src/rrd_resize.c

   1 /*****************************************************************************
   2  * RRDtool 1.2.23  Copyright by Tobi Oetiker, 1997-2007
   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 rrd_resize(
  12     int argc,
  13     char **argv)
  14 {
  15     char     *infilename, outfilename[11] = "resize.rrd";
  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     rrd_file_t *rrd_file, *rrd_out_file;
  25
  26     infilename = argv[1];
  27     if (!strcmp(infilename, "resize.rrd")) {
  28         rrd_set_error("resize.rrd is a reserved name");
  29         return (-1);
  30     }
  31     if (argc != 5) {
  32         rrd_set_error("wrong number of parameters");
  33         return (-1);
  34     }
  35
  36     target_rra = strtol(argv[2], &endptr, 0);
  37
  38     if (!strcmp(argv[3], "GROW"))
  39         grow = 1;
  40     else if (!strcmp(argv[3], "SHRINK"))
  41         shrink = 1;
  42     else {
  43         rrd_set_error("I can only GROW or SHRINK");
  44         return (-1);
  45     }
  46
  47     modify = strtol(argv[4], &endptr, 0);
  48
  49     if ((modify < 1)) {
  50         rrd_set_error("Please grow or shrink with at least 1 row");
  51         return (-1);
  52     }
  53
  54     if (shrink)
  55         modify = -modify;
  56
  57
  58     rrd_file = rrd_open(infilename, &rrdold, RRD_READWRITE);
  59     if (rrd_file == NULL) {
  60         rrd_set_error("could not open RRD");
  61         return (-1);
  62     }
  63     if (LockRRD(rrd_file->fd) != 0) {
  64         rrd_set_error("could not lock original RRD");
  65         rrd_free(&rrdold);
  66         close(rrd_file->fd);
  67         return (-1);
  68     }
  69
  70     if (target_rra >= rrdold.stat_head->rra_cnt) {
  71         rrd_set_error("no such RRA in this RRD");
  72         rrd_free(&rrdold);
  73         close(rrd_file->fd);
  74         return (-1);
  75     }
  76
  77     if (modify < 0)
  78         if ((long) rrdold.rra_def[target_rra].row_cnt <= -modify) {
  79             rrd_set_error("This RRA is not that big");
  80             rrd_free(&rrdold);
  81             close(rrd_file->fd);
  82             return (-1);
  83         }
  84
  85     rrd_out_file = rrd_open(outfilename, &rrdnew, RRD_READWRITE|RRD_CREAT);
  86     if (rrd_out_file == NULL) {
  87         rrd_set_error("Can't create '%s': %s", outfilename,
  88                       rrd_strerror(errno));
  89         return (-1);
  90     }
  91     if (LockRRD(rrd_out_file->fd) != 0) {
  92         rrd_set_error("could not lock new RRD");
  93         rrd_free(&rrdold);
  94         close(rrd_file->fd);
  95         close(rrd_out_file->fd);
  96         return (-1);
  97     }
  98 /*XXX: do one write for those parts of header that are unchanged */
  99     rrdnew.stat_head = rrdold.stat_head;
 100     rrdnew.ds_def = rrdold.ds_def;
 101     rrdnew.rra_def = rrdold.rra_def;
 102     rrdnew.live_head = rrdold.live_head;
 103     rrdnew.pdp_prep = rrdold.pdp_prep;
 104     rrdnew.cdp_prep = rrdold.cdp_prep;
 105     rrdnew.rra_ptr = rrdold.rra_ptr;
 106
 107     version = atoi(rrdold.stat_head->version);
 108     switch (version) {
 109     case 3:
 110         break;
 111     case 1:
 112         rrdold.stat_head->version[3] = '3';
 113         break;
 114     default:{
 115         rrd_set_error("Do not know how to handle RRD version %s",
 116                       rrdold.stat_head->version);
 117         rrd_free(&rrdold);
 118         close(rrd_file->fd);
 119         return (-1);
 120     }
 121     }
 122
 123
 124 /* XXX: Error checking? */
 125     rrd_write(rrd_out_file, rrdnew.stat_head, sizeof(stat_head_t) * 1);
 126     rrd_write(rrd_out_file, rrdnew.ds_def,
 127               sizeof(ds_def_t) * rrdnew.stat_head->ds_cnt);
 128     rrd_write(rrd_out_file, rrdnew.rra_def,
 129               sizeof(rra_def_t) * rrdnew.stat_head->rra_cnt);
 130     rrd_write(rrd_out_file, rrdnew.live_head, sizeof(live_head_t) * 1);
 131     rrd_write(rrd_out_file, rrdnew.pdp_prep,
 132               sizeof(pdp_prep_t) * rrdnew.stat_head->ds_cnt);
 133     rrd_write(rrd_out_file, rrdnew.cdp_prep,
 134               sizeof(cdp_prep_t) * rrdnew.stat_head->ds_cnt *
 135               rrdnew.stat_head->rra_cnt);
 136     rrd_write(rrd_out_file, rrdnew.rra_ptr,
 137               sizeof(rra_ptr_t) * rrdnew.stat_head->rra_cnt);
 138
 139     /* Move the CDPs from the old to the new database.
 140      ** This can be made (much) faster but isn't worth the effort. Clarity
 141      ** is much more important.
 142      */
 143
 144     /* Move data in unmodified RRAs
 145      */
 146     l = 0;
 147     for (rra = 0; rra < target_rra; rra++) {
 148         l += rrdnew.stat_head->ds_cnt * rrdnew.rra_def[rra].row_cnt;
 149     }
 150     while (l > 0) {
 151         rrd_read(rrd_file, &buffer, sizeof(rrd_value_t) * 1);
 152         rrd_write(rrd_out_file, &buffer, sizeof(rrd_value_t) * 1);
 153         l--;
 154     }
 155     /* Move data in this RRA, either removing or adding some rows
 156      */
 157     if (modify > 0) {
 158         /* Adding extra rows; insert unknown values just after the
 159          ** current row number.
 160          */
 161         l = rrdnew.stat_head->ds_cnt * (rrdnew.rra_ptr[target_rra].cur_row +
 162                                         1);
 163         while (l > 0) {
 164             rrd_read(rrd_file, &buffer, sizeof(rrd_value_t) * 1);
 165             rrd_write(rrd_out_file, &buffer, sizeof(rrd_value_t) * 1);
 166             l--;
 167         }
 168         buffer = DNAN;
 169         l = rrdnew.stat_head->ds_cnt * modify;
 170         while (l > 0) {
 171             rrd_write(rrd_out_file, &buffer, sizeof(rrd_value_t) * 1);
 172             l--;
 173         }
 174     } else {
 175         /* Removing rows. Normally this would be just after the cursor
 176          ** however this may also mean that we wrap to the beginning of
 177          ** the array.
 178          */
 179         signed long int remove_end = 0;
 180
 181         remove_end =
 182             (rrdnew.rra_ptr[target_rra].cur_row -
 183              modify) % rrdnew.rra_def[target_rra].row_cnt;
 184         if (remove_end <=
 185             (signed long int) rrdnew.rra_ptr[target_rra].cur_row) {
 186             while (remove_end >= 0) {
 187                 rrd_seek(rrd_file,
 188                          sizeof(rrd_value_t) * rrdnew.stat_head->ds_cnt,
 189                          SEEK_CUR);
 190                 rrdnew.rra_ptr[target_rra].cur_row--;
 191                 rrdnew.rra_def[target_rra].row_cnt--;
 192                 remove_end--;
 193                 modify++;
 194             }
 195             remove_end = rrdnew.rra_def[target_rra].row_cnt - 1;
 196         }
 197         for (l = 0; l <= rrdnew.rra_ptr[target_rra].cur_row; l++) {
 198             unsigned int tmp;
 199
 200             for (tmp = 0; tmp < rrdnew.stat_head->ds_cnt; tmp++) {
 201                 rrd_read(rrd_file, &buffer, sizeof(rrd_value_t) * 1);
 202                 rrd_write(rrd_out_file, &buffer, sizeof(rrd_value_t) * 1);
 203             }
 204         }
 205         while (modify < 0) {
 206             rrd_seek(rrd_file, sizeof(rrd_value_t) * rrdnew.stat_head->ds_cnt,
 207                      SEEK_CUR);
 208             rrdnew.rra_def[target_rra].row_cnt--;
 209             modify++;
 210         }
 211     }
 212     /* Move the rest of the CDPs
 213      */
 214     while (1) {
 215         if (rrd_read(rrd_file, &buffer, sizeof(rrd_value_t) * 1) <= 0)
 216             break;
 217         rrd_write(rrd_out_file, &buffer, sizeof(rrd_value_t) * 1);
 218     }
 219     rrdnew.rra_def[target_rra].row_cnt += modify;
 220     rrd_seek(rrd_out_file,
 221              sizeof(stat_head_t) +
 222              sizeof(ds_def_t) * rrdnew.stat_head->ds_cnt, SEEK_SET);
 223     rrd_write(rrd_out_file, rrdnew.rra_def,
 224               sizeof(rra_def_t) * rrdnew.stat_head->rra_cnt);
 225     rrd_seek(rrd_out_file, sizeof(live_head_t), SEEK_CUR);
 226     rrd_seek(rrd_out_file, sizeof(pdp_prep_t) * rrdnew.stat_head->ds_cnt,
 227              SEEK_CUR);
 228     rrd_seek(rrd_out_file,
 229              sizeof(cdp_prep_t) * rrdnew.stat_head->ds_cnt *
 230              rrdnew.stat_head->rra_cnt, SEEK_CUR);
 231     rrd_write(rrd_out_file, rrdnew.rra_ptr,
 232               sizeof(rra_ptr_t) * rrdnew.stat_head->rra_cnt);
 233
 234     close(rrd_out_file->fd);
 235     rrd_free(&rrdold);
 236     close(rrd_file->fd);
 237     return (0);
 238 }