ServerLogFileReader.cs :  » Build-Systems » CruiseControl.NET » ThoughtWorks » CruiseControl » Core » Logging » C# / CSharp Open Source

using System.Configuration;
using System.IO;
using ThoughtWorks.CruiseControl.Core.Util;

namespace ThoughtWorks.CruiseControl.Core.Logging{
  public class ServerLogFileReader
  {
    private const int DefaultMaxLines = 80;
    private string filename;
    private int maxLines;

    public ServerLogFileReader() : this(ReadFilenameFromConfig(), ReadMaxLinesFromConfig())
    {}

    public ServerLogFileReader(string filename, int maxLines)
    {
      this.filename = filename;
      this.maxLines = maxLines;
    }

    public string Read()
    {
      return Read(EnumeratorDirection.Forward);
    }

    public string Read(EnumeratorDirection direction)
    {
      return Read(direction, null);
    }

    public string Read(string project)
    {
      return Read(EnumeratorDirection.Forward, '[' + project);
    }

    private string Read(EnumeratorDirection direction, string match)
    {
      CircularArray buffer = new CircularArray(maxLines);
      using (Stream stream = OpenFile())
      {
        using (StreamReader reader = new StreamReader(stream,System.Text.Encoding.Default))
        {
          string line;
          while ((line = reader.ReadLine()) != null)
          {
            if (match == null || line.IndexOf(match) >= 0)
              buffer.Add(line);
                        // TODO: Messages can contain embedded newlines (e.g., exception reports).  
                        // TODO: This code should be changed to capture those "follow on" lines as well.
          }
        }
      }
      return buffer.ToString(direction);
    }

    private Stream OpenFile()
    {
      return new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
    }

    private static string ReadFilenameFromConfig()
    {
      string filename = ConfigurationManager.AppSettings["ServerLogFilePath"];
            return string.IsNullOrEmpty(filename) ? "ccnet.log" : filename;
    }

    private static int ReadMaxLinesFromConfig()
    {
            string linesToReadConfig = ConfigurationManager.AppSettings["ServerLogFileLines"];
            return (linesToReadConfig != null) ? int.Parse(ConfigurationManager.AppSettings["ServerLogFileLines"]) : DefaultMaxLines;
    }
  }
}