Source code of Windows XP (NT5)
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//+---------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1991 - 1992.
//
// File: RWEX.CXX
//
// Contents: Relevant word extraction
//
// Classes: CRelevantWord, CRWStore, CRWHeap
//
// History: 25-Apr-94 dlee Created
//
//----------------------------------------------------------------------------
#include <pch.cxx>
#pragma hdrstop
#include <rwex.hxx>
//+---------------------------------------------------------------------------
//
// Member: CRWStore::CRWStore, public
//
// Synopsis: Constructor for relevant word store
//
// Arguments: [pwList] -- array of work ids to operate over, must be in
// increasing order
// [cWids] -- # of items in pwList
// [cIds] -- # of relevant word key ids per wid to store
//
// History: 25-Apr-94 dlee Created.
//
//----------------------------------------------------------------------------
CRWStore::CRWStore(WORKID *pwList,ULONG cWids,ULONG cIds)
: _cWids(cWids), _cIds(cIds), _ulSearchLeftOff(0)
{
_cbRow = _RowSize(cIds);
for (ULONG x = 0; x < _cWids; x++)
{
SRWHeader *p = GetRow(x);
p->wid = pwList[x];
p->cItems = 0;
}
} //CRWStore
//+---------------------------------------------------------------------------
//
// Member: CRWStore::new, public
//
// Synopsis: Private new operator
//
// Arguments: [st] -- predefined param
// [cWids] -- # of rows for the array
// [cIds] -- # of relevant word key ids per wid to store
//
// History: 25-Apr-94 dlee Created.
//
//----------------------------------------------------------------------------
void * CRWStore::operator new(size_t st,ULONG cWids,ULONG cIds)
{
return (void *) ::new char[_ObjectSize(cWids,cIds)];
} //new
#if _MSC_VER >= 1200
void CRWStore::operator delete(void * p, ULONG cWids, ULONG cIds)
{
::delete (p);
}
#endif
//+---------------------------------------------------------------------------
//
// Member: CRWStore::Insert, public
//
// Synopsis: Inserts a keyid in a wid's heap if the rank is sufficient.
//
// Arguments: [wid] -- wid on whose heap is operated
// [keyid] -- keyid to add
// [lRank] -- rank of the keyid in the wid
//
// History: 17-Jun-94 dlee Created.
//
//----------------------------------------------------------------------------
void CRWStore::Insert(WORKID wid,KEYID keyid, LONG lRank)
{
SRWHeader *ph = _Find(wid,GetRow(_ulSearchLeftOff),
_cWids - _ulSearchLeftOff);
Win4Assert(ph != 0);
//
// This heap object is merely an accessor to a heap whose storage
// has already been allocated. The heap object operates on the heap
// but does not own the heap's memory.
//
CRWHeap heap(ph,_cIds);
heap.Insert(keyid,lRank);
//
// Start the next binary search one after where the last search
// left off, since we know the wids will come through in sorted order.
//
_ulSearchLeftOff = _HeaderToRow(ph) + 1;
} //Insert
//+---------------------------------------------------------------------------
//
// Member: CRWStore::_Find, private
//
// Synopsis: Finds a wid's heap in the array of heaps given a wid
//
// Arguments: [wid] -- wid of heap to find
// [base] -- pointer to first element in heap array
// [cRows] -- # of rows in the array
//
// Returns: pointer to the head of the heap for the wid or 0 if not found.
//
// History: 25-Apr-94 dlee Created.
//
//----------------------------------------------------------------------------
SRWHeader * CRWStore::_Find(WORKID wid,SRWHeader *pBase,ULONG cRows)
{
Win4Assert(cRows != 0);
SRWHeader *lo = pBase;
SRWHeader *hi = lo->Forward(cRows - 1,_cbRow);
SRWHeader *mid;
ULONG cHalf;
while (lo <= hi)
{
if (cHalf = cRows / 2)
{
mid = lo->Forward((cRows & 1) ? cHalf : (cHalf - 1),_cbRow);
if (wid == mid->wid)
{
return mid;
}
else if (wid < mid->wid)
{
hi = mid->Backward(1,_cbRow);
cRows = (cRows & 1) ? cHalf : (cHalf - 1);
}
else
{
lo = mid->Forward(1,_cbRow);
cRows = cHalf;
}
}
else if (cRows != 0)
{
if (wid == lo->wid)
return lo;
else
return 0;
}
else
{
break;
}
}
return 0;
} //_Find
//+---------------------------------------------------------------------------
//
// Member: CRWHeap::DeQueue, public
//
// Synopsis: Removes the lowest-ranking keyid in the heap for a wid
//
// Returns: keyid of the lowest-ranking member of the heap
//
// History: 25-Apr-94 dlee Created.
//
//----------------------------------------------------------------------------
KEYID CRWHeap::DeQueue()
{
ULONG ulL,ulR,ulMax;
KEYID kRet = _ph->aItems[0].kKeyId;
_ph->cItems--;
//
// Take out the bottom-right most leaf and bubble it down from
// the top of the tree until it is less than its parent.
//
SRWItem iFix = _ph->aItems[_ph->cItems];
ULONG ulPos = 0;
while (!_IsLeaf(ulPos))
{
ulL = _Left(ulPos);
ulR = _Right(ulPos);
if (!_IsValid(ulR))
ulMax = ulL;
else
{
if (_ph->aItems[ulL].lRank < _ph->aItems[ulR].lRank)
ulMax = ulL;
else
ulMax = ulR;
}
if (_ph->aItems[ulMax].lRank < iFix.lRank)
{
_ph->aItems[ulPos] = _ph->aItems[ulMax];
ulPos = ulMax;
}
else
{
break;
}
}
_ph->aItems[ulPos] = iFix;
return kRet;
} //DeQueue
//+---------------------------------------------------------------------------
//
// Member: CRWStore::Insert, public
//
// Synopsis: Inserts an keyid in the rw heap for a wid if the keyid's rank
// is greater than the lowest ranking keyid in the heap or if
// the heap is not yet full.
//
// Arguments: [keyid] -- item to insert
// [lRank] -- rank of the keyid
//
// History: 25-Apr-94 dlee Created.
//
//----------------------------------------------------------------------------
void CRWHeap::Insert(KEYID keyid, LONG lRank)
{
if ((_ph->cItems < _ulMaxIds) ||
(_ph->aItems[0].lRank < lRank))
{
//
// Pop off the top element if the list is full
//
if (_ph->cItems == _ulMaxIds)
DeQueue();
//
// Insert element as the rightmost bottom level leaf in the heap
//
ULONG ulPos = _ph->cItems++;
_ph->aItems[ulPos].kKeyId = keyid;
_ph->aItems[ulPos].lRank = lRank;
//
// bubble the element up until it fits correctly in the tree
//
while (ulPos)
{
ULONG ulParent = _Parent(ulPos);
if (_ph->aItems[ulPos].lRank < _ph->aItems[ulParent].lRank)
{
//
// swap the elements
//
SRWItem t = _ph->aItems[ulPos];
_ph->aItems[ulPos] = _ph->aItems[ulParent];
_ph->aItems[ulParent] = t;
ulPos = ulParent;
}
else
{
break;
}
}
}
} //Insert
//+---------------------------------------------------------------------------
//
// Member: CRelevantWord::CRelevantWord, public
//
// Synopsis: Constructor for the relevant word object
//
// Arguments: [pwid] -- array of wids in sorted order to track
// [cWidsUsed] -- # of wids in the array
// [cRW] -- # of relevant words per wid to track
//
// History: 25-Apr-94 dlee Created.
//
//----------------------------------------------------------------------------
CRelevantWord::CRelevantWord(WORKID *pwid,ULONG cWidsUsed,ULONG cRW)
: _pWidItem(0), _pstore(0), _cWidsAdded(0)
{
TRY
{
_pstore = new(cWidsUsed,cRW) CRWStore(pwid,cWidsUsed,cRW);
_pWidItem = new SRWWidItem[cWidsUsed];
}
CATCH ( CException, e )
{
delete _pWidItem;
delete _pstore;
RETHROW();
}
END_CATCH
} //CRelevantWord
//+---------------------------------------------------------------------------
//
// Member: CRelevantWord::~CRelevantWord
//
// Synopsis: Destructor for the relevant word object
//
// History: 25-Apr-94 dlee Created.
//
//----------------------------------------------------------------------------
CRelevantWord::~CRelevantWord()
{
delete _pWidItem;
delete _pstore; // may be 0
} //~CRelevantWord
//+---------------------------------------------------------------------------
//
// Member: CRelevantWord::DoneWithKey, public
//
// Synopsis: Computes rank for each wid occurance of a keyid and adjusts
// the heaps appropriately
//
// Arguments: [keyid] -- keyid on which to calculate
// [maxWid] -- # docs on disk
// [cWids] -- # docs with key on disk
//
// History: 25-Apr-94 dlee Created.
//
//----------------------------------------------------------------------------
void CRelevantWord::DoneWithKey(KEYID keyid,ULONG maxWid,ULONG cWids)
{
if (0 != cWids)
{
_SetWidInfo(maxWid,cWids);
for (ULONG x = 0; x < _cWidsAdded; x++)
{
Win4Assert(_pWidItem[x].wid != 0);
_pstore->Insert(_pWidItem[x].wid,keyid,_Rank(_pWidItem[x].cOcc));
}
_pstore->DoneWithKey();
_cWidsAdded = 0;
}
else
{
Win4Assert(0 == _cWidsAdded);
}
} //DoneWithKey
//+-------------------------------------------------------------------------
//
// Function: _SortULongArray, private
//
// Synopsis: Sorts an array of unsigned longs from low to high
//
// Arguments: [pulItems] -- list of IDs to be sorted
// [cItems] -- # of root words to be sorted
//
// Returns: void
//
// Algorithm: Heapsort, not quick sort. Give up 20% speed to save kernel
// stack and prevent against n*n performance on sorted lists.
//
// History: 14-Mar-94 Dlee Created
//
//--------------------------------------------------------------------------
#define _CompUL(x,y) ((*(x)) > (*(y)) ? 1 : (*(x)) == (*(y)) ? 0 : -1)
#define _SwapUL(x,y) { ULONG _t = *(x); *(x) = *(y); *(y) = _t; }
inline static void _AddRootUL(ULONG x,ULONG n,ULONG *p)
{
ULONG _x = x;
ULONG _j = (2 * (_x + 1)) - 1;
while (_j < n)
{
if (((_j + 1) < n) &&
(_CompUL(p + _j,p + _j + 1) < 0))
_j++;
if (_CompUL(p + _x,p + _j) < 0)
{
_SwapUL(p + _x,p + _j);
_x = _j;
_j = (2 * (_j + 1)) - 1;
}
else break;
}
} //_AddRootUL
void _SortULongArray(ULONG *pulItems,ULONG cItems)
{
if (cItems == 0)
return;
long z;
for (z = (((long) cItems + 1) / 2) - 1; z >= 0; z--)
{
_AddRootUL(z,cItems,pulItems);
}
for (z = cItems - 1; z != 0; z--)
{
_SwapUL(pulItems,pulItems + z);
_AddRootUL(0,(ULONG) z,pulItems);
}
} //_SortULongArray