FastDbAppender.cs :  » Logging-Tools » log4net » SampleAppendersApp » Appender » C# / CSharp Open Source

#region Copyright & License
//
// Copyright 2001-2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#endregion

using System.Data;
using System.Data.SqlClient;
using log4net.Appender;
using log4net.Core;

namespace SampleAppendersApp.Appender{
  /// <summary>
  /// Simple database appender
  /// </summary>
  /// <remarks>
  /// <para>
  /// This database appender is very simple and does not support a configurable
  /// data schema. The schema supported is hardcoded into the appender.
  /// Also by not extending the AppenderSkeleton base class this appender
  /// avoids the serializable locking that it enforces.
  /// </para>
  /// <para>
  /// This appender can be subclassed to change the database connection
  /// type, or the database schema supported.
  /// </para>
  /// <para>
  /// To change the database connection type the <see cref="GetConnection"/>
  /// method must be overridden.
  /// </para>
  /// <para>
  /// To change the database schema supported by the appender the <see cref="InitializeCommand"/>
  /// and <see cref="SetCommandValues"/> methods must be overridden.
  /// </para>
  /// </remarks>
  public class FastDbAppender : IAppender, IBulkAppender, IOptionHandler
  {
    private string m_name;
    private string m_connectionString;

    public string Name
    {
      get { return m_name; }
      set { m_name = value; }
    }

    public string ConnectionString
    {
      get { return m_connectionString; }
      set { m_connectionString = value; }
    }

    public virtual void ActivateOptions() 
    {
    }

    public virtual void Close()
    {
    }

    public virtual void DoAppend(LoggingEvent loggingEvent)
    {
      using(IDbConnection connection = GetConnection())
      {
        // Open the connection for each event, this takes advantage
        // of the builtin connection pooling
        connection.Open();

        using(IDbCommand command = connection.CreateCommand())
        {
          InitializeCommand(command);

          SetCommandValues(command, loggingEvent);
          command.ExecuteNonQuery();
        }
      }
    }

    public virtual void DoAppend(LoggingEvent[] loggingEvents)
    {
      using(IDbConnection connection = GetConnection())
      {
        // Open the connection for each event, this takes advantage
        // of the builtin connection pooling
        connection.Open();

        using(IDbCommand command = connection.CreateCommand())
        {
          InitializeCommand(command);

          foreach(LoggingEvent loggingEvent in loggingEvents)
          {
            SetCommandValues(command, loggingEvent);
            command.ExecuteNonQuery();
          }
        }
      }
    }

    /// <summary>
    /// Create the connection object
    /// </summary>
    /// <returns>the connection</returns>
    /// <remarks>
    /// <para>
    /// This implementation returns a <see cref="SqlConnection"/>.
    /// To change the connection subclass this appender and
    /// return a different connection type.
    /// </para>
    /// </remarks>
    virtual protected IDbConnection GetConnection()
    {
      return new SqlConnection(m_connectionString);
    }

    /// <summary>
    /// Initialize the command object supplied
    /// </summary>
    /// <param name="command">the command to initialize</param>
    /// <remarks>
    /// <para>
    /// This method must setup the database command and the
    /// parameters.
    /// </para>
    /// </remarks>
    virtual protected void InitializeCommand(IDbCommand command)
    {
      command.CommandType = CommandType.Text;
      command.CommandText = "INSERT INTO [LogTable] ([Time],[Logger],[Level],[Thread],[Message]) VALUES (@Time,@Logger,@Level,@Thread,@Message)";

      IDbDataParameter param = null;
      
      // @Time
      param = command.CreateParameter();
      param.ParameterName = "@Time";
      param.DbType = DbType.DateTime;
      command.Parameters.Add(param);
      
      // @Logger
      param = command.CreateParameter();
      param.ParameterName = "@Logger";
      param.DbType = DbType.String;
      command.Parameters.Add(param);
      
      // @Level
      param = command.CreateParameter();
      param.ParameterName = "@Level";
      param.DbType = DbType.String;
      command.Parameters.Add(param);
      
      // @Thread
      param = command.CreateParameter();
      param.ParameterName = "@Thread";
      param.DbType = DbType.String;
      command.Parameters.Add(param);
      
      // @Message
      param = command.CreateParameter();
      param.ParameterName = "@Message";
      param.DbType = DbType.String;
      command.Parameters.Add(param);
    }

    /// <summary>
    /// Set the values for the command parameters
    /// </summary>
    /// <param name="command">the command to update</param>
    /// <param name="loggingEvent">the current logging event to retrieve the values from</param>
    /// <remarks>
    /// <para>
    /// Set the values of the parameters created by the
    /// <see cref="InitializeCommand"/> method.
    /// </para>
    /// </remarks>
    virtual protected void SetCommandValues(IDbCommand command, LoggingEvent loggingEvent)
    {
      ((IDbDataParameter)command.Parameters["@Time"]).Value = loggingEvent.TimeStamp;
      ((IDbDataParameter)command.Parameters["@Logger"]).Value = loggingEvent.LoggerName;
      ((IDbDataParameter)command.Parameters["@Level"]).Value = loggingEvent.Level.Name;
      ((IDbDataParameter)command.Parameters["@Thread"]).Value = loggingEvent.ThreadName;
      ((IDbDataParameter)command.Parameters["@Message"]).Value = loggingEvent.RenderedMessage;
    }
  }
}