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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2008 WiredTiger Software.
* All rights reserved.
*
* $Id$
*/
#include "wt_internal.h"
static int __wt_bt_dbt_copyout(DB *, DBT *, DBT *, u_int8_t *, u_int32_t);
/*
* __wt_bt_dbt_return --
* Copy a WT_PAGE/WT_INDX pair into a key/data pair for return to the
* application.
*/
int
__wt_bt_dbt_return(DB *db,
DBT *key, DBT *data, WT_PAGE *page, WT_INDX *ip, int key_return)
{
IDB *idb;
DBT local_key, local_data;
WT_ITEM *item;
WT_ITEM_OVFL *ovfl;
int (*callback)(DB *, DBT *, DBT *);
idb = db->idb;
/*
* If the data DBT has been configured for a callback return, we don't
* have to build or copy anything except overflow key/data items. We
* don't want to overwrite the user's DBTs, however, so use local ones.
*/
if ((callback = data->callback) != NULL) {
if (key_return) {
key = &local_key;
WT_CLEAR(local_key);
}
data = &local_data;
WT_CLEAR(local_data);
}
/*
* Handle the key -- the key may be unchanged, in which case don't
* touch it.
*
* If the key is an overflow, it may not have been instantiated yet.
*/
if (key_return) {
if (ip->data == NULL)
WT_RET(__wt_bt_ovfl_to_indx(db, page, ip));
if (callback == NULL) {
WT_RET(__wt_bt_dbt_copyout(
db, key, &idb->key, ip->data, ip->size));
} else {
key->data = ip->data;
key->size = ip->size;
}
}
/*
* Handle the data item.
*/
item = ip->ditem;
switch (page->hdr->type) {
case WT_PAGE_LEAF:
if (WT_ITEM_TYPE(item) != WT_ITEM_DATA)
goto overflow;
if (callback == NULL) {
WT_RET(__wt_bt_dbt_copyout(db, data,
&idb->data, WT_ITEM_BYTE(item),
(u_int32_t)WT_ITEM_LEN(item)));
} else {
data->data = WT_ITEM_BYTE(item);
data->size = (u_int32_t)WT_ITEM_LEN(item);
}
break;
case WT_PAGE_DUP_LEAF:
if (WT_ITEM_TYPE(item) != WT_ITEM_DUP)
goto overflow;
if (callback == NULL) {
WT_RET(__wt_bt_dbt_copyout(db, data,
&idb->data, ip->data, ip->size));
} else {
data->data = ip->data;
data->size = ip->size;
}
break;
WT_DEFAULT_FORMAT(db);
}
if (0) {
overflow: /*
* Handle overflow data items.
*
* The overflow copy routines always attempt to resize the
* buffer if necessary, which isn't correct in the case of
* user-memory. Check before calling them.
*/
ovfl = (WT_ITEM_OVFL *)WT_ITEM_BYTE(ip->ditem);
if (F_ISSET(data, WT_DBT_ALLOC | WT_DBT_APPMEM)) {
if (F_ISSET(data, WT_DBT_APPMEM) &&
data->data_len < ovfl->len)
return (WT_TOOSMALL);
WT_RET(__wt_bt_ovfl_to_dbt(db, ovfl, data));
} else {
WT_RET(__wt_bt_ovfl_to_dbt(db, ovfl, &idb->data));
data->data = idb->data.data;
data->size = idb->data.size;
}
}
if (callback == NULL)
return (0);
return (callback(db, key, data));
}
/*
* __wt_bt_dbt_copyout --
* Do the actual allocation and copy for a returned DBT.
*/
static int
__wt_bt_dbt_copyout(
DB *db, DBT *dbt, DBT *local_dbt, u_int8_t *p, u_int32_t size)
{
ENV *env;
env = db->env;
/*
* By default, we use memory in the DB handle to return keys; if
* the DB handle is being used by multiple threads, however, we
* can't do that, we have to use memory in the DBT itself. Look
* for the appropriate flags.
*/
if (F_ISSET(dbt, WT_DBT_ALLOC)) {
if (dbt->data_len < size) {
WT_RET(__wt_realloc(
env, dbt->data_len, size, &dbt->data));
dbt->data_len = size;
}
} else if (F_ISSET(dbt, WT_DBT_APPMEM)) {
if (dbt->data_len < size)
return (WT_TOOSMALL);
} else {
if (local_dbt->data_len < size) {
WT_RET(__wt_realloc(
env, size, size + 40, &local_dbt->data));
local_dbt->data_len = size + 40;
}
dbt->data = local_dbt->data;
}
memcpy(dbt->data, p, size);
dbt->size = size;
return (0);
}
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