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windows-nt/Source/XPSP1/NT/com/ole32/stg/msf/fat.cxx

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//+-------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1992 - 1992.
//
// File: fat.cxx
//
// Contents: Allocation functions for MStream
//
// Classes: None. (defined in fat.hxx)
//
// History: 18-Jul-91 PhilipLa Created.
//
//--------------------------------------------------------------------------
#include "msfhead.cxx"
#pragma hdrstop
#include <difat.hxx>
#include <sstream.hxx>
#include <mread.hxx>
#define USE_NOSCRATCHINMARKSECT
//#define SECURETEST
//+---------------------------------------------------------------------------
//
// Member: CFat::IsFree, private
//
// Synopsis: Check and see if a given sector is really free, given all
// the permutations of ways a sector can be assigned.
//
// Arguments: [sect] -- Sector to check
//
// Returns: S_OK if sector is really free.
// S_FALSE if sector is really allocated.
// Appropriate error in error case.
//
// Modifies:
//
// History: 30-Mar-95 PhilipLa Created
// 15-Mar-97 BChapman Calls IsSectType()
//
//----------------------------------------------------------------------------
inline SCODE CFat::IsFree(SECT sect)
{
return IsSectType(sect, FREESECT);
}
//
//+---------------------------------------------------------------------------
//
// Member: CFat::IsSectType, private
//
// Synopsis: Check and see if a given sector is really of a given type,
// given all the permutations of ways a sector can be assigned.
// If we are looking for FREESECT there are extra checks.
//
// Arguments: [sect] -- Sector to check
// [sectType] -- Sector type to check against FREE, FAT, DIF.
//
// Returns: S_OK if sector is really free.
// S_FALSE if sector is really allocated.
// Appropriate error in error case.
//
// Modifies:
//
// History: 18-Feb-97 BChapman Created
//
//----------------------------------------------------------------------------
inline SCODE CFat::IsSectType(SECT sect, SECT sectType)
{
SCODE sc = S_OK;
SECT sectCurrent = sectType;
#ifdef DEBUG_ISSECTTYPE
msfDebugOut((DEB_ITRACE, "In CFat::IsSectType:%p(%x, %x)\n",
this, sect, sectType));
#endif
if((FREESECT == sectType))
{
if (sect < _sectNoSnapshot)
{
return S_FALSE;
}
if ((_sectNoSnapshotFree != ENDOFCHAIN)
&& (sect < _sectNoSnapshotFree))
{
return S_FALSE;
}
}
if (_pfatNoScratch != NULL)
{
msfAssert((!_pmsParent->IsScratch()) &&
aMsg("Scratch MS in Noscratch mode"));
FSINDEX ipfs;
FSOFFSET isect;
_pfatNoScratch->SectToPair(sect, &ipfs, &isect);
if (ipfs < _pfatNoScratch->_cfsTable)
{
//We need to check the NoScratch fat to make sure
//that this sector isn't already allocated into
//scratch space for a stream.
msfChk(_pfatNoScratch->GetNext(
sect,
&sectCurrent));
}
}
//Since the no-scratch fat will have a complete copy of everything
// in the shadow fat, we don't need to check both. So only do this
// when we're not in no-scratch mode.
//The no-scratch fat also has a copy of the read-only GetFree()
// returned stuff, so we only need to do that check when not in
// no-scratch.
else
{
if (_cUnmarkedSects > 0)
{
//We are in copy-on-write mode. Lookup this
//sector in the DIF and make sure that it is
//actually free.
msfAssert((_sectLastUsed > 0) &&
aMsg("Doing DIFat check when not in COW."));
msfChk(_pmsParent->GetDIFat()->Lookup(
sect,
&sectCurrent));
}
if (FREESECT == sectType)
{
if ((sect < _sectLastUsed) && (sectCurrent == FREESECT))
{
//We're in copy-on-write mode, so
// this sector may not be really free.
msfAssert(_sid != SIDMINIFAT &&
aMsg("Minifat in Copy-on-Write mode"));
msfAssert(_pfatReal != NULL &&
aMsg("Copy-On-Write mode without fat copy"));
msfAssert(_pfatReal->_cfsTable != 0 &&
aMsg("Copy-on-Write mode with empty fat copy"));
msfAssert(_pfatReal->_pmsParent->IsShadow() &&
aMsg("Copy-on-Write mode with non-shadow fat copy"));
msfChk(_pfatReal->GetNext(sect, &sectCurrent));
}
}
}
if (sectCurrent != sectType)
{
sc = S_FALSE;
}
#ifdef DEBUG_ISSECTTYPE
msfDebugOut((DEB_ITRACE, "Out CFat::IsSectType\n"));
#endif
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Method: CFatSect::Init, public
//
// Synopsis: CFatSect initialization function
//
// Effects: [uEntries] -- Number of entries in sector
//
// Algorithm: Allocate an array of SECT with size uEntries from
// the heap.
//
// History: 18-Jul-91 PhilipLa Created.
// 27-Dec-91 PhilipLa Converted to dynamic allocation
//
//--------------------------------------------------------------------------
SCODE CFatSect::Init(FSOFFSET uEntries)
{
msfDebugOut((DEB_FAT,"In CFatSect constructor\n"));
//This assumes that FREESECT is always 0xFFFFFFFF
memset(_asectEntry, 0xFF, uEntries * sizeof(SECT));
msfDebugOut((DEB_FAT,"Out CFatSect constructor\n"));
return S_OK;
}
//+-------------------------------------------------------------------------
//
// Method: CFatSect::InitCopy, public
//
// Synopsis: Initialization function for copying FatSects
//
// Arguments: [fsOld] -- Reference to FatSect to be copies
//
// Returns: S_OK if call completed successfully.
//
// Algorithm: Allocate a new array of SECT and copy old
// information in.
//
// History: 06-Feb-92 PhilipLa Created.
//
//--------------------------------------------------------------------------
SCODE CFatSect::InitCopy(USHORT uSize, CFatSect *pfsOld)
{
msfDebugOut((DEB_FAT,"In CFatSect copy constructor\n"));
msfDebugOut((DEB_FAT,"This = %p, fsOld = %p\n",this, pfsOld));
msfDebugOut((DEB_FAT,"Sector size is %u sectors\n", uSize));
memcpy(_asectEntry, &pfsOld->_asectEntry, sizeof(SECT)*uSize);
msfDebugOut((DEB_FAT,"Out CFatSect copy constructor\n"));
return S_OK;
}
//+-------------------------------------------------------------------------
//
// Method: CFat::CFat, public
//
// Synopsis: CFat constructor.
//
// Arguments: [pmsParent] -- Pointer to parent multistream.
//
// Algorithm: Set uFatEntries to match parent MS header info.
// Initialize all member variables.
//
// History: 18-Jul-91 PhilipLa Created.
// 27-Dec-91 PhilipLa Converted to use FatVector
// 30-Dec-91 PhilipLa Converted to use variable size sect.
//
// Notes:
//
//--------------------------------------------------------------------------
CFat::CFat(SID sid)
: _fv(sid),
_pfatReal(NULL),
_pfatNoScratch(NULL),
_sectNoSnapshot(0),
_sectNoSnapshotFree(ENDOFCHAIN),
_sid(sid),
_pmsParent(NULL),
_sectFirstFree(0),
_sectLastUsed(0),
_sectMax(ENDOFCHAIN)
{
_cUnmarkedSects = 0;
}
//+-------------------------------------------------------------------------
//
// Method: CFat::CFat, public
//
// Synopsis: CFat copy constructor
//
// Arguments: [fatOld] -- Fat to be copied.
//
// Algorithm: Set member variables to match fat being copied.
//
// History: 27-Dec-91 PhilipLa Created.
//
// Notes: This is for use in transactioning. It is the only proper
// way to create a Shadow Fat.
//
//--------------------------------------------------------------------------
CFat::CFat(CFat *pfatOld)
: _pmsParent(pfatOld->_pmsParent),
_fv(pfatOld->_sid),
_pfatReal(NULL),
_sid(pfatOld->_sid),
_sectFirstFree(0),
_sectLastUsed(0),
_sectMax(ENDOFCHAIN),
_sectNoSnapshot(pfatOld->_sectNoSnapshot)
{
_cUnmarkedSects = 0;
}
//+-------------------------------------------------------------------------
//
// Method: CFat::InitCopy, public
//
// Synopsis: Init function for CFat copying
//
// Arguments: [fatOld] -- reference to CFat to be copied
//
// Returns: S_OK if call completed OK.
//
// Algorithm: *Finish This*
//
// History: 18-Feb-92 PhilipLa Created.
//
// Notes:
//
//--------------------------------------------------------------------------
void CFat::InitCopy(CFat *pfatOld)
{
msfDebugOut((DEB_FAT,"In CFat Copy Constructor\n"));
_pmsParent = pfatOld->_pmsParent;
_uFatShift = pfatOld->_uFatShift;
_uFatMask = pfatOld->_uFatMask;
_fv.InitCommon(1 << _uFatShift, 1 << _uFatShift);
_cfsTable = pfatOld->_cfsTable;
_fv.InitCopy(&pfatOld->_fv);
_ulFreeSects = MAX_ULONG;
_sectFirstFree = pfatOld->_sectFirstFree;
_sectLastUsed = pfatOld->_sectLastUsed;
_sectMax = pfatOld->_sectMax;
_ipfsRangeLocks = pfatOld->_ipfsRangeLocks;
_isectRangeLocks = pfatOld->_isectRangeLocks;
msfDebugOut((DEB_FAT,"Out CFat Copy Constructor\n"));
}
//+---------------------------------------------------------------------------
//
// Member: CFat::Empty, public
//
// Synopsis: Empty all the control structures of this instance
//
// Arguments: None.
//
// Returns: void.
//
// History: 04-Dec-92 PhilipLa Created
//
//----------------------------------------------------------------------------
void CFat::Empty(void)
{
_fv.Empty();
_pmsParent = NULL;
_pfatReal = NULL;
_cfsTable = 0;
_ulFreeSects = MAX_ULONG;
_sectFirstFree = 0;
_sectLastUsed = 0;
_sectMax = ENDOFCHAIN;
_cUnmarkedSects = 0;
}
//+-------------------------------------------------------------------------
//
// Method: CFat::~CFat, public
//
// Synopsis: CFat Destructor
//
// Algorithm: delete dynamically allocated storage
//
// History: 18-Jul-91 PhilipLa Created.
// 27-Jul-91 PhilipLa Converted to use FatVect.
//
// Notes:
//
//--------------------------------------------------------------------------
CFat::~CFat()
{
msfDebugOut((DEB_FAT,"In CFat destructor. Size of fat is %lu\n",_cfsTable));
msfDebugOut((DEB_FAT,"Exiting CFat destructor\n"));
}
struct SGetFreeStruct
{
CVectBits *pfb;
SECT sect;
CFatSect *pfs;
FSOFFSET isect;
FSINDEX ipfs;
SECT sectLast;
FSINDEX ipfsLast;
FSOFFSET isectLast;
#ifdef USE_NOSCRATCHINMARKSECT
CFatSect *pfsNoScratch;
FSINDEX ipfsNoScratch;
#endif
};
//+---------------------------------------------------------------------------
//
// Member: CFat::InitGetFreeStruct, private
//
// Synopsis: Initialize an SGetFreeStruct
//
// Arguments: [pgf] -- Pointer to structure to initialize
//
// History: 03-Nov-95 PhilipLa Created
//
//----------------------------------------------------------------------------
void CFat::InitGetFreeStruct(SGetFreeStruct *pgf)
{
pgf->sectLast = ENDOFCHAIN;
pgf->pfs = NULL;
#ifdef USE_NOSCRATCHINMARKSECT
pgf->pfsNoScratch = NULL;
#endif
}
//+---------------------------------------------------------------------------
//
// Member: CFat::ReleaseGetFreeStruct, private
//
// Synopsis: Release an SGetFreeStruct
//
// Arguments: [pgf] -- Pointer to structure to release
//
// History: 03-Nov-95 PhilipLa Created
//
//----------------------------------------------------------------------------
void CFat::ReleaseGetFreeStruct(SGetFreeStruct *pgf)
{
if (pgf->pfs != NULL)
{
_fv.ReleaseTable(pgf->ipfs);
}
#ifdef USE_NOSCRATCHINMARKSECT
if (pgf->pfsNoScratch != NULL)
{
_pfatNoScratch->_fv.ReleaseTable(pgf->ipfsNoScratch);
}
#endif
}
//+---------------------------------------------------------------------------
//
// Member: CFat::MarkSect, private
//
// Synopsis: Mark a sector as used, for use from GetFree and GetFreeContig
//
// Arguments: [pgf] -- Pointer to SGetFreeStruct with information about
// which sector to mark. This structure also returns
// information to the caller, so that state can be
// preserved across multiple calls for optimization.
//
// Returns: Appropriate status code
//
// History: 27-Oct-95 PhilipLa Created
//
//----------------------------------------------------------------------------
inline SCODE CFat::MarkSect(SGetFreeStruct *pgf)
{
msfAssert(_ulFreeSects != MAX_ULONG &&
aMsg("Free sect count not set"));
SCODE sc = S_OK;
_ulFreeSects--;
CVectBits * &pfb = pgf->pfb;
SECT &sect = pgf->sect;
FSOFFSET &isect = pgf->isect;
FSINDEX &ipfs = pgf->ipfs;
CFatSect * &pfs = pgf->pfs;
#ifdef USE_NOSCRATCHINMARKSECT
CFatSect * &pfsNoScratch = pgf->pfsNoScratch;
FSINDEX &ipfsNoScratch = pgf->ipfsNoScratch;
#endif
SECT &sectLast = pgf->sectLast;
FSINDEX &ipfsLast = pgf->ipfsLast;
FSOFFSET &isectLast = pgf->isectLast;
//If we're tracking the first free sector, we know it must be
// after this one, so set firstfree.
if (pfb != NULL)
{
pfb->firstfree = isect + 1;
}
//Update _sectFirstFree, since the first free sector must be after then
// current one.
msfAssert(sect >= _sectFirstFree &&
aMsg("Found free sector before _sectFirstFree"));
_sectFirstFree = sect + 1;
//Mark the current sector as ENDOFCHAIN in the fat.
pfs->SetSect(isect, ENDOFCHAIN);
if (_pfatNoScratch != NULL)
{
#ifdef USE_NOSCRATCHINMARKSECT
//In no-scratch, update the no-scratch fat
//as well.
FSINDEX ipfsNoScratchChk;
FSOFFSET isectNoScratchChk;
_pfatNoScratch->SectToPair(sect,
&ipfsNoScratchChk,
&isectNoScratchChk);
if ((pfsNoScratch != NULL) && (ipfsNoScratch != ipfsNoScratchChk))
{
_pfatNoScratch->_fv.ReleaseTable(ipfsNoScratch);
pfsNoScratch = NULL;
}
if (pfsNoScratch == NULL)
{
//SetNext call will grow the no-scratch fat if necessary.
msfChk(_pfatNoScratch->SetNext(sect, ENDOFCHAIN));
msfChk(_pfatNoScratch->_fv.GetTable(ipfsNoScratchChk,
FB_DIRTY,
&pfsNoScratch));
ipfsNoScratch = ipfsNoScratchChk;
}
else
{
pfsNoScratch->SetSect(isectNoScratchChk, ENDOFCHAIN);
_pfatNoScratch->_ulFreeSects--;
}
#else
msfChk(_pfatNoScratch->SetNext(sect, ENDOFCHAIN)); // slow, unoptimized
#endif
}
//Dirty the current page.
if ((sectLast == ENDOFCHAIN) || (ipfs != ipfsLast))
{
//We only need to make this call if we're touching a new
// page for the first time.
msfChk(_fv.SetDirty(ipfs));
}
//If we're building a chain, we want to update it here.
if (sectLast != ENDOFCHAIN)
{
if (_pfatNoScratch != NULL)
{
#ifdef USE_NOSCRATCHINMARKSECT
FSINDEX ipfsNoScratchChk;
FSOFFSET isectNoScratchChk;
_pfatNoScratch->SectToPair(sectLast,
&ipfsNoScratchChk,
&isectNoScratchChk);
if (ipfsNoScratchChk == ipfsNoScratch)
{
msfAssert(pfsNoScratch != NULL);
pfsNoScratch->SetSect(isectNoScratchChk, sect);
}
else
{
msfChk(_pfatNoScratch->SetNext(sectLast, sect));
}
#else
msfChk(_pfatNoScratch->SetNext(sectLast, sect)); //slow,unoptimized
#endif
}
//If we're in the same page, we can do this cheaply.
if (ipfsLast == ipfs)
{
pfs->SetSect(isectLast, sect);
}
else
{
//If we're NOT on the same page, we have to go grab the
// old one again, which can be expensive if the page table is full
CFatSect *pfsLast;
//Since we may only have one available page for the scratch MS,
// we need to release the current one before proceeding.
//
if (_pmsParent->IsScratch())
{
_fv.ReleaseTable(ipfs);
}
msfChk(_fv.GetTable(ipfsLast,
FB_DIRTY,
&pfsLast));
pfsLast->SetSect(isectLast, sect);
_fv.ReleaseTable(ipfsLast);
//Reacquire the current page if we're in the scratch.
if (_pmsParent->IsScratch())
{
msfChk(_fv.GetTable(ipfs, FB_DIRTY, &pfs));
}
}
}
return S_OK;
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::GetFree, private
//
// Synposis: Locate and return a free sector in the FAT
//
// Effects: May modify full bit on full sectors
//
// Arguments: [psectRet] -- Pointer to return value
//
// Returns: S_OK if call completed successfully.
//
// Algorithm: Do a linear search of all tables until a free sector is
// found. If all tables are full, extend the FAT by one
// sector.
//
// History: 18-Jul-91 PhilipLa Created.
// 22-Jul-91 PhilipLa Added FAT extension.
// 17-Aug-91 PhilipLa Added full bits optimization
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::GetFree(ULONG ulCount, SECT *psectRet, BOOL fReadOnly)
{
SGetFreeStruct gf;
SECT &sect = gf.sect;
CVectBits * &pfb = gf.pfb;
FSOFFSET &isect = gf.isect;
FSINDEX &ipfs = gf.ipfs;
CFatSect * &pfs = gf.pfs;
SECT &sectLast = gf.sectLast;
FSINDEX &ipfsLast = gf.ipfsLast;
FSOFFSET &isectLast = gf.isectLast;
InitGetFreeStruct(&gf);
SCODE sc;
*psectRet = ENDOFCHAIN;
msfAssert((!_pmsParent->IsShadow()) &&
aMsg("Modifying shadow fat."));
msfAssert(((!fReadOnly) || (ulCount == 1)) &&
aMsg("Read-only GetFree called with ulCount != 1"));
if (_sectNoSnapshotFree != ENDOFCHAIN)
{
//We're resizing our control structures to prepare for
// no-snapshot commit.
msfAssert((ulCount == 1) &&
aMsg("No-snapshot GetFree called with ulCount != 1"));
msfAssert(fReadOnly &&
aMsg("No-snapshot GetFree called without fReadOnly"));
*psectRet = _sectNoSnapshotFree++;
_cUnmarkedSects++;
if ((_ulFreeSects != 0) && (_ulFreeSects != MAX_ULONG))
{
_ulFreeSects--;
}
if (*psectRet >= _sectMax)
{
_sectMax = *psectRet + 1;
}
return S_OK;
}
if ((fReadOnly) && (_pfatNoScratch != NULL))
{
//As an optimization, and to prevent loops, we can dispatch
//this call directly to the no-scratch fat, since it has a
//complete picture of everything allocated in this fat.
//Note that we don't need to pass the read-only flag to the
//no-scratch, since it's perfectly OK to scribble on it
//as much as we want.
//Further note that if fReadOnly is true, then ulCount must be
// 1, so we can just work with the constant.
msfChk(_pfatNoScratch->GetFree(1, psectRet, GF_WRITE));
if (_ulFreeSects != MAX_ULONG)
{
_ulFreeSects--;
}
_cUnmarkedSects++;
if (*psectRet >= _sectMax)
{
_sectMax = *psectRet + 1;
}
return S_OK;
}
while (TRUE)
{
//Make sure there are enough free sectors to hold the whole chain
// we're trying to allocate.
if (_ulFreeSects == MAX_ULONG)
{
msfChk(CountFree(&_ulFreeSects));
}
#if DBG == 1
else
{
CheckFreeCount();
}
#endif
while (ulCount > _ulFreeSects)
{
#if DBG == 1 && !defined(USE_NOSCRATCH)
ULONG ulFree = _ulFreeSects;
#endif
msfChk(Resize(_cfsTable +
((ulCount - _ulFreeSects + _fv.GetSectTable() - 1) >>
_uFatShift)));
#if DBG == 1 && !defined(USE_NOSCRATCH)
msfAssert(_ulFreeSects > ulFree &&
aMsg("Number of free sectors didn't increase after Resize."));
#endif
}
//Starting at the first known free sector, loop until we find
// enough sectors to complete the chain.
FSOFFSET isectStart;
FSINDEX ipfsStart;
SectToPair(_sectFirstFree, &ipfsStart, &isectStart);
for (ipfs = ipfsStart; ipfs < _cfsTable; ipfs++)
{
//Only check a page if it is not known to be full.
pfb = _fv.GetBits(ipfs);
if ((pfb == NULL) || (!pfb->full))
{
msfChk(_fv.GetTable(ipfs, FB_NONE, &pfs));
//Eliminate part of the search based on the first-known
// free entry for the page
if (pfb != NULL)
{
isectStart = pfb->firstfree;
}
for (isect = isectStart; isect < _fv.GetSectTable(); isect++)
{
SECT sectCurrent = pfs->GetSect(isect);
sect = PairToSect(ipfs, isect);
//If the sector is marked FREESECT, it still may not
// really be free. The IsFree function will return
// S_OK if it is OK to allocate.
if ((sectCurrent == FREESECT) &&
((sc = IsFree(sect)) == S_OK))
{
//If fReadOnly is TRUE (meaning we're being called
// by the DIFat), then we don't want to actually
// mark anything in the current fat. We'll return
// the current sector and then be done with it.
if (fReadOnly)
{
_cUnmarkedSects++;
_ulFreeSects--;
}
else
{
//Mark the sector as free and return it.
msfChkTo(Err_Rel, MarkSect(&gf));
}
if (*psectRet == ENDOFCHAIN)
{
*psectRet = sect;
}
ulCount--;
if (ulCount == 0)
{
//If we're done, release the current table,
// update _sectMax, and return.
if (sect >= _sectMax)
{
_sectMax = sect + 1;
}
ReleaseGetFreeStruct(&gf);
return S_OK;
}
else
{
//Otherwise update the internal counters and
// keep going.
sectLast = sect;
ipfsLast = ipfs;
isectLast = isect;
}
}
else
{
msfChkTo(Err_Rel, sc);
}
}
_fv.ReleaseTable(ipfs);
//If we are keeping a full bit, we can set it here, since
// we know we've allocated everything out of the current
// page.
// the vectbits pointer may have changed due to a resize
pfb = _fv.GetBits(ipfs);
if (pfb != NULL)
{
pfb->full = TRUE;
}
}
isectStart = 0;
}
//Keep _sectMax up to date for SetSize purposes.
if (sectLast >= _sectMax)
{
_sectMax = sectLast + 1;
}
}
msfAssert(0 &&
aMsg("GetFree exited improperly."));
sc = STG_E_ABNORMALAPIEXIT;
Err:
ReleaseGetFreeStruct(&gf);
return sc;
Err_Rel:
ReleaseGetFreeStruct(&gf);
return sc;
}
//+---------------------------------------------------------------------------
//
// Member: CFat::GetFreeContig, public
//
// Synopsis: Return a chain of free sectors, including contiguity
// information about the chain.
//
// Arguments: [ulCount] -- Number of sectors to allocate
// [aseg] -- Contig table to fill in
// [cSeg] -- Index of last used segment in contig table.
// [pcSegReturned] -- Pointer to return location for total
// number of segments returned.
//
// Returns: Appropriate status code
//
// History: 27-Oct-95 PhilipLa Created
//
//----------------------------------------------------------------------------
SCODE CFat::GetFreeContig(ULONG ulCount,
SSegment STACKBASED *aseg,
ULONG cSeg,
ULONG *pcSegReturned)
{
SGetFreeStruct gf;
SECT &sect = gf.sect;
CVectBits * &pfb = gf.pfb;
FSOFFSET &isect = gf.isect;
FSINDEX &ipfs = gf.ipfs;
CFatSect * &pfs = gf.pfs;
SECT &sectLast = gf.sectLast;
FSINDEX &ipfsLast = gf.ipfsLast;
FSOFFSET &isectLast = gf.isectLast;
InitGetFreeStruct(&gf);
FSINDEX ipfsFirstDirty;
SCODE sc;
//Variables used for tracking contiguity.
//cSegCurrent is the current segment being processed.
ULONG cSegCurrent = cSeg;
//sectLast is the last sector returned. We start this with the
// last thing in the current contig table, and the MarkSect
// function will patch up the chain for us.
sectLast = aseg[cSeg].sectStart + aseg[cSeg].cSect - 1;
SectToPair(sectLast, &ipfsLast, &isectLast);
ipfsFirstDirty = ipfsLast;
#if DBG == 1
SECT sectTest;
GetNext(sectLast, &sectTest);
msfAssert(sectTest == ENDOFCHAIN);
#endif
msfAssert((!_pmsParent->IsShadow()) &&
aMsg("Modifying shadow fat."));
while (TRUE)
{
//Make sure there are enough free sectors to hold the whole chain
// we're trying to allocate.
if (_ulFreeSects == MAX_ULONG)
{
msfChk(CountFree(&_ulFreeSects));
}
#if DBG == 1
else
{
CheckFreeCount();
}
#endif
while (ulCount > _ulFreeSects)
{
#if DBG == 1 && !defined(USE_NOSCRATCH)
ULONG ulFree = _ulFreeSects;
#endif
msfChk(Resize(_cfsTable +
((ulCount - _ulFreeSects + _fv.GetSectTable() - 1) >>
_uFatShift)));
#if DBG == 1 && !defined(USE_NOSCRATCH)
msfAssert(_ulFreeSects > ulFree &&
aMsg("Number of free sectors didn't increase after Resize."));
#endif
}
//Starting at the first known free sector, loop until we find
// enough sectors to complete the chain.
FSOFFSET isectStart;
FSINDEX ipfsStart;
SectToPair(_sectFirstFree, &ipfsStart, &isectStart);
for (ipfs = ipfsStart; ipfs < _cfsTable; ipfs++)
{
//Only check a page if it is not known to be full.
pfb = _fv.GetBits(ipfs);
if ((pfb == NULL) || (!pfb->full))
{
//This little contortion is necessary because the
// page containing the first sector may not get marked
// as dirty by MarkSect.
if (ipfs == ipfsFirstDirty)
{
msfChk(_fv.GetTable(ipfs, FB_DIRTY, &pfs));
}
else
{
msfChk(_fv.GetTable(ipfs, FB_NONE, &pfs));
}
//Eliminate part of the search based on the first-known
// free entry for the page
if (pfb != NULL)
{
isectStart = pfb->firstfree;
}
for (isect = isectStart; isect < _fv.GetSectTable(); isect++)
{
SECT sectCurrent = pfs->GetSect(isect);
sect = PairToSect(ipfs, isect);
//If the sector is marked FREESECT, it still may not
// really be free. The IsFree function will return
// TRUE if it is OK to allocate.
if ((sectCurrent == FREESECT) &&
((sc = IsFree(sect)) == S_OK))
{
//Mark the sector as free and return it.
msfChkTo(Err_Rel, MarkSect(&gf));
ulCount--;
//Update the contig table with this new information.
if (cSegCurrent < CSEG)
{
if (sect != sectLast + 1)
{
//Use a new entry in the contig table.
cSegCurrent++;
if (cSegCurrent < CSEG)
{
aseg[cSegCurrent].ulOffset =
aseg[cSegCurrent - 1].ulOffset +
aseg[cSegCurrent - 1].cSect;
aseg[cSegCurrent].sectStart = sect;
aseg[cSegCurrent].cSect = 1;
}
}
else
{
//Grow the current segment
aseg[cSegCurrent].cSect++;
}
}
if (ulCount == 0)
{
//If we're done, release the current table,
// update _sectMax, and return.
if (sect >= _sectMax)
{
_sectMax = sect + 1;
}
*pcSegReturned = cSegCurrent;
ReleaseGetFreeStruct(&gf);
#if DBG == 1
_fv.ResetBits();
CheckFreeCount();
#endif
return S_OK;
}
else
{
//Otherwise update the internal counters and
// keep going.
sectLast = sect;
ipfsLast = ipfs;
isectLast = isect;
}
}
else
{
msfChkTo(Err_Rel, sc);
}
}
_fv.ReleaseTable(ipfs);
//If we are keeping a full bit, we can set it here, since
// we know we've allocated everything out of the current
// page.
// the vectbits pointer may have changed due to a resize
pfb = _fv.GetBits(ipfs);
if (pfb != NULL)
{
pfb->full = TRUE;
}
}
isectStart = 0;
}
//Keep _sectMax up to date for SetSize purposes.
if (sectLast >= _sectMax)
{
_sectMax = sectLast + 1;
}
}
msfAssert(0 &&
aMsg("GetFree exited improperly."));
sc = STG_E_ABNORMALAPIEXIT;
Err:
ReleaseGetFreeStruct(&gf);
return sc;
Err_Rel:
ReleaseGetFreeStruct(&gf);
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::Contig, public
//
// Synposis: Create contiguous sector table
//
// Effects: Return contiguity information about a chain.
//
// Arguments: [aseg] -- Segment table to return data in
// [sect] -- Starting sector for table to begin
// [ulength] -- Runlength in sectors of table to produce
// [pcSeg] -- Returns count of segments in table
//
// Returns: Appropriate status code.
//
// Algorithm: Perform calls to CFat::GetNext(). Any call that is
// 1 higher than the previous represents contiguous blocks.
// Construct the Segment table on that basis.
//
// History: 16-Aug-91 PhilipLa Created.
// 20-May-92 AlexT Moved to CFat
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::Contig(
SSegment STACKBASED *aseg,
BOOL fWrite,
SECT sectStart,
ULONG ulLengthStart,
ULONG *pcSeg)
{
msfDebugOut((DEB_ITRACE,"In CFat::Contig(%lu,%lu)\n",sectStart,ulLengthStart));
SCODE sc = S_OK;
ULONG ulLength = ulLengthStart;
SECT sect = sectStart;
SECT stemp = sect;
ULONG ulCount = 1;
USHORT iseg = 0;
FSINDEX ipfs = (FSINDEX) -1;
FSINDEX ipfsOld = ipfs;
FSOFFSET isect;
CFatSect *pfs = NULL;
msfAssert(sect != ENDOFCHAIN &&
aMsg("Called Contig with ENDOFCHAIN start"));
msfAssert((ulLength > 0) && aMsg("Bad length passed to Contig()"));
aseg[iseg].sectStart = sect;
aseg[iseg].cSect = 1;
aseg[iseg].ulOffset = 0;
ulLength--;
while (TRUE)
{
msfAssert(sect != ENDOFCHAIN &&
aMsg("Contig found premature ENDOFCHAIN"));
SectToPair(sect, &ipfs, &isect);
if (ipfs != ipfsOld)
{
if (ipfsOld != (FSINDEX) -1)
{
_fv.ReleaseTable(ipfsOld);
}
msfChk(_fv.GetTable(ipfs, FB_NONE, &pfs));
ipfsOld = ipfs;
}
if (pfs != NULL)
sect = pfs->GetSect(isect);
if (sect == ENDOFCHAIN)
{
if ((ulLength < 1) || !fWrite)
break;
//Allocate new sectors.
#if 0
SECT sectNew;
msfChk(GetFree(ulLength, &sectNew, GF_WRITE));
msfChk(SetNext(stemp, sectNew));
sect = sectNew;
#else
//GetFreeContig will allocate new sectors and fill up
// our contig table. After this call, the chain will
// be the proper length and the contig table will either
// contain the entire chain, or will be full. Either
// way we can exit immediately.
if (ipfs != (FSINDEX) - 1)
{
_fv.ReleaseTable(ipfs);
}
ULONG isegRet = 0;
aseg[iseg].cSect = ulCount;
msfChk(GetFreeContig(ulLength, aseg, iseg, &isegRet));
if (isegRet == CSEG)
{
aseg[isegRet].ulOffset = 0;
aseg[isegRet].cSect = 0;
aseg[isegRet].sectStart = FREESECT;
}
else
{
aseg[isegRet + 1].sectStart = ENDOFCHAIN;
}
*pcSeg = isegRet + 1;
#if DBG == 1
SSegment segtab[CSEG + 1];
ULONG cSeg;
Contig(segtab, FALSE, sectStart, ulLengthStart, &cSeg);
msfAssert(cSeg == *pcSeg);
for (USHORT i = 0; i < cSeg; i++)
{
msfAssert(segtab[i].sectStart == aseg[i].sectStart);
msfAssert(segtab[i].ulOffset == aseg[i].ulOffset);
msfAssert(segtab[i].cSect == aseg[i].cSect);
}
#endif
return S_OK;
#endif
}
if (sect != (stemp + 1))
{
if (ulLength < 1)
break;
aseg[iseg].cSect = ulCount;
iseg++;
aseg[iseg].ulOffset = aseg[iseg - 1].ulOffset + ulCount;
aseg[iseg].sectStart = sect;
ulCount = 1;
stemp = sect;
}
else
{
ulCount++;
stemp = sect;
}
if (ulLength > 0)
ulLength--;
if (iseg >= CSEG)
break;
}
if (ipfs != (FSINDEX) -1)
{
_fv.ReleaseTable(ipfs);
}
if (iseg < CSEG)
{
aseg[iseg].cSect = ulCount;
aseg[iseg + 1].sectStart = ENDOFCHAIN;
}
else
{
aseg[iseg].ulOffset = 0;
aseg[iseg].cSect = 0;
aseg[iseg].sectStart = FREESECT;
}
*pcSeg = iseg + 1;
msfDebugOut((DEB_ITRACE,"Exiting Contig()\n"));
Err:
return sc;
}
//+---------------------------------------------------------------------------
//
// Member: CFat::ReserveSects, public
//
// Synopsis: Make sure the fat has at least a given number of free
// sectors in it.
//
// Arguments: [cSect] -- Number of sectors to reserve.
//
// Returns: Appropriate status code
//
// History: 18-Sep-95 PhilipLa Created
//
//----------------------------------------------------------------------------
SCODE CFat::ReserveSects(ULONG cSect)
{
SCODE sc = S_OK;
msfDebugOut((DEB_ITRACE, "In CFat::ReserveSects:%p()\n", this));
//Make sure there are enough free sectors to hold the whole chain
// we're trying to allocate.
if (_ulFreeSects == MAX_ULONG)
{
msfChk(CountFree(&_ulFreeSects));
}
#if DBG == 1
else
{
CheckFreeCount();
}
#endif
while (cSect > _ulFreeSects)
{
#if DBG == 1 && !defined(USE_NOSCRATCH)
ULONG ulFree = _ulFreeSects;
#endif
msfChk(Resize(_cfsTable +
((cSect - _ulFreeSects + _fv.GetSectTable() - 1) >>
_uFatShift)));
#if DBG == 1 && !defined(USE_NOSCRATCH)
msfAssert(_ulFreeSects > ulFree &&
aMsg("Number of free sectors didn't increase after Resize."));
#endif
}
msfDebugOut((DEB_ITRACE, "Out CFat::ReserveSects\n"));
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::GetLength, public
//
// Synposis: Return the length of a fat chain.
//
// Arguments: [sect] -- Sector to begin count at.
//
// Returns: Length of the chain, in sectors
//
// Algorithm: Traverse the chain until ENDOFCHAIN is reached.
//
// History: 18-Jul-91 PhilipLa Created.
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::GetLength(SECT sect, ULONG * pulRet)
{
msfDebugOut((DEB_FAT,"In CFat::GetLength(%lu)\n",sect));
SCODE sc = S_OK;
ULONG csect = 0;
const ULONG csectMax = PairToSect(_cfsTable+1,0);
while (sect != ENDOFCHAIN)
{
msfChk(GetNext(sect, &sect));
csect++;
if (csect > csectMax) // infinite loop in the chain
msfErr (Err, STG_E_DOCFILECORRUPT);
}
msfDebugOut((DEB_FAT,"FAT: GetLength returned %u\n",csect));
*pulRet = csect;
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::Init, public
//
// Synposis: Sets up a FAT, reading data from an existing stream
//
// Effects: Changes all _apfsTable entries, _cfsTable, and all
// flags fields
//
// Arguments: None.
//
// Returns: S_OK if call completed OK.
//
// Algorithm: Read size from first FAT in stream.
// Resize array to necessary size.
// Read in FAT sectors sequentially.
//
// History: 18-Jul-91 PhilipLa Created.
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::Init(CMStream *pmsParent,
FSINDEX cFatSect,
BOOL fConvert)
{
SCODE sc;
msfDebugOut((DEB_FAT,"CFat::setup thinks the FAT is size %lu\n",cFatSect));
_pmsParent = P_TO_BP(CBasedMStreamPtr, pmsParent);
_uFatShift = pmsParent->GetSectorShift() - 2;
_uFatMask = (pmsParent->GetSectorSize() >> 2) - 1;
_fv.InitCommon(1 << _uFatShift, 1 << _uFatShift);
msfChk(_fv.Init(pmsParent, cFatSect));
_cfsTable = cFatSect;
USHORT cbSectorSize;
cbSectorSize = pmsParent->GetSectorSize();
InitRangeLocksSector();
_ulFreeSects = MAX_ULONG;
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Method: CFat::InitConvert, public
//
// Synopsis: Init function used for conversion
//
// Arguments: [sectData] -- number of sectors used by file
//
// Returns: S_OK if call completed OK.
//
// Algorithm: *Finish This*
//
// History: 28-May-92 PhilipLa Created.
//
// Notes:
//
//--------------------------------------------------------------------------
SCODE CFat::InitConvert(CMStream *pmsParent,
SECT sectData)
{
SCODE sc;
msfDebugOut((DEB_FAT,"Doing conversion\n"));
_pmsParent = P_TO_BP(CBasedMStreamPtr, pmsParent);
msfAssert((sectData != 0) &&
aMsg("Attempt to convert zero length file."));
SECT sectMax = 0;
FSINDEX csectFat = 0;
FSINDEX csectLast;
_uFatShift = pmsParent->GetSectorShift() - 2;
_uFatMask = (pmsParent->GetSectorSize() >> 2) - 1;
_fv.InitCommon(1 << _uFatShift, 1 << _uFatShift);
InitRangeLocksSector ();
if (_sid == SIDFAT)
{
SECT sectTotal;
//Since the fat needs to represent itself, we can't determine
// the actual number of sectors needed in one pass. We
// therefore loop, factoring in the number of fat sectors
// at each iteration, until we reach a stable state.
//
//As an example, consider the case where each fat sector represents
// 128 sectors and the file being converted is 128 sectors long.
// There will be no DIFat - therefore, we have 128 sectors needed
// on the first pass, which will require 1 fat sector to
// represent them. On the second pass, we discover that we
// actually need 2 fat sectors, since we now have 129 total
// sectors to allocate space for. The third pass will result
// in a stable state.
do
{
csectLast = csectFat;
sectTotal = sectData + pmsParent->GetHeader()->GetDifLength() +
csectFat + 1;
csectFat = (sectTotal + _fv.GetSectTable() - 1) >> _uFatShift;
}
while (csectLast != csectFat);
sectMax = sectData + pmsParent->GetHeader()->GetDifLength();
}
else
{
//The minifat doesn't need to represent itself, so we can
// compute the number of sectors needed in one pass.
sectMax = sectData;
csectFat = (sectMax + _fv.GetSectTable() -1) >> _uFatShift;
}
msfChk(_fv.Init(pmsParent, csectFat));
FSINDEX i;
if (_sid == SIDMINIFAT)
{
SECT sectFirst;
msfChk(pmsParent->GetFat()->Allocate(csectFat, &sectFirst));
pmsParent->GetHeader()->SetMiniFatStart(sectFirst);
pmsParent->GetHeader()->SetMiniFatLength(csectFat);
}
for (i = 0; i < csectFat; i++)
{
CFatSect *pfs;
msfChk(_fv.GetTable(i, FB_NEW, &pfs));
if (_sid == SIDFAT)
{
_fv.SetSect(i, sectMax + i);
pmsParent->GetDIFat()->SetFatSect(i, sectMax + i);
}
else
{
msfAssert(_pfatNoScratch == NULL);
SECT sect;
msfChk(pmsParent->GetESect(_sid, i, &sect));
_fv.SetSect(i, sect);
}
_fv.ReleaseTable(i);
}
_cfsTable = csectFat;
if (_sid != SIDMINIFAT)
{
pmsParent->GetHeader()->SetFatLength(_cfsTable);
SECT sect;
if (sectData > 1)
{
for (sect = 0; sect < sectData - 2; sect++)
{
msfChk(SetNext(sect, sect + 1));
}
msfChk(SetNext(sectData - 2, ENDOFCHAIN));
msfChk(SetNext(sectData - 1, 0));
}
else
{
//In the event that the file to be converted is less
// than one sector long, we don't need to create a
// real chain, just a single terminated sector.
msfChk(SetNext(0, ENDOFCHAIN));
}
for (sect = sectData; sect < sectMax; sect++)
{
msfChk(SetNext(sect, DIFSECT));
}
for (USHORT i2 = 0; i2 < csectFat; i2++)
{
msfChk(SetNext(sectMax + i2, FATSECT));
}
//Set up directory chain.
msfChk(SetNext(sectMax + i, ENDOFCHAIN));
pmsParent->GetHeader()->SetDirStart(sectMax + i);
_ulFreeSects = (_cfsTable << _uFatShift) - (sectMax + csectFat + 1);
}
else
{
for (SECT sect = 0; sect < sectData -1; sect++)
{
msfChk(SetNext(sect, sect + 1));
}
msfChk(SetNext(sectData - 1, ENDOFCHAIN));
_ulFreeSects = (_cfsTable << _uFatShift) - sectData;
}
if (!pmsParent->IsScratch())
{
msfChk(pmsParent->SetSize());
}
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::InitNew, public
//
// Synposis: Sets up a FAT for a newly created multi-strean
//
// Effects: Changes all _apfsTable entries, _cfsTable, and all
// flags fields
//
// Arguments: [pmsparent] -- pointer to parent Mstream
//
// Returns: S_OK if call completed OK.
//
// Algorithm: Set parent pointer.
// Allocate 1 sector for FAT and 1 for Directory.
//
// History: 18-Jul-91 PhilipLa Created.
// 17-Aug-91 PhilipLa Added dirty bits optimization (Dump)
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::InitNew(CMStream *pmsParent)
{
msfDebugOut((DEB_FAT,"In CFat::InitNew()\n"));
SCODE sc;
_pmsParent = P_TO_BP(CBasedMStreamPtr, pmsParent);
_uFatShift = pmsParent->GetSectorShift() - 2;
_uFatMask = (pmsParent->GetSectorSize() >> 2) - 1;
_fv.InitCommon(1 << _uFatShift, 1 << _uFatShift);
FSINDEX count;
if (SIDMINIFAT == _sid)
count = pmsParent->GetHeader()->GetMiniFatLength();
else
count = pmsParent->GetHeader()->GetFatLength();
msfDebugOut((DEB_FAT,"Setting up Fat of size %lu\n",count));
msfChk(_fv.Init(pmsParent, count));
_cfsTable = count;
InitRangeLocksSector();
if (SIDFAT == _sid)
{
FSINDEX ipfs;
FSOFFSET isect;
CFatSect *pfs;
SectToPair(pmsParent->GetHeader()->GetFatStart(), &ipfs, &isect);
msfChk(_fv.GetTable(ipfs, FB_NEW, &pfs));
_fv.SetSect(ipfs, pmsParent->GetHeader()->GetFatStart());
_fv.ReleaseTable(ipfs);
msfChk(SetNext(pmsParent->GetHeader()->GetFatStart(), FATSECT));
msfDebugOut((DEB_ITRACE,"Set sector %lu (FAT) to ENDOFCHAIN\n",pmsParent->GetHeader()->GetFatStart()));
msfChk(SetNext(pmsParent->GetHeader()->GetDirStart(), ENDOFCHAIN));
msfDebugOut((DEB_ITRACE,"Set sector %lu (DIR) to ENDOFCHAIN\n",pmsParent->GetHeader()->GetDirStart()));
_ulFreeSects = (count << _uFatShift) - 2;
}
else
{
_ulFreeSects = 0;
}
if (!pmsParent->IsScratch())
{
msfChk(pmsParent->SetSize());
}
msfDebugOut((DEB_FAT,"Exiting CFat::setupnew()\n"));
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::Resize, private
//
// Synposis: Resize FAT, both in memory and in the file
//
// Effects: Modifies _cfsTable, _apfsTable, and all flags fields
//
// Arguments: [ulSize] -- New size (in # of tables) for FAT
//
// Returns: S_OK if call completed OK.
//
// Algorithm: Allocate new array of new size.
// Copy over all old pointers.
// Allocate new tables for any necessary.
//
// History: 18-Jul-91 PhilipLa Created.
// 18-Aug-91 PhilipLa Added dirty bits optimization
//
// Notes: This routine currently cannot reduce the size of a fat.
//
//---------------------------------------------------------------------------
SCODE CFat::Resize(ULONG ulSize)
{
msfDebugOut((DEB_FAT,"In CFat::Resize(%lu)\n",ulSize));
SCODE sc;
if (ulSize == _cfsTable)
{
return S_OK;
}
ULONG csect = _cfsTable;
msfAssert(ulSize > _cfsTable &&
aMsg("Attempted to shrink Fat"));
// 512byte sector docfiles are restricted to 2G for now
if (_pmsParent->GetSectorShift() == SECTORSHIFT512 &&
ulSize > _ipfsRangeLocks)
return STG_E_DOCFILETOOLARGE;
ULONG ipfs;
SECT sectNew;
CFat *pfat = _pmsParent->GetFat();
if ((!_pmsParent->IsScratch()) && (_sid == SIDFAT))
{
//Make sure we have enough space for all of the sectors
// to be allocated.
ULONG csectFat = ulSize - _cfsTable;
ULONG csectPerDif = (1 << _uFatShift) - 1;
ULONG csectDif = (csectFat + csectPerDif - 1) / csectPerDif;
//Assuming all the free sectors are at the end of the file,
// we need a file csectNew sectors long to hold them.
ULONG csectOld, csectNew;
msfChk(FindMaxSect(&csectOld));
// Every new sector added can conceivably cause a remap of
// another sector while in COW mode.
csectNew = csectOld +
((csectFat + csectDif) * ((_sectLastUsed > 0) ? 2 : 1));
ULARGE_INTEGER cbSize;
#ifdef LARGE_DOCFILE
cbSize.QuadPart = ConvertSectOffset(
csectNew,
0,
_pmsParent->GetSectorShift());
#else
ULISet32(cbSize, ConvertSectOffset(
csectNew,
0,
_pmsParent->GetSectorShift()));
#endif
#ifdef LARGE_DOCFILE
if (cbSize.QuadPart > _pmsParent->GetParentSize())
#else
if (ULIGetLow(cbSize) > _pmsParent->GetParentSize())
#endif
{
msfHChk(_pmsParent->GetILB()->SetSize(cbSize));
}
//If we are the fat, we have enough space in the file for
// ourselves at this point.
}
else if (_sid != SIDFAT)
{
if (_cfsTable == 0)
{
msfChk(pfat->Allocate(ulSize, &sectNew));
_pmsParent->GetHeader()->SetMiniFatStart(sectNew);
}
else
{
sectNew = _pmsParent->GetHeader()->GetMiniFatStart();
SECT sectLast;
msfChk(pfat->GetESect(sectNew, ulSize - 1, &sectLast));
}
if (!_pmsParent->IsScratch())
{
msfChk(_pmsParent->SetSize());
}
msfChk(pfat->GetSect(sectNew, csect, &sectNew));
//If we are the Minifat, we have enough space in the underlying
// file for ourselves at this point.
}
_fv.Resize(ulSize);
for (ipfs = csect; ipfs < ulSize; ipfs++)
{
CFatSect *pfs;
msfChk(_fv.GetTable(ipfs, FB_NEW, &pfs));
_cfsTable = ipfs + 1;
if (_sid == SIDFAT)
{
if (ipfs == _ipfsRangeLocks)
{
CVectBits *pfb;
pfs->SetSect(_isectRangeLocks, ENDOFCHAIN);
pfb = _fv.GetBits(_ipfsRangeLocks);
if (pfb != NULL && pfb->full == FALSE &&
_isectRangeLocks == pfb->firstfree)
{
pfb->firstfree = _isectRangeLocks + 1;
}
_ulFreeSects--;
}
if (_sectNoSnapshotFree != ENDOFCHAIN)
{
SECT sectStart, sectEnd;
_pmsParent->GetHeader()->SetFatLength(_cfsTable);
msfChk(GetFree(1, &sectNew, GF_READONLY));
_pmsParent->GetDIFat()->CacheUnmarkedSect(sectNew,
FATSECT,
ENDOFCHAIN);
msfChk(_pmsParent->GetDIFat()->SetFatSect(ipfs, sectNew));
msfAssert((_ulFreeSects != MAX_ULONG) &&
aMsg("Free count not set in no-snapshot"));
//We don't need to look at anything less than
//_sectNoSnapshotFree, since those are all by definition
//not free.
sectStart = max(PairToSect(ipfs, 0), _sectNoSnapshotFree);
sectEnd = PairToSect(ipfs, 0) + _fv.GetSectTable();
for (SECT sectChk = sectStart;
sectChk < sectEnd;
sectChk++)
{
if (IsFree(sectChk) == S_OK)
{
_ulFreeSects++;
}
}
CheckFreeCount();
}
else
{
if (_pfatNoScratch != NULL)
{
SECT sectStart, sectEnd;
msfChk(GetFree(1, &sectNew, GF_READONLY));
_pmsParent->GetDIFat()->CacheUnmarkedSect(sectNew,
FATSECT,
ENDOFCHAIN);
if (_ulFreeSects != MAX_ULONG)
{
sectStart = PairToSect(ipfs, 0);
sectEnd = sectStart + _fv.GetSectTable();
for (SECT sectChk = sectStart;
sectChk < sectEnd;
sectChk++)
{
if (IsFree(sectChk) == S_OK)
{
_ulFreeSects++;
}
}
CheckFreeCount();
}
}
else
{
_ulFreeSects += (1 << _uFatShift);
msfChk(pfat->GetFree(1, &sectNew, GF_WRITE));
msfChk(pfat->SetNext(sectNew, FATSECT));
}
msfChk(_pmsParent->GetDIFat()->SetFatSect(ipfs, sectNew));
}
}
msfAssert(sectNew != ENDOFCHAIN &&
aMsg("Bad sector returned for fatsect."));
_fv.SetSect(ipfs, sectNew);
_fv.ReleaseTable(ipfs);
if (_sid == SIDMINIFAT)
{
_ulFreeSects += (1 << _uFatShift);
msfChk(pfat->GetNext(sectNew, &sectNew));
}
}
CheckFreeCount();
msfDebugOut((DEB_FAT,"CFat::Resize() - all new objects allocated\n"));
if (SIDMINIFAT == _sid)
{
_pmsParent->GetHeader()->SetMiniFatLength(_cfsTable);
}
else
_pmsParent->GetHeader()->SetFatLength(_cfsTable);
//This setsize should only shrink the file.
#if DBG == 1
STATSTG stat;
msfHChk(_pmsParent->GetILB()->Stat(&stat, STATFLAG_NONAME));
#endif
if (!_pmsParent->IsScratch())
{
msfChk(_pmsParent->SetSize());
}
if ((_pfatNoScratch != NULL) && (_ulFreeSects == MAX_ULONG))
{
msfChk(CountFree(&_ulFreeSects));
}
#if DBG == 1
STATSTG statNew;
msfHChk(_pmsParent->GetILB()->Stat(&statNew, STATFLAG_NONAME));
#ifdef LARGE_DOCFILE
if (ulSize < _ipfsRangeLocks && !(_pmsParent->IsInCOW()))
msfAssert(statNew.cbSize.QuadPart <= stat.cbSize.QuadPart);
#else
if (!(_pmsParent->IsInCOW())
msfAssert(ULIGetLow(statNew.cbSize) <= ULIGetLow(stat.cbSize));
#endif
#endif
msfDebugOut((DEB_FAT,"Out CFat::Resize(%lu)\n",ulSize));
Err:
msfAssert((_ulFreeSects != MAX_ULONG) &&
aMsg("Free sect count not set after Resize()."));
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::Extend, private
//
// Synposis: Increase the size of an existing chain
//
// Effects: Modifies ulSize sectors within the fat. Causes one or
// more sector writes.
//
// Arguments: [sect] -- Sector ID of last sector in chain to be extended
// [ulSize] -- Number of sectors to add to chain
//
// Requires: sect must be at the end of a chain.
//
// Returns: S_OK if call completed OK.
//
// Algorithm: Use calls to GetFree to allocate chain.
//
// History: 18-Jul-91 PhilipLa Created.
// 17-Aug-91 PhilipLa Added dirty bits opt (Dump)
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::Extend(SECT sect, ULONG ulSize)
{
SCODE sc;
msfDebugOut((DEB_FAT,"In CFat::Extend(%lu,%lu)\n",sect,ulSize));
SECT sectTemp;
msfChk(GetFree(ulSize, &sectTemp, GF_WRITE));
//If this SetSize fails, clean up the new space and don't do anything
// to the original chain.
if (!_pmsParent->IsScratch())
{
msfChkTo(EH_OOD, _pmsParent->SetSize());
}
//If this SetNext fail calls, we're in trouble. Return the error but
// don't attempt to cleanup.
msfChk(SetNext(sect, sectTemp));
msfDebugOut((DEB_FAT,"Out CFat::Extend()\n"));
Err:
return sc;
EH_OOD:
SetChainLength(sectTemp, 0);
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::GetNext, public
//
// Synposis: Returns the next sector in a chain, given a sector
//
// Arguments: [sect] -- Sector ID of any sector in a chain.
//
// Returns: Sector ID of next sector in chain, ENDOFCHAIN if at end
//
// History: 18-Jul-91 PhilipLa Created.
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::GetNext(const SECT sect, SECT * psRet)
{
SCODE sc;
FSINDEX ipfs;
FSOFFSET isect;
msfAssert(sect <= MAXREGSECT &&
aMsg("Called GetNext() on invalid sector"));
SectToPair(sect, &ipfs, &isect);
CFatSect *pfs;
msfChk(_fv.GetTable(ipfs, FB_NONE, &pfs));
*psRet = pfs->GetSect(isect);
_fv.ReleaseTable(ipfs);
if (sect == *psRet)
{
msfAssert(sect != *psRet &&
aMsg("Detected loop in fat chain."));
return STG_E_ABNORMALAPIEXIT;
}
return S_OK;
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::SetNext, private
//
// Synposis: Set the next sector in a chain
//
// Effects: Modifies a single entry within the fat.
//
// Arguments: [sectFirst] -- Sector ID of first sector
// [sectNext] -- Sector ID of next sector
//
// Returns: void
//
// History: 18-Jul-91 PhilipLa Created.
// 17-Aug-91 PhilipLa Added dirty bits optimization
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::SetNext(SECT sectFirst, SECT sectNext)
{
FSINDEX ipfs;
FSOFFSET isect;
SCODE sc;
msfAssert((!_pmsParent->IsShadow()) &&
aMsg("Modifying shadow fat."));
// creating infinite loops is a no-no
msfAssert(sectFirst != sectNext &&
aMsg("Attempted to create loop in Fat chain"));
msfAssert(sectFirst <= MAXREGSECT &&
aMsg("Called SetNext on invalid sector"));
SectToPair(sectFirst, &ipfs, &isect);
CFatSect *pfs;
SECT sectCurrent;
if (ipfs >= _cfsTable)
{
msfChk(Resize(ipfs + 1));
}
msfAssert(ipfs <= _cfsTable);
msfChk(_fv.GetTable(ipfs, FB_DIRTY, &pfs));
sectCurrent = pfs->GetSect(isect);
pfs->SetSect(isect,sectNext);
_fv.ReleaseTable(ipfs);
if (sectNext == FREESECT)
{
CVectBits *pfb;
pfb = _fv.GetBits(ipfs);
if ((pfb != NULL) &&
((pfb->full == TRUE) || (isect < pfb->firstfree)))
{
pfb->full = FALSE;
pfb->firstfree = isect;
}
if (sectFirst == _sectMax - 1)
{
_sectMax = ENDOFCHAIN;
}
if (sectFirst < _sectFirstFree)
{
_sectFirstFree = sectFirst;
}
if (_ulFreeSects != MAX_ULONG)
{
SECT sectOld = FREESECT;
msfChk(IsFree(sectFirst));
if (sc != S_FALSE)
{
_ulFreeSects++;
}
sc = S_OK; // Don't return S_FALSE.
}
}
else if (_pfatNoScratch != NULL)
{
//We need to update the noscratch fat as well.
msfChk(_pfatNoScratch->SetNext(sectFirst, sectNext));
}
else if (sectFirst >= _sectMax)
{
_sectMax = sectFirst + 1;
#if DBG == 1
SECT sectLast;
msfChk(FindLast(&sectLast));
msfAssert(((_sectMax == sectLast) || (_sectMax == _sectLastUsed)) &&
aMsg("_sectMax doesn't match actual last sector"));
#endif
}
//If we're the no-scratch fat, then we may be marking a free sector
//as allocated due to the real fat allocating it. In this case, we
//need to update our free sector count.
if ((_sid == SIDMINIFAT) && (_pmsParent->IsScratch()) &&
(sectCurrent == FREESECT) && (sectNext != FREESECT) &&
(_ulFreeSects != MAX_ULONG))
{
_ulFreeSects--;
}
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::CountFree, private
//
// Synposis: Count and return the number of free sectors in the Fat
//
// Arguments: void.
//
// Returns: void.
//
// Algorithm: Do a linear search of the Fat, counting free sectors.
// If a FatSect has its full bit set, it is not necessary
// to search that FatSect.
//
// History: 11-Sep-91 PhilipLa Created.
//
// Notes: This includes all the FREESECT's in the tail of the last FAT
// block (past the last allocated sector) as free. So it is possible
// That CountFree() could be greater than FindLast()!
//---------------------------------------------------------------------------
SCODE CFat::CountFree(ULONG * pulRet)
{
msfDebugOut((DEB_FAT,"In CFat::CountFree()\n"));
SCODE sc = S_OK;
FSINDEX ipfs;
ULONG csectFree=0;
FSOFFSET isectStart;
FSINDEX ipfsStart;
SectToPair(_sectFirstFree, &ipfsStart, &isectStart);
for (ipfs = ipfsStart; ipfs < _cfsTable; ipfs++)
{
CVectBits *pfb = _fv.GetBits(ipfs);
if ((pfb == NULL) || (!pfb->full))
{
msfDebugOut((DEB_FAT,"Checking table %lu\n",ipfs));
CFatSect *pfs;
msfChk(_fv.GetTable(ipfs, FB_NONE, &pfs));
if (pfb != NULL)
{
isectStart = pfb->firstfree;
}
FSOFFSET isect;
for (isect = isectStart; isect < _fv.GetSectTable(); isect++)
{
SECT sectCurrent = pfs->GetSect(isect);
SECT sectNew = PairToSect(ipfs, isect);
if (sectCurrent == FREESECT)
{
msfChkTo(Err_Rel, IsFree(sectNew));
if (sc == S_FALSE)
{
sectCurrent = ENDOFCHAIN;
}
}
if (sectCurrent == FREESECT)
{
csectFree++;
}
}
_fv.ReleaseTable(ipfs);
}
isectStart = 0;
}
msfDebugOut((DEB_FAT,"Countfree returned %lu\n",csectFree));
*pulRet = csectFree;
Err:
return sc;
Err_Rel:
_fv.ReleaseTable(ipfs);
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::CountSectType, private
//
// Synposis: Count and return the number of sectors of a given
// type in the Fat
//
// Arguments: [out] count The returned count of sectors.
// [in] sectStart The first sector of the range to examine.
// [in] sectEnd The last sector of the range to examine.
// [in] sectType The type of sector looked for.
//
// Returns: SCODE.
//
// Algorithm: Do a linear search of the Fat, counting sectors of the given
// type in the given range.
//
// History: 18-Feb-97 BChapman Created.
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::CountSectType(
ULONG * pulRet,
SECT sectStart,
SECT sectEnd,
SECT sectType)
{
msfDebugOut((DEB_FAT,"In CFat::CountSect(0x%x, 0x%x, 0x%x)\n",
sectStart, sectEnd, sectType));
SCODE sc = S_OK;
FSINDEX ipfs;
ULONG csectType=0;
FSOFFSET isectStart; // starting index into the current FAT
FSOFFSET isectEnd; // ending index into the current FAT
FSOFFSET isectFirstStart; // starting index into the first FAT
FSOFFSET isectLastEnd; // ending index into the last FAT
FSINDEX ipfsStart; // Starting FAT block number
FSINDEX ipfsEnd; // Ending FAT block number
SectToPair(sectStart, &ipfsStart, &isectFirstStart);
SectToPair(sectEnd, &ipfsEnd, &isectLastEnd);
for (ipfs = ipfsStart; ipfs <= ipfsEnd; ipfs++)
{
//
// If we are counting FREESECTS and this FAT blocks is
// known to be full then just skip it.
//
if(FREESECT == sectType)
{
CVectBits *pfb = _fv.GetBits(ipfs);
if ((pfb != NULL) && pfb->full)
continue;
}
msfDebugOut((DEB_FAT,"Checking table %lu\n",ipfs));
CFatSect *pfs;
msfChk(_fv.GetTable(ipfs, FB_NONE, &pfs));
//
// If this is the first FAT block in the given range use the given
// starting offset-index. Otherwise start at the beginning.
//
if(ipfs == ipfsStart)
isectStart = isectFirstStart;
else
isectStart = 0;
//
// If this is the last FAT block in the given range use the given
// ending fooset-index, otherwise scan to the end of the block.
//
if(ipfs == ipfsEnd)
isectEnd = isectLastEnd;
else
isectEnd = _fv.GetSectTable();
FSOFFSET isect;
for (isect = isectStart; isect < isectEnd; isect++)
{
SECT sectCurrent = pfs->GetSect(isect);
SECT sectNew = PairToSect(ipfs, isect);
if (sectCurrent == sectType)
{
msfChkTo(Err_Rel, IsSectType(sectNew, sectType));
if (sc != S_FALSE)
{
csectType++;
}
}
}
_fv.ReleaseTable(ipfs);
isectStart = 0;
}
msfDebugOut((DEB_FAT,"CountSectType returned %lu\n",csectType));
*pulRet = csectType;
Err:
return sc;
Err_Rel:
_fv.ReleaseTable(ipfs);
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::GetSect, public
//
// Synposis: Return the nth sector in a chain
//
// Arguments: [sect] -- Sector ID of beginning of chain
// [uNum] -- indicator of which sector is to be returned
// [psectReturn] -- Pointer to storage for return value
//
// Returns: S_OK.
//
// Algorithm: Linearly traverse chain until numth sector
//
// History: 18-Jul-91 PhilipLa Created.
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::GetSect(SECT sect, ULONG ulNum, SECT * psectReturn)
{
msfDebugOut((DEB_FAT,"In CFat::GetSect(%lu,%lu)\n",sect,ulNum));
SCODE sc = S_OK;
if (ulNum == 0)
{
msfDebugOut((DEB_FAT,"Out CFat::GetSect()=>%lu\n",sect));
}
else if ((SIDFAT == _sid) &&
(_pmsParent->GetHeader()->GetFatStart() == sect))
{
msfChk(_pmsParent->GetDIFat()->GetFatSect(ulNum, &sect));
}
else for (ULONG i = 0; i < ulNum; i++)
{
msfChk(GetNext(sect, &sect));
if (sect > MAXREGSECT)
{
//The stream isn't long enough, so stop.
msfAssert(sect == ENDOFCHAIN &&
aMsg("Found invalid sector in fat chain."));
break;
}
}
*psectReturn = sect;
msfDebugOut((DEB_FAT,"Out CFat::GetSect()=>%lu\n",sect));
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Member: CFat::GetESect
//
// Synposis: Return the nth sector in a chain, extending the chain
// if necessary.
//
// Effects: Modifies fat (via Extend) if necessary
//
// Arguments: [sect] -- Sector ID of beginning of chain
// [ulNum] -- Indicates which sector is to be returned
// [psectReturn] -- Pointer to storage for return value
//
// Returns: S_OK if call completed OK.
//
// Algorithm: Linearly search chain until numth sector is found. If
// the chain terminates early, extend it as necessary.
//
// History: 18-Jul-91 PhilipLa Created.
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::GetESect(SECT sect, ULONG ulNum, SECT *psectReturn)
{
msfDebugOut((DEB_FAT,"In CFat::GetESect(%lu,%lu)\n",sect,ulNum));
SCODE sc = S_OK;
ULONG i = 0;
while (i < ulNum)
{
SECT temp;
msfChk(GetNext(sect, &temp));
msfAssert(temp != FREESECT &&
aMsg("FREESECT found in chain."));
if (temp == ENDOFCHAIN)
{
//The stream isn't long enough, so extend it somehow.
ULONG need = ulNum - i;
msfAssert((SIDMINIFAT == _sid ||
sect != _pmsParent->GetHeader()->GetFatStart()) &&
aMsg("Called GetESect on Fat chain"));
msfChk(Extend(sect,need));
}
else
{
sect = temp;
i++;
}
}
msfDebugOut((DEB_FAT,"Exiting GetESect with result %lu\n",sect));
*psectReturn = sect;
Err:
return sc;
}
#if DBG == 1
//+-------------------------------------------------------------------------
//
// Member: CFat::checksanity, private
//
// Synposis: Print out a FAT chain. Used for debugging only.
//
// Arguments: [sectStart] -- sector to begin run at.
//
// Returns: void
//
// History: 18-Jul-91 PhilipLa Created.
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::checksanity(SECT sectStart)
{
msfDebugOut((DEB_FAT,"Sanity Check (%i)\n\t",sectStart));
SCODE sc = S_OK;
while (sectStart != ENDOFCHAIN)
{
msfDebugOut((DEB_FAT | DEB_NOCOMPNAME,"%lu, ",sectStart));
msfChk(GetNext(sectStart, &sectStart));
}
msfDebugOut((DEB_FAT | DEB_NOCOMPNAME,"ENDOFCHAIN\n"));
Err:
return sc;
}
#endif
//+-------------------------------------------------------------------------
//
// Member: CFat::SetChainLength, private
//
// Synposis: Set the length of a fat chain. This is used to reduce
// the length of the chain only. To extend a chain, use
// Extend or GetESect
//
// Effects: Modifies the fat
//
// Arguments: [sectStart] -- Sector to begin at (head of chain)
// [uLength] -- New length for chain
//
// Returns: void.
//
// Algorithm: Traverse chain until uLength is reached or the chain
// terminates. If it terminates prematurely, return with
// no other action. Otherwise, deallocate all remaining
// sectors in the chain.
//
// History: 14-Aug-91 PhilipLa Created.
//
// Notes:
//
//---------------------------------------------------------------------------
SCODE CFat::SetChainLength(SECT sectStart, ULONG ulLength)
{
msfDebugOut((DEB_FAT,"In CFat::SetChainLength(%lu,%lu)\n",sectStart,ulLength));
SCODE sc;
if (sectStart == ENDOFCHAIN) return S_OK;
for (ULONG ui = 1; ui < ulLength; ui++)
{
msfChk(GetNext(sectStart, &sectStart));
if (sectStart == ENDOFCHAIN) return S_OK;
}
msfAssert(sectStart != ENDOFCHAIN &&
aMsg("Called SetChainLength is ENDOFCHAIN start"));
SECT sectEnd;
sectEnd = sectStart;
msfChk(GetNext(sectStart, &sectStart));
if (ulLength != 0)
{
msfChk(SetNext(sectEnd, ENDOFCHAIN));
}
else
{
msfChk(SetNext(sectEnd, FREESECT));
}
while (sectStart != ENDOFCHAIN)
{
SECT sectTemp;
msfChk(GetNext(sectStart, &sectTemp));
msfChk(SetNext(sectStart, FREESECT));
sectStart = sectTemp;
}
msfDebugOut((DEB_FAT,"Out CFat::SetChainLength()\n"));
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Method: CFat::DirtyAll, public
//
// Synopsis: Dirty every sector in the FAT. This had the effect in
// consolidation of copying the whole FAT down lower in the
// file.
//
// Returns: SCODE success or failure code.
//
// Algorithm: Load each FAT sector into the cache "for-writing".
//
// History: 24-Feb-1997 BChapman Created.
//
// Notes: For use
//
//--------------------------------------------------------------------------
SCODE CFat::DirtyAll()
{
SCODE sc = S_OK;
CFatSect *pfs;
FSINDEX i;
for(i=0; i<_cfsTable; i++)
{
msfChk(_fv.GetTable(i, FB_DIRTY, &pfs));
_fv.ReleaseTable(i);
}
Err:
return sc;
}
//+-------------------------------------------------------------------------
//
// Method: CFat::FindLast, private
//
// Synopsis: Find last used sector in a fat
//
// Returns: Location of last used sector
//
// Algorithm: Perform a backward linear search until a non-free
// sector is found.
//
// History: 18-Dec-91 PhilipLa Created.
//
// Notes: Used for shadow fats only.
//
//--------------------------------------------------------------------------
SCODE CFat::FindLast(SECT * psectRet)
{
SCODE sc = S_OK;
FSINDEX ipfs = _cfsTable;
SECT sect = 0;
while (ipfs > 0)
{
ipfs--;
FSOFFSET isect = _fv.GetSectTable();
CFatSect *pfs;
msfChk(_fv.GetTable(ipfs, FB_NONE, &pfs));
while (isect > 0)
{
isect--;
SECT sectCurrent = pfs->GetSect(isect);
SECT sectNew = PairToSect(ipfs, isect);
if (sectCurrent == FREESECT)
{
msfChkTo(Err_Rel, IsFree(sectNew));
if (sc == S_FALSE)
sectCurrent = ENDOFCHAIN;
}
if (ipfs == _ipfsRangeLocks && isect == _isectRangeLocks)
sectCurrent = FREESECT;
if (sectCurrent != FREESECT)
{
msfDebugOut((DEB_FAT,"FindLast returns %lu\n",PairToSect(ipfs,isect)));
sect = sectNew + 1;
break;
}
}
_fv.ReleaseTable(ipfs);
if (sect != 0)
break;
}
//We need additional checks here since in some cases there aren't
//enough pages in the fat to hold _sectNoSnapshot (or _sectNoSnapshotFree).
//Returning too small a value could result in SetSizing the file to too
//small a size, which is data loss.
if (sect < _sectNoSnapshot)
{
sect = _sectNoSnapshot;
}
if ((_sectNoSnapshotFree != ENDOFCHAIN) && (sect < _sectNoSnapshotFree))
{
sect = _sectNoSnapshotFree;
}
*psectRet = sect;
Err:
return sc;
Err_Rel:
_fv.ReleaseTable(ipfs);
return sc;
}
//+-------------------------------------------------------------------------
//
// Method: CFat::Remap, public
//
// Synopsis: Remap a portion of a chain for copy-on-write
//
// Effects:
//
// Arguments: [sectStart] -- Sector marking the first sector in the chain
// [oStart] -- Offset in sectors at which to begin the remap
// [ulRunLength] -- Number of sectors to remap
// [psectOldStart] -- Returns old location of first remapped
// sector.
// [psectNewStart] -- Returns new location of first sector
// [psectOldEnd] -- Returns old location of last sector
// [psectNewEnd] -- Returns new location of last sector
//
// Returns: Appropriate status code.
// S_FALSE if everything succeeded but no sectors were
// remapped.
//
// History: 18-Feb-92 PhilipLa Created.
//
//--------------------------------------------------------------------------
SCODE CFat::Remap(
SECT sectStart,
ULONG oStart,
ULONG ulRunLength,
SECT *psectOldStart,
SECT *psectNewStart,
SECT *psectOldEnd,
SECT *psectNewEnd)
{
msfDebugOut((DEB_FAT,"In CFat::Remap(%lu, %lu, %lu)\n",sectStart,oStart,ulRunLength));
msfAssert(SIDMINIFAT != _sid &&
aMsg("Called Remap on Minifat"));
msfAssert(ulRunLength != 0 &&
aMsg("Called Remap with 0 runlength"));
msfAssert(!_pmsParent->IsScratch() &&
aMsg("Called Remap on scratch."));
BOOL fRemapped = FALSE;
SCODE sc = S_OK;
SECT sectPrev = ENDOFCHAIN;
SECT sect;
ULONG uCount = 0;
*psectNewStart = ENDOFCHAIN;
*psectNewEnd = ENDOFCHAIN;
#if DBG == 1
*psectOldStart = ENDOFCHAIN;
*psectOldEnd = ENDOFCHAIN;
#endif
if (oStart == 0)
{
sectPrev = ENDOFCHAIN;
sect = sectStart;
}
else
{
msfChk(GetESect(sectStart, oStart - 1, &sectPrev));
msfChk(GetNext(sectPrev, &sect));
}
*psectOldStart = sect;
while ((uCount < ulRunLength) && (sect != ENDOFCHAIN))
{
if (uCount == ulRunLength - 1)
{
*psectOldEnd = sect;
}
msfChk(QueryRemapped(sect));
if (sc == S_FALSE)
{
SECT sectNew;
msfChk(GetFree(1, &sectNew, GF_WRITE));
msfDebugOut((DEB_ITRACE,"Remapping sector %lu to %lu\n",sect,sectNew));
if (sectPrev != ENDOFCHAIN)
{
msfChk(SetNext(sectPrev, sectNew));
if (_pfatNoScratch != NULL)
{
msfChk(_pfatNoScratch->SetNext(sectPrev, sectNew));
}
}
msfAssert((sect != ENDOFCHAIN) &&
aMsg("Remap precondition failed."));
SECT sectTemp;
msfChk(GetNext(sect, &sectTemp));
msfChk(SetNext(sectNew, sectTemp));
if (_pfatNoScratch != NULL)
{
msfChk(_pfatNoScratch->SetNext(sectNew, sectTemp));
}
msfChk(SetNext(sect, FREESECT));
fRemapped = TRUE;
if (uCount == 0)
{
*psectNewStart = sectNew;
}
if (uCount == ulRunLength - 1)
{
*psectNewEnd = sectNew;
}
sect = sectNew;
}
sectPrev = sect;
msfChk(GetNext(sect, &sect));
uCount++;
}
if ((*psectNewStart != ENDOFCHAIN) && (oStart == 0))
{
if (sectStart == _pmsParent->GetHeader()->GetDirStart())
_pmsParent->GetHeader()->SetDirStart(*psectNewStart);
if (sectStart == _pmsParent->GetHeader()->GetMiniFatStart())
_pmsParent->GetHeader()->SetMiniFatStart(*psectNewStart);
}
msfDebugOut((DEB_FAT,"Out CFat::Remap()=>%lu\n",*psectNewStart));
Err:
if ((sc == S_OK) && !fRemapped)
sc = S_FALSE;
return sc;
}
//+-------------------------------------------------------------------------
//
// Method: CFat::FindMaxSect, private
//
// Synopsis: Return last used sector in current Fat.
//
// Arguments: None.
//
// Returns: Last used sector in current Fat
//
// History: 15-Dec-91 PhilipLa Created.
//
//--------------------------------------------------------------------------
SCODE CFat::FindMaxSect(SECT *psectRet)
{
SCODE sc = S_OK;
if (_pfatNoScratch != NULL)
{
return _pfatNoScratch->FindMaxSect(psectRet);
}
if (_sectMax == ENDOFCHAIN)
{
msfChk(FindLast(psectRet));
}
else
{
#if DBG == 1
SECT sectLast;
msfChk(FindLast(&sectLast));
msfAssert(((_sectMax == sectLast) || (_sectMax == _sectLastUsed)) &&
aMsg("_sectMax doesn't match actual last sector"));
#endif
*psectRet = _sectMax;
}
if (*psectRet < _sectLastUsed)
{
*psectRet = _sectLastUsed;
}
Err:
return sc;
}
//+---------------------------------------------------------------------------
//
// Member: CFat::InitScratch, public
//
// Synopsis: Initialize the fat based on another fat. This is used
// for NOSCRATCH mode. The fats may have different sector
// sizes.
//
// Arguments: [pfat] -- Pointer to fat to copy.
// [fNew] -- TRUE if this is being called on an empty fat.
//
// Returns: Appropriate status code
//
// History: 20-Mar-95 PhilipLa Created
//
//----------------------------------------------------------------------------
SCODE CFat::InitScratch(CFat *pfat, BOOL fNew)
{
SCODE sc;
msfAssert((_sid == SIDMINIFAT) && (_pmsParent->IsScratch()) &&
aMsg("Called InitScratch on the wrong thing."));
USHORT cbSectorOriginal = pfat->_pmsParent->GetSectorSize();
USHORT cSectPerRealSect = _pmsParent->GetSectorSize() /
cbSectorOriginal;
//This routine copies the fat from the multistream passed in into
// the _minifat_ of the current multistream.
ULONG cfatOriginal = pfat->_cfsTable;
//Our minifat must be large enough to hold all of the necessary
//sectors. Set the size appropriately.
ULONG cMiniFatSize = (cfatOriginal + cSectPerRealSect - 1) /
cSectPerRealSect;
msfAssert(((!fNew) || (_cfsTable == 0)) &&
aMsg("fNew TRUE when fat non-empty."));
msfAssert(((fNew) || (_pfatReal == pfat)) &&
aMsg("Fat pointer changed between calls to InitScratch"));
_pfatReal = P_TO_BP(CBasedFatPtr, pfat);
if (cMiniFatSize > _cfsTable)
{
msfChk(Resize(cMiniFatSize));
}
ULONG ifs;
for (ifs = 0; ifs < cfatOriginal; ifs++)
{
CFatSect *pfs;
CFatSect *pfsCurrent;
//Get the sector from the original fat
msfChk(pfat->_fv.GetTable(ifs, FB_NONE, &pfs));
msfAssert(pfs != NULL);
//Write the sector into the appropriate place in this fat.
ULONG ifsCurrent;
ifsCurrent = ifs / cSectPerRealSect;
OFFSET off;
off = (USHORT)((ifs % cSectPerRealSect) * cbSectorOriginal);
msfChk(_fv.GetTable(ifsCurrent, FB_DIRTY, &pfsCurrent));
if (fNew)
{
memcpy((BYTE *)pfsCurrent + off, pfs, cbSectorOriginal);
}
else
{
//Merge the table into the current one.
for (USHORT i = 0; i < cbSectorOriginal / sizeof(SECT); i++)
{
SECT sectCurrent;
OFFSET offCurrent;
offCurrent = i + (off / sizeof(SECT));
sectCurrent = pfsCurrent->GetSect(offCurrent);
if (sectCurrent != STREAMSECT)
{
pfsCurrent->SetSect(offCurrent, pfs->GetSect(i));
}
}
}
_fv.ReleaseTable(ifsCurrent);
pfat->_fv.ReleaseTable(ifs);
}
msfAssert((pfat->_cUnmarkedSects == 0) &&
aMsg("Fat being copied has changes in DIF"));
_fv.ResetBits();
_ulFreeSects = MAX_ULONG;
_sectFirstFree = 0;
_sectLastUsed = 0;
_sectMax = ENDOFCHAIN;
Err:
return sc;
}
//+---------------------------------------------------------------------------
//
// Member: CFat::ResizeNoSnapshot, public
//
// Synopsis: Resize the fat to handle a no-snapshot commit. In
// no-snapshot mode it is possible that another commit has
// grown the file to the point where it cannot be contained in
// the existing fat in this open, so we need to grow it before
// we can continue with anything else.
//
// Arguments: None.
//
// Returns: Appropriate SCODE.
//
// History: 19-Jun-96 PhilipLa Created
//
//----------------------------------------------------------------------------
SCODE CFat::ResizeNoSnapshot(void)
{
SCODE sc = S_OK;
FSINDEX ipfs;
FSOFFSET isect;
//If we need to grow the fat to handle the previous commits (which is
// possible if other opens are doing a lot of writing), we do it here,
// since we know for certain that the first available sector is at
// _sectNoSnapshot.
SectToPair(_sectNoSnapshot, &ipfs, &isect);
if (ipfs >= _cfsTable)
{
//We know we have no free sectors, so we can set this here and
// Resize will end up with the correct value.
_ulFreeSects = 0;
//This Resize will also cause a resize in the DIFat if necessary.
sc = Resize(ipfs + 1);
CheckFreeCount();
}
return sc;
}
#if DBG == 1
void CFat::CheckFreeCount(void)
{
SCODE sc; // check is disabled if fat grows above >1G
if ((_ulFreeSects != MAX_ULONG) && (_cfsTable < _ipfsRangeLocks/2))
{
ULONG ulFree;
msfChk(CountFree(&ulFree));
if (ulFree != _ulFreeSects)
{
msfDebugOut((DEB_ERROR,
"Free count mismatch. Cached: %lu, Real: %lu."
" Difference: %li\n",
_ulFreeSects,
ulFree,
ulFree - _ulFreeSects));
}
msfAssert((ulFree == _ulFreeSects) &&
aMsg("Free count doesn't match cached value."));
}
Err:
return;
}
#endif
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