Issue #1226 implemented

[Exef]

Both Put() and CleanUp() methods in class SimpleDnsCache.Cache are now immutable.

It's my first pull request, so if you find any issues let me know and I'll fix them. Any ideas what unit test should I add?

[Aaronontheweb]

@Exef need to rebase your branch on dev so we can merge it though! CONTRIBUTING.MD contains a guide that'll explain how to do this.

I haven't reviewed the code yet though - but I'll take a look.

[Exef]

@Aaronontheweb Sure, my bad. I'll fix it today. I've read everything that was linked from README.md, but there was no link to CONTRIBUTING.md. I'll open docs issue to fix this.

[rogeralsing]

There is still some mutability going on in the Cleanup method:

             public Cache Cleanup()
             {
                 var now = _clock();
                 while (_queue.Any() && !_queue.First().IsValid(now))
                 {
                     var minEntry = _queue.First();
                     var name = minEntry.Name;
                     _queue.Remove(minEntry);  //<-------------------------------------------- here
                     if (_cache.ContainsKey(name) && !_cache[name].IsValid(now))
                         _cache.Remove(name); //<-------------------------------------------- here
                 }
                 return new Cache(_queue, _cache, _clock);
             }

It does return a new Cache, which is good, but the old Cache is now changed.

[Exef]

Yeah, I've missed it. Also putting an element to new Cache also put to old cleaned-up cache.

[Exef]

Ok, done. What else should I do? EDIT: Fix the test.

[rogeralsing]

👍 Thanks