461 lines
11 KiB
C++
461 lines
11 KiB
C++
/*************************************************************************
|
||
*
|
||
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
||
*
|
||
* Copyright 2008 by Sun Microsystems, Inc.
|
||
*
|
||
* OpenOffice.org - a multi-platform office productivity suite
|
||
*
|
||
* $RCSfile: hashtbl.cxx,v $
|
||
* $Revision: 1.7 $
|
||
*
|
||
* This file is part of OpenOffice.org.
|
||
*
|
||
* OpenOffice.org is free software: you can redistribute it and/or modify
|
||
* it under the terms of the GNU Lesser General Public License version 3
|
||
* only, as published by the Free Software Foundation.
|
||
*
|
||
* OpenOffice.org is distributed in the hope that it will be useful,
|
||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
* GNU Lesser General Public License version 3 for more details
|
||
* (a copy is included in the LICENSE file that accompanied this code).
|
||
*
|
||
* You should have received a copy of the GNU Lesser General Public License
|
||
* version 3 along with OpenOffice.org. If not, see
|
||
* <http://www.openoffice.org/license.html>
|
||
* for a copy of the LGPLv3 License.
|
||
*
|
||
************************************************************************/
|
||
|
||
// MARKER(update_precomp.py): autogen include statement, do not remove
|
||
#include "precompiled_soltools.hxx"
|
||
|
||
#include "hashtbl.hxx"
|
||
#include <string.h>
|
||
|
||
// -------------------------------------------------------------
|
||
// class HashItem
|
||
//
|
||
class HashItem
|
||
{
|
||
enum ETag { TAG_EMPTY, TAG_USED, TAG_DELETED };
|
||
|
||
void* m_pObject;
|
||
ETag m_Tag;
|
||
char* m_Key;
|
||
|
||
public:
|
||
HashItem() { m_Tag = TAG_EMPTY; m_Key = NULL; m_pObject = NULL; }
|
||
~HashItem() { delete [] m_Key; }
|
||
|
||
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; delete [] m_Key; m_Key = new char[ 1 ]; m_Key[ 0 ] = 0; m_pObject = NULL; }
|
||
|
||
const char *GetKey() const
|
||
{ return m_Key; }
|
||
|
||
void* GetObject() const
|
||
{ return m_pObject; }
|
||
|
||
void SetObject(const char * Key, void *pObject)
|
||
{ m_Tag = TAG_USED; delete [] m_Key; m_Key = new char[ strlen( Key ) + 1 ]; strcpy( 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 = 0.5;
|
||
/*static*/ double HashTable::m_defDefGrowFactor = 2.0;
|
||
|
||
HashTable::HashTable(unsigned long 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(2.0,MIN(5.0,dGrowFactor)); // 1.3 ... 5.0
|
||
m_pData = new HashItem [lSize];
|
||
}
|
||
|
||
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(unsigned long lPos) const
|
||
// Gibt Objekt zur<75>ck, wenn es eines gibt, sonst NULL;
|
||
{
|
||
HashItem *pItem = &m_pData[lPos];
|
||
|
||
return pItem->IsUsed() ? pItem->GetObject() : NULL;
|
||
}
|
||
|
||
void HashTable::OnDeleteObject(void*)
|
||
{
|
||
}
|
||
|
||
unsigned long HashTable::Hash(const char *Key) const
|
||
{
|
||
// Hashfunktion von P.J. Weinberger
|
||
// aus dem "Drachenbuch" von Aho/Sethi/Ullman
|
||
unsigned long i,n;
|
||
unsigned long h = 0;
|
||
unsigned long g = 0;
|
||
|
||
for (i=0,n=strlen( Key ); i<n; i++)
|
||
{
|
||
h = (h<<4) + (unsigned long)(unsigned short)Key[i];
|
||
g = h & 0xf0000000;
|
||
|
||
if (g != 0)
|
||
{
|
||
h = h ^ (g >> 24);
|
||
h = h ^ g;
|
||
}
|
||
}
|
||
|
||
return h % m_lSize;
|
||
}
|
||
|
||
unsigned long HashTable::DHash(const char* Key, unsigned long lOldHash) const
|
||
{
|
||
unsigned long lHash = lOldHash;
|
||
unsigned long i,n;
|
||
|
||
for (i=0,n=strlen( Key ); i<n; i++)
|
||
{
|
||
lHash *= 256L;
|
||
lHash += (unsigned long)(unsigned short)Key[i];
|
||
lHash %= m_lSize;
|
||
}
|
||
return lHash;
|
||
}
|
||
|
||
unsigned long HashTable::Probe(unsigned long 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(const char * 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())
|
||
{
|
||
return false;
|
||
}
|
||
|
||
if (FindPos(Key) != NULL )
|
||
return false;
|
||
|
||
unsigned long lPos = Hash(Key);
|
||
HashItem *pItem = &m_pData[lPos];
|
||
|
||
// first hashing
|
||
//
|
||
if (pItem->IsEmpty())
|
||
{
|
||
pItem->SetObject(Key, pObject);
|
||
m_lElem++;
|
||
|
||
return true;
|
||
}
|
||
|
||
// double hashing
|
||
//
|
||
lPos = DHash(Key,lPos);
|
||
pItem = &m_pData[lPos];
|
||
|
||
if (pItem->IsEmpty())
|
||
{
|
||
pItem->SetObject(Key, pObject);
|
||
m_lElem++;
|
||
|
||
return true;
|
||
}
|
||
|
||
// linear probing
|
||
//
|
||
do
|
||
{
|
||
lPos = Probe(lPos);
|
||
pItem = &m_pData[lPos];
|
||
}
|
||
while(!pItem->IsEmpty());
|
||
|
||
pItem->SetObject(Key, pObject);
|
||
m_lElem++;
|
||
return true;
|
||
}
|
||
|
||
HashItem* HashTable::FindPos(const char * Key) const
|
||
// sucht den Key; gibt Refrenz auf den Eintrag (gefunden)
|
||
// oder NULL (nicht gefunden) zur<75>ck
|
||
//
|
||
// pre: -
|
||
// post: -
|
||
{
|
||
// first hashing
|
||
//
|
||
unsigned long lPos = Hash(Key);
|
||
HashItem *pItem = &m_pData[lPos];
|
||
|
||
if (pItem->IsUsed()
|
||
&& !(strcmp( pItem->GetKey(), Key )))
|
||
{
|
||
return pItem;
|
||
}
|
||
|
||
// double hashing
|
||
//
|
||
if (pItem->IsDeleted() || pItem->IsUsed())
|
||
{
|
||
lPos = DHash(Key,lPos);
|
||
pItem = &m_pData[lPos];
|
||
|
||
if (pItem->IsUsed()
|
||
&& (!strcmp( pItem->GetKey(), Key)))
|
||
{
|
||
return pItem;
|
||
}
|
||
|
||
// linear probing
|
||
//
|
||
if (pItem->IsDeleted() || pItem->IsUsed())
|
||
{
|
||
unsigned long n = 0;
|
||
bool bFound = false;
|
||
bool bEnd = false;
|
||
|
||
do
|
||
{
|
||
n++;
|
||
lPos = Probe(lPos);
|
||
pItem = &m_pData[lPos];
|
||
|
||
bFound = pItem->IsUsed()
|
||
&& !( strcmp( pItem->GetKey(), Key ));
|
||
|
||
bEnd = !(n<m_lSize || pItem->IsFree());
|
||
}
|
||
while(!bFound && !bEnd);
|
||
|
||
return bFound ? pItem : NULL;
|
||
}
|
||
}
|
||
|
||
// nicht gefunden
|
||
//
|
||
return NULL;
|
||
}
|
||
|
||
void* HashTable::Find(const char *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
|
||
&& ( !strcmp( pItem->GetKey(), Key )))
|
||
return pItem->GetObject();
|
||
else
|
||
return NULL;
|
||
}
|
||
|
||
void* HashTable::Delete( const char * 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
|
||
&& ( !strcmp( 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
|
||
|
||
unsigned long lOldSize = m_lSize; // alte Daten sichern
|
||
HashItem* pOldData = m_pData;
|
||
|
||
m_lSize = (unsigned long) (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 (unsigned long 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);
|
||
}
|
||
|
||
return pObject;
|
||
}
|