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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997, 1998
* Sleepycat Software. All rights reserved.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)db_ret.c 10.13 (Sleepycat) 5/7/98";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#endif
#include "db_int.h"
#include "db_page.h"
#include "btree.h"
#include "db_am.h"
/*
* __db_ret --
* Build return DBT.
*
* PUBLIC: int __db_ret __P((DB *,
* PUBLIC: PAGE *, u_int32_t, DBT *, void **, u_int32_t *));
*/
int
__db_ret(dbp, h, indx, dbt, memp, memsize)
DB *dbp;
PAGE *h;
u_int32_t indx;
DBT *dbt;
void **memp;
u_int32_t *memsize;
{
BKEYDATA *bk;
HOFFPAGE ho;
BOVERFLOW *bo;
u_int32_t len;
u_int8_t *hk;
void *data;
switch (TYPE(h)) {
case P_HASH:
hk = P_ENTRY(h, indx);
if (HPAGE_PTYPE(hk) == H_OFFPAGE) {
memcpy(&ho, hk, sizeof(HOFFPAGE));
return (__db_goff(dbp, dbt,
ho.tlen, ho.pgno, memp, memsize));
}
len = LEN_HKEYDATA(h, dbp->pgsize, indx);
data = HKEYDATA_DATA(hk);
break;
case P_DUPLICATE:
case P_LBTREE:
case P_LRECNO:
bk = GET_BKEYDATA(h, indx);
if (B_TYPE(bk->type) == B_OVERFLOW) {
bo = (BOVERFLOW *)bk;
return (__db_goff(dbp, dbt,
bo->tlen, bo->pgno, memp, memsize));
}
len = bk->len;
data = bk->data;
break;
default:
return (__db_pgfmt(dbp, h->pgno));
}
return (__db_retcopy(dbt, data, len, memp, memsize,
F_ISSET(dbt, DB_DBT_INTERNAL) ? NULL : dbp->db_malloc));
}
/*
* __db_retcopy --
* Copy the returned data into the user's DBT, handling special flags.
*
* PUBLIC: int __db_retcopy __P((DBT *,
* PUBLIC: void *, u_int32_t, void **, u_int32_t *, void *(*)(size_t)));
*/
int
__db_retcopy(dbt, data, len, memp, memsize, db_malloc)
DBT *dbt;
void *data;
u_int32_t len;
void **memp;
u_int32_t *memsize;
void *(*db_malloc) __P((size_t));
{
/* If returning a partial record, reset the length. */
if (F_ISSET(dbt, DB_DBT_PARTIAL)) {
data = (u_int8_t *)data + dbt->doff;
if (len > dbt->doff) {
len -= dbt->doff;
if (len > dbt->dlen)
len = dbt->dlen;
} else
len = 0;
}
/*
* Return the length of the returned record in the DBT size field.
* This satisfies the requirement that if we're using user memory
* and insufficient memory was provided, return the amount necessary
* in the size field.
*/
dbt->size = len;
/*
* Allocate memory to be owned by the application: DB_DBT_MALLOC.
*
* !!!
* We always allocate memory, even if we're copying out 0 bytes. This
* guarantees consistency, i.e., the application can always free memory
* without concern as to how many bytes of the record were requested.
*
* XXX
* Never allocate 0 bytes, it's known to make malloc/realloc unhappy.
*
* Use the memory specified by the application: DB_DBT_USERMEM.
*
* !!!
* If the length we're going to copy is 0, the application-supplied
* memory pointer is allowed to be NULL.
*/
if (F_ISSET(dbt, DB_DBT_MALLOC)) {
dbt->data = db_malloc == NULL ?
(void *)__db_malloc(len) :
(void *)db_malloc(len + 1);
if (dbt->data == NULL)
return (ENOMEM);
} else if (F_ISSET(dbt, DB_DBT_USERMEM)) {
if (len != 0 && (dbt->data == NULL || dbt->ulen < len))
return (ENOMEM);
} else if (memp == NULL || memsize == NULL) {
return (EINVAL);
} else {
if (len != 0 && (*memsize == 0 || *memsize < len)) {
*memp = *memp == NULL ?
(void *)__db_malloc(len) :
(void *)__db_realloc(*memp, len);
if (*memp == NULL) {
*memsize = 0;
return (ENOMEM);
}
*memsize = len;
}
dbt->data = *memp;
}
if (len != 0)
memcpy(dbt->data, data, len);
return (0);
}
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