/// <summary>
/// Get a non running message from queue
/// </summary>
/// <param name="query">query where top level fields do not contain operators. Lower level fields can however. eg: valid {a: {$gt: 1}, "b.c": 3}, invalid {$and: [{...}, {...}]}</param>
/// <param name="resetRunning">duration before this message is considered abandoned and will be given with another call to Get()</param>
/// <param name="wait">duration to keep polling before returning null</param>
/// <param name="poll">duration between poll attempts</param>
/// <returns>message or null</returns>
/// <exception cref="ArgumentNullException">query is null</exception>
public BsonDocument Get(QueryDocument query, TimeSpan resetRunning, TimeSpan wait, TimeSpan poll)
{
if (query == null) throw new ArgumentNullException("query");
//reset stuck messages
collection.Update(
new QueryDocument { { "running", true }, { "resetTimestamp", new BsonDocument("$lte", DateTime.UtcNow) } },
new UpdateDocument("$set", new BsonDocument("running", false)),
UpdateFlags.Multi
);
var builtQuery = new QueryDocument("running", false);
foreach (var field in query)
builtQuery.Add("payload." + field.Name, field.Value);
builtQuery.Add("earliestGet", new BsonDocument("$lte", DateTime.UtcNow));
var resetTimestamp = DateTime.UtcNow;
try
{
resetTimestamp += resetRunning;
}
catch (ArgumentOutOfRangeException)
{
resetTimestamp = resetRunning > TimeSpan.Zero ? DateTime.MaxValue : DateTime.MinValue;
}
var sort = new SortByDocument { { "priority", 1 }, { "created", 1 } };
var update = new UpdateDocument("$set", new BsonDocument { { "running", true }, { "resetTimestamp", resetTimestamp } });
var fields = new FieldsDocument("payload", 1);
var end = DateTime.UtcNow;
try
{
end += wait;
}
catch (ArgumentOutOfRangeException)
{
end = wait > TimeSpan.Zero ? DateTime.MaxValue : DateTime.MinValue;
}
while (true)
{
var message = collection.FindAndModify(builtQuery, sort, update, fields, false, false).ModifiedDocument;
if (message != null)
//using merge without overwriting so a possible id in payload doesnt wipe it out the generated one
return new BsonDocument("id", message["_id"]).Merge(message["payload"].AsBsonDocument);
if (DateTime.UtcNow >= end)
return null;
try
{
Thread.Sleep(poll);
}
catch (ArgumentOutOfRangeException)
{
poll = poll < TimeSpan.Zero ? TimeSpan.Zero : TimeSpan.FromMilliseconds(int.MaxValue);
Thread.Sleep(poll);
}
}
}
public void TestFieldsDocumentConstructor()
{
var document1 = new FieldsDocument(dictionary);
var document2 = new FieldsDocument(hashtable);
var document3 = new FieldsDocument(idictionaryNonGeneric);
var document4 = new FieldsDocument(idictionary);
Assert.AreEqual("Dictionary<string, object>", document1["type"].AsString);
Assert.AreEqual("Hashtable", document2["type"].AsString);
Assert.AreEqual("IDictionary", document3["type"].AsString);
Assert.AreEqual("IDictionary<string, object>", document4["type"].AsString);
}
/// <summary>
/// Get a non running message from queue
/// </summary>
/// <param name="query">query where top level fields do not contain operators. Lower level fields can however. eg: valid {a: {$gt: 1}, "b.c": 3}, invalid {$and: [{...}, {...}]}</param>
/// <param name="resetRunning">duration before this message is considered abandoned and will be given with another call to Get()</param>
/// <param name="wait">duration to keep polling before returning null</param>
/// <param name="poll">duration between poll attempts</param>
/// <param name="approximateWait">whether to fluctuate the wait time randomly by +-10 percent. This ensures Get() calls seperate in time when multiple Queues are used in loops started at the same time</param>
/// <returns>message or null</returns>
/// <exception cref="ArgumentNullException">query is null</exception>
public Message Get(QueryDocument query, TimeSpan resetRunning, TimeSpan wait, TimeSpan poll, bool approximateWait)
{
if (query == null)
throw new ArgumentNullException ("query");
//reset stuck messages
collection.Update(
new QueryDocument { { "running", true }, { "resetTimestamp", new BsonDocument("$lte", DateTime.UtcNow) } },
new UpdateDocument("$set", new BsonDocument("running", false)),
UpdateFlags.Multi
);
var builtQuery = new QueryDocument("running", false);
foreach (var field in query)
builtQuery.Add("payload." + field.Name, field.Value);
builtQuery.Add("earliestGet", new BsonDocument("$lte", DateTime.UtcNow));
var resetTimestamp = DateTime.UtcNow;
try
{
resetTimestamp += resetRunning;
}
catch (ArgumentOutOfRangeException)
{
resetTimestamp = resetRunning > TimeSpan.Zero ? DateTime.MaxValue : DateTime.MinValue;
}
var sort = new SortByDocument { { "priority", 1 }, { "created", 1 } };
var update = new UpdateDocument("$set", new BsonDocument { { "running", true }, { "resetTimestamp", resetTimestamp } });
var fields = new FieldsDocument { { "payload", 1 }, { "streams", 1 } };
var end = DateTime.UtcNow;
try
{
if (approximateWait)
//fluctuate randomly by 10 percent
wait += TimeSpan.FromMilliseconds(wait.TotalMilliseconds * GetRandomDouble(-0.1, 0.1));
end += wait;
}
catch (Exception e)
{
if (!(e is OverflowException) && !(e is ArgumentOutOfRangeException))
throw e;//cant cover
end = wait > TimeSpan.Zero ? DateTime.MaxValue : DateTime.MinValue;
}
while (true)
{
var findModifyArgs = new FindAndModifyArgs { Query = builtQuery, SortBy = sort, Update = update, Fields = fields, Upsert = false };
var message = collection.FindAndModify(findModifyArgs).ModifiedDocument;
if (message != null)
{
var handleStreams = new List<KeyValuePair<BsonValue, Stream>>();
var messageStreams = new Dictionary<string, Stream>();
foreach (var streamId in message["streams"].AsBsonArray)
{
var fileInfo = gridfs.FindOneById(streamId);
var stream = fileInfo.OpenRead();
handleStreams.Add(new KeyValuePair<BsonValue, Stream>(streamId, stream));
messageStreams.Add(fileInfo.Name, stream);
}
var handle = new Handle(message["_id"].AsObjectId, handleStreams);
return new Message(handle, message["payload"].AsBsonDocument, messageStreams);
}
if (DateTime.UtcNow >= end)
return null;
try
{
Thread.Sleep(poll);
}
catch (ArgumentOutOfRangeException)
{
if (poll < TimeSpan.Zero)
poll = TimeSpan.Zero;
else
poll = TimeSpan.FromMilliseconds(int.MaxValue);
Thread.Sleep(poll);
}
if (DateTime.UtcNow >= end)
return null;
}
}
