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/*-
* Copyright (c) 2004 - 2011 CTPP Team
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the CTPP Team nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* CTPP2HashTable.cpp
*
* $CTPP$
*/
#include "CTPP2HashTable.hpp"
#include <stdio.h>
namespace CTPP // C++ Template Engine
{
//
// hash function
//
UINT_64 HashFunc(CCHAR_P sKey,
const UINT_32 iLength)
{
UINT_64 ulHash = 5381;
UCCHAR_P sEnd = (UCCHAR_P)sKey + iLength;
while ((UCCHAR_P)sKey != sEnd)
{
ulHash += (ulHash << 5);
ulHash ^= (UINT_64) *(UCCHAR_P)sKey++;
}
return ulHash;
}
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Class ReducedHashTable
//
//
// Constructor
//
ReducedHashTable::ReducedHashTable(const HashElement * aIElements,
const UINT_32 iIPower): aElements(aIElements),
iPower(iIPower)
{
iBase = (1 << iPower) - 1;
}
//
// Get value from hash
//
UINT_64 ReducedHashTable::Get(CCHAR_P szKey,
const UINT_32 iKeyLength) const
{
// 1. Calculate hash
const UINT_64 iHash = HashFunc(szKey, iKeyLength);
// 2. Get position in array
const UINT_64 iPos = iHash & iBase;
// 3. Check hash value
const HashElement & oElement = aElements[iPos];
// Mistake?
if (iHash != oElement.hash) { return (UINT_64)-1; }
return oElement.value;
}
//
// Get hash size
//
UINT_64 ReducedHashTable::Size() const { return UINT_64(1 << iPower); }
//
// A destructor
//
ReducedHashTable::~ReducedHashTable() throw() { ;; }
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Class HashTable
//
//
// Constructor
//
HashTable::HashTable(): iPower(1)
{
const UINT_32 iNewElements = 1 << iPower;
aElements = new HashElement[iNewElements];
iBase = iNewElements - 1;
iUsed = 0;
UINT_32 iPos = 0;
for(; iPos < iNewElements; ++iPos)
{
HashElement & oNewElement = aElements[iPos];
oNewElement.hash = (UINT_64)-1;
oNewElement.value = (UINT_64)-1;
}
}
//
// Get value from hash
//
INT_64 HashTable::Get(CCHAR_P szKey,
const UINT_32 iKeyLength) const
{
// 1. Calculate hash
const UINT_64 iHash = HashFunc(szKey, iKeyLength);
// 2. Get position in array
const UINT_64 iPos = iHash & iBase;
// 3. Check hash value
const HashElement & oElement = aElements[iPos];
// Mistake?
if (iHash != oElement.hash) { return -1; }
return oElement.value;
}
//
// Get hash size
//
UINT_64 HashTable::Size() const { return UINT_64(1 << iPower); }
//
// Put value into hash
//
UINT_32 HashTable::Put(CCHAR_P szKey,
const UINT_32 iKeyLength,
const UINT_64 iValue)
{
// 1. Calculate hash
const UINT_64 iHash = HashFunc(szKey, iKeyLength);
for (;;)
{
// 2. Get position in array
const UINT_64 iPos = iHash & iBase;
// 3. Check hash value
HashElement & oElement = aElements[iPos];
// Duplicate!
if (oElement.hash == iHash) { return (UINT_32)-1; }
// Resize hash
if (oElement.value != (UINT_64)-1) { Resize(); }
else
{
++iUsed;
oElement.hash = iHash;
oElement.value = iValue;
return 0;
}
}
// Make compiler happy
return (UINT_32)-1;
}
//
// Resize hash
//
void HashTable::Resize()
{
const UINT_32 iOldElements = 1 << iPower;
++iPower;
const UINT_32 iNewElements = 1 << iPower;
// Create new array of elements
HashElement * aTMP = new HashElement[iNewElements];
iBase = iNewElements - 1;
UINT_32 iPos = 0;
for(; iPos < iNewElements; ++iPos)
{
HashElement & oNewElement = aTMP[iPos];
oNewElement.hash = (UINT_64)-1;
oNewElement.value = (UINT_64)-1;
}
for(iPos = 0; iPos < iOldElements; ++iPos)
{
// Element in old array
const HashElement & oOldElement = aElements[iPos];
if (oOldElement.hash != (UINT_64)-1)
{
// Get new position in array
const UINT_64 iNewPos = oOldElement.hash & iBase;
HashElement & oNewElement = aTMP[iNewPos];
oNewElement.hash = oOldElement.hash;
oNewElement.value = oOldElement.value;
}
}
delete [] aElements;
aElements = aTMP;
}
//
// A destructor
//
HashTable::~HashTable() throw()
{
delete [] aElements;
}
} // namespace CTPP
// End.
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