windows-nt/Source/XPSP1/NT/enduser/stuff/itircl/common/btree/btktszi.c

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2020-09-26 03:20:57 -05:00
/*****************************************************************************
* *
* BTKTSZI.C *
* *
* Copyright (C) Microsoft Corporation 1989 - 1994. *
* All Rights reserved. *
* *
******************************************************************************
* *
* Module Intent *
* *
* Functions for SZI (0-terminated case insensitive string) keys. *
* *
******************************************************************************
* *
* Current Owner: UNDONE *
* *
*****************************************************************************/
static char s_aszModule[] = __FILE__; /* For error report */
#include <mvopsys.h>
#include <orkin.h>
#include <misc.h>
#include <iterror.h>
#include <wrapstor.h>
#include <mvsearch.h>
#include <_mvutil.h>
#include "common.h"
/***************************************************************************
*
* @doc INTERNAL
*
* @func BK FAR PASCAL | BkScanSziInternal |
* Scan an internal node for a 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
*
* @parm QW | qiKey |
* address of an int or NULL to not get it
*
* @parm QBTHR | qbthr |
* qbthr->qCache - bk's block will be cached
*
* @parm QW | qiKey |
* index into rgbBlock of first key >= key
*
* @rdesc bk of subtree that might contain key; bkNil on error
* Side Effects: bk's block will be cached
*
***************************************************************************/
PUBLIC BK FAR PASCAL BkScanSziInternal(BK bk, KEY key, SHORT wLevel,
QBTHR qbthr, QW qiKey, PHRESULT phr)
{
QCB qcb;
QB q;
SHORT cKeys;
LPB lpLigatureTable;
if ((qcb = QFromBk(bk, wLevel, qbthr, phr)) == NULL)
{
return bkNil;
}
q = qcb->db.rgbBlock;
cKeys = qcb->db.cKeys;
bk = (BK)GETLONG(q);
q += sizeof(BK);
lpLigatureTable = (LPB)(((LPCHARTAB)*qbthr->lrglpCharTab)->lpLigature);
while (cKeys-- > 0)
{
if (WCmpiSz((SZ)key, (SZ)q, lpLigatureTable) >= 0)
{
q += STRLEN((SZ)q) + 1;
bk = GETLONG(q);
q += sizeof(BK);
}
else
break;
}
if (qiKey != NULL)
{
*qiKey = (WORD)(q - (QB)qcb->db.rgbBlock);
}
return bk;
}
/***************************************************************************
*
* @doc INTERNAL
*
* @func HRESULT FAR PASCAL | RcScanSziLeaf |
* 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
*
* @parm QV | qRec |
* if found, record gets copied into this buffer
*
* @parm QTPOS | qbtpos |
* pos of first key >= key goes here
*
* @rdesc ERR_SUCCESS if found; ERR_NOTEXIST if not found
* 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.
*
***************************************************************************/
PUBLIC HRESULT FAR PASCAL RcScanSziLeaf( BK bk, KEY key, SHORT wLevel,
QBTHR qbthr, QV qRec, QBTPOS qbtpos)
{
QCB qcb;
SZ sz;
SHORT w, cKey;
QB qb;
HRESULT rc;
HRESULT errb;
LPB lpLigatureTable;
if ((qcb = QFromBk(bk, wLevel, qbthr, &errb)) == NULL) {
return errb;
}
rc = E_NOTEXIST;
sz = qcb->db.rgbBlock + 2 * sizeof(BK);
lpLigatureTable = (LPB)(((LPCHARTAB)*qbthr->lrglpCharTab)->lpLigature);
for (cKey = 0; cKey < qcb->db.cKeys; cKey++)
{
w = WCmpiSz((SZ)key, sz, lpLigatureTable);
if (w > 0) /* still looking for key */
{
sz += STRLEN(sz) + 1;
sz += CbSizeRec(sz, qbthr);
}
else if (w < 0) /* key not found */
{
break;
}
else /* matched the key */
{
if (qRec != NULL)
{
qb = (QB)sz + STRLEN(sz) + 1;
QVCOPY(qRec, qb, (LONG)CbSizeRec(qb, qbthr));
}
rc = S_OK;
break;
}
}
if (qbtpos != NULL)
{
qbtpos->bk = bk;
qbtpos->cKey = cKey;
qbtpos->iKey = (int)((QB)sz - (QB)qcb->db.rgbBlock);
}
return rc;
}
/* EOF */