#include "stdafx.h"

#include <string.h>
#include "MemoryUtils.h"
#include "NameToCharCode.h"

//------------------------------------------------------------------------

struct NameToCharCodeEntry 
{
	char    *sName;
	CharCode nCode;
};

//------------------------------------------------------------------------

NameToCharCode::NameToCharCode() 
{
	m_nSize = 31;
	m_nLen = 0;
	m_pTable = (NameToCharCodeEntry *)MemUtilsMallocArray( m_nSize, sizeof(NameToCharCodeEntry));

	for ( int nIndex = 0; nIndex < m_nSize; ++nIndex ) 
	{
		m_pTable[nIndex].sName = NULL;
	}
}

NameToCharCode::~NameToCharCode() 
{
	for ( int nIndex = 0; nIndex < m_nSize; ++nIndex ) 
	{
		if ( m_pTable[nIndex].sName ) 
		{
			MemUtilsFree( m_pTable[nIndex].sName );
		}
	}
	MemUtilsFree( m_pTable );
}

void NameToCharCode::Add(char *sName, CharCode nCode) 
{
	// Увеличиваем таблицу, в случае необходимости
	if ( m_nLen >= m_nSize / 2 ) 
	{
		int nOldSize = m_nSize;
		NameToCharCodeEntry *pOldTable = m_pTable;
		m_nSize = 2 * m_nSize + 1;
		m_pTable = (NameToCharCodeEntry *)MemUtilsMallocArray( m_nSize, sizeof(NameToCharCodeEntry) );
		for ( int nIndex = 0; nIndex < m_nSize; ++nIndex ) 
		{
			m_pTable[nIndex].sName = NULL;
		}
		for ( int nIndex = 0; nIndex < nOldSize; ++nIndex ) 
		{
			if ( pOldTable[nIndex].sName ) 
			{
				int nHash = Hash( pOldTable[nIndex].sName );
				while ( m_pTable[nHash].sName ) 
				{
					if ( ++nHash == m_nSize ) 
					{
						nHash = 0;
					}
				}
				m_pTable[nHash] = pOldTable[nIndex];
			}
		}
		MemUtilsFree( pOldTable );
	}

	// Добавляем новое имя
	int nHash = Hash( sName );
	while ( m_pTable[nHash].sName && strcmp( m_pTable[nHash].sName, sName) ) 
	{
		if (++nHash == m_nSize) 
		{
			nHash = 0;
		}
	}
	if ( !m_pTable[nHash].sName ) 
	{
		m_pTable[nHash].sName = CopyString( sName );
	}
	m_pTable[nHash].nCode = nCode;

	++m_nLen;
}

CharCode NameToCharCode::Lookup(char *sName) 
{
	int nHash = Hash(sName);
	while ( m_pTable[nHash].sName ) 
	{
		if ( !strcmp( m_pTable[nHash].sName, sName ) ) 
		{
			return m_pTable[nHash].nCode;
		}
		if ( ++nHash == m_nSize ) 
		{
			nHash = 0;
		}
	}
	return 0;
}

int NameToCharCode::Hash(char *sName) 
{
	char *pCur;
	unsigned int unHash = 0;
	for ( pCur = sName; *pCur; ++pCur ) 
	{
		unHash = 17 * unHash + (int)(*pCur & 0xff);
	}
	return (int)(unHash % m_nSize);
}