235 lines
8.2 KiB
C
235 lines
8.2 KiB
C
#ifdef WIN32
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#pragma pack(1)
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#endif
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/*****************************************************************************
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* *
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* BTPRIV.H *
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* *
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* Copyright (C) Microsoft Corporation 1989, 1990. *
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* All Rights reserved. *
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* *
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******************************************************************************
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* *
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* Module Intent *
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* Private header for btree files. *
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* *
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******************************************************************************
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* *
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* Testing Notes *
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* *
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******************************************************************************
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* *
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* Current Owner: JohnSc *
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* *
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******************************************************************************
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* *
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* Released by Development: long long ago *
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* *
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*****************************************************************************/
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/*****************************************************************************
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*
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* Revision History: Created 03/08/89 by JohnSc
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*
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* 08/21/90 JohnSc autodocified
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*
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*****************************************************************************/
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// _subsystem( btree );
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/***************************************************************************\
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*
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* Defines
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*
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\***************************************************************************/
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/* default btree record format */
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_public
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#define rgchBtreeFormatDefault "z4"
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//#define wLevelsMax 5
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/* cache flags */
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#define fCacheDirty 1
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#define fCacheValid 4
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/***************************************************************************\
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*
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* Macros
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*
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\***************************************************************************/
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/* Get the real size of a cache block */
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_private
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#define CbCacheBlock( qbthr ) \
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( sizeof( CACHE_BLOCK ) - sizeof( DISK_BLOCK ) + (qbthr)->bth.cbBlock )
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/* convert a BK into a file offset */
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_private
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#define LifFromBk( bk, qbthr ) \
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( (LONG)(bk) * (LONG)(qbthr)->bth.cbBlock + (LONG)sizeof( BTH ) )
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/* get a pointer to the cache block cached for the given level */
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_private
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#define QCacheBlock( qbthr, wLevel ) \
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((QCB)( (qbthr)->qCache + (wLevel) * CbCacheBlock( qbthr ) ))
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/* get and set prev and next BK (defined for leaf blocks only) */
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_private
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#define BkPrev( qcb ) *(BK FAR *)((qcb)->db.rgbBlock)
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_private
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#define BkNext( qcb ) *(((BK FAR *)((qcb)->db.rgbBlock)) + 1 )
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_private
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#define SetBkPrev( qcb, bk ) BkPrev( qcb ) = bk
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_private
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#define SetBkNext( qcb, bk ) BkNext( qcb ) = bk
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// For btree map functions: returns byte number of x-th btree map record //
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_private
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#define LcbFromBk(x) ((LONG)sizeof( INT ) + x * sizeof( MAPREC ))
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/***************************************************************************\
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*
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* Types
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*
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\***************************************************************************/
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/*
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Header of a btree file.
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*/
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_private
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typedef struct _btree_header
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{
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WORD wMagic;
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BYTE bVersion;
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BYTE bFlags; // r/o, open r/o, dirty, isdir
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INT cbBlock; // # bytes in a disk block
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CHAR rgchFormat[ wMaxFormat + 1 ]; // key and record format string
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BK bkFirst; // first leaf block in tree
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BK bkLast; // last leaf block in tree
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BK bkRoot; // root block
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BK bkFree; // head of free block list
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BK bkEOF; // next bk to use if free list empty
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INT cLevels; // # levels currently in tree
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LONG lcEntries; // # keys in btree
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} BTH;
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/*
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In-memory struct referring to a btree.
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*/
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_private
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typedef struct _bthr
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{
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BTH bth; // copy of header from disk
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HF hf; // file handle of open btree file
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INT cbRecordSize; // 0 means variable size record
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GH ghCache; // handle to cache array
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QB qCache; // pointer to locked cache
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BYTE far *qbLigatures; // MATTSMI 9/28/92
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// KT specific routines
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BK (FAR PASCAL *BkScanInternal)( BK, KEY, INT, struct _bthr FAR *, QI );
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RC (FAR PASCAL *RcScanLeaf)( BK, KEY, INT, struct _bthr FAR *, QV, QBTPOS );
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} BTH_RAM, FAR *QBTHR;
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/*
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Btree leaf or internal node. Keys and records live in rgbBlock[].
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See btree.doc for details.
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*/
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_private
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typedef struct _disk_btree_block
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{
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INT cbSlack; // unused bytes in block
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INT cKeys; // count of keys in block
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BYTE rgbBlock[1]; // the block (real size cbBlock - 4)
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} DISK_BLOCK;
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/*
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Btree node as it exists in the in-memory cache.
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*/
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_private
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typedef struct _cache_btree_block
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{
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BK bk; // IDs which block is cached
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BYTE bFlags; // dirty, cache valid
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DISK_BLOCK db;
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} CACHE_BLOCK, FAR *QCB;
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/*
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One record of a btree map.
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*/
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_private
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typedef struct _btree_map_record // One record of a btree map
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{
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LONG cPreviousKeys; // total # of keys in previous blocks
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BK bk; // The block number
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} MAPREC, FAR *QMAPREC;
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/*
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Auxiliary index of btree leaves.
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Used for indexing a given % of the way into a btree.
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*/
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_private
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typedef struct _btree_map
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{
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INT cTotalBk;
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MAPREC table[1]; // sorted by MAPREC's cPreviousKeys field
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} MAPBT, FAR *QMAPBT; // and is in-order list of leaf nodes
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/***************************************************************************\
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*
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* Function Prototypes
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*
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\***************************************************************************/
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RC FAR PASCAL RcGetIOError(void);
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RC FAR PASCAL SetIOErrorRc(RC);
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RC FAR PASCAL RcGetFSError(void);
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RC FAR PASCAL SetFSErrorRc(RC);
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RC FAR PASCAL RcGetBtreeError(void);
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RC FAR PASCAL SetBtreeErrorRc(RC);
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INT CbSizeRec ( QV, QBTHR );
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QCB QFromBk ( BK, INT, QBTHR );
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RC RcGetKey ( QV, KEY, KEY *, KT );
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INT WCmpKey ( KEY, KEY, QBTHR );
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INT CbSizeKey ( KEY, QBTHR, BOOL );
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BOOL FReadBlock ( QCB, QBTHR );
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RC RcWriteBlock ( QCB, QBTHR );
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BK BkAlloc ( QBTHR );
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void FreeBk ( QBTHR, BK );
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RC RcSplitLeaf ( QCB, QCB, QBTHR );
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void SplitInternal ( QCB, QCB, QBTHR, QI );
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RC RcInsertInternal( BK, KEY, INT, QBTHR );
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RC FAR PASCAL RcFlushCache ( QBTHR );
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RC FAR PASCAL RcMakeCache ( QBTHR );
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// KT specific routines
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BK FAR PASCAL BkScanSzInternal( BK, KEY, INT, QBTHR, QI );
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RC FAR PASCAL RcScanSzLeaf ( BK, KEY, INT, QBTHR, QV, QBTPOS );
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BK FAR PASCAL BkScanLInternal ( BK, KEY, INT, QBTHR, QI );
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RC FAR PASCAL RcScanLLeaf ( BK, KEY, INT, QBTHR, QV, QBTPOS );
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BK FAR PASCAL BkScanSziInternal ( BK, KEY, INT, QBTHR, QI );
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RC FAR PASCAL RcScanSziLeaf ( BK, KEY, INT, QBTHR, QV, QBTPOS );
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BK FAR PASCAL BkScanSziScandInternal( BK, KEY, INT, QBTHR, QI );
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RC FAR PASCAL RcScanSziScandLeaf ( BK, KEY, INT, QBTHR, QV, QBTPOS );
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/* EOF */
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#define _MAX_PATH 260
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#ifdef WIN32
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#pragma pack()
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#endif
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