/// <summary>
/// Uses a <see cref="QueueCursor"/> to look for messages with a matching <paramref name="correlationId"/>
/// Returns the matching message or NULL if no matching message can be found with the allowed <paramref name="timeout"/>.
/// </summary>
public static async Task <Message> ReadByCorrelationIdAsync(this QueueReader queue, MessageId correlationId, Properties properties = Properties.All, TimeSpan?timeout = null, QueueTransaction transaction = null)
{
timeout = timeout ?? QueueReader.Infinite;
var start = DateTime.UtcNow;
using (var cur = new QueueCursor(queue))
{
var msg = await cur.PeekAsync(Properties.CorrelationId | Properties.LookupId, timeout);
for (;;)
{
if (msg == null)
{
return(null);
}
if (msg.CorrelationId == correlationId)
{
return(queue.Lookup(properties, msg.LookupId, LookupAction.ReceiveCurrent, TimeSpan.Zero, transaction));
}
var elapsed = DateTime.UtcNow - start;
var remaining = timeout - elapsed;
if (remaining <= TimeSpan.Zero)
{
return(null);
}
msg = await cur.PeekNextAsync(Properties.CorrelationId | Properties.LookupId, remaining);
}
}
}
/// <summary>Move the message specified by <paramref name="lookupId"/> from <paramref name="sourceQueue"/> to the <paramref name="targetQueue"/>.</summary>
/// <remarks>
/// Moving message is 10 to 100 times faster than sending the message to another queue.
/// Within a transaction you cannot receive a message that you moved to a subqueue.
/// </remarks>
public static void MoveMessage(QueueReader sourceQueue, SubQueue targetQueue, long lookupId, QueueTransaction transaction = null)
{
Contract.Requires(sourceQueue != null);
Contract.Requires(targetQueue != null);
if (sourceQueue.IsClosed)
{
throw new ObjectDisposedException(nameof(sourceQueue));
}
if (targetQueue.IsClosed)
{
throw new ObjectDisposedException(nameof(targetQueue));
}
int res;
IntPtr txnHandle;
if (transaction.TryGetHandle(out txnHandle))
{
res = Native.MoveMessage(sourceQueue._handle, targetQueue.MoveHandle, lookupId, txnHandle);
}
else
{
res = Native.MoveMessage(sourceQueue._handle, targetQueue.MoveHandle, lookupId, transaction.InternalTransaction);
}
if (Native.IsError(res))
{
throw new QueueException(res);
}
}
/// <summary>Creates a new cursor for queue represented by the <paramref name="reader"/>.</summary>
public QueueCursor(QueueReader reader)
{
Contract.Requires(reader != null);
_reader = reader;
int res = Native.CreateCursor(reader._handle, out _cursorHandle);
if (Native.IsError(res))
{
throw new QueueException(res);
}
}
/// <summary>Returns the transactional property of the queue</summary>
public static void Purge(string formatName)
{
using (var q = new QueueReader(formatName))
q.Purge();
}
