/// <summary>
/// Asks MSMQ to attempt to deliver a message.
/// To ensure the message reached the queue you need to check acknowledgement messages sent to the <see cref="Message.AdministrationQueue"/>
/// </summary>
/// <param name="message">The message to try to send</param>
/// <param name="transaction">can be NULL for no transaction, a <see cref="QueueTransaction"/>, <see cref="QueueTransaction.Single"/>, or <see cref="QueueTransaction.Dtc"/>.</param>
public void Write(Message message, QueueTransaction transaction = null)
{
Contract.Requires(message != null);
message.Props.PrepareToSend();
var props = message.Props.Allocate();
try
{
int res;
IntPtr txnHandle;
if (transaction.TryGetHandle(out txnHandle))
{
res = Native.SendMessage(_handle, props, txnHandle);
}
else
{
res = Native.SendMessage(_handle, props, transaction.InternalTransaction);
}
if (Native.IsError(res))
{
throw new QueueException(res);
}
}
finally
{
message.Props.Free();
}
}
internal static bool TryGetHandle(this QueueTransaction transaction, out IntPtr handle)
{
if (transaction == null)
{
handle = IntPtr.Zero;
return(true);
}
var fake = transaction as QueueTransaction.SpecialTransaction;
if (fake != null)
{
handle = fake.SpecialId;
return(true);
}
handle = IntPtr.Zero;
return(false);
}
/// <summary>Tries to read the current message from the queue without removing the message from the queue.</summary>
/// <remarks>Within a transaction you cannot peek a message that you moved to a subqueue</remarks>
/// <param name="properties">The properties to read</param>
/// <param name="timeout">The time allowed, defaults to infinite. Use <see cref="TimeSpan.Zero"/> to return without waiting</param>
/// <param name="transaction">can be NULL for no transaction, a <see cref="QueueTransaction"/>, <see cref="QueueTransaction.Single"/>, or <see cref="QueueTransaction.Dtc"/>.</param>
/// <returns>The message, or NULL if the receive times out</returns>
public Message Peek(Properties properties = Properties.All, TimeSpan?timeout = null, QueueTransaction transaction = null)
{
return(Receive(properties, ReadAction.PeekCurrent, timeout, transaction, CursorHandle.None));
}
/// <summary>Tries to peek (or receive) a message using the queue-specific <paramref name="lookupId"/></summary>
/// <remarks>Within a transaction you cannot receive a message that you moved to a subqueue within the same transaction</remarks>
/// <param name="properties">The properties to read</param>
/// <param name="lookupId">The <see cref="Message.LookupId"/> of the message to read</param>
/// <param name="action">Receive or peek a message?</param>
/// <param name="timeout">The time allowed, defaults to infinite. Use <see cref="TimeSpan.Zero"/> to return without waiting</param>
/// <param name="transaction">can be NULL for no transaction, a <see cref="QueueTransaction"/>, <see cref="QueueTransaction.Single"/>, or <see cref="QueueTransaction.Dtc"/>.</param>
/// <returns>The message, or NULL if the message was not found or the receive times out</returns>
public unsafe Message Lookup(Properties properties, long lookupId, LookupAction action = LookupAction.ReceiveCurrent, TimeSpan?timeout = null, QueueTransaction transaction = null)
{
if (IsClosed)
{
throw new ObjectDisposedException(nameof(Queue));
}
uint timeoutMS = TimeoutInMs(timeout);
var msg = new Message();
int res;
msg.Props.SetForRead(properties);
for (;;) // loop because we might need to adjust memory size
{
var props = msg.Props.Allocate();
try
{
IntPtr txnHandle;
if (transaction.TryGetHandle(out txnHandle))
{
res = Native.ReceiveMessageByLookupId(_handle, lookupId, action, props, null, null, txnHandle);
}
else
{
res = Native.ReceiveMessageByLookupId(_handle, lookupId, action, props, null, null, transaction.InternalTransaction);
}
}
finally
{
msg.Props.Free();
}
if ((ErrorCode)res == ErrorCode.IOTimeout || (ErrorCode)res == ErrorCode.MessageNotFound)
{
return(null);
}
if (Native.NotEnoughMemory(res))
{
msg.Props.IncreaseBufferSize();
continue; // try again
}
if (Native.IsError(res))
{
throw new QueueException(res);
}
msg.Props.ResizeBody();
return(msg);
}
}
/// <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>Tries to receive a message from the queue</summary>
/// <remarks>Within a transaction you cannot receive a message that you moved to a subqueue</remarks>
/// <param name="properties">The properties to read</param>
/// <param name="timeout">The time allowed, defaults to infinite. Use <see cref="TimeSpan.Zero"/> to return without waiting</param>
/// <param name="transaction">can be NULL for no transaction, a <see cref="QueueTransaction"/>, <see cref="QueueTransaction.Single"/>, or <see cref="QueueTransaction.Dtc"/>.</param>
/// <returns>The message, or NULL if the receive times out</returns>
public Message Read(Properties properties = Properties.All, TimeSpan?timeout = null, QueueTransaction transaction = null)
{
return(_reader.Receive(properties, ReadAction.Receive, timeout, transaction, _cursorHandle));
}
/// <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);
}
}