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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996,2007 Oracle. All rights reserved.
*
* $Id: db_dup.c,v 12.11 2007/05/17 15:14:56 bostic Exp $
*/
#include "db_config.h"
#include "db_int.h"
#include "dbinc/db_page.h"
#include "dbinc/mp.h"
#include "dbinc/db_am.h"
/*
* __db_ditem --
* Remove an item from a page.
*
* PUBLIC: int __db_ditem __P((DBC *, PAGE *, u_int32_t, u_int32_t));
*/
int
__db_ditem(dbc, pagep, indx, nbytes)
DBC *dbc;
PAGE *pagep;
u_int32_t indx, nbytes;
{
DB *dbp;
DBT ldbt;
db_indx_t cnt, *inp, offset;
int ret;
u_int8_t *from;
dbp = dbc->dbp;
DB_ASSERT(dbp->dbenv, IS_DIRTY(pagep));
DB_ASSERT(dbp->dbenv, indx < NUM_ENT(pagep));
if (DBC_LOGGING(dbc)) {
ldbt.data = P_ENTRY(dbp, pagep, indx);
ldbt.size = nbytes;
if ((ret = __db_addrem_log(dbp, dbc->txn,
&LSN(pagep), 0, DB_REM_DUP, PGNO(pagep),
(u_int32_t)indx, nbytes, &ldbt, NULL, &LSN(pagep))) != 0)
return (ret);
} else
LSN_NOT_LOGGED(LSN(pagep));
/*
* If there's only a single item on the page, we don't have to
* work hard.
*/
if (NUM_ENT(pagep) == 1) {
NUM_ENT(pagep) = 0;
HOFFSET(pagep) = dbp->pgsize;
return (0);
}
inp = P_INP(dbp, pagep);
/*
* Pack the remaining key/data items at the end of the page. Use
* memmove(3), the regions may overlap.
*/
from = (u_int8_t *)pagep + HOFFSET(pagep);
DB_ASSERT(dbp->dbenv, inp[indx] >= HOFFSET(pagep));
memmove(from + nbytes, from, inp[indx] - HOFFSET(pagep));
HOFFSET(pagep) += nbytes;
/* Adjust the indices' offsets. */
offset = inp[indx];
for (cnt = 0; cnt < NUM_ENT(pagep); ++cnt)
if (inp[cnt] < offset)
inp[cnt] += nbytes;
/* Shift the indices down. */
--NUM_ENT(pagep);
if (indx != NUM_ENT(pagep))
memmove(&inp[indx], &inp[indx + 1],
sizeof(db_indx_t) * (NUM_ENT(pagep) - indx));
return (0);
}
/*
* __db_pitem --
* Put an item on a page.
*
* PUBLIC: int __db_pitem
* PUBLIC: __P((DBC *, PAGE *, u_int32_t, u_int32_t, DBT *, DBT *));
*/
int
__db_pitem(dbc, pagep, indx, nbytes, hdr, data)
DBC *dbc;
PAGE *pagep;
u_int32_t indx;
u_int32_t nbytes;
DBT *hdr, *data;
{
DB *dbp;
BKEYDATA bk;
DBT thdr;
db_indx_t *inp;
int ret;
u_int8_t *p;
dbp = dbc->dbp;
DB_ASSERT(dbp->dbenv, IS_DIRTY(pagep));
if (nbytes > P_FREESPACE(dbp, pagep)) {
DB_ASSERT(dbp->dbenv, nbytes <= P_FREESPACE(dbp, pagep));
return (EINVAL);
}
/*
* Put a single item onto a page. The logic figuring out where to
* insert and whether it fits is handled in the caller. All we do
* here is manage the page shuffling. We cheat a little bit in that
* we don't want to copy the dbt on a normal put twice. If hdr is
* NULL, we create a BKEYDATA structure on the page, otherwise, just
* copy the caller's information onto the page.
*
* This routine is also used to put entries onto the page where the
* entry is pre-built, e.g., during recovery. In this case, the hdr
* will point to the entry, and the data argument will be NULL.
*
* !!!
* There's a tremendous potential for off-by-one errors here, since
* the passed in header sizes must be adjusted for the structure's
* placeholder for the trailing variable-length data field.
*/
if (DBC_LOGGING(dbc)) {
if ((ret = __db_addrem_log(dbp, dbc->txn,
&LSN(pagep), 0, DB_ADD_DUP, PGNO(pagep),
(u_int32_t)indx, nbytes, hdr, data, &LSN(pagep))) != 0)
return (ret);
} else
LSN_NOT_LOGGED(LSN(pagep));
if (hdr == NULL) {
B_TSET(bk.type, B_KEYDATA);
bk.len = data == NULL ? 0 : data->size;
thdr.data = &bk;
thdr.size = SSZA(BKEYDATA, data);
hdr = &thdr;
}
inp = P_INP(dbp, pagep);
/* Adjust the index table, then put the item on the page. */
if (indx != NUM_ENT(pagep))
memmove(&inp[indx + 1], &inp[indx],
sizeof(db_indx_t) * (NUM_ENT(pagep) - indx));
HOFFSET(pagep) -= nbytes;
inp[indx] = HOFFSET(pagep);
++NUM_ENT(pagep);
p = P_ENTRY(dbp, pagep, indx);
memcpy(p, hdr->data, hdr->size);
if (data != NULL)
memcpy(p + hdr->size, data->data, data->size);
return (0);
}
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