first commit for openGauss connect odbc code

psqlodbc.c

@@ -0,0 +1,203 @@
+/*--------
+ * Module:			psqlodbc.c
+ *
+ * Description:		This module contains the main entry point (DllMain)
+ *					for the library.  It also contains functions to get
+ *					and set global variables for the driver in the registry.
+ *
+ * Classes:			n/a
+ *
+ * API functions:	none
+ *
+ * Comments:		See "readme.txt" for copyright and license information.
+ *--------
+ */
+
+#ifdef	WIN32
+#ifdef	_DEBUG
+#include <crtdbg.h>
+#endif /* _DEBUG */
+#endif /* WIN32 */
+#include "psqlodbc.h"
+#include "dlg_specific.h"
+#include "environ.h"
+#include "misc.h"
+#include <string.h>
+
+#ifdef WIN32
+#include "loadlib.h"
+#define DEF_GS_VERSION "openGauss 1.0.0"
+#else
+#include <libgen.h>
+#endif
+
+static int	exepgm = 0;
+const char *odbcVersionString = "openGauss 1.0.0";
+BOOL isMsAccess(void) {return 1 == exepgm;}
+BOOL isMsQuery(void) {return 2 == exepgm;}
+BOOL isSqlServr(void) {return 3 == exepgm;}
+
+
+RETCODE SQL_API SQLDummyOrdinal(void);
+
+#if defined(WIN_MULTITHREAD_SUPPORT)
+extern	CRITICAL_SECTION	conns_cs, common_cs;
+#elif defined(POSIX_MULTITHREAD_SUPPORT)
+extern	pthread_mutex_t 	conns_cs, common_cs;
+
+#ifdef	POSIX_THREADMUTEX_SUPPORT
+#ifdef	PG_RECURSIVE_MUTEXATTR
+static	pthread_mutexattr_t	recur_attr;
+const	pthread_mutexattr_t*	getMutexAttr(void)
+{
+	static int	init = 1;
+
+	if (init)
+	{
+		if (0 != pthread_mutexattr_init(&recur_attr))
+			return NULL;
+		if (0 != pthread_mutexattr_settype(&recur_attr, PG_RECURSIVE_MUTEXATTR))
+			return NULL;
+	}
+	init = 0;
+
+	return	&recur_attr;
+}
+#else
+const	pthread_mutexattr_t*	getMutexAttr(void)
+{
+	return NULL;
+}
+#endif /* PG_RECURSIVE_MUTEXATTR */
+#endif /* POSIX_THREADMUTEX_SUPPORT */
+#endif /* WIN_MULTITHREAD_SUPPORT */
+
+int	initialize_global_cs(void)
+{
+	static	int	init = 1;
+
+	if (!init)
+		return 0;
+	init = 0;
+#ifdef	WIN32
+#ifdef	_DEBUG
+#ifdef	_MEMORY_DEBUG_
+	_CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF|_CRTDBG_LEAK_CHECK_DF);
+#endif /* _MEMORY_DEBUG_ */
+#endif /* _DEBUG */
+#endif /* WIN32 */
+#ifdef	POSIX_THREADMUTEX_SUPPORT
+	getMutexAttr();
+#endif /* POSIX_THREADMUTEX_SUPPORT */
+	InitializeLogging();
+	INIT_CONNS_CS;
+	INIT_COMMON_CS;
+
+	return 0;
+}
+
+static void finalize_global_cs(void)
+{
+	DELETE_COMMON_CS;
+	DELETE_CONNS_CS;
+	FinalizeLogging();
+}
+
+#ifdef WIN32
+HINSTANCE s_hModule;		/* Saved module handle. */
+/*	This is where the Driver Manager attaches to this Driver */
+BOOL		WINAPI
+DllMain(HANDLE hInst, ULONG ul_reason_for_call, LPVOID lpReserved)
+{
+	const char *exename = GetExeProgramName();
+
+	switch (ul_reason_for_call)
+	{
+		case DLL_PROCESS_ATTACH:
+			s_hModule = hInst;	/* Save for dialog boxes */
+
+
+			if (stricmp(exename, "msaccess") == 0)
+				exepgm = 1;
+			else if (strnicmp(exename, "msqry", 5) == 0)
+				exepgm = 2;
+			else if (strnicmp(exename, "sqlservr", 8) == 0)
+				exepgm = 3;
+			initialize_global_cs();
+			MYLOG(0, "exe name=%s\n", exename);
+			break;
+
+		case DLL_THREAD_ATTACH:
+			break;
+
+		case DLL_PROCESS_DETACH:
+			MYLOG(0, "DETACHING %s\n", DRIVER_FILE_NAME);
+			CleanupDelayLoadedDLLs();
+			/* my(q)log is unavailable from here */
+			finalize_global_cs();
+			return TRUE;
+
+		case DLL_THREAD_DETACH:
+			break;
+
+		default:
+			break;
+	}
+
+	return TRUE;
+
+	UNREFERENCED_PARAMETER(lpReserved);
+}
+
+#else							/* not WIN32 */
+
+#if defined(__GNUC__) || defined(__SUNPRO_C)
+
+/* Shared library initializer and destructor, using gcc's attributes */
+
+static void
+__attribute__((constructor))
+psqlodbc_init(void)
+{
+	initialize_global_cs();
+}
+
+static void
+__attribute__((destructor))
+psqlodbc_fini(void)
+{
+	finalize_global_cs();
+}
+
+#else							/* not __GNUC__ */
+
+/* Shared library initialization on non-gcc systems. */
+BOOL
+_init(void)
+{
+	initialize_global_cs();
+	return TRUE;
+}
+
+BOOL
+_fini(void)
+{
+	finalize_global_cs();
+	return TRUE;
+}
+#endif   /* not __GNUC__ */
+#endif   /* not WIN32 */
+
+
+/*
+ *	This function is used to cause the Driver Manager to
+ *	call functions by number rather than name, which is faster.
+ *	The ordinal value of this function must be 199 to have the
+ *	Driver Manager do this.  Also, the ordinal values of the
+ *	functions must match the value of fFunction in SQLGetFunctions()
+ */
+RETCODE		SQL_API
+SQLDummyOrdinal(void)
+{
+	return SQL_SUCCESS;
+}