2.11BSD#431 - /usr/ingres/source/access/scan_dups.c

   1: # include   "../ingres.h"
   2: # include   "../symbol.h"
   3: # include   "../access.h"
   4: # include   "../lock.h"
   5: 
   6: scan_dups(d, tidx, tuple)
   7: struct descriptor   *d;
   8: struct tup_id       *tidx;
   9: char            *tuple;
  10: 
  11: /*
  12: **	Scan for duplicates. Start with the page
  13: **	specified by tid and
  14: **	continue until there are no more pages
  15: **
  16: **	Scan_dups guarantees that the same page will
  17: **	be in the buffer on entry and exit
  18: **
  19: **	returns:
  20: **		<0 if fatal error
  21: **		0  if not duplicate
  22: **		1  if duplicate
  23: */
  24: 
  25: {
  26:     register int        dup, pagerr;
  27:     register struct tup_id  *tid;
  28:     struct tup_id       savetid;
  29: 
  30:     tid = tidx;
  31: 
  32:     stuff_page(&savetid, &Acc_head->thispage);
  33: 
  34:     Acclock = FALSE;    /* turn concurrency off */
  35:     dup = 0;    /* assume success */
  36: 
  37:     do
  38:     {
  39:         if (pagerr = get_page(d, tid))
  40:             break;  /* fatal error */
  41: 
  42:         if (dup = dup_check(d, tid, tuple))
  43:             break;  /* found duplicate */
  44: 
  45:         stuff_page(tid, &Acc_head->ovflopg);
  46:     } while (Acc_head->ovflopg);
  47: 
  48:     if (pagerr || (pagerr = get_page(d, &savetid)))
  49:         dup = pagerr;   /* return fatal page error */
  50: 
  51:     Acclock = TRUE;     /* turn concurency on */
  52:     return (dup);
  53: }
  54: 
  55: 
  56: dup_check(dx, tid, tuple1)
  57: struct descriptor   *dx;
  58: struct tup_id       *tid;
  59: char            *tuple1;
  60: 
  61: /*
  62: **	Check current page for a duplicate of tuple;
  63: **
  64: **	returns:
  65: **		0 if not duplicate
  66: **		1 if duplicate
  67: */
  68: 
  69: {
  70:     register struct descriptor  *d;
  71:     register int            i, dom;
  72:     int             *lp, len, lastline, tups_equal;
  73:     char                *tup1, *tup2;
  74:     char                tuple2[MAXTUP];
  75:     char                *getint_tuple();
  76: 
  77:     d = dx;
  78: 
  79: 
  80:     /* determine starting and ending points */
  81:     lastline = Acc_head->nxtlino;
  82:     lp = &Acc_head->linetab[0];
  83: 
  84:     /* check each tuple for duplication */
  85:     for (i = 0; i < lastline; i++)
  86:     {
  87: 
  88:         /* is this line used? */
  89:         if (*lp--)
  90:         {
  91:             /* yes. get tuple and check it */
  92:             tid->line_id = i;
  93:             tup2 = getint_tuple(d, tid, tuple2);
  94:             tup1 = tuple1;
  95:             tups_equal = TRUE;  /* assume equal */
  96: 
  97:             /* now check each domain for duplication */
  98:             for (dom = 1; dom <= d->relatts; dom++)
  99:             {
 100:                 len = d->relfrml[dom] & I1MASK;
 101:                 if (d->relfrmt[dom] == CHAR)
 102:                     tups_equal = scompare(tup1, len, tup2, len) == 0;
 103:                 else
 104:                     tups_equal = bequal(tup1, tup2, len);
 105:                 if (!tups_equal)
 106:                 {
 107:                     /* not duplicates */
 108:                     break;
 109:                 }
 110:                 tup1 += len;
 111:                 tup2 += len;
 112:             }
 113:             if (tups_equal)
 114:                 return (1); /* duplicate */
 115:         }
 116:     }
 117:     return (0); /* no duplicate */
 118: }

Defined functions