public DeleteError DeleteMessage(string queueName, long messageId, string popReceipt)
{
using (var dc = new Data.MessageDataContext())
{
var msg = dc.Messages.First(m => m.Id == messageId);
if (msg == null) return DeleteError.NotFound;
if (msg.Queue != queueName) return DeleteError.NotFound;
if (msg.PopReceipt.GetValueOrDefault().ToString("N") != popReceipt) return DeleteError.LostOwnership;
dc.Messages.DeleteOnSubmit(msg);
dc.SubmitChanges();
}
return DeleteError.Ok;
}
public Message[] GetMessages(string queueName, int numberOfMessages, TimeSpan visibilityTimeout)
{
Utils.Initialize();
using (var dc = new Data.MessageDataContext())
{
var now = DateTime.UtcNow;
var qry = dc.ExecuteQuery<Data.Message>(Utils.GetMessageSql,
numberOfMessages,
Guid.NewGuid(),
now + visibilityTimeout,
now,
queueName);
return qry.Select(m => m.ToMessage()).ToArray();
}
}
public void PutMessage(string queueName, Message message, TimeSpan timeToLive)
{
var msg = new Data.Message();
msg.Queue = queueName;
if (message.Content != null)
msg.Content = message.Content;
using (var dc = new Data.MessageDataContext())
{
dc.Messages.InsertOnSubmit(msg);
dc.SubmitChanges();
}
}
public Message[] PeekMessages(string queueName, int numberOfMessages)
{
Utils.Initialize();
using (var dc = new Data.MessageDataContext())
{
var qry = dc.ExecuteQuery<Data.Message>(Utils.PeekMessageSql,
numberOfMessages,
queueName);
return qry.Select(m => m.ToMessage()).Select(m => { m.PopReceipt = null; return m; }).ToArray();
}
}
internal static void Initialize()
{
if (_initialized) return;
lock (_sync)
{
if (_initialized) return;
var dc = new Data.MessageDataContext();
var mt = dc.Mapping.GetMetaType(typeof(Data.Message));
var queue = mt.GetMetaDataMember(m => m.Queue);
var takenTill = mt.GetMetaDataMember(m => m.TakenTill);
var popReceipt = mt.GetMetaDataMember(m => m.PopReceipt);
var id = mt.GetMetaDataMember(m => m.Id);
PeekMessageSql = String.Format("select top({{0}}) * from {0} where [{1}] = {{1}} order by [{2}]",
mt.Table.TableName,
queue.MappedName,
id.MappedName);
GetMessageSql = String.Format(@"
update top({{0}}) {0}
set [{1}] = {{1}}, [{2}] = {{2}}
output inserted.*
from {0} with(readpast, index([Message.IX.ByQueue]))
where
([{2}] is null or [{2}] <= {{3}})
and [{3}] = {{4}}",
mt.Table.TableName,
popReceipt.MappedName,
takenTill.MappedName,
queue.MappedName);
_initialized = true;
}
}
