private static CommandInfo InitCommand(DapperAccessLayer layer, MethodInfo method)
{
CommandAttribute attr = method.GetCustomAttributes(typeof(CommandAttribute), false).Cast <CommandAttribute>().Single();
CommandInfo info = new CommandInfo()
{
Attribute = attr,
TimeoutSeconds = attr.CommandTimeout > 0 ? attr.CommandTimeout : (int?)null
};
// Find all method parameters that shall be wrapped by runtime DTO type
PropertyDefinition[] properties = method.GetParameters()
.Where(p => IsDatabaseType(p.ParameterType))
.Select(p => new PropertyDefinition(p.Name, p.ParameterType))
.ToArray();
// If any, create runtime dto type
if (properties.Length > 0)
{
// First create an interface definining the properties
string interfaceTypeName = method.DeclaringType.FullName.Replace('+', '_') + "." + method.Name + "_" + method.GetHashCode().ToString();
Type interfaceType = s_Factory.Module.Assembly.GetType(interfaceTypeName);
if (interfaceType == null)
{
interfaceType = s_Factory.Module.DefineInterface(interfaceTypeName, null, properties);
}
// Then implement that by runtime dto type
info.ParameterType = s_ParameterFactory.Implement(interfaceType);
info.ParameterTypeProperties = info.ParameterType.GetProperties();
}
return(info);
}
protected static object ExecNonQuery(DapperAccessLayer layer, CommandInfo info, object[] parameters)
{
// Define how to execute on open connection
Func <IDbConnection, object, object> exec = (connection, parameter) =>
{
// Let Dapper do the hard work
return(connection.Execute(info.Attribute.CommandText, parameter, null, info.TimeoutSeconds, info.Attribute.CommandType));
};
return(ExecCommand(layer, info, parameters, exec));
}
/// <summary>
/// Called once for each interface method when runtime class instance is created.
/// </summary>
/// <param name="layer"></param>
/// <param name="method"></param>
/// <returns></returns>
protected static CommandInfo InitQuery(DapperAccessLayer layer, MethodInfo method)
{
CommandInfo info = InitCommand(layer, method);
// Extract row type from signature and create specialized execute method
Type rowType = method.ReturnType.GetGenericArguments().Single();
MethodInfo execMethod = s_ExecCommandMethod.MakeGenericMethod(rowType);
info.ExecQuery = (Func <DapperAccessLayer, CommandInfo, object[], object>)Delegate.CreateDelegate(typeof(Func <DapperAccessLayer, CommandInfo, object[], object>), execMethod);
return(info);
}
private static object ExecQueryGeneric <T>(DapperAccessLayer layer, CommandInfo info, object[] parameters)
{
// See if we shall read lazy or not
bool buffered = ((QueryAttribute)info.Attribute).Buffered;
// Define how to execute on open connection
Func <IDbConnection, object, object> exec = (connection, parameter) =>
{
// Let Dapper do the hard work
return(connection.Query <T>(info.Attribute.CommandText, parameter, buffered: buffered, commandType: info.Attribute.CommandType, commandTimeout: info.TimeoutSeconds));
};
return(ExecCommand(layer, info, parameters, exec));
}
private static object ExecCommand(DapperAccessLayer layer, CommandInfo info, object[] parameters, Func <IDbConnection, object, object> command)
{
// Make sure we have an open connection
IDbConnection con = layer._connectionFactory();
bool close = con.State != ConnectionState.Open;
if (close)
{
con.Open();
}
try
{
// Default is to use DTO provided as single param to interface method (the Dapper style)
object parameter = parameters.FirstOrDefault();
// If we're using runtime dto type, create instance of it and set properties from method parameters
if (info.ParameterType != null)
{
parameter = Activator.CreateInstance(info.ParameterType);
for (int i = 0; i < info.ParameterTypeProperties.Length; i++)
{
info.ParameterTypeProperties[i].SetValue(parameter, parameters[i], null);
}
}
return(command(con, parameter));
}
finally
{
if (close)
{
con.Close();
}
}
}
protected static CommandInfo InitNonQuery(DapperAccessLayer layer, MethodInfo method)
{
return(InitCommand(layer, method));
}
/// <summary>
/// Called whenever interface method is executed.
/// </summary>
/// <param name="layer"></param>
/// <param name="info"></param>
/// <param name="parameters"></param>
/// <returns></returns>
protected static object ExecQuery(DapperAccessLayer layer, CommandInfo info, object[] parameters)
{
// Execute in specialized generic method to be able to call Dapper query
return(info.ExecQuery(layer, info, parameters));
}