Refactor filesystems (again)

src/Umbraco.Core/IO/ShadowFileSystems.cs

@@ -1,41 +1,26 @@
 using System;
-using System.Collections.Generic;
-using Umbraco.Core.Logging;
 
 namespace Umbraco.Core.IO
 {
+    // shadow filesystems is definitively ... too convoluted
+
     internal class ShadowFileSystems : ICompletable
     {
-        private static readonly object Locker = new object();
-        private static Guid _currentId = Guid.Empty;
-
-        private readonly Guid _id;
-        private readonly ShadowWrapper[] _wrappers;
-        private readonly ILogger _logger;
-
+        private readonly FileSystems _fileSystems;
         private bool _completed;
 
         // invoked by the filesystems when shadowing
-        // can only be 1 shadow at a time (static)
-        public ShadowFileSystems(Guid id, ShadowWrapper[] wrappers, ILogger logger)
+        public ShadowFileSystems(FileSystems fileSystems, Guid id)
         {
-            lock (Locker)
-            {
-                // if we throw here, it means that something very wrong happened.
-                if (_currentId != Guid.Empty)
-                    throw new InvalidOperationException("Already shadowing.");
-                _currentId = id;
-            }
+            _fileSystems = fileSystems;
+            Id = id;
 
-            _logger = logger;
-            _logger.Debug<ShadowFileSystems>("Shadow '{ShadowId}'", id);
-            _id = id;
-
-            _wrappers = wrappers;
-            foreach (var wrapper in _wrappers)
-                wrapper.Shadow(id);
+            _fileSystems.BeginShadow(id);
         }
 
+        // for tests
+        public Guid Id { get; }
+
         // invoked by the scope when exiting, if completed
         public void Complete()
         {
@@ -45,41 +30,7 @@ namespace Umbraco.Core.IO
         // invoked by the scope when exiting
         public void Dispose()
         {
-            lock (Locker)
-            {
-                // if we throw here, it means that something very wrong happened.
-                if (_currentId == Guid.Empty)
-                    throw new InvalidOperationException("Not shadowing.");
-                if (_id != _currentId)
-                    throw new InvalidOperationException("Not the current shadow.");
-
-                _logger.Debug<ShadowFileSystems>("UnShadow '{ShadowId}' {Status}", _id, _completed ? "complete" : "abort");
-
-                var exceptions = new List<Exception>();
-                foreach (var wrapper in _wrappers)
-                {
-                    try
-                    {
-                        // this may throw an AggregateException if some of the changes could not be applied
-                        wrapper.UnShadow(_completed);
-                    }
-                    catch (AggregateException ae)
-                    {
-                        exceptions.Add(ae);
-                    }
-                }
-
-                _currentId = Guid.Empty;
-
-                if (exceptions.Count > 0)
-                    throw new AggregateException(_completed ? "Failed to apply all changes (see exceptions)." : "Failed to abort (see exceptions).", exceptions);
-            }
-        }
-
-        // for tests
-        internal static void ResetId()
-        {
-            _currentId = Guid.Empty;
+            _fileSystems.EndShadow(Id, _completed);
         }
     }
 }