From f4c20290509d7ed3a8fd5304577e7a4cc0b9d974 Mon Sep 17 00:00:00 2001 From: Mike Buland Date: Tue, 3 Apr 2007 03:49:53 +0000 Subject: Ok, no code is left in src, it's all in src/old. We'll gradually move code back into src as it's fixed and re-org'd. This includes tests, which, I may write a unit test system into libbu++ just to make my life easier. --- src/old/hashtable.cpp | 424 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 424 insertions(+) create mode 100644 src/old/hashtable.cpp (limited to 'src/old/hashtable.cpp') diff --git a/src/old/hashtable.cpp b/src/old/hashtable.cpp new file mode 100644 index 0000000..dbcd964 --- /dev/null +++ b/src/old/hashtable.cpp @@ -0,0 +1,424 @@ +#include +#include +#include + +#include "hashtable.h" + +HashTable::HashTable( HashFunction *hNewFunc, unsigned long int nInitSize, bool bAllowDupes ) +{ + hFunc = hNewFunc; + nTableSize = nextPrime( nInitSize ); + aTable = new HashNode[nTableSize]; + //for( int j = 0; j < nTableSize; j++ ) if( aTable[j].id || aTable[j].data || aTable[j].bDeleted ) printf("Unclean entry\n"); + nSize = 0; + nFilled = 0; + this->bAllowDupes = bAllowDupes; +} + +HashTable::~HashTable() +{ + delete[] aTable; + delete hFunc; +} + +void HashTable::set( int j, const void *newID, const void *newData ) +{ + if( newData == NULL ) + { + printf("Inserting NULL data is indestinguishable from uninserted data!\n"); + } + aTable[j].id = newID; + aTable[j].data = newData; +} + +void HashTable::clear() +{ + memset( aTable, 0, sizeof(HashNode) * nTableSize ); +} + +bool HashTable::isFilled( int j ) +{ + return (aTable[j].id != NULL)||(aTable[j].bDeleted); +} + +void HashTable::reHash( unsigned long int nNewSize ) +{ + HashNode *aOldTable = aTable; + unsigned long int oldSize = nTableSize; + + // If the table can still be used if we just get rid of deleted items, don't + // change the size of the table, otherwise, go ahead and use the number + // passed in. + if( nSize > nTableSize>>1 ) + { + nTableSize = nextPrime( nNewSize ); + } + + aTable = newTable( nTableSize ); + //for( int j = 0; j < nTableSize; j++ ) if( aTable[j].id || aTable[j].data || aTable[j].bDeleted ) printf("Unclean entry\n"); + + nSize = 0; + nFilled = 0; + + for( unsigned long int j = 0; j < oldSize; j++ ) + { + if( aOldTable[j].id != NULL && aOldTable[j].bDeleted == false ) + { + insert( aOldTable[j].id, aOldTable[j].data ); + } + } + + delete[] aOldTable; +} + +unsigned long int HashTable::probe( unsigned long int nStart, const void *id ) +{ + int nHash = nStart; + nStart = nStart%nTableSize; + if( bAllowDupes == true ) + { + for( + unsigned long int j=0; + isFilled( nStart ) && j < 32; + nStart = (nStart+(1<cmpIDs( aTable[nStart].id, id ) == true && + aTable[nStart].bDeleted == false ) + { + return nStart; + } + } + } + } + // This is our insurance, if the table is full, then go ahead and rehash, + // then try again. + if( isFilled( nStart ) ) + { + reHash( getCapacity()*2 ); + return probe( nHash, id ); + } + return nStart; +} + +HashTable::HashNode *HashTable::newTable( unsigned long int nNewSize ) +{ + return new HashNode[nNewSize]; +} + +#ifdef HASH_DEBUG_VIS +void HashTable::printDebugLine( const char *exData ) +{ + char *buf = new char[getCapacity()+3]; + int j; + buf[0] = '['; + for( j = 0; j < getCapacity(); j++ ) + { + buf[j+1] = (aTable[j].bDeleted)?('X'):((isFilled( j ))?('#'):('-')); + } + buf[j+1] = ']'; + buf[j+2] = '\0'; + printf("%s %s\n", buf, exData ); + delete[] buf; +} +#endif + +bool HashTable::insert( const void *id, const void *data ) +{ + unsigned long int nPos = probe( hFunc->hash( id ), id )%nTableSize; + + if( bAllowDupes == true ) + { + if( aTable[nPos].id == NULL && aTable[nPos].bDeleted == false ) + { + set( nPos, id, data ); +#ifdef HASH_DEBUG_VIS + printDebugLine( (const char *)id ); +#endif + nSize++; + nFilled++; + return true; + } + else + { + return false; + } + } + else + { + if( aTable[nPos].id == NULL && aTable[nPos].bDeleted == false ) + { + set( nPos, id, data ); +#ifdef HASH_DEBUG_VIS + printDebugLine( (const char *)id ); +#endif + nSize++; + nFilled++; + return true; + } + else if( hFunc->cmpIDs( aTable[nPos].id, id ) == true ) + { + set( nPos, id, data ); +#ifdef HASH_DEBUG_VIS + printDebugLine( (const char *)id ); +#endif + return true; + } + else + { + return false; + } + } +} + +const void *HashTable::get( const void *id, unsigned long int nSkip ) +{ + unsigned long int nPos = hFunc->hash( id )%nTableSize; + + for( unsigned long int j=0; j < 32; nPos = (nPos+(1<cmpIDs( id, aTable[nPos].id ) ) + { + if( nSkip == 0 ) + { + return aTable[nPos].data; + } + else + { + nSkip--; + } + } + } + } + + if( bAllowDupes ) + { + unsigned long int nOldPos = nPos; + for( nPos++; nPos != nOldPos; nPos=(nPos+1)%nTableSize ) + { + if( !isFilled( nPos ) ) return NULL; + if( aTable[nPos].bDeleted == false ) + { + if( hFunc->cmpIDs( id, aTable[nPos].id ) ) + { + if( nSkip == 0 ) + { + return aTable[nPos].data; + } + else + { + nSkip--; + } + } + } + } + } + + return NULL; +} + +const void *HashTable::getKey( const void *id, unsigned long int nSkip ) +{ + unsigned long int nPos = hFunc->hash( id )%nTableSize; + + for( unsigned long int j=0; j < 32; nPos = (nPos+(1<cmpIDs( id, aTable[nPos].id ) ) + { + if( nSkip == 0 ) + { + return aTable[nPos].id; + } + else + { + nSkip--; + } + } + } + } + + if( bAllowDupes ) + { + unsigned long int nOldPos = nPos; + for( nPos++; nPos != nOldPos; nPos=(nPos+1)%nTableSize ) + { + if( !isFilled( nPos ) ) return NULL; + if( aTable[nPos].bDeleted == false ) + { + if( hFunc->cmpIDs( id, aTable[nPos].id ) ) + { + if( nSkip == 0 ) + { + return aTable[nPos].id; + } + else + { + nSkip--; + } + } + } + } + } + + return NULL; +} + +void *HashTable::getFirstItemPos() +{ + HashPos *pos = new HashPos; + return pos; +} + +const void *HashTable::getItemData( void *xPos ) +{ + return aTable[((HashPos *)xPos)->nPos].data; +} + +const void *HashTable::getItemID( void *xPos ) +{ + return aTable[((HashPos *)xPos)->nPos].id; +} + +void *HashTable::getNextItemPos( void *xPos ) +{ + HashPos *pos = (HashPos *)xPos; + if( pos->bStarted == false ) + { + pos->bStarted = true; + pos->nPos = 0; + } + else + { + pos->nPos++; + } + if( pos->nPos < nTableSize ) + { + for( ; pos->nPos < nTableSize; pos->nPos++ ) + { + if( isFilled( pos->nPos ) && + aTable[pos->nPos].bDeleted == false ) + { + return xPos; + } + } + } + + delete pos; + + return NULL; +} + +// Big-O sqrt(n) +// Change this to be erethpothynies table with a storage +// lookup later on. +bool HashTable::isPrime (int num) +{ + if (num == 2) // the only even prime + return true; + else if (num % 2 == 0) // other even numbers are composite + return false; + else + { + //bool prime = true; + int divisor = 3; + int upperLimit = static_cast(sqrt(num) + 1); + while (divisor <= upperLimit) + { + if (num % divisor == 0) + return false; + // prime = false; + divisor +=2; + } + return true; + } +} + +// Big-O n^(3/2) +int HashTable::nextPrime( int base ) +{ + int nPrime; + for( nPrime = base; isPrime( nPrime ) == false; nPrime++ ); + return nPrime; +} + +unsigned long int HashTable::getCapacity() +{ + return nTableSize; +} + +unsigned long int HashTable::getSize() +{ + return nSize; +} + +double HashTable::getLoad() +{ + return (double)(nFilled)/(double)(nTableSize); +} + +const void *HashTable::operator[](const void *id) +{ + return get( id ); +} + +bool HashTable::del( const void *id, int nSkip ) +{ + unsigned long int nPos = hFunc->hash( id )%nTableSize; + + for( unsigned long int j=0; j < 32; nPos = (nPos+(1<cmpIDs( id, aTable[nPos].id ) && + aTable[nPos].bDeleted == false ) + { + if( nSkip == 0 ) + { + aTable[nPos].bDeleted = true; + nSize--; +#ifdef HASH_DEBUG_VIS + printDebugLine( (const char *)id ); +#endif + return true; + } + else + { + nSkip--; + } + } + } + + return false; +} + -- cgit v1.2.3