AzureStreamingLoggerProvider

AzureStreamingLoggerProvider.cs

public class AzureStreamingLoggerProvider : ILoggerProvider
{
    public ILogger Create(string name)
    {
        return new AzureLogger(name);
    }

    private class AzureLogger : ILogger
    {
        private readonly string _name;
        private readonly object _writerLock = new object();
        private int? _numFiles;
        private int _numLines;

        private const int MaxLines = 1000;

        public AzureLogger(string name)
        {
            _name = name;
        }

        public IDisposable BeginScope(object state)
        {
            return null;
        }

        public bool IsEnabled(LogLevel logLevel)
        {
            return true;
        }

        public void Write(LogLevel logLevel, int eventId, object state, Exception exception, Func<object, Exception, string> formatter)
        {
            var message = string.Empty;
            if (formatter != null)
            {
                message = formatter(state, exception);
            }
            else
            {
                if (state != null)
                {
                    message += state;
                }
                if (exception != null)
                {
                    message += Environment.NewLine + exception;
                }
            }

            if (string.IsNullOrEmpty(message))
            {
                return;
            }

            var severity = logLevel.ToString().ToUpperInvariant();

            Log(string.Format("[{0}:{1}] {2}", severity, _name, message));
        }

        private void Log(string text)
        {
            var applicationLogFilesPath = Path.Combine(Environment.GetEnvironmentVariable("HOME"), "LogFiles", "Application");

            lock (_writerLock)
            {
                if (_numFiles == null || _numLines > MaxLines)
                {
                    if (_numFiles == null)
                    {
                        var fileNumbers = Directory.GetFiles(applicationLogFilesPath, "logs_*.txt")
                                             .Select(Path.GetFileNameWithoutExtension)
                                             .Select(p => p.Substring("logs_".Length))
                                             .Select(Int32.Parse);

                        if (fileNumbers.Any())
                        {
                            _numFiles = fileNumbers.Max();
                        }
                    }

                    _numFiles = _numFiles ?? 0;
                    _numLines = 0;
                    _numFiles++;

                    Directory.CreateDirectory(applicationLogFilesPath);
                }

                var path = Path.Combine(applicationLogFilesPath, "logs_" + _numFiles + ".txt");

                File.AppendAllText(path, text + Environment.NewLine);
                _numLines++;
            }
        }
    }
}