Core/DB: Some DB improvements

Source/Framework/Database/SQLQueryHolder.cs

@@ -16,45 +16,62 @@
  */
 
 using System.Collections.Generic;
+using System.Threading.Tasks;
 
 namespace Framework.Database
 {
     public class SQLQueryHolder<T>
     {
-        public void SetQuery(T index, PreparedStatement _stmt)
-        {
-            m_queries[index] = new SQLResultPair(_stmt);
-        }
+        public Dictionary<T, PreparedStatement> m_queries = new Dictionary<T, PreparedStatement>();
+        Dictionary<T, SQLResult> _results = new Dictionary<T, SQLResult>();
 
         public void SetQuery(T index, string sql, params object[] args)
         {
             SetQuery(index, new PreparedStatement(string.Format(sql, args)));
         }
 
-        public void SetResult(T index, SQLResult _result)
+        public void SetQuery(T index, PreparedStatement stmt)
         {
-            m_queries[index].result = _result;
+            m_queries[index] = stmt;
+        }
+
+        public void SetResult(T index, SQLResult result)
+        {
+            _results[index] = result;
         }
 
         public SQLResult GetResult(T index)
         {
-            if (!m_queries.ContainsKey(index))
+            if (!_results.ContainsKey(index))
                 return new SQLResult();
 
-            return m_queries[index].result;
-        }
-
-        public Dictionary<T, SQLResultPair> m_queries = new Dictionary<T, SQLResultPair>();
-
-        public class SQLResultPair
-        {
-            public SQLResultPair(PreparedStatement _stmt)
-            {
-                stmt = _stmt;
-            }
-
-            public PreparedStatement stmt;
-            public SQLResult result;
+            return _results[index];
         }
     }
+
+    class SQLQueryHolderTask<R> : ISqlOperation
+    {
+        SQLQueryHolder<R> m_holder;
+        TaskCompletionSource<SQLQueryHolder<R>> m_result;
+
+        public SQLQueryHolderTask(SQLQueryHolder<R> holder)
+        {
+            m_holder = holder;
+            m_result = new TaskCompletionSource<SQLQueryHolder<R>>();
+        }
+
+        public bool Execute<T>(MySqlBase<T> mySqlBase)
+        {
+            if (m_holder == null)
+                return false;
+
+            // execute all queries in the holder and pass the results
+            foreach (var pair in m_holder.m_queries)
+                m_holder.SetResult(pair.Key, mySqlBase.Query(pair.Value));
+
+            return m_result.TrySetResult(m_holder);
+        }
+
+        public Task<SQLQueryHolder<R>> GetFuture() { return m_result.Task; }
+    }
 }