Rescanning the configuration file in groovy - groovy

I need to implement a configuration file, which should be rescanned periodically or after an edit, what should I do?
I tried
config = new ConfigSlurper().parse(Config);
its not working when Config.groovy changes dynamically.
Example (from comment below)
MyConfig.groovy
class MyConfig {
public static ConfigObject config
public static void run() {
config = new ConfigSlurper().parse(Config)
}
public static void printconfig() {
println config.options.video.enable
}
}
MyConfig.run()
for( int i = 0 ; i < 10 ; i++ ) {
Thread.sleep(3000)
MyConfig.printconfig()
}
Config.groovy
options { video { enable = false } }

You seem to parse the config file once, then never re-parse it...
What you could do is store the last modified date of the file, and call run() again from printConfig if it detects the file has been modified...
Also, I assume you have a copy/paste error... Shouldn't:
config = new ConfigSlurper().parse(Config)
be:
config = new ConfigSlurper().parse( MyConfig.class.getResource( 'Config.groovy' ) )
Or something?

Related

No logging with configuration made in code using latest version of slf4net (1.0.0)

I'm using the slf4net.log4net nuget package to handle logging in a project. Because it must be possible for the loglevel to change at runtime, I made the configuration in code. The issue is that this code works fine in slf4net.log4net version 0.1.32.1 but when I upgrade it to version 1.0.0, the logfile is created, but the logs are not present on the logfile. I've created a dummy project to show this issue. I do not see how I can add a zip file here, so I'll just post the code here. It is a console app in net framework 4.7.2;
class Program
{
private static string GetLoggingPath()
{
var path = Path.Combine(
Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData,
Environment.SpecialFolderOption.DoNotVerify), "LoggingTesting");
Directory.CreateDirectory(path);
return path;
}
static void Main(string[] args)
{
var layout = new PatternLayout
{
ConversionPattern = "%d{ABSOLUTE}: %message %newline"
};
layout.ActivateOptions();
var fileAppender = new RollingFileAppender();
fileAppender.RollingStyle = log4net.Appender.RollingFileAppender.RollingMode.Date;
fileAppender.Layout = layout;
var path = GetLoggingPath();
fileAppender.File = path + System.IO.Path.DirectorySeparatorChar + "LISlogging_.txt";
fileAppender.AppendToFile = true;
fileAppender.PreserveLogFileNameExtension = true;
fileAppender.StaticLogFileName = false;
fileAppender.DatePattern = "yyyy-MM-dd";
fileAppender.MaxSizeRollBackups = 10;
fileAppender.ActivateOptions();
ILoggerRepository repository = log4net.LogManager.GetRepository(Assembly.GetCallingAssembly());
BasicConfigurator.Configure(repository, fileAppender);
var root = (repository as Hierarchy)?.Root;
if (root == null) return;
root.Level = log4net.Core.Level.All;
// Create log4net ILoggerFactory and set the resolver
var factory = new slf4net.log4net.Log4netLoggerFactory();
var resolver = new SimpleFactoryResolver(factory);
slf4net.LoggerFactory.SetFactoryResolver(resolver);
// trigger logging
var log = slf4net.LoggerFactory.GetLogger(typeof(Program));
log.Info("log this line");
}
}
public class SimpleFactoryResolver : IFactoryResolver
{
private readonly slf4net.ILoggerFactory _factory;
public SimpleFactoryResolver(slf4net.ILoggerFactory factory)
{
_factory = factory;
}
public slf4net.ILoggerFactory GetFactory()
{
return _factory;
}
}
This dummy project was created in .net framework, but I need this in a .net core project. That is why I need to version 1.0.0 .
I've also post this issue on the github page of slf4net (because it looks like a bug) : https://github.com/ef-labs/slf4net/issues/6
My main question for here on stack overflow is if there is a workaround so this can work with slf4net.log4net version 1.0.0
I've found a workaround for this. Maybe not the cleanest solution but it works. If anyone knows a cleaner solution please add it here.
When looking at the slf4net.log4net code I found out that when it tries to configure log4net it uses xml files or config files, which is a nightmare if you want to set the loglevel at runtime. You can pass a customconfigurator as parameter of the Log4netLoggerFactory . This customconfigurator needs to implement IXmlConfigurator.
The CustomConfigurator I've made accepts an IAppender and a loglevel (log4net.Core.Level). In the implementation of the Configure(ICollection(ILoggerRepository repository) method. I've set the root log level and Configured with the BasicConfigurator.
The CustomConfigurator looks like this:
public class CustomConfigurator: IXmlConfigurator
{
private readonly IAppender _appender;
private readonly log4net.Core.Level _logLevel;
public CustomConfigurator(IAppender appender, log4net.Core.Level logLevel)
{
_appender = appender;
_logLevel = logLevel;
}
public ICollection Configure(ILoggerRepository repository)
{
var root = (repository as Hierarchy)?.Root;
if (root != null)
{
root.Level = _logLevel;
}
return BasicConfigurator.Configure(repository, _appender);
}
public ICollection Configure(ILoggerRepository repository, XmlElement element)
{
return XmlConfigurator.Configure(repository, element);
}
public ICollection Configure(ILoggerRepository repository, FileInfo configFile)
{
return XmlConfigurator.Configure(repository, configFile);
}
public ICollection ConfigureAndWatch(ILoggerRepository repository, FileInfo configFile)
{
return XmlConfigurator.ConfigureAndWatch(repository, configFile);
}
}
Now you can create an appender in code like shown in the question (until fileappender.ActivateOptions) Then when constructing the log4netLoggerFactory you pass an instance of CustomConfigurator which takes the fileAppender and a loglevel as parameter.
var factory = new slf4net.log4net.Log4netLoggerFactory(new CustomConfigurator(fileAppender, Level.All));
var resolver = new SimpleFactoryResolver(factory);
slf4net.LoggerFactory.SetFactoryResolver(resolver);
This should work.

Using RazorEngine with TextWriter

I want to use RazorEngine to generate some html files. It's easy to generate strings first, then write them to files. But if the generated strings are too large, that will cause memory issues.
So I wonder is there a non-cached way to use RazorEngine, like using StreamWriter as its output rather than a string.
I google this for a while, but with no luck.
I think use a custom base template should be the right way, but the documents are so few(even out of date) on the offcial homepage of RazorEngine.
Any hint will be helpful!
OK. I figured it out.
Create a class that inherits TemplateBase<T>, and take a TextWrite parameter in the constructor.
public class TextWriterTemplate<T> : TemplateBase<T>
{
private readonly TextWriter _tw;
public TextWriterTemplate(TextWriter tw)
{
_tw = tw;
}
// override Write and WriteLiteral methods, write text using the TextWriter.
public override void Write(object value)
{
_tw.Write(value);
}
public override void WriteLiteral(string literal)
{
_tw.Write(literal);
}
}
Then use the template as this:
private static void Main(string[] args)
{
using (var sw = new StreamWriter(#"output.txt"))
{
var config = new FluentTemplateServiceConfiguration(c =>
c.WithBaseTemplateType(typeof(TextWriterTemplate<>))
.ActivateUsing(context => (ITemplate)Activator.CreateInstance(context.TemplateType, sw))
);
using (var service = new TemplateService(config))
{
service.Parse("Hello #Model.Name", new {Name = "Waku"}, null, null);
}
}
}
The content of output.txt should be Hello WAKU.

NLog MemoryTarget maximum size

Since I have a global exception handler that reports uncaught errors via e-mail, next step is to add some context to it by having some 10-20 last lines of log that are collected.
So I am using MemoryTarget like so:
MemoryTarget _logTarget;
_logTarget = new MemoryTarget();
_logTarget.Layout = "${longdate}|${level:uppercase=true}|${logger}|${message}${exception}";
LoggingRule loggingRule = new LoggingRule("*", LogLevel.Debug, _logTarget);
LogManager.Configuration.AddTarget("exceptionMemory", _logTarget);
LogManager.Configuration.LoggingRules.Add(loggingRule);
LogManager.Configuration.Reload();
Apps containing this should run forever, and if I leave logs in memory, unchecked, I'll have neatly designed memory leak.
How to address this? How to truncate MemoryTarget.Logs to have at most say 100 lines?
Your best bet is probably to write your own MemoryTarget... Something like this (untested) should work.
namespace NLog.Targets
{
using System.Collections.Generic;
[Target("LimitedMemory")]
public sealed class LimitedMemoryTarget : TargetWithLayout
{
private Queue<string> logs = new Queue<string>();
public LimitedMemoryTarget()
{
this.Logs = new List<string>();
}
public IEnumerable<string> Logs
{
get { return logs; }
private set { logs = value; }
}
[DefaultValue(100)]
public int Limit { get; set; }
protected override void Write(LogEventInfo logEvent)
{
string msg = this.Layout.Render(logEvent);
logs.Enqueue(msg);
if (logs.Count > Limit)
{
logs.Dequeue();
}
}
}
}
This example is based on the NLog MemoryTarget, the source code for which you can find here:
https://github.com/NLog/NLog
NLog docs are here:
http://nlog-project.org/documentation/v2.0.1/
I didn't see anything like you are asking about in either location.

How to write an NLog target using Signalr

I'm trying to write a target for NLog to send messages out to connected clients using SignalR.
Here's what I have now. What I'm wondering is should I be using resolving the ConnectionManager like this -or- somehow obtain a reference to the hub (SignalrTargetHub) and call a SendMessage method on it?
Are there performance ramifications for either?
[Target("Signalr")]
public class SignalrTarget:TargetWithLayout
{
public SignalR.IConnectionManager ConnectionManager { get; set; }
public SignalrTarget()
{
ConnectionManager = AspNetHost.DependencyResolver.Resolve<IConnectionManager>();
}
protected override void Write(NLog.LogEventInfo logEvent)
{
dynamic clients = GetClients();
var logEventObject = new
{
Message = this.Layout.Render(logEvent),
Level = logEvent.Level.Name,
TimeStamp = logEvent.TimeStamp.ToString("yyyy-MM-dd HH:mm:ss.fff")
};
clients.onLoggedEvent(logEventObject);
}
private dynamic GetClients()
{
return ConnectionManager.GetClients<SignalrTargetHub>();
}
}
I ended up with the basic the same basic structure that I started with. Just a few tweaks to get the information I needed.
Added exception details.
Html encoded the final message.
[Target("Signalr")]
public class SignalrTarget:TargetWithLayout
{
protected override void Write(NLog.LogEventInfo logEvent)
{
var sb = new System.Text.StringBuilder();
sb.Append(this.Layout.Render(logEvent));
if (logEvent.Exception != null)
sb.AppendLine().Append(logEvent.Exception.ToString());
var message = HttpUtility.HtmlEncode(sb.ToString());
var logEventObject = new
{
Message = message,
Logger = logEvent.LoggerName,
Level = logEvent.Level.Name,
TimeStamp = logEvent.TimeStamp.ToString("HH:mm:ss.fff")
};
GetClients().onLoggedEvent(logEventObject);
}
private dynamic GetClients()
{
return AspNetHost.DependencyResolver.Resolve<IConnectionManager>().GetClients<SignalrTargetHub>();
}
}
In my simple testing it's working well. Still remains to be seen if this adds any significant load when under stress.

Loading an object from a db4o database

I am developing an e-commerce website that utilises db4o as the backend. All was well until last week when I came across a problem that I have been unable to solve. The code below is quite straight forward. I open a database file, save an object and then try to retrieve it. However I get nothing back. The "users" variable has a count of zero.
public class Program
{
private static string _connectionString = string.Format(#"c:\aaarrrr.db4o");
static void Main(string[] args)
{
TestUser container = new TestUser() { id = 1, Name = "Mohammad", Surname = "Rafiq" };
Db4oFactory.Configure().Diagnostic().AddListener(new DiagnosticToConsole());
using (var dbc = Db4oFactory.OpenFile(_connectionString))
{
dbc.Store(container);
}
IList<TestUser> users = null;
using (var dbc = Db4oFactory.OpenFile(_connectionString))
{
users = dbc.Query<TestUser>(x => x.id == 1).ToList();
}
if (users.Count > 0)
{
Console.WriteLine("{0} {1} with id of {2}", users.First().Name, users.First().Surname, users.First().id);
}
else
{
Console.WriteLine("\nNo data returned.");
}
Console.ReadLine();
}
}
public class TestUser
{
[Indexed]
private int _id = 0;
private string _name = string.Empty;
private string _surname = string.Empty;
public int id { get { return _id; } set { _id = value; } }
public string Name { get { return _name; } set { _name = value; } }
public string Surname { get { return _surname; } set { _surname = value; } }
}
I have attached db4o diagnostic listener and I see nothing in the console output. Everything seems fine. I know I am writing to the file because I can see the file size increase and the timestamp is also updated. I have checked all the project settings and they are all set to default. I am using .net 4, visual studio 2010 beta and windows 7. I have done some reading regarding reflection permission but I cant see how this applies here. Any help or ideas would be knidly appreciated.
After calling store(), you need to commit() before leaving the using{} statement. You closed your database before committing your changes.

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