[public/netxms.git] / src / db / libnxdb / drivers.cpp

/*
** NetXMS - Network Management System
** Copyright (C) 2003-2014 Victor Kirhenshtein
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU Lesser General Public License as published by
** the Free Software Foundation; either version 3 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU Lesser General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** File: drivers.cpp
**
**/

#include "libnxdb.h"

/**
 * Log message codes
 */
UINT32 g_logMsgCode = 0;
UINT32 g_sqlErrorMsgCode = 0;

/**
 * Long-running query threshold
 */
UINT32 g_sqlQueryExecTimeThreshold = 0xFFFFFFFF;

/**
 * Loaded drivers
 */
static DB_DRIVER s_drivers[MAX_DB_DRIVERS];
static MUTEX s_driverListLock;

/**
 * Options
 */
static bool s_writeLog = false;
static bool s_logSqlErrors = false;

/**
 * Get symbol address and log errors
 */
static void *DLGetSymbolAddrEx(HMODULE hModule, const char *pszSymbol, bool mandatory = true)
{
   void *pFunc;
   TCHAR szErrorText[256];

   pFunc = DLGetSymbolAddr(hModule, pszSymbol, szErrorText);
   if ((pFunc == NULL) && mandatory && s_writeLog)
      __DBWriteLog(EVENTLOG_WARNING_TYPE, _T("Unable to resolve symbol \"%hs\": %s"), pszSymbol, szErrorText);
   return pFunc;
}

/**
 * Init DB library
 */
bool LIBNXDB_EXPORTABLE DBInit(DWORD logMsgCode, DWORD sqlErrorMsgCode)
{
	memset(s_drivers, 0, sizeof(s_drivers));
	s_driverListLock = MutexCreate();

	g_logMsgCode = logMsgCode;
   s_writeLog = (logMsgCode > 0);
	g_sqlErrorMsgCode = sqlErrorMsgCode;
   s_logSqlErrors = (sqlErrorMsgCode > 0) && s_writeLog;

	return true;
}

/**
 * Load and initialize database driver
 * If logMsgCode == 0, logging will be disabled
 * If sqlErrorMsgCode == 0, failed SQL queries will not be logged
 *
 * @return driver handle on success, NULL on failure
 */
DB_DRIVER LIBNXDB_EXPORTABLE DBLoadDriver(const TCHAR *module, const TCHAR *initParameters,
														bool dumpSQL, void (* fpEventHandler)(DWORD, const WCHAR *, const WCHAR *, bool, void *),
														void *userArg)
{
   static DWORD dwVersionZero = 0;
   bool (* fpDrvInit)(const char *);
   DWORD *pdwAPIVersion;
   TCHAR szErrorText[256];
	const char *driverName;
	DB_DRIVER driver;
	bool alreadyLoaded = false;
	int position = -1;
   int i; // have to define it here because otherwise HP aCC complains at goto statements

	MutexLock(s_driverListLock);

	driver = (DB_DRIVER)malloc(sizeof(db_driver_t));
	memset(driver, 0, sizeof(db_driver_t));

	driver->m_logSqlErrors = s_logSqlErrors;
   driver->m_dumpSql = dumpSQL;
   driver->m_fpEventHandler = fpEventHandler;
	driver->m_userArg = userArg;

   // Load driver's module
#ifdef _WIN32
   driver->m_handle = DLOpen(module, szErrorText);
#else
	TCHAR fullName[MAX_PATH];
	if (_tcschr(module, _T('/')) == NULL)
	{
      const TCHAR *homeDir = _tgetenv(_T("NETXMS_HOME"));
      if ((homeDir != NULL) && (*homeDir != 0))
      {
         _sntprintf(fullName, MAX_PATH, _T("%s/lib/netxms/dbdrv/%s"), homeDir, module);
      }
      else
      {
		   _sntprintf(fullName, MAX_PATH, _T("%s/dbdrv/%s"), PKGLIBDIR, module);
      }
	}
	else
	{
		nx_strncpy(fullName, module, MAX_PATH);
	}
   driver->m_handle = DLOpen(fullName, szErrorText);
#endif
   if (driver->m_handle == NULL)
   {
      if (s_writeLog)
         __DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Unable to load database driver module \"%s\": %s"), module, szErrorText);
		goto failure;
   }

   // Check API version supported by driver
   pdwAPIVersion = (DWORD *)DLGetSymbolAddr(driver->m_handle, "drvAPIVersion", NULL);
   if (pdwAPIVersion == NULL)
      pdwAPIVersion = &dwVersionZero;
   if (*pdwAPIVersion != DBDRV_API_VERSION)
   {
      if (s_writeLog)
         __DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Database driver \"%s\" cannot be loaded because of API version mismatch (server: %d; driver: %d)"),
                  module, (int)(DBDRV_API_VERSION), (int)(*pdwAPIVersion));
		goto failure;
   }

	// Check name
	driverName = *((const char **)DLGetSymbolAddr(driver->m_handle, "drvName", NULL));
	if (driverName == NULL)
	{
		if (s_writeLog)
			__DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Unable to find all required entry points in database driver \"%s\""), module);
		goto failure;
	}

	for(i = 0; i < MAX_DB_DRIVERS; i++)
	{
		if ((s_drivers[i] != NULL) && (!stricmp(s_drivers[i]->m_name, driverName)))
		{
			alreadyLoaded = true;
			position = i;
			break;
		}
		if (s_drivers[i] == NULL)
			position = i;
	}

	if (alreadyLoaded)
	{
      if (s_writeLog)
			__DBWriteLog(EVENTLOG_INFORMATION_TYPE, _T("Reusing already loaded database driver \"%hs\""), s_drivers[position]->m_name);
		goto reuse_driver;
	}

	if (position == -1)
	{
      if (s_writeLog)
			__DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Unable to load database driver \"%s\": too many drivers already loaded"), module);
		goto failure;
	}

   // Import symbols
   fpDrvInit = (bool (*)(const char *))DLGetSymbolAddrEx(driver->m_handle, "DrvInit");
   driver->m_fpDrvConnect = (DBDRV_CONNECTION (*)(const char *, const char *, const char *, const char *, const char *, WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvConnect");
   driver->m_fpDrvDisconnect = (void (*)(DBDRV_CONNECTION))DLGetSymbolAddrEx(driver->m_handle, "DrvDisconnect");
   driver->m_fpDrvSetPrefetchLimit = (bool (*)(DBDRV_CONNECTION, int))DLGetSymbolAddrEx(driver->m_handle, "DrvSetPrefetchLimit", false);
	driver->m_fpDrvPrepare = (DBDRV_STATEMENT (*)(DBDRV_CONNECTION, const WCHAR *, DWORD *, WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvPrepare");
	driver->m_fpDrvFreeStatement = (void (*)(DBDRV_STATEMENT))DLGetSymbolAddrEx(driver->m_handle, "DrvFreeStatement");
	driver->m_fpDrvOpenBatch = (bool (*)(DBDRV_STATEMENT))DLGetSymbolAddrEx(driver->m_handle, "DrvOpenBatch", false);
	driver->m_fpDrvNextBatchRow = (void (*)(DBDRV_STATEMENT))DLGetSymbolAddrEx(driver->m_handle, "DrvNextBatchRow", false);
	driver->m_fpDrvBind = (void (*)(DBDRV_STATEMENT, int, int, int, void *, int))DLGetSymbolAddrEx(driver->m_handle, "DrvBind");
	driver->m_fpDrvExecute = (DWORD (*)(DBDRV_CONNECTION, DBDRV_STATEMENT, WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvExecute");
   driver->m_fpDrvQuery = (DWORD (*)(DBDRV_CONNECTION, const WCHAR *, WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvQuery");
   driver->m_fpDrvSelect = (DBDRV_RESULT (*)(DBDRV_CONNECTION, const WCHAR *, DWORD *, WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvSelect");
   driver->m_fpDrvSelectUnbuffered = (DBDRV_UNBUFFERED_RESULT (*)(DBDRV_CONNECTION, const WCHAR *, DWORD *, WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvSelectUnbuffered");
	driver->m_fpDrvSelectPrepared = (DBDRV_RESULT (*)(DBDRV_CONNECTION, DBDRV_STATEMENT, DWORD *, WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvSelectPrepared");
   driver->m_fpDrvSelectPreparedUnbuffered = (DBDRV_UNBUFFERED_RESULT (*)(DBDRV_CONNECTION, DBDRV_STATEMENT, DWORD *, WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvSelectPreparedUnbuffered");
   driver->m_fpDrvFetch = (bool (*)(DBDRV_UNBUFFERED_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvFetch");
   driver->m_fpDrvGetFieldLength = (LONG (*)(DBDRV_RESULT, int, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldLength");
   driver->m_fpDrvGetFieldLengthUnbuffered = (LONG (*)(DBDRV_UNBUFFERED_RESULT, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldLengthUnbuffered");
   driver->m_fpDrvGetField = (WCHAR* (*)(DBDRV_RESULT, int, int, WCHAR *, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetField");
   driver->m_fpDrvGetFieldUTF8 = (char* (*)(DBDRV_RESULT, int, int, char *, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldUTF8", false); // optional entry point
   driver->m_fpDrvGetFieldUnbuffered = (WCHAR* (*)(DBDRV_UNBUFFERED_RESULT, int, WCHAR *, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldUnbuffered");
   driver->m_fpDrvGetFieldUnbufferedUTF8 = (char* (*)(DBDRV_UNBUFFERED_RESULT, int, char *, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldUnbufferedUTF8");
   driver->m_fpDrvGetNumRows = (int (*)(DBDRV_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvGetNumRows");
   driver->m_fpDrvGetColumnCount = (int (*)(DBDRV_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvGetColumnCount");
   driver->m_fpDrvGetColumnName = (const char* (*)(DBDRV_RESULT, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetColumnName");
   driver->m_fpDrvGetColumnCountUnbuffered = (int (*)(DBDRV_UNBUFFERED_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvGetColumnCountUnbuffered");
   driver->m_fpDrvGetColumnNameUnbuffered = (const char* (*)(DBDRV_UNBUFFERED_RESULT, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetColumnNameUnbuffered");
   driver->m_fpDrvFreeResult = (void (*)(DBDRV_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvFreeResult");
   driver->m_fpDrvFreeUnbufferedResult = (void (*)(DBDRV_UNBUFFERED_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvFreeUnbufferedResult");
   driver->m_fpDrvBegin = (DWORD (*)(DBDRV_CONNECTION))DLGetSymbolAddrEx(driver->m_handle, "DrvBegin");
   driver->m_fpDrvCommit = (DWORD (*)(DBDRV_CONNECTION))DLGetSymbolAddrEx(driver->m_handle, "DrvCommit");
   driver->m_fpDrvRollback = (DWORD (*)(DBDRV_CONNECTION))DLGetSymbolAddrEx(driver->m_handle, "DrvRollback");
   driver->m_fpDrvUnload = (void (*)(void))DLGetSymbolAddrEx(driver->m_handle, "DrvUnload");
   driver->m_fpDrvPrepareStringA = (char* (*)(const char *))DLGetSymbolAddrEx(driver->m_handle, "DrvPrepareStringA");
   driver->m_fpDrvPrepareStringW = (WCHAR* (*)(const WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvPrepareStringW");
   driver->m_fpDrvIsTableExist = (int (*)(DBDRV_CONNECTION, const WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvIsTableExist");
   if ((fpDrvInit == NULL) || (driver->m_fpDrvConnect == NULL) || (driver->m_fpDrvDisconnect == NULL) ||
	    (driver->m_fpDrvPrepare == NULL) || (driver->m_fpDrvBind == NULL) || (driver->m_fpDrvFreeStatement == NULL) ||
       (driver->m_fpDrvQuery == NULL) || (driver->m_fpDrvSelect == NULL) || (driver->m_fpDrvGetField == NULL) ||
       (driver->m_fpDrvGetNumRows == NULL) || (driver->m_fpDrvFreeResult == NULL) || (driver->m_fpDrvSelectPrepared == NULL) ||
       (driver->m_fpDrvSelectPreparedUnbuffered == NULL) || (driver->m_fpDrvUnload == NULL) ||
       (driver->m_fpDrvSelectUnbuffered == NULL) || (driver->m_fpDrvFetch == NULL) ||
       (driver->m_fpDrvFreeUnbufferedResult == NULL) || (driver->m_fpDrvGetFieldUnbuffered == NULL) ||
       (driver->m_fpDrvBegin == NULL) || (driver->m_fpDrvCommit == NULL) || (driver->m_fpDrvRollback == NULL) ||
		 (driver->m_fpDrvGetColumnCount == NULL) || (driver->m_fpDrvGetColumnName == NULL) ||
		 (driver->m_fpDrvGetColumnCountUnbuffered == NULL) || (driver->m_fpDrvGetColumnNameUnbuffered == NULL) ||
       (driver->m_fpDrvGetFieldLength == NULL) || (driver->m_fpDrvGetFieldLengthUnbuffered == NULL) ||
		 (driver->m_fpDrvPrepareStringA == NULL) || (driver->m_fpDrvPrepareStringW == NULL) || (driver->m_fpDrvIsTableExist == NULL))
   {
      if (s_writeLog)
         __DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Unable to find all required entry points in database driver \"%s\""), module);
		goto failure;
   }

   // Initialize driver
#ifdef UNICODE
   char mbInitParameters[1024];
   if (initParameters != NULL)
   {
      WideCharToMultiByte(CP_ACP, WC_COMPOSITECHECK | WC_DEFAULTCHAR, initParameters, -1, mbInitParameters, 1024, NULL, NULL);
      mbInitParameters[1023] = 0;
   }
   else
   {
      mbInitParameters[0] = 0;
   }
   if (!fpDrvInit(mbInitParameters))
#else
   if (!fpDrvInit(CHECK_NULL_EX(initParameters)))
#endif
   {
      if (s_writeLog)
         __DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Database driver \"%s\" initialization failed"), module);
		goto failure;
   }

   // Success
   driver->m_mutexReconnect = MutexCreate();
	driver->m_name = driverName;
	driver->m_refCount = 1;
   driver->m_defaultPrefetchLimit = 10;
	s_drivers[position] = driver;
   if (s_writeLog)
      __DBWriteLog(EVENTLOG_INFORMATION_TYPE, _T("Database driver \"%s\" loaded and initialized successfully"), module);
	MutexUnlock(s_driverListLock);
   return driver;

failure:
	if (driver->m_handle != NULL)
		DLClose(driver->m_handle);
	free(driver);
	MutexUnlock(s_driverListLock);
	return NULL;

reuse_driver:
	if (driver->m_handle != NULL)
		DLClose(driver->m_handle);
	free(driver);
	s_drivers[position]->m_refCount++;
	MutexUnlock(s_driverListLock);
	return s_drivers[position];
}

/**
 * Unload driver
 */
void LIBNXDB_EXPORTABLE DBUnloadDriver(DB_DRIVER driver)
{
   if (driver == NULL)
      return;

	MutexLock(s_driverListLock);

	for(int i = 0; i < MAX_DB_DRIVERS; i++)
	{
		if (s_drivers[i] == driver)
		{
			driver->m_refCount--;
			if (driver->m_refCount <= 0)
			{
				driver->m_fpDrvUnload();
				DLClose(driver->m_handle);
				MutexDestroy(driver->m_mutexReconnect);
				free(driver);
				s_drivers[i] = NULL;
			}
			break;
		}
	}

	MutexUnlock(s_driverListLock);
}

/**
 * Get name of loaded driver
 */
const char LIBNXDB_EXPORTABLE *DBGetDriverName(DB_DRIVER driver)
{
	return driver->m_name;
}
Commit	Line	Data
80e96a82 VK	1	/*
80e96a82 VK	2	** NetXMS - Network Management System
43526096	3	** Copyright (C) 2003-2014 Victor Kirhenshtein
80e96a82 VK	4	**
	5	** This program is free software; you can redistribute it and/or modify
	6	** it under the terms of the GNU Lesser General Public License as published by
	7	** the Free Software Foundation; either version 3 of the License, or
	8	** (at your option) any later version.
	9	**
	10	** This program is distributed in the hope that it will be useful,
	11	** but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	** GNU General Public License for more details.
	14	**
	15	** You should have received a copy of the GNU Lesser General Public License
	16	** along with this program; if not, write to the Free Software
	17	** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	18	**
	19	** File: drivers.cpp
	20	**
	21	**/
	22
	23	#include "libnxdb.h"
	24
ef33dc5f VK	25	/**
	26	* Log message codes
	27	*/
58f1f627 VK	28	UINT32 g_logMsgCode = 0;
	29	UINT32 g_sqlErrorMsgCode = 0;
	30
	31	/**
	32	* Long-running query threshold
	33	*/
	34	UINT32 g_sqlQueryExecTimeThreshold = 0xFFFFFFFF;
80e96a82	35
ef33dc5f VK	36	/**
	37	* Loaded drivers
	38	*/
80e96a82 VK	39	static DB_DRIVER s_drivers[MAX_DB_DRIVERS];
80e96a82 VK	40	static MUTEX s_driverListLock;
ef33dc5f VK	41
	42	/**
	43	* Options
	44	*/
80e96a82 VK	45	static bool s_writeLog = false;
	46	static bool s_logSqlErrors = false;
	47
ef33dc5f VK	48	/**
	49	* Get symbol address and log errors
	50	*/
e2bb9f48	51	static void DLGetSymbolAddrEx(HMODULE hModule, const char pszSymbol, bool mandatory = true)
80e96a82 VK	52	{
	53	void *pFunc;
	54	TCHAR szErrorText[256];
	55
	56	pFunc = DLGetSymbolAddr(hModule, pszSymbol, szErrorText);
e2bb9f48	57	if ((pFunc == NULL) && mandatory && s_writeLog)
dda7c270	58	__DBWriteLog(EVENTLOG_WARNING_TYPE, _T("Unable to resolve symbol \"%hs\": %s"), pszSymbol, szErrorText);
80e96a82 VK	59	return pFunc;
	60	}
	61
ef33dc5f VK	62	/**
	63	* Init DB library
	64	*/
80e96a82 VK	65	bool LIBNXDB_EXPORTABLE DBInit(DWORD logMsgCode, DWORD sqlErrorMsgCode)
	66	{
	67	memset(s_drivers, 0, sizeof(s_drivers));
	68	s_driverListLock = MutexCreate();
	69
	70	g_logMsgCode = logMsgCode;
	71	s_writeLog = (logMsgCode > 0);
	72	g_sqlErrorMsgCode = sqlErrorMsgCode;
	73	s_logSqlErrors = (sqlErrorMsgCode > 0) && s_writeLog;
	74
	75	return true;
	76	}
	77
ef33dc5f VK	78	/**
	79	* Load and initialize database driver
	80	* If logMsgCode == 0, logging will be disabled
	81	* If sqlErrorMsgCode == 0, failed SQL queries will not be logged
	82	*
	83	* @return driver handle on success, NULL on failure
	84	*/
80e96a82	85	DB_DRIVER LIBNXDB_EXPORTABLE DBLoadDriver(const TCHAR module, const TCHAR initParameters,
526ae8b8	86	bool dumpSQL, void (* fpEventHandler)(DWORD, const WCHAR , const WCHAR , bool, void *),
80e96a82 VK	87	void *userArg)
	88	{
	89	static DWORD dwVersionZero = 0;
2df047f4	90	bool (* fpDrvInit)(const char *);
80e96a82 VK	91	DWORD *pdwAPIVersion;
	92	TCHAR szErrorText[256];
	93	const char *driverName;
	94	DB_DRIVER driver;
	95	bool alreadyLoaded = false;
	96	int position = -1;
ef33dc5f	97	int i; // have to define it here because otherwise HP aCC complains at goto statements
80e96a82	98
c17f6cbc	99	MutexLock(s_driverListLock);
80e96a82 VK	100
	101	driver = (DB_DRIVER)malloc(sizeof(db_driver_t));
	102	memset(driver, 0, sizeof(db_driver_t));
	103
	104	driver->m_logSqlErrors = s_logSqlErrors;
	105	driver->m_dumpSql = dumpSQL;
	106	driver->m_fpEventHandler = fpEventHandler;
	107	driver->m_userArg = userArg;
	108
	109	// Load driver's module
	110	#ifdef _WIN32
	111	driver->m_handle = DLOpen(module, szErrorText);
	112	#else
	113	TCHAR fullName[MAX_PATH];
	114	if (_tcschr(module, _T('/')) == NULL)
	115	{
38ffd4b0 VK	116	const TCHAR *homeDir = _tgetenv(_T("NETXMS_HOME"));
	117	if ((homeDir != NULL) && (*homeDir != 0))
	118	{
	119	_sntprintf(fullName, MAX_PATH, _T("%s/lib/netxms/dbdrv/%s"), homeDir, module);
	120	}
	121	else
	122	{
	123	_sntprintf(fullName, MAX_PATH, _T("%s/dbdrv/%s"), PKGLIBDIR, module);
	124	}
80e96a82 VK	125	}
	126	else
	127	{
	128	nx_strncpy(fullName, module, MAX_PATH);
	129	}
	130	driver->m_handle = DLOpen(fullName, szErrorText);
	131	#endif
	132	if (driver->m_handle == NULL)
	133	{
	134	if (s_writeLog)
	135	__DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Unable to load database driver module \"%s\": %s"), module, szErrorText);
	136	goto failure;
	137	}
	138
	139	// Check API version supported by driver
dda7c270	140	pdwAPIVersion = (DWORD *)DLGetSymbolAddr(driver->m_handle, "drvAPIVersion", NULL);
80e96a82 VK	141	if (pdwAPIVersion == NULL)
	142	pdwAPIVersion = &dwVersionZero;
	143	if (*pdwAPIVersion != DBDRV_API_VERSION)
	144	{
	145	if (s_writeLog)
6e3a99d7	146	__DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Database driver \"%s\" cannot be loaded because of API version mismatch (server: %d; driver: %d)"),
80e96a82 VK	147	module, (int)(DBDRV_API_VERSION), (int)(*pdwAPIVersion));
	148	goto failure;
	149	}
	150
	151	// Check name
dda7c270	152	driverName = ((const char *)DLGetSymbolAddr(driver->m_handle, "drvName", NULL));
80e96a82 VK	153	if (driverName == NULL)
	154	{
	155	if (s_writeLog)
	156	__DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Unable to find all required entry points in database driver \"%s\""), module);
	157	goto failure;
	158	}
	159
ef33dc5f	160	for(i = 0; i < MAX_DB_DRIVERS; i++)
80e96a82 VK	161	{
	162	if ((s_drivers[i] != NULL) && (!stricmp(s_drivers[i]->m_name, driverName)))
	163	{
	164	alreadyLoaded = true;
	165	position = i;
	166	break;
	167	}
	168	if (s_drivers[i] == NULL)
	169	position = i;
	170	}
	171
	172	if (alreadyLoaded)
	173	{
	174	if (s_writeLog)
9a222d39	175	__DBWriteLog(EVENTLOG_INFORMATION_TYPE, _T("Reusing already loaded database driver \"%hs\""), s_drivers[position]->m_name);
80e96a82 VK	176	goto reuse_driver;
	177	}
	178
	179	if (position == -1)
	180	{
	181	if (s_writeLog)
	182	__DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Unable to load database driver \"%s\": too many drivers already loaded"), module);
	183	goto failure;
	184	}
	185
	186	// Import symbols
2df047f4	187	fpDrvInit = (bool ()(const char ))DLGetSymbolAddrEx(driver->m_handle, "DrvInit");
dda7c270 VK	188	driver->m_fpDrvConnect = (DBDRV_CONNECTION ()(const char , const char , const char , const char , const char , WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvConnect");
dda7c270 VK	189	driver->m_fpDrvDisconnect = (void (*)(DBDRV_CONNECTION))DLGetSymbolAddrEx(driver->m_handle, "DrvDisconnect");
85dfb586	190	driver->m_fpDrvSetPrefetchLimit = (bool (*)(DBDRV_CONNECTION, int))DLGetSymbolAddrEx(driver->m_handle, "DrvSetPrefetchLimit", false);
dda7c270 VK	191	driver->m_fpDrvPrepare = (DBDRV_STATEMENT ()(DBDRV_CONNECTION, const WCHAR , DWORD , WCHAR ))DLGetSymbolAddrEx(driver->m_handle, "DrvPrepare");
dda7c270 VK	192	driver->m_fpDrvFreeStatement = (void (*)(DBDRV_STATEMENT))DLGetSymbolAddrEx(driver->m_handle, "DrvFreeStatement");
66c11d49 VK	193	driver->m_fpDrvOpenBatch = (bool (*)(DBDRV_STATEMENT))DLGetSymbolAddrEx(driver->m_handle, "DrvOpenBatch", false);
66c11d49 VK	194	driver->m_fpDrvNextBatchRow = (void (*)(DBDRV_STATEMENT))DLGetSymbolAddrEx(driver->m_handle, "DrvNextBatchRow", false);
dda7c270 VK	195	driver->m_fpDrvBind = (void ()(DBDRV_STATEMENT, int, int, int, void , int))DLGetSymbolAddrEx(driver->m_handle, "DrvBind");
	196	driver->m_fpDrvExecute = (DWORD ()(DBDRV_CONNECTION, DBDRV_STATEMENT, WCHAR ))DLGetSymbolAddrEx(driver->m_handle, "DrvExecute");
	197	driver->m_fpDrvQuery = (DWORD ()(DBDRV_CONNECTION, const WCHAR , WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvQuery");
	198	driver->m_fpDrvSelect = (DBDRV_RESULT ()(DBDRV_CONNECTION, const WCHAR , DWORD , WCHAR ))DLGetSymbolAddrEx(driver->m_handle, "DrvSelect");
f17cf019	199	driver->m_fpDrvSelectUnbuffered = (DBDRV_UNBUFFERED_RESULT ()(DBDRV_CONNECTION, const WCHAR , DWORD , WCHAR ))DLGetSymbolAddrEx(driver->m_handle, "DrvSelectUnbuffered");
dda7c270	200	driver->m_fpDrvSelectPrepared = (DBDRV_RESULT ()(DBDRV_CONNECTION, DBDRV_STATEMENT, DWORD , WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvSelectPrepared");
f17cf019 VK	201	driver->m_fpDrvSelectPreparedUnbuffered = (DBDRV_UNBUFFERED_RESULT ()(DBDRV_CONNECTION, DBDRV_STATEMENT, DWORD , WCHAR *))DLGetSymbolAddrEx(driver->m_handle, "DrvSelectPreparedUnbuffered");
f17cf019 VK	202	driver->m_fpDrvFetch = (bool (*)(DBDRV_UNBUFFERED_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvFetch");
dda7c270	203	driver->m_fpDrvGetFieldLength = (LONG (*)(DBDRV_RESULT, int, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldLength");
f17cf019	204	driver->m_fpDrvGetFieldLengthUnbuffered = (LONG (*)(DBDRV_UNBUFFERED_RESULT, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldLengthUnbuffered");
dda7c270	205	driver->m_fpDrvGetField = (WCHAR* ()(DBDRV_RESULT, int, int, WCHAR , int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetField");
e2bb9f48	206	driver->m_fpDrvGetFieldUTF8 = (char* ()(DBDRV_RESULT, int, int, char , int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldUTF8", false); // optional entry point
f17cf019	207	driver->m_fpDrvGetFieldUnbuffered = (WCHAR* ()(DBDRV_UNBUFFERED_RESULT, int, WCHAR , int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldUnbuffered");
7f8e3ccf	208	driver->m_fpDrvGetFieldUnbufferedUTF8 = (char* ()(DBDRV_UNBUFFERED_RESULT, int, char , int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetFieldUnbufferedUTF8");
dda7c270 VK	209	driver->m_fpDrvGetNumRows = (int (*)(DBDRV_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvGetNumRows");
	210	driver->m_fpDrvGetColumnCount = (int (*)(DBDRV_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvGetColumnCount");
	211	driver->m_fpDrvGetColumnName = (const char* (*)(DBDRV_RESULT, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetColumnName");
f17cf019 VK	212	driver->m_fpDrvGetColumnCountUnbuffered = (int (*)(DBDRV_UNBUFFERED_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvGetColumnCountUnbuffered");
f17cf019 VK	213	driver->m_fpDrvGetColumnNameUnbuffered = (const char* (*)(DBDRV_UNBUFFERED_RESULT, int))DLGetSymbolAddrEx(driver->m_handle, "DrvGetColumnNameUnbuffered");
dda7c270	214	driver->m_fpDrvFreeResult = (void (*)(DBDRV_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvFreeResult");
f17cf019	215	driver->m_fpDrvFreeUnbufferedResult = (void (*)(DBDRV_UNBUFFERED_RESULT))DLGetSymbolAddrEx(driver->m_handle, "DrvFreeUnbufferedResult");
dda7c270 VK	216	driver->m_fpDrvBegin = (DWORD (*)(DBDRV_CONNECTION))DLGetSymbolAddrEx(driver->m_handle, "DrvBegin");
	217	driver->m_fpDrvCommit = (DWORD (*)(DBDRV_CONNECTION))DLGetSymbolAddrEx(driver->m_handle, "DrvCommit");
	218	driver->m_fpDrvRollback = (DWORD (*)(DBDRV_CONNECTION))DLGetSymbolAddrEx(driver->m_handle, "DrvRollback");
	219	driver->m_fpDrvUnload = (void (*)(void))DLGetSymbolAddrEx(driver->m_handle, "DrvUnload");
	220	driver->m_fpDrvPrepareStringA = (char* ()(const char ))DLGetSymbolAddrEx(driver->m_handle, "DrvPrepareStringA");
	221	driver->m_fpDrvPrepareStringW = (WCHAR* ()(const WCHAR ))DLGetSymbolAddrEx(driver->m_handle, "DrvPrepareStringW");
daf3c104	222	driver->m_fpDrvIsTableExist = (int ()(DBDRV_CONNECTION, const WCHAR ))DLGetSymbolAddrEx(driver->m_handle, "DrvIsTableExist");
80e96a82 VK	223	if ((fpDrvInit == NULL) \|\| (driver->m_fpDrvConnect == NULL) \|\| (driver->m_fpDrvDisconnect == NULL) \|\|
	224	(driver->m_fpDrvPrepare == NULL) \|\| (driver->m_fpDrvBind == NULL) \|\| (driver->m_fpDrvFreeStatement == NULL) \|\|
	225	(driver->m_fpDrvQuery == NULL) \|\| (driver->m_fpDrvSelect == NULL) \|\| (driver->m_fpDrvGetField == NULL) \|\|
	226	(driver->m_fpDrvGetNumRows == NULL) \|\| (driver->m_fpDrvFreeResult == NULL) \|\| (driver->m_fpDrvSelectPrepared == NULL) \|\|
f17cf019 VK	227	(driver->m_fpDrvSelectPreparedUnbuffered == NULL) \|\| (driver->m_fpDrvUnload == NULL) \|\|
	228	(driver->m_fpDrvSelectUnbuffered == NULL) \|\| (driver->m_fpDrvFetch == NULL) \|\|
	229	(driver->m_fpDrvFreeUnbufferedResult == NULL) \|\| (driver->m_fpDrvGetFieldUnbuffered == NULL) \|\|
80e96a82 VK	230	(driver->m_fpDrvBegin == NULL) \|\| (driver->m_fpDrvCommit == NULL) \|\| (driver->m_fpDrvRollback == NULL) \|\|
80e96a82 VK	231	(driver->m_fpDrvGetColumnCount == NULL) \|\| (driver->m_fpDrvGetColumnName == NULL) \|\|
f17cf019 VK	232	(driver->m_fpDrvGetColumnCountUnbuffered == NULL) \|\| (driver->m_fpDrvGetColumnNameUnbuffered == NULL) \|\|
f17cf019 VK	233	(driver->m_fpDrvGetFieldLength == NULL) \|\| (driver->m_fpDrvGetFieldLengthUnbuffered == NULL) \|\|
daf3c104	234	(driver->m_fpDrvPrepareStringA == NULL) \|\| (driver->m_fpDrvPrepareStringW == NULL) \|\| (driver->m_fpDrvIsTableExist == NULL))
80e96a82 VK	235	{
	236	if (s_writeLog)
	237	__DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Unable to find all required entry points in database driver \"%s\""), module);
	238	goto failure;
	239	}
	240
	241	// Initialize driver
	242	#ifdef UNICODE
6d0fb256	243	char mbInitParameters[1024];
	244	if (initParameters != NULL)
	245	{
	246	WideCharToMultiByte(CP_ACP, WC_COMPOSITECHECK \| WC_DEFAULTCHAR, initParameters, -1, mbInitParameters, 1024, NULL, NULL);
	247	mbInitParameters[1023] = 0;
	248	}
	249	else
	250	{
	251	mbInitParameters[0] = 0;
	252	}
2df047f4	253	if (!fpDrvInit(mbInitParameters))
80e96a82	254	#else
2df047f4	255	if (!fpDrvInit(CHECK_NULL_EX(initParameters)))
80e96a82 VK	256	#endif
	257	{
	258	if (s_writeLog)
	259	__DBWriteLog(EVENTLOG_ERROR_TYPE, _T("Database driver \"%s\" initialization failed"), module);
	260	goto failure;
	261	}
	262
	263	// Success
	264	driver->m_mutexReconnect = MutexCreate();
	265	driver->m_name = driverName;
	266	driver->m_refCount = 1;
85dfb586	267	driver->m_defaultPrefetchLimit = 10;
80e96a82 VK	268	s_drivers[position] = driver;
	269	if (s_writeLog)
	270	__DBWriteLog(EVENTLOG_INFORMATION_TYPE, _T("Database driver \"%s\" loaded and initialized successfully"), module);
	271	MutexUnlock(s_driverListLock);
	272	return driver;
	273
	274	failure:
	275	if (driver->m_handle != NULL)
	276	DLClose(driver->m_handle);
	277	free(driver);
	278	MutexUnlock(s_driverListLock);
	279	return NULL;
	280
	281	reuse_driver:
	282	if (driver->m_handle != NULL)
	283	DLClose(driver->m_handle);
	284	free(driver);
	285	s_drivers[position]->m_refCount++;
	286	MutexUnlock(s_driverListLock);
	287	return s_drivers[position];
	288	}
	289
ef33dc5f VK	290	/**
	291	* Unload driver
	292	*/
80e96a82 VK	293	void LIBNXDB_EXPORTABLE DBUnloadDriver(DB_DRIVER driver)
80e96a82 VK	294	{
7c7a57b9 VK	295	if (driver == NULL)
	296	return;
	297
c17f6cbc	298	MutexLock(s_driverListLock);
80e96a82 VK	299
	300	for(int i = 0; i < MAX_DB_DRIVERS; i++)
	301	{
	302	if (s_drivers[i] == driver)
	303	{
	304	driver->m_refCount--;
	305	if (driver->m_refCount <= 0)
	306	{
	307	driver->m_fpDrvUnload();
	308	DLClose(driver->m_handle);
	309	MutexDestroy(driver->m_mutexReconnect);
	310	free(driver);
	311	s_drivers[i] = NULL;
	312	}
	313	break;
	314	}
	315	}
	316
	317	MutexUnlock(s_driverListLock);
	318	}
13d69c7d	319
ef33dc5f VK	320	/**
	321	* Get name of loaded driver
	322	*/
13d69c7d VK	323	const char LIBNXDB_EXPORTABLE *DBGetDriverName(DB_DRIVER driver)
	324	{
	325	return driver->m_name;
	326	}