/// <inheritdoc />
public async Task Start(CancellationToken cancellationToken)
{
await Task.Yield();
var interval = _configuration.GetSection("Interval").Get <string>();
if (string.IsNullOrWhiteSpace(interval))
{
_logger.LogWarning("no interval configured via 'SnapshotConfiguration:Triggers:{{NAME}}:Trigger:Interval'");
return;
}
_logger.LogInformation($"using interval '{interval}'");
// creating snapshots in sub-minute resolution is not necessary
var schedule = CrontabSchedule.Parse(interval, new CrontabSchedule.ParseOptions {
IncludingSeconds = false
});
// calculate next interval and
// account for inaccuracy of Timer by adding another second on top
var nextOccurrence = schedule.GetNextOccurrence(DateTime.UtcNow);
var sleepTime = nextOccurrence - DateTime.UtcNow + TimeSpan.FromSeconds(1);
_logger.LogInformation($"using interval '{interval}' the next occurence / trigger is at '{nextOccurrence:O}' - sleeping for {sleepTime:c}");
_timer.Elapsed += (sender, args) => SnapshotTriggered?.Invoke(this, EventArgs.Empty);
_timer.Interval = sleepTime.TotalMilliseconds;
_timer.Start();
}
private void OnOnDemandSnapshotTriggered(object sender, EventArgs e) => SnapshotTriggered?.Invoke(this, EventArgs.Empty);
