#region License
// The PostgreSQL License
//
// Copyright (C) 2018 The Npgsql Development Team
//
// Permission to use, copy, modify, and distribute this software and its
// documentation for any purpose, without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph and the following two paragraphs appear in all copies.
//
// IN NO EVENT SHALL THE NPGSQL DEVELOPMENT TEAM BE LIABLE TO ANY PARTY
// FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
// INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
// DOCUMENTATION, EVEN IF THE NPGSQL DEVELOPMENT TEAM HAS BEEN ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
//
// THE NPGSQL DEVELOPMENT TEAM SPECIFICALLY DISCLAIMS ANY WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
// ON AN "AS IS" BASIS, AND THE NPGSQL DEVELOPMENT TEAM HAS NO OBLIGATIONS
// TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
#endregion
using System;
using System.Data.Common;
using System.Reflection;
using JetBrains.Annotations;
namespace Npgsql
{
///
/// A factory to create instances of various Npgsql objects.
///
[Serializable]
public sealed class NpgsqlFactory : DbProviderFactory, IServiceProvider
{
///
/// Gets an instance of the .
/// This can be used to retrieve strongly typed data objects.
///
public static readonly NpgsqlFactory Instance = new NpgsqlFactory();
NpgsqlFactory() {}
///
/// Returns a strongly typed instance.
///
[NotNull] public override DbCommand CreateCommand() => new NpgsqlCommand();
///
/// Returns a strongly typed instance.
///
[NotNull] public override DbConnection CreateConnection() => new NpgsqlConnection();
///
/// Returns a strongly typed instance.
///
[NotNull] public override DbParameter CreateParameter() => new NpgsqlParameter();
///
/// Returns a strongly typed instance.
///
[NotNull] public override DbConnectionStringBuilder CreateConnectionStringBuilder() => new NpgsqlConnectionStringBuilder();
///
/// Returns a strongly typed instance.
///
[NotNull] public override DbCommandBuilder CreateCommandBuilder() => new NpgsqlCommandBuilder();
///
/// Returns a strongly typed instance.
///
[NotNull] public override DbDataAdapter CreateDataAdapter() => new NpgsqlDataAdapter();
#region IServiceProvider Members
///
/// Gets the service object of the specified type.
///
/// An object that specifies the type of service object to get.
/// A service object of type serviceType, or null if there is no service object of type serviceType.
[CanBeNull]
public object GetService([NotNull] Type serviceType)
{
if (serviceType == null)
throw new ArgumentNullException(nameof(serviceType));
// In legacy Entity Framework, this is the entry point for obtaining Npgsql's
// implementation of DbProviderServices. We use reflection for all types to
// avoid any dependencies on EF stuff in this project.
if (serviceType.FullName == "System.Data.Common.DbProviderServices")
{
// User has requested a legacy EF DbProviderServices implementation. Check our cache first.
if (_legacyEntityFrameworkServices != null)
return _legacyEntityFrameworkServices;
// First time, attempt to find the EntityFramework5.Npgsql assembly and load the type via reflection
var assemblyName = typeof(NpgsqlFactory).GetTypeInfo().Assembly.GetName();
assemblyName.Name = "EntityFramework5.Npgsql";
Assembly npgsqlEfAssembly;
try {
npgsqlEfAssembly = Assembly.Load(new AssemblyName(assemblyName.FullName));
} catch (Exception e) {
throw new Exception("Could not load EntityFramework5.Npgsql assembly, is it installed?", e);
}
Type npgsqlServicesType;
if ((npgsqlServicesType = npgsqlEfAssembly.GetType("Npgsql.NpgsqlServices")) == null ||
npgsqlServicesType.GetProperty("Instance") == null)
throw new Exception("EntityFramework5.Npgsql assembly does not seem to contain the correct type!");
return _legacyEntityFrameworkServices = npgsqlServicesType.GetProperty("Instance", BindingFlags.Public | BindingFlags.Static).GetMethod.Invoke(null, new object[0]);
}
return null;
}
[CanBeNull]
static object _legacyEntityFrameworkServices;
#endregion
}
}