46 lines
1.8 KiB
C
46 lines
1.8 KiB
C
/*****************************************************************************
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* *
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* ZECK.H *
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* *
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* Copyright (C) Microsoft Corporation 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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* *
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* Zeck compression routines for bitmaps & topic 2K blocks.
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* *
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*****************************************************************************/
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// This structure is passed to the compression routine to specify ranges
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// in which to suppress compression:
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typedef struct struct_suppresszeck SUPPRESSZECK, *QSUPPRESSZECK;
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// REVIEW: can we switch to DWORDs?
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struct struct_suppresszeck {
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PBYTE rbSuppress; // beginning of range for suppression.
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WORD cbSuppress; // number of bytes to suppress compression.
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PBYTE rbNewpos; // pointer into dest buffer where suppressed range
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// ended up after compression (an OUT param value).
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WORD iBitdex; // offset from rbNewpos of zeck code bits, used when
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// back patching.
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QSUPPRESSZECK next; // next suppression range in this list.
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};
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#define BITDEX_NONE (-1) // indicates no compression took place, and
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// backpatch should not adjust for the
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// code bits.
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int STDCALL LcbCompressZeck(PBYTE pbSrc, PBYTE pbDest, int cbSrc,
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int cbDest, int * qulSrcUsed = NULL, QSUPPRESSZECK qSuppress = NULL);
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void STDCALL FAllocateZeckGlobals(void);
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void STDCALL FreeZeckGlobals(void);
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void STDCALL VMemBackpatchZeck(QSUPPRESSZECK qsuppresszeck, DWORD ulOffset, int ulValue);
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void STDCALL FDiskBackpatchZeck(HF hf, DWORD fcl, DWORD ulOffset, int iBitdex, DWORD ulValue);
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int STDCALL LcbUncompressZeck(PBYTE pbSrc, PBYTE pbDest, int cbSrc);
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