better var/method naming for confirm sequence number

also start count at 1 not 0 since the latter has a special meaning in basic.ack

Author: rade

projects/client/RabbitMQ.Client/src/client/api/IModel.cs

@@ -143,9 +143,9 @@ public interface IModel: IDisposable
         ///== null.</summary>
         bool IsOpen { get; }
 
-        ///<summary>Returns the number of messages published since the
-        ///channel was put in confirm mode.</summary>
-        ulong? PublishedMessageCount { get; }
+        ///<summary>Returns the sequence number of the next message to be published that requires confirmation. 0 if we are not in confirm mode.
+        ///</summary>
+        ulong NextPublishSeqNo { get; }
 
         ///<summary>Construct a completely empty content header for
         ///use with the Basic content class.</summary>

projects/client/RabbitMQ.Client/src/client/impl/ModelBase.cs

@@ -89,7 +89,7 @@ public abstract class ModelBase : IFullModel
         public ManualResetEvent m_flowControlBlock = new ManualResetEvent(true);
         private readonly object m_flowSendLock = new object();
 
-        private ulong? m_pubMsgCount = null;
+        private ulong m_nextPubSeqNo;
 
         public event ModelShutdownEventHandler ModelShutdown
         {
@@ -458,11 +458,11 @@ public bool IsOpen
             }
         }
 
-        public ulong? PublishedMessageCount
+        public ulong NextPublishSeqNo
         {
             get
             {
-                return m_pubMsgCount;
+                return m_nextPubSeqNo;
             }
         }
 
@@ -753,7 +753,7 @@ public void ConfirmSelect() {
         }
 
         public void ConfirmSelect(bool nowait) {
-            m_pubMsgCount = 0;
+            m_nextPubSeqNo = 1;
             _Private_ConfirmSelect(nowait);
         }
 
@@ -994,8 +994,7 @@ public void BasicPublish(string exchange,
             {
                 basicProperties = CreateBasicProperties();
             }
-            if (m_pubMsgCount.HasValue)
-                m_pubMsgCount++;
+            if (m_nextPubSeqNo > 0) m_nextPubSeqNo++;
             _Private_BasicPublish(exchange,
                                   routingKey,
                                   mandatory,