Initial Commit

Systems/SystemAvailable.cs

@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Reflection;
+
+namespace Sdaleo.Systems
+{
+    /// <summary>
+    /// This class will try to load the needed assembly(s) for the specified DB System.
+    /// If the Assembly load fails, we know that this system won't work (isn't available)
+    /// </summary>
+    public static class SystemAvailable
+    {
+        /// <summary>
+        /// Keep track of previous checks, no need to do it over and over again
+        /// </summary>
+        private static Dictionary<DBSystem, bool> _PrevCheckMap = new Dictionary<DBSystem, bool>();
+
+        /// <summary>
+        /// Try to load the assembly(s) for the specified DB System
+        /// </summary>
+        /// <param name="dbsystem">DB system to load assembly(s) for</param>
+        /// <returns>true, if successfully loaded, false otherwise</returns>
+        public static bool Check(DBSystem dbsystem)
+        {
+            try
+            {
+                // Performance Optimization
+                if (_PrevCheckMap.ContainsKey(dbsystem))
+                    return _PrevCheckMap[dbsystem];
+
+                // ... Else we must check
+                switch (dbsystem)
+                {
+                    case DBSystem.SQL_SERVER:
+                        {
+                            Assembly asm = Assembly.Load("System.Data");
+                            _PrevCheckMap[dbsystem] = (asm != null);
+                            return _PrevCheckMap[dbsystem];
+                        }
+
+                    case DBSystem.SQL_CE:
+                        {
+                            Assembly asm = Assembly.Load("System.Data.SqlServerCe");
+                            _PrevCheckMap[dbsystem] = (asm != null);
+                            return _PrevCheckMap[dbsystem];
+                        }
+
+                    case DBSystem.ADVANTAGE:
+                        {
+                            Assembly asm = Assembly.Load("Advantage.Data.Provider");
+                            _PrevCheckMap[dbsystem] = (asm != null);
+                            return _PrevCheckMap[dbsystem];
+                        }
+
+                    case DBSystem.CTREE:
+                        {
+                            Assembly asm = Assembly.Load("System.Data.SqlServerCe");
+                            _PrevCheckMap[dbsystem] = (asm != null);
+                            return _PrevCheckMap[dbsystem];
+                        }
+
+                    case DBSystem.MYSQL:
+                        {
+                            Assembly asm = Assembly.Load("System.Data.SqlServerCe");
+                            _PrevCheckMap[dbsystem] = (asm != null);
+                            return _PrevCheckMap[dbsystem];
+                        }
+
+                    case DBSystem.POSTGRES:
+                        {
+                            Assembly asm = Assembly.Load("Devart.Data");
+                            if(asm != null)
+                               asm = Assembly.Load("Devart.Data.PostgreSql");
+                            _PrevCheckMap[dbsystem] = (asm != null);
+                            return _PrevCheckMap[dbsystem];
+                        }
+
+                    default:
+                        _PrevCheckMap[dbsystem] = false;
+                        return false;
+                }
+            }
+            catch (Exception) { /* ignore */ }
+            _PrevCheckMap[dbsystem] = false;
+            return false;
+        }
+    }
+}