private async Task ExecuteAsync(Database database)
{
using (var connection = GetConnection())
using (var command = connection.CreateCommand())
{
var virtualDeviceName = $"sqlsnap-{Guid.NewGuid()}";
command.CommandText = GetSqlCommand(virtualDeviceName, database.Name);
command.CommandTimeout = _timeout;
var config = new VDConfig
{
DeviceCount = 1,
Features = VDFeature.SnapshotPrepare
};
Log.Debug("Creating virtual device {virtualDeviceName}", virtualDeviceName);
var virtualDeviceSet = (IClientVirtualDeviceSet2) new ClientVirtualDeviceSet2();
virtualDeviceSet.CreateEx(_instanceName, virtualDeviceName, ref config);
try
{
Log.Debug("Executing SQL query: {commandText}", command.CommandText);
var queryTask = command.ExecuteNonQueryAsync();
await Task.Run(() =>
{
Log.Debug("Waiting for virtual device to be ready");
var virtualDevice = WaitForDevice(virtualDeviceSet, virtualDeviceName);
Log.Debug("Receiving commands from virtual device");
HandleCommands(database, virtualDevice);
});
Log.Debug("Waiting for query to finish");
await queryTask;
}
finally
{
try
{
virtualDeviceSet.Close();
}
catch
{
// ignore errors when closing
}
}
}
}
private IClientVirtualDevice WaitForDevice(IClientVirtualDeviceSet2 virtualDeviceSet, string virtualDeviceName)
{
var config = new VDConfig();
while (true)
{
try
{
virtualDeviceSet.GetConfiguration(1000, ref config);
break;
}
catch (COMException ex)
{
if ((uint)ex.ErrorCode == 0x80770003) // timeout
{
continue;
}
throw;
}
}
return(virtualDeviceSet.OpenDevice(virtualDeviceName));
}
