public FluentNHibernateFetchedJob(
FluentNHibernateJobStorage storage,
FetchedJob fetchedJob)
{
_storage = storage ?? throw new ArgumentNullException(nameof(storage));
_id = fetchedJob?.Id ?? throw new ArgumentNullException(nameof(fetchedJob));
JobId = fetchedJob.JobId.ToString(CultureInfo.InvariantCulture);
Queue = fetchedJob.Queue;
}
public IFetchedJob Dequeue(string[] queues, CancellationToken cancellationToken)
{
if (queues == null)
{
throw new ArgumentNullException("queues");
}
if (queues.Length == 0)
{
throw new ArgumentException("Queue array must be non-empty.", "queues");
}
queues = queues.Select(x => x.ToLower()).ToArray();
Logger.Debug("Attempting to dequeue");
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
try
{
using (new FluentNHibernateDistributedLock(_storage, "JobQueue", TimeSpan.FromSeconds(60))
.Acquire())
{
var fluentNHibernateFetchedJob = SqlUtil.WrapForTransaction(() =>
{
var token = Guid.NewGuid().ToString();
if (queues.Any())
{
using (var session = _storage.GetSession())
{
using (var transaction =
session.BeginTransaction(IsolationLevel.Serializable))
{
var jobQueueFetchedAt = _storage.UtcNow;
var next = jobQueueFetchedAt.AddSeconds(
_options.InvisibilityTimeout.Negate().TotalSeconds);
var jobQueue = session.Query <_JobQueue>()
.FirstOrDefault(i =>
(i.FetchedAt == null ||
i.FetchedAt < next) &&
queues.Contains(i.Queue.ToLower()));
if (jobQueue != null)
{
jobQueue.FetchedAt = jobQueueFetchedAt;
jobQueue.FetchToken = token;
session.Update(jobQueue);
session.Flush();
transaction.Commit();
Logger.DebugFormat("Dequeued job id {0} from queue {1}", jobQueue.Job.Id,
jobQueue.Queue);
var fetchedJob = new FetchedJob
{
Id = jobQueue.Id,
JobId = jobQueue.Job.Id,
Queue = jobQueue.Queue
};
return(new FluentNHibernateFetchedJob(_storage, fetchedJob));
}
}
}
}
return(null);
});
if (fluentNHibernateFetchedJob != null)
{
return(fluentNHibernateFetchedJob);
}
}
}
catch (FluentNHibernateDistributedLockException)
{
// do nothing
}
catch (Exception ex)
{
Logger.ErrorException(ex.Message, ex);
throw;
}
cancellationToken.WaitHandle.WaitOne(_options.QueuePollInterval);
cancellationToken.ThrowIfCancellationRequested();
}
}
public IFetchedJob Dequeue(string[] queues, CancellationToken cancellationToken)
{
if (queues == null)
{
throw new ArgumentNullException(nameof(queues));
}
if (queues.Length == 0)
{
throw new ArgumentException("Queue array must be non-empty.", "queues");
}
Logger.Debug("Attempting to dequeue");
var timeoutSeconds = _storage.Options.InvisibilityTimeout.Negate().TotalSeconds;
while (!cancellationToken.IsCancellationRequested)
{
var fluentNHibernateDistributedLock = new FluentNHibernateDistributedLock(_storage, "JobQueue",
_storage.Options.JobQueueDistributedLockTimeout)
.Acquire();
if (fluentNHibernateDistributedLock == null)
{
if (cancellationToken.IsCancellationRequested)
{
return(null);
}
cancellationToken.WaitHandle.WaitOne(_storage.Options.QueuePollInterval);
}
else
{
using (fluentNHibernateDistributedLock)
{
var fluentNHibernateFetchedJob = SqlUtil.WrapForTransaction(() =>
{
var token = Guid.NewGuid().ToString();
using (var session = _storage.GetStatelessSession())
{
using (var transaction =
session.BeginTransaction(IsolationLevel.Serializable))
{
var jobQueueFetchedAt = _storage.UtcNow;
var cutoff = jobQueueFetchedAt.AddSeconds(timeoutSeconds);
if (Logger.IsDebugEnabled())
{
Logger.Debug(string.Format("Getting jobs where {0}=null or {0}<{1}",
nameof(_JobQueue.FetchedAt), cutoff));
}
var jobQueue = session.Query <_JobQueue>()
.FirstOrDefault(i =>
(i.FetchedAt == null ||
i.FetchedAt < cutoff) && queues.Contains(i.Queue));
if (jobQueue != null)
{
jobQueue.FetchToken = token;
jobQueue.FetchedAt = jobQueueFetchedAt;
session.Update(jobQueue);
transaction.Commit();
Logger.DebugFormat("Dequeued job id {0} from queue {1}",
jobQueue.Job.Id,
jobQueue.Queue);
var fetchedJob = new FetchedJob
{
Id = jobQueue.Id,
JobId = jobQueue.Job.Id,
Queue = jobQueue.Queue
};
return(new FluentNHibernateFetchedJob(_storage, fetchedJob));
}
}
}
return(null);
});
if (fluentNHibernateFetchedJob != null)
{
return(fluentNHibernateFetchedJob);
}
}
}
}
return(null);
}
