internal unsafe void GetDataSource(OleDbConnectionString constr, ref DataSourceWrapper datasrcWrapper)
{
OleDbHResult hr;
UnsafeNativeMethods.IDataInitializeGetDataSource GetDataSource = DangerousIDataInitializeGetDataSource !;
bool mustRelease = false;
RuntimeHelpers.PrepareConstrainedRegions();
try
{
DangerousAddRef(ref mustRelease);
// this is the string that DataLinks / OLE DB Services will use to create the provider
string connectionString = constr.ActualConnectionString !;
// base.handle is the 'this' pointer for making the COM call to GetDataSource
// the datasrcWrapper will store the IID_IDBInitialize pointer
// call IDataInitiailze::GetDataSource via the delegate
fixed(char *connectionStringPtr = connectionString)
fixed(Guid * riid = &ODB.IID_IDBInitialize)
{
bool addRefd = false;
DataSourceWrapper newWrapper = new DataSourceWrapper();
datasrcWrapper.DangerousAddRef(ref addRefd);
IntPtr originalHandle = datasrcWrapper.DangerousGetHandle();
IntPtr handle = originalHandle;
try
{
hr = GetDataSource(base.handle, IntPtr.Zero, ODB.CLSCTX_ALL, connectionStringPtr, riid, &handle);
}
finally
{
if (addRefd)
{
datasrcWrapper.DangerousRelease();
}
if (handle != originalHandle)
{
Marshal.InitHandle(newWrapper, handle);
datasrcWrapper = newWrapper;
}
}
}
}
finally
{
if (mustRelease)
{
DangerousRelease();
}
}
if (hr < 0)
{ // ignore infomsg
if (OleDbHResult.REGDB_E_CLASSNOTREG == hr)
{
throw ODB.ProviderUnavailable(constr.Provider, null);
}
Exception?e = OleDbConnection.ProcessResults(hr, null, null);
Debug.Assert(null != e, "CreateProviderError");
throw e;
}
else if (datasrcWrapper.IsInvalid)
{
SafeNativeMethods.Wrapper.ClearErrorInfo();
throw ODB.ProviderUnavailable(constr.Provider, null);
}
Debug.Assert(!datasrcWrapper.IsInvalid, "bad DataSource");
}
