rec_search.c File Reference

#include <sys/types.h>
#include <errno.h>
#include <stdio.h>
#include "../include/db.h"
#include "recno.h"

Include dependency graph for rec_search.c:

Go to the source code of this file.

Functions
EPG *	__rec_search (BTREE *t, recno_t recno, enum SRCHOP op)

Function Documentation

__rec_search()

EPG* __rec_search	(	BTREE *	t,
		recno_t	recno,
		enum SRCHOP	op
	)

Definition at line 64 of file rec_search.c.

References BT_CLR, _btree::bt_cur, _btree::bt_mp, BT_POP, BT_PUSH, errno, _page::flags, GETRINTERNAL, _epgno::index, _epg::index, MPOOL_DIRTY, mpool_get(), mpool_put(), NEXTINDEX, _rinternal::nrecs, NULL, P_RLEAF, P_ROOT, _epg::page, _rinternal::pgno, _epgno::pgno, SDELETE, SEARCH, SINSERT, and total.

Referenced by __rec_get(), __rec_iput(), __rec_seq(), and rec_rdelete().

{
   register indx_t index;
   register PAGE *h;
   EPGNO *parent;
   RINTERNAL *r;
   pgno_t pg;
   indx_t top;
   recno_t total;
   int sverrno;

   BT_CLR(t);
   for (pg = P_ROOT, total = 0;;) {
      if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
         goto err;
      if (h->flags & P_RLEAF) {
         t->bt_cur.page = h;
         t->bt_cur.index = recno - total;
         return (&t->bt_cur);
      }
      for (index = 0, top = NEXTINDEX(h);;) {
         r = GETRINTERNAL(h, index);
         if (++index == top || total + r->nrecs > recno)
            break;
         total += r->nrecs;
      }

      BT_PUSH(t, pg, index - 1);

      pg = r->pgno;
      switch (op) {
      case SDELETE:
         --GETRINTERNAL(h, (index - 1))->nrecs;
         mpool_put(t->bt_mp, h, MPOOL_DIRTY);
         break;
      case SINSERT:
         ++GETRINTERNAL(h, (index - 1))->nrecs;
         mpool_put(t->bt_mp, h, MPOOL_DIRTY);
         break;
      case SEARCH:
         mpool_put(t->bt_mp, h, 0);
         break;
      }

   }
   /* Try and recover the tree. */
err:  sverrno = errno;
   if (op != SEARCH)
      while  ((parent = BT_POP(t)) != NULL) {
         if ((h = mpool_get(t->bt_mp, parent->pgno, 0)) == NULL)
            break;
         if (op == SINSERT)
            --GETRINTERNAL(h, parent->index)->nrecs;
         else
            ++GETRINTERNAL(h, parent->index)->nrecs;
                        mpool_put(t->bt_mp, h, MPOOL_DIRTY);
                }
   errno = sverrno;
   return (NULL);
}