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/* xbblkread.h
XBase64 Software Library
Copyright (c) 1997,2003,2014,2022 Gary A Kunkel
The xb64 software library is covered under the terms of the GPL Version 3, 2007 license.
Email Contact:
XDB-devel@lists.sourceforge.net
XDB-users@lists.sourceforge.net
*/
#ifndef __XB_BLKREAD_H__
#define __XB_BLKREAD_H__
namespace xb{
#ifdef XB_BLOCKREAD_SUPPORT
//! @brief xbBlockRead class.
/*!
The xbBlockRead class can be used to read blocks of records at one time
rather than one record at a time for perfomance improvements when reading a DBF file sequentially.<br>
*/
class XBDLLEXPORT xbBlockRead {
public:
xbBlockRead( xbDbf * d );
~xbBlockRead();
#ifdef XB_DEBUG_SUPPORT
void DumpReadBlockInternals();
#endif
xbInt16 Init( xbUInt32 ulBlkSize = 0 );
xbUInt32 GetBlockFirstRecNo() const;
xbUInt32 GetBlockRecCnt() const;
xbUInt32 GetBlockSize() const;
xbInt16 GetRecord( xbUInt32 ulRecNo ); // retrieve a data record from a block to RecBuf
xbInt16 SetBlockSize( xbUInt32 ulBlkSize );
private:
xbInt16 GetBlockForRecNo( xbUInt32 ulRecNo ); // retrieve block from disk for a given record number
char *pBlock; // block pointer
xbUInt32 ulBlkSize; // block size in bytes
xbUInt32 ulFirstBlkRec; // first recod number in the block
xbUInt32 ulRecCnt; // number of records in block
xbUInt32 ulMaxRecs; // max number of records block can handle
xbBool bEof; // EOF flag
xbDbf *dbf; // reference to associated dbf file
// xbXBase *xbase; // reference to main xbXBase structure
time_t tFmTime; // file modify time at time of block read
};
#endif // XB_BLOCKREAD
} /* namespace */
#endif /* __XB_BLOCKREAD_H__ */
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