public MySqlFetchedJob(
MySqlStorage storage,
IDbConnection connection,
FetchedJob fetchedJob)
{
if (fetchedJob == null)
{
throw new ArgumentNullException("fetchedJob");
}
_storage = storage ?? throw new ArgumentNullException("storage");
_connection = connection ?? throw new ArgumentNullException("connection");
_id = fetchedJob.Id;
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");
}
FetchedJob fetchedJob = null;
MySqlConnection connection = null;
do
{
cancellationToken.ThrowIfCancellationRequested();
connection = _storage.CreateAndOpenConnection();
try
{
using (new MySqlDistributedLock(_storage, _options, "JobQueue", TimeSpan.FromSeconds(30)))
{
string token = Guid.NewGuid().ToString();
int nUpdated = connection.Execute(
$"update {_options.TablePrefix}_JobQueue set FetchedAt = UTC_TIMESTAMP(), FetchToken = @fetchToken " +
"where (FetchedAt is null or FetchedAt < DATE_ADD(UTC_TIMESTAMP(), INTERVAL @timeout SECOND)) " +
" and Queue in @queues " +
"LIMIT 1;",
new
{
queues = queues,
timeout = _options.InvisibilityTimeout.Negate().TotalSeconds,
fetchToken = token
});
if (nUpdated != 0)
{
fetchedJob =
connection
.Query <FetchedJob>(
$"select Id, JobId, Queue from {_options.TablePrefix}_JobQueue where FetchToken = @fetchToken;",
new
{
fetchToken = token
})
.SingleOrDefault();
}
}
}
catch (MySqlException ex)
{
Logger.ErrorException(ex.Message, ex);
_storage.ReleaseConnection(connection);
throw;
}
if (fetchedJob == null)
{
_storage.ReleaseConnection(connection);
cancellationToken.WaitHandle.WaitOne(_options.QueuePollInterval);
cancellationToken.ThrowIfCancellationRequested();
}
} while (fetchedJob == null);
return(new MySqlFetchedJob(_storage, connection, fetchedJob, _options));
}
public IFetchedJob Dequeue(string[] queues, CancellationToken cancellationToken)
{
if (queues == null)
{
throw new ArgumentNullException("queues");
}
if (queues.Length == 0)
{
throw new ArgumentException("Queue array must be non-empty.", "queues");
}
FetchedJob fetchedJob = null;
MySqlConnection connection = null;
int timeOut = 0;
string token = string.Empty;
bool updated = false;
do
{
cancellationToken.ThrowIfCancellationRequested();
connection = _storage.CreateAndOpenConnection();
updated = false;
try
{
using (new MySqlDistributedLock(_storage, "JobQueue", TimeSpan.FromSeconds(30)))
{
token = Guid.NewGuid().ToString();
timeOut = _options.InvisibilityTimeout.Negate().Seconds;
int nUpdated = connection.Execute(
"update JobQueue set FetchedAt = UTC_TIMESTAMP(), FetchToken = @fetchToken " +
"where (FetchedAt is null or FetchedAt < DATE_ADD(UTC_TIMESTAMP(), INTERVAL @timeout SECOND)) " +
" and Queue in @queues " +
"LIMIT 1;",
new
{
queues = queues,
timeout = timeOut,
fetchToken = token
});
updated = true;
if (nUpdated != 0)
{
fetchedJob =
connection
.Query <FetchedJob>(
"select Id, JobId, Queue " +
"from JobQueue " +
"where FetchToken = @fetchToken;",
new
{
fetchToken = token
})
.SingleOrDefault();
}
}
}
catch (MySqlException ex)
{
Logger.ErrorException(ex.Message, ex);
_storage.ReleaseConnection(connection);
throw new Exception($"Error dequeue in {(updated ? "select" : "update")}" +
$"Parameters: queues = {queues}, timeout = {timeOut}, fetchToken = {token} ", ex);
}
if (fetchedJob == null)
{
_storage.ReleaseConnection(connection);
cancellationToken.WaitHandle.WaitOne(_options.QueuePollInterval);
cancellationToken.ThrowIfCancellationRequested();
}
} while (fetchedJob == null);
return(new MySqlFetchedJob(_storage, connection, fetchedJob));
}