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.

{
    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);
}

References B_MODIFIED, _btree::bt_cursor, _btree::bt_mp, _btree::bt_nrecs, _btree::bt_pinned, CURS_INIT, DBT::data, dbp, 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().

__rec_dleaf()

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

Definition at line 154 of file rec_delete.c.

{
    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);
}

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().

rec_rdelete()

static int rec_rdelete ( BTREE *  t, recno_t  nrec  )

static

Definition at line 120 of file rec_delete.c.

{
    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);
}

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().