/// <summary>
/// Constructs a new instance based on the schedule expression passed in./>
/// </summary>
/// <param name="expression">A schedule expression. This can either be a crontab expression
/// <a href="http://en.wikipedia.org/wiki/Cron#CRON_expression"/> or a <see cref="TimeSpan"/> string.</param>
public TimerTriggerAttribute(string expression)
{
CronSchedule cronSchedule = null;
if (CronSchedule.TryCreate(expression, out cronSchedule))
{
Schedule = cronSchedule;
DateTime[] nextOccurrences = cronSchedule.InnerSchedule.GetNextOccurrences(DateTime.Now, DateTime.Now + TimeSpan.FromMinutes(1)).ToArray();
if (nextOccurrences.Length > 1)
{
// if there is more than one occurrence due in the next minute,
// assume that this is a sub-minute constant schedule and disable
// persistence
UseMonitor = false;
}
else
{
UseMonitor = true;
}
}
else
{
TimeSpan periodTimespan = TimeSpan.Parse(expression);
Schedule = new ConstantSchedule(periodTimespan);
// for very frequent constant schedules, we want to disable persistence
UseMonitor = periodTimespan.TotalMinutes >= 1;
}
}
internal static TimerSchedule Create(TimerTriggerAttribute attribute, INameResolver nameResolver)
{
TimerSchedule schedule = null;
if (!string.IsNullOrEmpty(attribute.ScheduleExpression))
{
string resolvedExpression = nameResolver.ResolveWholeString(attribute.ScheduleExpression);
CronSchedule cronSchedule = null;
if (CronSchedule.TryCreate(resolvedExpression, out cronSchedule))
{
schedule = cronSchedule;
DateTime[] nextOccurrences = cronSchedule.InnerSchedule.GetNextOccurrences(DateTime.Now, DateTime.Now + TimeSpan.FromMinutes(1)).ToArray();
if (nextOccurrences.Length > 1)
{
// if there is more than one occurrence due in the next minute,
// assume that this is a sub-minute constant schedule and disable
// persistence
attribute.UseMonitor = false;
}
else if (!attribute.UseMonitor.HasValue)
{
// if the user hasn't specified a value
// set to true
attribute.UseMonitor = true;
}
}
else
{
TimeSpan periodTimespan = TimeSpan.Parse(resolvedExpression);
schedule = new ConstantSchedule(periodTimespan);
if (periodTimespan.TotalMinutes < 1)
{
// for very frequent constant schedules, we want to disable persistence
attribute.UseMonitor = false;
}
else if (!attribute.UseMonitor.HasValue)
{
// if the user hasn't specified a value
// set to true
attribute.UseMonitor = true;
}
}
}
else
{
schedule = (TimerSchedule)Activator.CreateInstance(attribute.ScheduleType);
if (!attribute.UseMonitor.HasValue)
{
// if the user hasn't specified a value
// set to true
attribute.UseMonitor = true;
}
}
return(schedule);
}
internal static TimerSchedule Create(TimerTriggerAttribute attribute, INameResolver nameResolver)
{
TimerSchedule schedule = null;
if (!string.IsNullOrEmpty(attribute.ScheduleExpression))
{
string resolvedExpression = nameResolver.ResolveWholeString(attribute.ScheduleExpression);
CronSchedule cronSchedule = null;
TimeSpan periodTimespan;
if (CronSchedule.TryCreate(resolvedExpression, out cronSchedule))
{
schedule = cronSchedule;
DateTime[] nextOccurrences = cronSchedule.InnerSchedule.GetNextOccurrences(DateTime.Now, DateTime.Now + TimeSpan.FromMinutes(1)).ToArray();
if (nextOccurrences.Length > 1)
{
// if there is more than one occurrence due in the next minute,
// assume that this is a sub-minute constant schedule and disable
// persistence
attribute.UseMonitor = false;
}
}
else if (TimeSpan.TryParse(resolvedExpression, out periodTimespan))
{
schedule = new ConstantSchedule(periodTimespan);
if (periodTimespan.TotalMinutes < 1)
{
// for very frequent constant schedules, we want to disable persistence
attribute.UseMonitor = false;
}
}
else
{
throw new ArgumentException("The schedule expression was not recognized as a valid cron expression or timespan string.");
}
}
else
{
schedule = (TimerSchedule)Activator.CreateInstance(attribute.ScheduleType);
}
return(schedule);
}
internal static TimerSchedule Create(TimerTriggerAttribute attribute, INameResolver nameResolver, ILogger logger)
{
TimerSchedule schedule = null;
if (!string.IsNullOrEmpty(attribute.ScheduleExpression))
{
string resolvedExpression = nameResolver.ResolveWholeString(attribute.ScheduleExpression);
if (CronSchedule.TryCreate(resolvedExpression, out CronSchedule cronSchedule))
{
schedule = cronSchedule;
if (attribute.UseMonitor && ShouldDisableScheduleMonitor(cronSchedule, DateTime.Now))
{
logger.LogDebug("UseMonitor changed to false based on schedule frequency.");
attribute.UseMonitor = false;
}
}
else if (TimeSpan.TryParse(resolvedExpression, out TimeSpan periodTimespan))
{
schedule = new ConstantSchedule(periodTimespan);
if (attribute.UseMonitor && periodTimespan.TotalMinutes < 1)
{
// for very frequent constant schedules, we want to disable persistence
logger.LogDebug("UseMonitor changed to false based on schedule frequency.");
attribute.UseMonitor = false;
}
}
else
{
throw new ArgumentException(string.Format("The schedule expression '{0}' was not recognized as a valid cron expression or timespan string.", resolvedExpression));
}
}
else
{
schedule = (TimerSchedule)Activator.CreateInstance(attribute.ScheduleType);
}
return(schedule);
}
