rrdnew.stat_head->ds_cnt * rrdnew.rra_def[rra].row_cnt;
 130     }
 131     while (l>0) {
 132         fread(&buffer,sizeof(rrd_value_t),1,infile);
 133         fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 134         l--;
 135     }
 136     /* Move data in this RRA, either removing or adding some rows
 137     */
 138     if (modify>0) {
 139         /* Adding extra rows; insert unknown values just after the
 140         ** current row number.
 141         */
 142         l = rrdnew.stat_head->ds_cnt * (rrdnew.rra_ptr[target_rra].cur_row+1);
 143         while (l>0) {
 144             fread(&buffer,sizeof(rrd_value_t),1,infile);
 145             fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 146             l--;
 147         }
 148         buffer=DNAN;
 149         l=rrdnew.stat_head->ds_cnt * modify;
 150         while (l>0) {
 151             fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 152             l--;
 153         }
 154     } else {
 155         /* Removing rows. Normally this would be just after the cursor
 156         ** however this may also mean that we wrap to the beginning of
 157         ** the array.
 158         */
 159         signed long int remove_end=0;
 160
 161         remove_end=(rrdnew.rra_ptr[target_rra].cur_row-modify)%rrdnew.rra_def[target_rra].row_cnt;
 162         if (remove_end <= (signed long int)rrdnew.rra_ptr[target_rra].cur_row) {
 163             while (remove_end >= 0) {
 164                 fseek(infile,sizeof(rrd_value_t)*rrdnew.stat_head->ds_cnt,SEEK_CUR);
 165                 rrdnew.rra_ptr[target_rra].cur_row--;
 166                 rrdnew.rra_def[target_rra].row_cnt--;
 167                 remove_end--;
 168                 modify++;
 169             }
 170             remove_end=rrdnew.rra_def[target_rra].row_cnt-1;
 171         }
 172         for (l=0;l<=rrdnew.rra_ptr[target_rra].cur_row;l++) {
 173             unsigned int tmp;
 174             for (tmp=0;tmp<rrdnew.stat_head->ds_cnt;tmp++) {
 175                 fread(&buffer,sizeof(rrd_value_t),1,infile);
 176                 fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 177             }
 178         }
 179         while (modify<0) {
 180             fseek(infile,sizeof(rrd_value_t)*rrdnew.stat_head->ds_cnt,SEEK_CUR);
 181             rrdnew.rra_def[target_rra].row_cnt--;
 182             modify++;
 183         }
 184     }
 185     /* Move the rest of the CDPs
 186     */
 187     while (1) {
 188         fread(&buffer,sizeof(rrd_value_t),1,infile);
 189         if (feof(infile))
 190             break;
 191         fwrite(&buffer,sizeof(rrd_value_t),1,outfile);
 192     }
 193     rrdnew.rra_def[target_rra].row_cnt += modify;
 194     fseek(outfile,sizeof(stat_head_t)+sizeof(ds_def_t)*rrdnew.stat_head->ds_cnt,SEEK_SET);
 195     fwrite(rrdnew.rra_def,sizeof(rra_def_t),rrdnew.stat_head->rra_cnt, outfile);
 196     fseek(outfile,sizeof(live_head_t),SEEK_CUR);
 197     fseek(outfile,sizeof(pdp_prep_t)*rrdnew.stat_head->ds_cnt,SEEK_CUR);
 198     fseek(outfile,sizeof(cdp_prep_t)*rrdnew.stat_head->ds_cnt*rrdnew.stat_head->rra_cnt,SEEK_CUR);
 199     fwrite(rrdnew.rra_ptr,sizeof(rra_ptr_t),rrdnew.stat_head->rra_cnt, outfile);
 200
 201     fclose(outfile);
 202     rrd_free(&rrdold);
 203     fclose(infile);
 204     return(0);
 205 }