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Diffstat (limited to 'src/include/xbmemo.h')
| -rwxr-xr-x | src/include/xbmemo.h | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/src/include/xbmemo.h b/src/include/xbmemo.h new file mode 100755 index 0000000..ad9aac2 --- /dev/null +++ b/src/include/xbmemo.h @@ -0,0 +1,224 @@ +/* xbmemo.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_XBMEMO_H__ +#define __XB_XBMEMO_H__ + + +// dont use "#pragma interface" with abstract classes +// #ifdef CMAKE_COMPILER_IS_GNUCC +// #pragma interface +// #endif + +#ifdef XB_MEMO_SUPPORT + + + + +namespace xb{ + +//! @brief Base class for memo files. +/*! + +The xbMemo class is used as a base class for accessing memo files. + +Any DBF file which has any memo fields, will also have a DBT file with the same name. +Memo fields are stored in the DBT file in 512 or 1024 byte sized blocks. + +Calls to the memo routines to read and access memo fields are supported from within +the dbf class via the GetMemoField and UpdateMemoField routines. +From an application program point of view, the application program does not need to +be concerned with the memo classes.<br> + +The main difference between the version 3 and version 4 memo files is that +the version 4 files will reclaim and reuse blocks if available. The version 3 +memo file logic does not.<br> + +If you are adding a new style memo table to the logic, you can create a new class +modeled after xbMemoDbt3 or xbDbtMemo4, using the xbMemo class as a base class. + +*/ + +class XBDLLEXPORT xbMemo : public xbFile { + public: + + xbMemo( xbDbf *dbf, xbString const &sFileName ); + + /* virtual methods */ + virtual ~xbMemo(); + virtual xbInt16 Abort () = 0; + virtual xbInt16 CloseMemoFile (); + virtual xbInt16 Commit () = 0; + virtual xbInt16 CreateMemoFile () = 0; + + virtual xbInt16 DumpMemoHeader () = 0; + + + virtual xbInt16 GetMemoField ( xbInt16 iFieldNo, xbString &sMemoData ) = 0; + virtual xbInt16 GetMemoFieldLen ( xbInt16 iFieldNo, xbUInt32 &ulMemoFieldLen ) = 0; + virtual xbInt16 OpenMemoFile () = 0; + virtual xbInt16 GetMemoFileType (); + virtual xbInt16 PackMemo ( void (*memoStatusFunc)(xbUInt32 ulItemNum, xbUInt32 ulNumItems)) = 0; + virtual xbInt16 UpdateMemoField ( xbInt16 iFieldNo, const xbString &sMemoData ) = 0; + + #ifdef XB_DEBUG_SUPPORT + virtual xbInt16 DumpMemoFreeChain() = 0; + #endif + + #ifdef XB_LOCKING_SUPPORT + virtual xbInt16 LockMemo ( xbInt16 iLockFunction ); + virtual xbBool GetMemoLocked () const; + #endif + + + + // *********** FIXME ************* + // next two methods should be protected but are called in the xb_test_xxxx programs testing routines + // so for now, they are kept as public + virtual xbInt16 CalcLastDataBlock ( xbUInt32 &lLastDataBlock ); + virtual xbInt16 GetHdrNextBlock ( xbUInt32 &ulBlockNo ); + + protected: + friend class xbDbf; + + virtual xbInt16 ReadDbtHeader ( xbInt16 iOption ) = 0; + virtual xbInt16 UpdateHeaderName () = 0; + virtual xbInt16 UpdateHeadNextNode(); + virtual xbInt16 Zap () = 0; + + xbDbf *dbf; /* pointer to related dbf instance */ + char cVersion; /* byte 16 off the header block, 0x03 for V3, version IV - ? */ + xbInt16 iMemoFileType; /* 3 = version III, 4 = version IV */ + xbUInt32 ulHdrNextBlock; /* next available block , bytes 0-3 of the memo header */ + void * mbb; /* memo block buffer */ + + + private: + + #ifdef XB_LOCKING_SUPPORT + xbBool bFileLocked; /* memo file locked */ + #endif + +}; + + + +#ifdef XB_DBF3_SUPPORT +//! @brief Derived class for version 3 memo files. +/*! + +The xbMemoDbt3 class is derived from the xbMome class and is used for accessing the +older Version 3 memo files. + +The main difference between the version 3 and version 4 memo files is that +the version 4 files will reclaim and reuse blocks if available. The version 3 +memo file logic does not.<br> + +*/ + + +class XBDLLEXPORT xbMemoDbt3 : public xbMemo { + public: + xbMemoDbt3( xbDbf *dbf, xbString const &sFileName ); + ~xbMemoDbt3(); + virtual xbInt16 Abort (); + virtual xbInt16 Commit (); + virtual xbInt16 CreateMemoFile (); + virtual xbInt16 DumpMemoHeader (); + virtual xbInt16 GetMemoField ( xbInt16 iFieldNo, xbString &sMemoData ); + virtual xbInt16 GetMemoFieldLen( xbInt16 iFieldNo, xbUInt32 &ulMemoFieldLen ); + virtual xbInt16 OpenMemoFile (); + virtual xbInt16 PackMemo ( void (*memoStatusFunc) (xbUInt32 ulItemNum, xbUInt32 ulNumItems)); + virtual xbInt16 UpdateMemoField( xbInt16 iFieldNo, const xbString &sMemoData ); + + #ifdef XB_DEBUG_SUPPORT + virtual xbInt16 DumpMemoFreeChain(); + #endif + + protected: + virtual xbInt16 ReadDbtHeader( xbInt16 iOption ); + virtual xbInt16 UpdateHeaderName(); + virtual xbInt16 Zap(); + + private: +}; +#endif + + +#ifdef XB_DBF4_SUPPORT + +//! @brief Derived class for version 4 memo files. +/*! + +The xbMemoDbt4 class is derived from the xbMeme class and is used for accessing the +current Version 4 memo files. + +The main difference between the version 3 and version 4 memo files is that +the version 4 files will reclaim and reuse blocks if available. The version 3 +memo file logic does not.<br> +*/ + +class XBDLLEXPORT xbMemoDbt4 : public xbMemo { + public: + xbMemoDbt4( xbDbf *dbf, xbString const &sFileName ); + ~xbMemoDbt4(); + virtual xbInt16 Abort (); + virtual xbInt16 Commit (); + virtual xbInt16 CreateMemoFile (); + virtual xbInt16 DumpMemoHeader (); + virtual xbInt16 GetMemoField ( xbInt16 iFieldNo, xbString &sMemoData ); + virtual xbInt16 GetMemoFieldLen ( xbInt16 iFieldNo, xbUInt32 &ulMemoFieldLen ); + virtual xbInt16 GetMemoFieldLen ( xbInt16 iFieldNo, xbUInt32 &ulMemoFieldLen, xbUInt32 &lBlockNo ); + virtual xbInt16 OpenMemoFile (); + virtual xbInt16 PackMemo ( void (*memoStatusFunc) (xbUInt32 ulItemNum, xbUInt32 ulNumItems)); + virtual xbInt16 UpdateMemoField ( xbInt16 iFieldNo, const xbString &sMemoData ); + + #ifdef XB_DEBUG_SUPPORT + virtual xbInt16 DumpMemoFreeChain (); + virtual xbInt16 DumpMemoInternals (); + virtual xbInt16 ReadFreeBlockHeader( xbUInt32 ulBlockNo, xbUInt32 &ulNextBlock, xbUInt32 &ulFreeBlockCnt ); + #endif + + protected: + virtual xbInt16 FindBlockSetInChain( xbUInt32 ulBlocksNeeded, xbUInt32 &ulLastDataBlock, xbUInt32 &ulLocation, xbUInt32 &ulPrevNode, xbBool &bFound ); + virtual xbInt16 FreeMemoBlockChain( xbUInt32 ulBlockNo ); + virtual xbInt16 FreeMemoBlockChain( xbUInt32 ulBlockNo, xbUInt32 &ulLastDataBlock ); + virtual xbInt16 GetBlockSetFromChain( xbUInt32 ulBlocksNeeded, xbUInt32 ulLocation, xbUInt32 ulPrevNode ); + virtual xbInt16 ReadDbtHeader( xbInt16 iOption ); + virtual xbInt16 ReadBlockHeader( xbUInt32 ulBlockNo, xbInt16 iOption ); + virtual xbInt16 UpdateHeaderName (); + virtual xbInt16 WriteBlockHeader( xbUInt32 ulBlockNo, xbInt16 iOption ); + virtual xbInt16 Zap(); + + private: + xbString sDbfFileNameWoExt; + xbUInt32 ulNextFreeBlock; + xbUInt32 ulFreeBlockCnt; + xbInt16 iField1; + xbInt16 iStartPos; + xbUInt32 ulFieldLen; + + xbLinkList<xbUInt32> llOldBlocks; // list of previously used memo blocks for field, used by Commit() / Abort() + xbLinkList<xbUInt32> llNewBlocks; // list of newly updated memo blocks for field, used by Commit() / Abort() + +}; +#endif + + +} /* namespace xb */ +#endif /* XB_MEMO_SUPPORT */ +#endif /* __XB_MEMO_H__ */ + |