removing old position reports from SQLite storage

AIS/bsmd.AIS2Service/AISManager.cs

@@ -17,7 +17,8 @@ namespace bsmd.AIS2Service
         private static readonly ILog _log = LogManager.GetLogger(typeof(AISManager));
         private static readonly ConcurrentDictionary<int, AIS_Target> _sitRepList = new ConcurrentDictionary<int, AIS_Target>();
         private static readonly ConcurrentQueue<AIS_Target> _dbSaveTargets = new ConcurrentQueue<AIS_Target>();
-        private static Timer _staleTargetTimer;
+        private static Timer _staleTargetTimer; // cleanup sitrep
+        private static Timer _stalePosReportTimer; // clean db
 
         public static async void Start()
         {
@@ -41,8 +42,9 @@ namespace bsmd.AIS2Service
                 task.FatalErrorOccurred += Task_FatalErrorOccurred;
             }
 
-            _staleTargetTimer = new Timer(StaleTimerCheck, null, 0, 60000); // check every minute            
-
+            // init timer tasks
+            _staleTargetTimer = new Timer(StaleTargetTimerCheck, null, 0, 60000); // check every minute, start immediately            
+            _stalePosReportTimer = new Timer(StalePosReportCheck, sqliteStorage, 0, 60000 * 10); // every ten minutes, 
         }
 
         private static void Task_FatalErrorOccurred(object sender, EventArgs e)
@@ -50,7 +52,7 @@ namespace bsmd.AIS2Service
             throw new NotImplementedException("TBD: shutdown the whole operation?");
         }
 
-        private static void StaleTimerCheck(object state)
+        private static void StaleTargetTimerCheck(object state)
         {
             List<int> removeKeyList = new List<int>();
             foreach (int key in _sitRepList.Keys)
@@ -68,6 +70,14 @@ namespace bsmd.AIS2Service
             }
         }
 
+        private static void StalePosReportCheck(object state)
+        {
+            if (state is AIS_SQLiteStorage storage)
+            {
+                storage.RemoveOldPosReports();
+            }
+        }
+
         public static void Stop()
         {
             foreach (var task in _tasks)

AIS/bsmd.AIS2Service/AIS_SQLiteStorage.cs

@@ -220,11 +220,33 @@ namespace bsmd.AIS2Service
                     _storageTargets.Add(target.MMSI, target);
                 }
                 reader.Close();
+                cmd.Dispose();
             });
 
             return _storageTargets;
         }
 
+        /// <summary>
+        /// cleanup DB by removing past pos reports
+        /// </summary>
+        public void RemoveOldPosReports()
+        {
+            try
+            {
+                string removeQuery = string.Format("DELETE FROM posreport where timestamp <= datetime('now', '-{0} day')",
+                    Properties.Settings.Default.PosReportDBCleanupDays);
+                SQLiteCommand cmd = new SQLiteCommand(removeQuery, _connection);
+                int rows = cmd.ExecuteNonQuery();
+                if(rows > 0)
+                    _log.InfoFormat("Removed {0} position reports older than {1} days", rows, Properties.Settings.Default.PosReportDBCleanupDays);
+                cmd.Dispose();
+            }
+            catch(SQLiteException ex)
+            {
+                _log.ErrorFormat("Failed to delete stale position reports: {0}", ex.Message);
+            }
+        }
+
         #endregion
 
         #region IAISThread implementation

AIS/bsmd.AIS2Service/App.config

@@ -52,6 +52,9 @@
             <setting name="SQLiteDBConnectionString" serializeAs="String">
                 <value>Data Source=ais_initial.db;Version=3;</value>
             </setting>
+            <setting name="PosReportDBCleanupDays" serializeAs="String">
+                <value>7</value>
+            </setting>
         </bsmd.AIS2Service.Properties.Settings>
     </applicationSettings>
 </configuration>

AIS/bsmd.AIS2Service/Properties/Settings.Designer.cs

@@ -76,5 +76,14 @@ namespace bsmd.AIS2Service.Properties {
                 return ((string)(this["SQLiteDBConnectionString"]));
             }
         }
+        
+        [global::System.Configuration.ApplicationScopedSettingAttribute()]
+        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+        [global::System.Configuration.DefaultSettingValueAttribute("7")]
+        public int PosReportDBCleanupDays {
+            get {
+                return ((int)(this["PosReportDBCleanupDays"]));
+            }
+        }
     }
 }

AIS/bsmd.AIS2Service/Properties/Settings.settings

@@ -20,5 +20,8 @@
     <Setting Name="SQLiteDBConnectionString" Type="System.String" Scope="Application">
       <Value Profile="(Default)">Data Source=ais_initial.db;Version=3;</Value>
     </Setting>
+    <Setting Name="PosReportDBCleanupDays" Type="System.Int32" Scope="Application">
+      <Value Profile="(Default)">7</Value>
+    </Setting>
   </Settings>
 </SettingsFile>