Implemented skip and maxcount parameters for Tapeti.Cmd import

Tapeti.Cmd/Verbs/ImportVerb.cs

@@ -29,6 +29,12 @@ namespace Tapeti.Cmd.Verbs
         [Option('e', "exchange", HelpText = "If specified publishes to the originating exchange using the original routing key. By default these are ignored and the message is published directly to the originating queue.")]
         public bool PublishToExchange { get; set; }
         
+        [Option("skip", HelpText = "(Default: 0) Number of messages in the input to skip. Useful if a previous import was interrupted.", Default = 0)]
+        public int Skip { get; set; }
+
+        [Option('n', "maxcount", HelpText = "(Default: all) Maximum number of messages to import.")]
+        public int? MaxCount { get; set; }
+
         [Option("maxrate", HelpText = "The maximum amount of messages per second to import.")]
         public int? MaxRate { get; set; }
         
@@ -61,6 +67,7 @@ namespace Tapeti.Cmd.Verbs
 
             var totalCount = messageSerializer.GetMessageCount();
             var messageCount = 0;
+            var skip = Math.Max(options.Skip, 0);
 
 
             ProgressBar progress = null;
@@ -70,9 +77,12 @@ namespace Tapeti.Cmd.Verbs
             {
                 foreach (var message in messageSerializer.Deserialize(channel))
                 {
-                    if (console.Cancelled)
+                    if (console.Cancelled || (options.MaxCount.HasValue && messageCount >= options.MaxCount.Value))
                         break;
 
+                    if (skip > 0)
+                        skip--;
+                    else
                         rateLimiter.Execute(() =>
                         {
                             if (console.Cancelled)

docs/tapeticmd.rst

@@ -82,6 +82,12 @@ Read messages from disk as previously exported and publish them to a queue.
 -e, --exchange
   If specified publishes to the originating exchange using the original routing key. By default these are ignored and the message is published directly to the originating queue.
 
+--skip <count>
+  Number of messages in the input to skip. Useful if a previous import was interrupted.
+
+-n <count>, --maxcount <count>
+  Maximum number of messages to import. If not specified all messages are imported.
+
 -s <method>, --serialization <method>
   The method used to serialize the message for import or export. Valid options: SingleFileJSON, EasyNetQHosepipe. Defaults to SingleFileJSON. See Serialization methods below for more information.