office-gobmx/soldep/bootstrp/hashtbl.cxx
Vladimir Glazounov 72d3bb5def INTEGRATION: CWS obo17 (1.2.6); FILE MERGED
2007/10/18 07:45:52 obo 1.2.6.1: #150903# unxmacxi support
2007-10-22 13:41:55 +00:00

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12 KiB
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/*************************************************************************
#*
#* $Workfile:$
#*
#* class Klassenname(n)
#*
#* Beschreibung DOKUNAME.DOC oder
#* Beschreibung des Moduls
#*
#* Ersterstellung XX TT.MM.JJ
#* Letzte Aenderung $Author: vg $ $Date: 2007-10-22 14:41:55 $
#* $Revision: 1.3 $
#*
#* $Logfile:$
#*
#* Copyright (c) 1989 - 2000, STAR DIVISION
#*
#*************************************************************************
Source Code Control System - Header
$Header: /zpool/svn/migration/cvs_rep_09_09_08/code/soldep/bootstrp/hashtbl.cxx,v 1.3 2007-10-22 14:41:55 vg Exp $
Source Code Control System - Update
$Log: not supported by cvs2svn $
Revision 1.2.6.1 2007/10/18 07:45:52 obo
#150903# unxmacxi support
Revision 1.2 2007/06/27 23:37:39 hr
INTEGRATION: CWS vgbugs07 (1.1.22); FILE MERGED
2007/06/04 13:35:21 vg 1.1.22.1: #i76605# Remove -I .../inc/module hack introduced by hedaburemove01
Revision 1.1.22.1 2007/06/04 13:35:21 vg
#i76605# Remove -I .../inc/module hack introduced by hedaburemove01
Revision 1.1 2006/04/26 12:25:22 obo
initial revision
Revision 1.3 2001/09/14 13:14:56 nf
Handling of invisible objects
Revision 1.2 2000/11/02 10:31:12 hjs
unicode first shot
Revision 1.1 1999/06/11 17:02:54 hjs
aus tools\workben
*************************************************************************/
#include <tools/gen.hxx>
#include <tools/debug.hxx>
#include <soldep/hashtbl.hxx>
// -------------------------------------------------------------
// class HashItem
//
class HashItem
{
enum ETag { TAG_EMPTY, TAG_USED, TAG_DELETED };
void* m_pObject;
ETag m_Tag;
ByteString m_Key;
public:
HashItem() { m_Tag = TAG_EMPTY; m_pObject = NULL; }
BOOL IsDeleted() const
{ return m_Tag == TAG_DELETED; }
BOOL IsEmpty() const
{ return m_Tag == TAG_DELETED || m_Tag == TAG_EMPTY; }
BOOL IsFree() const
{ return m_Tag == TAG_EMPTY; }
BOOL IsUsed() const
{ return m_Tag == TAG_USED; }
void Delete()
{ m_Tag = TAG_DELETED; m_Key = ""; m_pObject = NULL; }
ByteString const& GetKey() const
{ return m_Key; }
void* GetObject() const
{ return m_pObject; }
void SetObject(ByteString const Key, void *pObject)
{ m_Tag = TAG_USED; m_Key = Key; m_pObject = pObject; }
};
#define MIN(a,b) (a)<(b)?(a):(b)
#define MAX(a,b) (a)>(b)?(a):(b)
// -------------------------------------------------------------
// class HashTable
//
/*static*/ double HashTable::m_defMaxLoadFactor = 0.8;
/*static*/ double HashTable::m_defDefGrowFactor = 2.0;
HashTable::HashTable(ULONG lSize, BOOL bOwner, double dMaxLoadFactor, double dGrowFactor)
{
m_lSize = lSize;
m_bOwner = bOwner;
m_lElem = 0;
m_dMaxLoadFactor = MAX(0.5,MIN(1.0,dMaxLoadFactor)); // 0.5 ... 1.0
m_dGrowFactor = MAX(1.3,MIN(5.0,dGrowFactor)); // 1.3 ... 5.0
m_pData = new HashItem [lSize];
// Statistik
#ifdef DBG_UTIL
m_aStatistic.m_lSingleHash = 0;
m_aStatistic.m_lDoubleHash = 0;
m_aStatistic.m_lProbe = 0;
#endif
}
HashTable::~HashTable()
{
// Wenn die HashTable der Owner der Objecte ist,
// m<>ssen die Destruktoren separat gerufen werden.
// Dies geschieht <20>ber die virtuelle Methode OnDeleteObject()
//
// Problem: Virtuelle Funktionen sind im Destructor nicht virtuell!!
// Der Code mu<6D> deshalb ins Macro
/*
if (m_bOwner)
{
for (ULONG i=0; i<GetSize(); i++)
{
void *pObject = GetObjectAt(i);
if (pObject != NULL)
OnDeleteObject(pObject());
}
}
*/
// Speicher f<>r HashItems freigeben
delete [] m_pData;
}
void* HashTable::GetObjectAt(ULONG lPos) const
// Gibt Objekt zur<75>ck, wenn es eines gibt, sonst NULL;
{
DBG_ASSERT(lPos<m_lSize, "HashTable::GetObjectAt()");
HashItem *pItem = &m_pData[lPos];
return pItem->IsUsed() ? pItem->GetObject() : NULL;
}
void HashTable::OnDeleteObject(void*)
{
DBG_ERROR("HashTable::OnDeleteObject(void*) nicht <20>berladen")
}
ULONG HashTable::Hash(ByteString const& Key) const
{
/*
ULONG lHash = 0;
ULONG i,n;
for (i=0,n=Key.Len(); i<n; i++)
{
lHash *= 256L;
lHash += (ULONG)(USHORT)Key.GetStr()[i];
lHash %= m_lSize;
}
return lHash;
*/
// Hashfunktion von P.J. Weinberger
// aus dem "Drachenbuch" von Aho/Sethi/Ullman
ULONG i,n;
ULONG h = 0;
ULONG g = 0;
for (i=0,n=Key.Len(); i<n; i++)
{
h = (h<<4) + (ULONG)(USHORT)Key.GetBuffer()[i];
g = h & 0xf0000000;
if (g != 0)
{
h = h ^ (g >> 24);
h = h ^ g;
}
}
return h % m_lSize;
}
ULONG HashTable::DHash(ByteString const& Key, ULONG lOldHash) const
{
ULONG lHash = lOldHash;
ULONG i,n;
for (i=0,n=Key.Len(); i<n; i++)
{
lHash *= 256L;
lHash += (ULONG)(USHORT)Key.GetBuffer()[i];
lHash %= m_lSize;
}
return lHash;
/* return
(
lHash
+ (char)Key.GetStr()[0] * 256
+ (char)Key.GetStr()[Key.Len()-1]
+ 1
)
% m_lSize;
*/
}
ULONG HashTable::Probe(ULONG lPos) const
// gibt den Folgewert von lPos zur<75>ck
{
lPos++; if (lPos==m_lSize) lPos=0;
return lPos;
}
BOOL HashTable::IsFull() const
{
return m_lElem>=m_lSize;
}
BOOL HashTable::Insert(ByteString const& Key, void* pObject)
// pre: Key ist nicht im Dictionary enthalten, sonst return FALSE
// Dictionary ist nicht voll, sonst return FALSE
// post: pObject ist unter Key im Dictionary; m_nElem wurde erh<72>ht
{
SmartGrow();
if (IsFull())
{
DBG_ERROR("HashTable::Insert() is full");
return FALSE;
}
if (FindPos(Key) != NULL )
return FALSE;
ULONG lPos = Hash(Key);
HashItem *pItem = &m_pData[lPos];
// first hashing
//
if (pItem->IsEmpty())
{
pItem->SetObject(Key, pObject);
m_lElem++;
#ifdef DBG_UTIL
m_aStatistic.m_lSingleHash++;
#endif
return TRUE;
}
// double hashing
//
lPos = DHash(Key,lPos);
pItem = &m_pData[lPos];
if (pItem->IsEmpty())
{
pItem->SetObject(Key, pObject);
m_lElem++;
#ifdef DBG_UTIL
m_aStatistic.m_lDoubleHash++;
#endif
return TRUE;
}
// linear probing
//
do
{
#ifdef DBG_UTIL
m_aStatistic.m_lProbe++;
#endif
lPos = Probe(lPos);
pItem = &m_pData[lPos];
}
while(!pItem->IsEmpty());
pItem->SetObject(Key, pObject);
m_lElem++;
return TRUE;
}
HashItem* HashTable::FindPos(ByteString const& Key) const
// sucht den Key; gibt Refrenz auf den Eintrag (gefunden)
// oder NULL (nicht gefunden) zur<75>ck
//
// pre: -
// post: -
{
// first hashing
//
ULONG lPos = Hash(Key);
HashItem *pItem = &m_pData[lPos];
if (pItem->IsUsed()
&& pItem->GetKey() == Key)
{
return pItem;
}
// double hashing
//
if (pItem->IsDeleted() || pItem->IsUsed())
{
lPos = DHash(Key,lPos);
pItem = &m_pData[lPos];
if (pItem->IsUsed()
&& pItem->GetKey() == Key)
{
return pItem;
}
// linear probing
//
if (pItem->IsDeleted() || pItem->IsUsed())
{
ULONG n = 0;
BOOL bFound = FALSE;
BOOL bEnd = FALSE;
do
{
n++;
lPos = Probe(lPos);
pItem = &m_pData[lPos];
bFound = pItem->IsUsed()
&& pItem->GetKey() == Key;
bEnd = !(n<m_lSize || pItem->IsFree());
}
while(!bFound && !bEnd);
return bFound ? pItem : NULL;
}
}
// nicht gefunden
//
return NULL;
}
void* HashTable::Find(ByteString const& Key) const
// Gibt Verweis des Objektes zur<75>ck, das unter Key abgespeichert ist,
// oder NULL wenn nicht vorhanden.
//
// pre: -
// post: -
{
HashItem *pItem = FindPos(Key);
if (pItem != NULL
&& pItem->GetKey() == Key)
return pItem->GetObject();
else
return NULL;
}
void* HashTable::Delete(ByteString const& Key)
// L<>scht Objekt, das unter Key abgespeichert ist und gibt Verweis
// darauf zur<75>ck.
// Gibt NULL zur<75>ck, wenn Key nicht vorhanden ist.
//
// pre: -
// post: Objekt ist nicht mehr enthalten; m_lElem dekrementiert
// Wenn die HashTable der Owner ist, wurde das Object gel<65>scht
{
HashItem *pItem = FindPos(Key);
if (pItem != NULL
&& pItem->GetKey() == Key)
{
void* pObject = pItem->GetObject();
if (m_bOwner)
OnDeleteObject(pObject);
pItem->Delete();
m_lElem--;
return pObject;
}
else
{
return NULL;
}
}
double HashTable::CalcLoadFactor() const
// prozentuale Belegung der Hashtabelle berechnen
{
return double(m_lElem) / double(m_lSize);
}
void HashTable::SmartGrow()
// Achtung: da die Objekte umkopiert werden, darf die OnDeleteObject-Methode
// nicht gerufen werden
{
double dLoadFactor = CalcLoadFactor();
if (dLoadFactor <= m_dMaxLoadFactor)
return; // nothing to grow
ULONG lOldSize = m_lSize; // alte Daten sichern
HashItem* pOldData = m_pData;
m_lSize = ULONG (m_dGrowFactor * m_lSize); // neue Gr<47><72>e
m_pData = new HashItem[m_lSize]; // neue Daten holen
// kein Speicher:
// Zustand "Tabelle voll" wird in Insert abgefangen
//
if (m_pData == NULL)
{
m_lSize = lOldSize;
m_pData = pOldData;
return;
}
m_lElem = 0; // noch keine neuen Daten
// Umkopieren der Daten
//
for (ULONG i=0; i<lOldSize; i++)
{
HashItem *pItem = &pOldData[i];
if (pItem->IsUsed())
Insert(pItem->GetKey(),pItem->GetObject());
}
delete [] pOldData;
}
// Iterator ---------------------------------------------------------
//
HashTableIterator::HashTableIterator(HashTable const& aTable)
: m_aTable(aTable)
{
m_lAt = 0;
}
void* HashTableIterator::GetFirst()
{
m_lAt = 0;
return FindValidObject(TRUE /* forward */);
}
void* HashTableIterator::GetLast()
{
m_lAt = m_aTable.GetSize() -1;
return FindValidObject(FALSE /* backward */);
}
void* HashTableIterator::GetNext()
{
if (m_lAt+1 >= m_aTable.GetSize())
return NULL;
m_lAt++;
return FindValidObject(TRUE /* forward */);
}
void* HashTableIterator::GetPrev()
{
if (m_lAt <= 0)
return NULL;
m_lAt--;
return FindValidObject(FALSE /* backward */);
}
void* HashTableIterator::FindValidObject(BOOL bForward)
// Sucht nach einem vorhandenen Objekt ab der aktuellen
// Position.
//
// pre: ab inkl. m_lAt soll die Suche beginnen
// post: if not found then
// if bForward == TRUE then
// m_lAt == m_aTable.GetSize() -1
// else
// m_lAt == 0
// else
// m_lAt ist die gefundene Position
{
void *pObject = m_aTable.GetObjectAt(m_lAt);
if (pObject != NULL)
return pObject;
while (pObject == NULL
&& (bForward ? ((m_lAt+1) < m_aTable.GetSize())
: m_lAt > 0))
{
if (bForward)
m_lAt++;
else
m_lAt--;
pObject = m_aTable.GetObjectAt(m_lAt);
}
#ifdef DBG_UTIL
if (pObject == NULL)
{
DBG_ASSERT(bForward ? m_lAt == m_aTable.GetSize() -1 : m_lAt == 0,
"HashTableIterator::FindValidObject()");
}
#endif
return pObject;
}