Added IConfigStore interface

IPA.Loader/Config/IConfigStore.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace IPA.Config
+{
+    /// <summary>
+    /// A storage for a config structure.
+    /// </summary>
+    public interface IConfigStore
+    {
+        /// <summary>
+        /// A synchronization object for the save thread to wait on for changes. 
+        /// It should be signaled whenever the internal state of the object is changed.
+        /// The writer will never signal this handle. 
+        /// </summary>
+        WaitHandle SyncObject { get; }
+
+        /// <summary>
+        /// A synchronization object for the load thread and accessors to maintain safe synchronization.
+        /// Any readers should take a read lock with <see cref="ReaderWriterLockSlim.EnterReadLock()"/> or
+        /// <see cref="ReaderWriterLockSlim.EnterUpgradeableReadLock()"/>, and any writers should take a 
+        /// write lock with <see cref="ReaderWriterLockSlim.EnterWriteLock()"/>.
+        /// </summary>
+        /// <remarks>
+        /// Read and write are read and write to *this object*, not to the file on disk.
+        /// </remarks>
+        ReaderWriterLockSlim WriteSyncObject { get; }
+
+        /// <summary>
+        /// Writes the config structure stored by the current <see cref="IConfigStore"/> to the given
+        /// <see cref="IConfigProvider"/>.
+        /// </summary>
+        /// <param name="provider">the provider to write to</param>
+        void WriteTo(IConfigProvider provider);
+
+        /// <summary>
+        /// Reads the config structure from the given <see cref="IConfigProvider"/> into the current 
+        /// <see cref="IConfigStore"/>.
+        /// </summary>
+        /// <param name="provider"></param>
+        void ReadFrom(IConfigProvider provider);
+
+    }
+}