191 lines
5.1 KiB
C
191 lines
5.1 KiB
C
/*****************************************************************************
|
|
* *
|
|
* BTKTLONG.C *
|
|
* *
|
|
* Copyright (C) Microsoft Corporation 1989 - 1994. *
|
|
* All Rights reserved. *
|
|
* *
|
|
******************************************************************************
|
|
* *
|
|
* Module Intent *
|
|
* *
|
|
* Functions for LONG keys. *
|
|
* *
|
|
******************************************************************************
|
|
* *
|
|
* Current Owner: BinhN *
|
|
* *
|
|
*****************************************************************************/
|
|
|
|
static char s_aszModule[] = __FILE__; /* For error report */
|
|
|
|
#include <mvopsys.h>
|
|
#include <orkin.h>
|
|
#include <iterror.h>
|
|
#include <misc.h>
|
|
#include <wrapstor.h>
|
|
#include <_mvutil.h>
|
|
|
|
|
|
/***************************************************************************
|
|
*
|
|
* @doc INTERNAL
|
|
*
|
|
* @func BK FAR PASCAL | BkScanLInternal |
|
|
* Scan an internal node for a LONG key and return child BK.
|
|
*
|
|
* @parm BK | bk |
|
|
* BK of internal node to scan
|
|
*
|
|
* @parm KEY | key |
|
|
* key to search for
|
|
*
|
|
* @parm SHORT | wLevel |
|
|
* level of btree bk lives on
|
|
*
|
|
* @parm QBTHR | qbthr |
|
|
* btree header containing cache, and btree specs
|
|
*
|
|
* @rdesc bk of subtree that might contain key; bkNil on error
|
|
* args OUT: qbthr->qCache - bk's block will be cached
|
|
*
|
|
* Side Effects: bk's block will be cached
|
|
*
|
|
* @comm Method: Should use binary search. Doesn't, yet.
|
|
*
|
|
***************************************************************************/
|
|
|
|
PUBLIC BK FAR PASCAL BkScanLInternal(BK bk, KEY key, SHORT wLevel,
|
|
QBTHR qbthr, QW qiKey, PHRESULT phr)
|
|
{
|
|
QCB qcb;
|
|
QB q;
|
|
SHORT cKeys;
|
|
LONG dwKeyVal;
|
|
|
|
dwKeyVal = *(LONG FAR *)key;
|
|
|
|
if ((qcb = QFromBk(bk, wLevel, qbthr, phr)) == NULL)
|
|
{
|
|
return bkNil;
|
|
}
|
|
q = qcb->db.rgbBlock;
|
|
cKeys = qcb->db.cKeys;
|
|
bk = SWAPLONG(*(LPUL)q);
|
|
q += sizeof(BK);
|
|
|
|
while (cKeys-- > 0)
|
|
{
|
|
|
|
if (dwKeyVal >= (LONG) SWAPLONG(*(LPUL)q))
|
|
{
|
|
q += sizeof(LONG);
|
|
bk = SWAPLONG(*(LPUL)q);
|
|
q += sizeof(BK);
|
|
}
|
|
else
|
|
break;
|
|
}
|
|
|
|
if (qiKey != NULL)
|
|
{
|
|
*qiKey = (WORD)(q - (QB)qcb->db.rgbBlock);
|
|
}
|
|
|
|
return bk;
|
|
}
|
|
|
|
/***************************************************************************
|
|
*
|
|
* @doc INTERNAL
|
|
*
|
|
* @func HRESULT FAR PASCAL | RcScanLLeaf |
|
|
* Scan a leaf node for a key and copy the associated data.
|
|
*
|
|
* @parm BK | bk |
|
|
* the leaf block
|
|
*
|
|
* @parm KEY | key |
|
|
* the key we're looking for
|
|
*
|
|
* @parm SHORT | wLevel |
|
|
* the level of leaves (unnecessary)
|
|
*
|
|
* @parm QBTHR | qbthr |
|
|
* the btree header
|
|
*
|
|
* @rdesc ERR_SUCCESS if found; ERR_NOTEXIST if not found
|
|
* args OUT: qRec - if found, record gets copied into this buffer
|
|
* qbtpos - pos of first key >= key goes here
|
|
*
|
|
* @comm If we are scanning for a key greater than any key in this
|
|
* block, the pos returned will be invalid and will point just
|
|
* past the last valid key in this block.
|
|
*
|
|
* Method: Should use binary search if fixed record size. Doesn't, yet.
|
|
*
|
|
***************************************************************************/
|
|
|
|
PUBLIC HRESULT FAR PASCAL RcScanLLeaf(BK bk, KEY key, SHORT wLevel,
|
|
QBTHR qbthr, QV qRec, QBTPOS qbtpos)
|
|
{
|
|
QCB qcb;
|
|
QB qb;
|
|
SHORT cKey;
|
|
HRESULT rc;
|
|
LONG dwKeyVal;
|
|
HRESULT errb;
|
|
|
|
dwKeyVal = *(LONG FAR *)key;
|
|
|
|
|
|
if ((qcb = QFromBk(bk, wLevel, qbthr, &errb)) == NULL)
|
|
{
|
|
return (errb);
|
|
}
|
|
|
|
rc = E_NOTEXIST;
|
|
|
|
qb = qcb->db.rgbBlock + 2 * sizeof(BK);
|
|
|
|
for (cKey = 0; cKey < qcb->db.cKeys; cKey++)
|
|
{
|
|
LONG dwVal = (LONG)GETLONG ((LPUL)qb);
|
|
if (dwKeyVal > dwVal)
|
|
{
|
|
// still looking for key
|
|
qb += sizeof(LONG);
|
|
qb += CbSizeRec(qb, qbthr);
|
|
}
|
|
else if (dwKeyVal < dwVal)
|
|
{
|
|
// key not found
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
// matched the key
|
|
if (qRec != NULL)
|
|
{
|
|
qb += sizeof(LONG);
|
|
QVCOPY(qRec, qb, (LONG)CbSizeRec(qb, qbthr));
|
|
}
|
|
|
|
rc = S_OK;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (qbtpos != NULL)
|
|
{
|
|
qbtpos->bk = bk;
|
|
qbtpos->iKey = (WORD)(qb - (QB)qcb->db.rgbBlock);
|
|
qbtpos->cKey = cKey;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
|
|
/* EOF */
|