ConnectionManagerT.cs

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//-----------------------------------------------------------------------
// <copyright file="ConnectionManagerT.cs" company="Marimer LLC">
//     Copyright (c) Marimer LLC. All rights reserved.
//     Website: https://cslanet.com
// </copyright>
// <summary>Provides an automated way to reuse open</summary>
//-----------------------------------------------------------------------
using System;
using Csla.Configuration;
using System.Data;
using Csla.Properties;
 
namespace Csla.Data
{
  public class ConnectionManager<C> : IDisposable where C : IDbConnection, new()
  {
    private static object _lock = new object();
    private C _connection;
    private string _connectionString;
    private string _label;
 
    public static ConnectionManager<C> GetManager(string database)
    {
      return GetManager(database, true);
    }
 
    public static ConnectionManager<C> GetManager(string database, string label)
    {
      return GetManager(database, true, label);
    }
 
    public static ConnectionManager<C> GetManager(string database, bool isDatabaseName)
    {
      return GetManager(database, isDatabaseName, "default");
    }
 
    public static ConnectionManager<C> GetManager(string database, bool isDatabaseName, string label)
    {
      if (isDatabaseName)
      {
#if NETSTANDARD2_0 || NET5_0
        throw new NotSupportedException("isDatabaseName==true");
#else
        var connection = ConfigurationManager.ConnectionStrings[database];
        if (connection == null)
          throw new System.Configuration.ConfigurationErrorsException(String.Format(Resources.DatabaseNameNotFound, database));
 
        var conn = ConfigurationManager.ConnectionStrings[database].ConnectionString;
        if (string.IsNullOrEmpty(conn))
          throw new System.Configuration.ConfigurationErrorsException(String.Format(Resources.DatabaseNameNotFound, database));
        database = conn;
#endif
      }
 
      ConnectionManager<C> mgr = null;
      var ctxName = GetContextName(database, label);
      lock (_lock)
      {
        var cached = ApplicationContext.LocalContext.GetValueOrNull(ctxName);
        if (cached != null)
        {
          mgr = (ConnectionManager<C>)cached;
          mgr.AddRef();
        }
      }
 
      if (mgr == null)
      {
        mgr = new ConnectionManager<C>(database, label);
        lock (_lock)
        {
          ApplicationContext.LocalContext[ctxName] = mgr;
          mgr.AddRef();
        }
      }
      return mgr;
    }
 
    private ConnectionManager(string connectionString, string label)
    {
      _label = label;
      _connectionString = connectionString;
 
      // open connection
      _connection = new C { ConnectionString = connectionString };
      _connection.Open();
    }
 
    private static string GetContextName(string connectionString, string label)
    {
      return "__db:" + label + "-" + connectionString;
    }
 
    public C Connection
    {
      get
      {
        return _connection;
      }
    }
 
    private int _refCount;
 
    public int RefCount
    {
      get { return _refCount; }
    }
 
    private void AddRef()
    {
      _refCount += 1;
    }
 
    private void DeRef()
    {
      _refCount -= 1;
      if (_refCount == 0)
      {
        _connection.Close();
        _connection.Dispose();
        lock (_lock)
          ApplicationContext.LocalContext.Remove(GetContextName(_connectionString, _label));
      }
    }
 
    public void Dispose()
    {
      DeRef();
    }
  }
}