New: Limit grabs to 1 per second to reduce rapid API calls

src/NzbDrone.Core/Download/ProcessDownloadDecisions.cs

@@ -2,8 +2,10 @@
 using System.Collections.Generic;
 using System.Linq;
 using NLog;
+using NzbDrone.Common;
 using NzbDrone.Core.DecisionEngine;
 using NzbDrone.Core.Download.Pending;
+using NzbDrone.Core.Parser.Model;
 
 namespace NzbDrone.Core.Download
 {
@@ -37,6 +39,9 @@ namespace NzbDrone.Core.Download
             var grabbed = new List<DownloadDecision>();
             var pending = new List<DownloadDecision>();
 
+            //Limits to 1 grab every 1 second to reduce rapid API hits
+            using (var rateGate = new RateGate(1, TimeSpan.FromSeconds(1)))
+            {
                 foreach (var report in prioritizedDecisions)
                 {
                     var remoteEpisode = report.RemoteEpisode;
@@ -71,6 +76,7 @@ namespace NzbDrone.Core.Download
 
                     try
                     {
+                        rateGate.WaitToProceed();
                         _downloadService.DownloadReport(remoteEpisode);
                         grabbed.Add(report);
                     }
@@ -81,6 +87,7 @@ namespace NzbDrone.Core.Download
                         _logger.WarnException("Couldn't add report to download queue. " + remoteEpisode, e);
                     }
                 }
+            }           
 
             return new ProcessedDecisions(grabbed, pending, decisions.Where(d => d.Rejected).ToList());
         }