public IFetchedJob Dequeue(string[] queues, CancellationToken cancellationToken)
{
if (queues is null || !queues.Any())
{
throw new ArgumentException("Queue array must be non-empty.", nameof(queues));
}
var token = Guid.NewGuid().ToString();
// I'm not sure if this is used correctly...
var expiration = _options.InvisibilityTimeout;
// the connection variable is mutable, it job is claimed then this connection
// is passed to job itself, and variable is set to null so it does not get
// disposed here in such case
var connection = _storage.CreateAndOpenConnection();
try
{
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
using (ResourceLock.AcquireOne(
connection, _options.TablesPrefix, LockableResource.Queue))
{
var updated = ClaimJob(connection, queues, expiration, token);
if (updated != 0)
{
var fetchedJob = FetchJobByToken(connection, token);
return(new MySqlFetchedJob(
_storage, _options,
Interlocked.Exchange(ref connection, null),
fetchedJob));
}
}
cancellationToken.WaitHandle.WaitOne(_options.QueuePollInterval);
cancellationToken.ThrowIfCancellationRequested();
}
}
catch (MySqlException ex)
{
Logger.ErrorException(ex.Message, ex);
throw;
}
finally
{
if (connection != null)
{
_storage.ReleaseConnection(connection);
}
}
}
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, "JobQueue", TimeSpan.FromSeconds(30), _options))
{
string token = Guid.NewGuid().ToString();
int nUpdated = connection.Execute(
$"update `{_options.TablesPrefix}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.TablesPrefix}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 MySqlDistributedLock(MySqlStorage storage, MySqlStorageOptions options, string resource, TimeSpan timeout)
: this(storage.CreateAndOpenConnection(), options, resource, timeout)
{
_storage = storage;
}
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, "JobQueue", TimeSpan.FromSeconds(30)))
{
fetchedJob =
connection
.Query <FetchedJob>(
"select Id, JobId, Queue " +
"from JobQueue " +
"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
})
.SingleOrDefault();
if (fetchedJob != null)
{
connection
.Execute(
"update JobQueue set FetchedAt = @fetchedAt where Id = @id",
new { fetchedAt = DateTime.UtcNow, id = fetchedJob.Id });
}
}
}
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));
}
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();
try
{
connection = _storage.CreateAndOpenConnection();
//var joinedQueues = string.Join(",", queues.Select(q => "'" + q.Replace("'", "''") + "'"));
/*var resource = ("JobQueue:" + joinedQueues);
* if (resource.Length > 100)
* resource = resource.Substring(0, 100);
*
* using (new MySqlDistributedLock(_storage, resource, TimeSpan.FromSeconds(70)))*/
{
string token = Guid.NewGuid().ToString();
int nUpdated;
while (!_semaphoreSlim.WaitOne(TimeSpan.FromSeconds(5)))
{
cancellationToken.ThrowIfCancellationRequested();
}
//_semaphoreSlim.Wait(cancellationToken);
try
{
nUpdated = MySqlStorageConnection.AttemptActionReturnObject(() => connection.Execute(
"update JobQueue set FetchedAt = DATE_ADD(UTC_TIMESTAMP(), INTERVAL @timeout SECOND), FetchToken = @fetchToken " +
"where (FetchedAt is null or FetchedAt < UTC_TIMESTAMP()) " +
" and Queue in @queues " +
// "ORDER BY FIELD(Queue, " + joinedQueues + "), JobId " +
"ORDER BY Priority DESC, JobId " +
"LIMIT 1;",
new
{
queues = queues,
timeout = 45, //_options.InvisibilityTimeout.Negate().TotalSeconds,
fetchToken = token
},
commandTimeout: 15), 3);
}
finally
{
_semaphoreSlim.Release();
}
if (nUpdated != 0)
{
fetchedJob =
MySqlStorageConnection.AttemptActionReturnObject(() => connection
.Query <FetchedJob>(
"select Id, JobId, Queue " +
"from JobQueue " +
"where FetchToken = @fetchToken;",
new
{
fetchToken = token
},
commandTimeout: 15)
.SingleOrDefault(), 3);
if (fetchedJob != null)
{
nUpdated = MySqlStorageConnection.AttemptActionReturnObject(() => connection.Execute(
"update JobQueue set FetchedAt = DATE_ADD(UTC_TIMESTAMP(), INTERVAL @timeout SECOND), FetchToken = @fetchToken " +
"where FetchToken = @fetchToken;",
new
{
timeout = _options.InvisibilityTimeout.TotalSeconds,
fetchToken = token
}, commandTimeout: 15), 5);
if (nUpdated == 0)
{
fetchedJob = null;
}
}
}
}
}
catch (MySqlException ex)
{
Logger.ErrorException(ex.Message, ex);
throw;
}
finally
{
_storage.ReleaseConnection(connection);
}
if (fetchedJob == null)
{
cancellationToken.WaitHandle.WaitOne(_options.QueuePollInterval);
cancellationToken.ThrowIfCancellationRequested();
}
} while (fetchedJob == null);
return(new MySqlFetchedJob(_storage, fetchedJob));
}
public MySqlDistributedLock(MySqlStorage storage, string resource, TimeSpan timeout)
: this(storage.CreateAndOpenConnection(), resource, timeout)
{
_storage = storage;
}