#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2012 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Common;

namespace HeuristicLab.Services.Hive.Interfaces {
  /// <summary>
  /// This interface provides functionality to create transactionscoped and non-transactionscoped database connection.
  /// It also helps to clean the connections after their last usage.
  /// </summary>
  public interface IConnectionProvider {
    /// <summary>
    /// Creates or returns an already opened database connection for the given connectionStringName.
    /// If there is no surrounding transaction, a new connection will be returned. This connection
    /// must be closed by using the ReleaseConnection method.
    /// If there is a surrounding transaction and no connection exists for the connectionStringName,
    /// a new connection will be returned.
    /// If there is a surrounding transaction and an existing connection for the connectionStringName,
    /// the existing connection will be returned.
    /// </summary>
    /// <param name="connectionStringName">The name of the connectionString within the app.config (or web.config) file</param>
    /// <returns>
    /// A new connection to the database. If a transaction is already open for this connectionString, 
    /// the same connection will be returned. Whenever a connection is not needed anymore, call the 
    /// ReleaseConnection to release it properly.
    /// </returns>
    DbConnection GetOpenConnection(string connectionStringName);
    /// <summary>
    /// Releases a given database connection only if there is no active transaction.
    /// Note: Connections within transactions will be released automatically after the transaction ended,
    /// if the user created the connection with GetOpenConnection within a transaction.
    /// </summary>
    /// <param name="connection"></param>
    void ReleaseConnection(DbConnection connection);
  }
}