public static void ResetCommandTimeout(this ICancellableCommand command)
{
var session = command.Connection?.Session;
if (session is not null)
{
if (command.CommandTimeout == 0 || session.CancellationTimeout == 0)
{
session.SetTimeout(Constants.InfiniteTimeout);
}
else
{
var commandTimeUntilCanceled = command.GetCommandTimeUntilCanceled() * 1000;
if (session.CancellationTimeout > 0)
{
// try to cancel first, then close socket
command.SetTimeout(commandTimeUntilCanceled);
session.SetTimeout(commandTimeUntilCanceled + session.CancellationTimeout * 1000);
}
else
{
// close socket once the timeout is reached
session.SetTimeout(commandTimeUntilCanceled);
}
}
}
}
public static int GetCommandTimeUntilCanceled(this ICancellableCommand command)
{
var commandTimeout = command.CommandTimeout;
var session = command.Connection?.Session;
if (commandTimeout == 0 || session is null)
{
return(0);
}
// the total cancellation period (graphically) is [===CommandTimeout===][=CancellationTimeout=], which can't
// exceed int.MaxValue/1000 because it has to be multiplied by 1000 to be converted to milliseconds
return(Math.Min(commandTimeout, Math.Max(1, (int.MaxValue / 1000) - session.CancellationTimeout)));
}
/// <summary>
/// Causes the effective command timeout to be reset back to the value specified by <see cref="CommandTimeout"/>.
/// </summary>
/// <remarks>As per the <a href="https://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.commandtimeout.aspx">MSDN documentation</a>,
/// "This property is the cumulative time-out (for all network packets that are read during the invocation of a method) for all network reads during command
/// execution or processing of the results. A time-out can still occur after the first row is returned, and does not include user processing time, only network
/// read time. For example, with a 30 second time out, if Read requires two network packets, then it has 30 seconds to read both network packets. If you call
/// Read again, it will have another 30 seconds to read any data that it requires."
/// The <see cref="ResetCommandTimeout"/> method is called by public ADO.NET API methods to reset the effective time remaining at the beginning of a new
/// method call.</remarks>
public static void ResetCommandTimeout(this ICancellableCommand command)
{
var commandTimeout = command.CommandTimeout;
command.Connection?.Session?.SetTimeout(commandTimeout == 0 ? Constants.InfiniteTimeout : commandTimeout * 1000);
}
/// <summary>
/// Creates a new instance that cancels <paramref name="command"/>.
/// </summary>
/// <param name="command">A command to cancel.</param>
public CancelCommand(ICancellableCommand command)
{
Ensure.NotNull(command, "command");
this.command = command;
this.command.CanExecuteChanged += OnCanExecuteChanged;
}