4.3BSD - /usr/ingres/source/iutil/btreerange.c

   1: # include   <ingres.h>
   2: # include   <btree.h>
   3: # include   <sccs.h>
   4: 
   5: SCCSID(@(#)btreerange.c	8.1	12/31/84)
   6: 
   7: /*
   8: **	Btreerange finds the smallest and largest tids corresponding to
   9: **	the lids found between two given lids.
  10: */
  11: 
  12: btreerange(d, low_lid, high_lid, lotid, hitid)
  13: 
  14: DESC *d;
  15: long low_lid[], high_lid[];
  16: register TID *lotid, *hitid;
  17: {
  18:     register int    i;
  19:     long        l, h, tid, temp;
  20:     struct locator  block;
  21:     long        page, t, last, hbtid, last_lid();
  22:     int     done, first;
  23:     long        start, next;
  24: 
  25:     /* find tid corresponding to high lid */
  26:     page = RT;
  27:     for (i = 0; i < d->reldum.reldim; ++i)
  28:     {
  29:         if ((t = get_tid(page, high_lid[i], &block)) < 0)
  30:             syserr("get_tid error in btreerange, lid = %ld\n", high_lid[i]);
  31:         page = t;
  32:     }
  33:     hbtid = page;
  34:     /* find starting point of scan */
  35:     page = RT;
  36:     for (i = 0; i < d->reldum.reldim - 1; ++i)
  37:     {
  38:         last = last_lid(page) - 1;
  39:         if (low_lid[i] > last)
  40:             low_lid[i] = last;
  41:         if ((t = get_tid(page, low_lid[i], &block)) < 0)
  42:             syserr("get_tid error in btreerange, lid = %ld\n", low_lid[i]);
  43:         page = t;
  44:     }
  45:     first = 1;
  46:     last = last_lid(page) - 1;
  47:     if (low_lid[d->reldum.reldim - 1] > last)
  48:         low_lid[d->reldum.reldim - 1] = last;
  49:     start = low_lid[d->reldum.reldim - 1];
  50:     do
  51:     {
  52:         get_node(page, &block.page);
  53:         next = block.page.nexttree;
  54:         if ((tid = get_tid(page, start, &block)) < 0)
  55:             syserr("get_tid error in btreerange, lid = %ld\n", low_lid[d->reldum.reldim - 1]);
  56:         /* set high and low to intial value */
  57:         if (first)
  58:         {
  59:             first = 0;
  60:             pluck_page(&tid, &l);
  61:             pluck_page(&tid, &h);
  62:         }
  63:         page = block.pageno;
  64:         done = 0;
  65:         while (done == 0)
  66:         {
  67:             for (i = 0; i < block.page.nelmts && done == 0; ++i)
  68:             {
  69:                 tid = block.page.node.leafnode.tid_pos[block.page.node.leafnode.tid_loc[i]];
  70:                 pluck_page(&tid, &temp);
  71:                 if (temp > h)
  72:                     h = temp;
  73:                 else if (temp < l)
  74:                     l = temp;
  75:                 if (tid == hbtid)
  76:                     done = 1;
  77:             }
  78:             page = block.page.node.leafnode.nextleaf;
  79:             if (page == NULL)
  80:                 done = 1;
  81:             else
  82:                 get_node(page, &block.page);
  83:         }
  84:         start = 1;
  85:     } while (page = next && !done);
  86:     stuff_page(lotid, &l);
  87:     stuff_page(hitid, &h);
  88:     lotid->line_id = hitid->line_id = -1;
  89: }

Defined functions