rec_delete.c File Reference

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

Include dependency graph for rec_delete.c:

Go to the source code of this file.

Functions
static int rec_rdelete	__P ((BTREE *, recno_t))
int	__rec_delete (DB *dbp, const DBT *key, u_int flags) const
int	__rec_dleaf (BTREE *t, PAGE *h, u_int32_t idx)
static int	rec_rdelete (BTREE *t, recno_t nrec)

Function Documentation

__P()

static int rec_rdelete __P ( (BTREE *, recno_t)  )

static

__rec_delete()

int __rec_delete	(	DB *	dbp,
		const DBT *	key,
		u_int	flags
	)		const

Definition at line 64 of file rec_delete.c.

References B_MODIFIED, _btree::bt_cursor, _btree::bt_mp, _btree::bt_nrecs, _btree::bt_pinned, CURS_INIT, DBT::data, errno, F_ISSET, F_SET, __db::internal, mpool_put(), NULL, R_CURSOR, R_MODIFIED, _cursor::rcursor, rec_rdelete(), RET_ERROR, RET_SPECIAL, RET_SUCCESS, and status.

Referenced by __rec_open().

{
   BTREE *t;
   recno_t nrec;
   int status;

   t = dbp->internal;

   /* Toss any page pinned across calls. */
   if (t->bt_pinned != NULL) {
      mpool_put(t->bt_mp, t->bt_pinned, 0);
      t->bt_pinned = NULL;
   }

   switch(flags) {
   case 0:
      if ((nrec = *(recno_t *)key->data) == 0)
         goto einval;
      if (nrec > t->bt_nrecs)
         return (RET_SPECIAL);
      --nrec;
      status = rec_rdelete(t, nrec);
      break;
   case R_CURSOR:
      if (!F_ISSET(&t->bt_cursor, CURS_INIT))
         goto einval;
      if (t->bt_nrecs == 0)
         return (RET_SPECIAL);
      status = rec_rdelete(t, t->bt_cursor.rcursor - 1);
      if (status == RET_SUCCESS)
         --t->bt_cursor.rcursor;
      break;
   default:
einval:     errno = EINVAL;
      return (RET_ERROR);
   }

   if (status == RET_SUCCESS)
      F_SET(t, B_MODIFIED | R_MODIFIED);
   return (status);
}

__rec_dleaf()

int __rec_dleaf	(	BTREE *	t,
		PAGE *	h,
		u_int32_t	idx
	)

Definition at line 154 of file rec_delete.c.

References __ovfl_delete(), _btree::bt_nrecs, _rleaf::bytes, _rleaf::flags, GETRLEAF, _page::linp, _page::lower, NEXTINDEX, NRLEAF, P_BIGDATA, RET_ERROR, RET_SUCCESS, and _page::upper.

Referenced by __rec_iput(), and rec_rdelete().

{
   RLEAF *rl;
   indx_t *ip, cnt, offset;
   u_int32_t nbytes;
   char *from;
   void *to;

   /*
    * Delete a record from a recno leaf page.  Internal records are never
    * deleted from internal pages, regardless of the records that caused
    * them to be added being deleted.  Pages made empty by deletion are
    * not reclaimed.  They are, however, made available for reuse.
    *
    * Pack the remaining entries at the end of the page, shift the indices
    * down, overwriting the deleted record and its index.  If the record
    * uses overflow pages, make them available for reuse.
    */
   to = rl = GETRLEAF(h, idx);
   if (rl->flags & P_BIGDATA && __ovfl_delete(t, rl->bytes) == RET_ERROR)
      return (RET_ERROR);
   nbytes = NRLEAF(rl);

   /*
    * Compress the key/data pairs.  Compress and adjust the [BR]LEAF
    * offsets.  Reset the headers.
    */
   from = (char *)h + h->upper;
   memmove(from + nbytes, from, (char *)to - from);
   h->upper += nbytes;

   offset = h->linp[idx];
   for (cnt = &h->linp[idx] - (ip = &h->linp[0]); cnt--; ++ip)
      if (ip[0] < offset)
         ip[0] += nbytes;
   for (cnt = &h->linp[NEXTINDEX(h)] - ip; --cnt; ++ip)
      ip[0] = ip[1] < offset ? ip[1] + nbytes : ip[1];
   h->lower -= sizeof(indx_t);
   --t->bt_nrecs;
   return (RET_SUCCESS);
}

rec_rdelete()

static int rec_rdelete ( BTREE *  t, recno_t  nrec  )

static

Definition at line 120 of file rec_delete.c.

References __rec_dleaf(), __rec_search(), _btree::bt_mp, _epg::index, MPOOL_DIRTY, mpool_put(), NULL, _epg::page, RET_ERROR, RET_SUCCESS, SDELETE, and status.

Referenced by __rec_delete().

{
   EPG *e;
   PAGE *h;
   int status;

   /* Find the record; __rec_search pins the page. */
   if ((e = __rec_search(t, nrec, SDELETE)) == NULL)
      return (RET_ERROR);

   /* Delete the record. */
   h = e->page;
   status = __rec_dleaf(t, h, e->index);
   if (status != RET_SUCCESS) {
      mpool_put(t->bt_mp, h, 0);
      return (status);
   }
   mpool_put(t->bt_mp, h, MPOOL_DIRTY);
   return (RET_SUCCESS);
}