Renamed the project to Umbraco.PublishedCache.NuCache - and move non NuCache related stuff to abstractions and infrastructure.

src/Umbraco.PublishedCache.NuCache/DataSource/BTree.cs

@@ -0,0 +1,78 @@
+using System.Configuration;
+using CSharpTest.Net.Collections;
+using CSharpTest.Net.Serialization;
+
+namespace Umbraco.Web.PublishedCache.NuCache.DataSource
+{
+    internal class BTree
+    {
+        public static BPlusTree<int, ContentNodeKit> GetTree(string filepath, bool exists)
+        {
+            var keySerializer = new PrimitiveSerializer();
+            var valueSerializer = new ContentNodeKitSerializer();
+            var options = new BPlusTree<int, ContentNodeKit>.OptionsV2(keySerializer, valueSerializer)
+            {
+                CreateFile = exists ? CreatePolicy.IfNeeded : CreatePolicy.Always,
+                FileName = filepath,
+
+                // read or write but do *not* keep in memory
+                CachePolicy = CachePolicy.None,
+
+                // default is 4096, min 2^9 = 512, max 2^16 = 64K
+                FileBlockSize = GetBlockSize(),
+
+                // other options?
+            };
+
+            var tree = new BPlusTree<int, ContentNodeKit>(options);
+
+            // anything?
+            //btree.
+
+            return tree;
+        }
+
+        private static int GetBlockSize()
+        {
+            var blockSize = 4096;
+
+            var appSetting = ConfigurationManager.AppSettings["Umbraco.Web.PublishedCache.NuCache.BTree.BlockSize"];
+            if (appSetting == null)
+                return blockSize;
+
+            if (!int.TryParse(appSetting, out blockSize))
+                throw new ConfigurationErrorsException($"Invalid block size value \"{appSetting}\": not a number.");
+
+            var bit = 0;
+            for (var i = blockSize; i != 1; i >>= 1)
+                bit++;
+            if (1 << bit != blockSize)
+                throw new ConfigurationErrorsException($"Invalid block size value \"{blockSize}\": must be a power of two.");
+            if (blockSize < 512 || blockSize > 65536)
+                throw new ConfigurationErrorsException($"Invalid block size value \"{blockSize}\": must be >= 512 and <= 65536.");
+
+            return blockSize;
+        }
+
+        /*
+        class ListOfIntSerializer : ISerializer<List<int>>
+        {
+            public List<int> ReadFrom(Stream stream)
+            {
+                var list = new List<int>();
+                var count = PrimitiveSerializer.Int32.ReadFrom(stream);
+                for (var i = 0; i < count; i++)
+                    list.Add(PrimitiveSerializer.Int32.ReadFrom(stream));
+                return list;
+            }
+
+            public void WriteTo(List<int> value, Stream stream)
+            {
+                PrimitiveSerializer.Int32.WriteTo(value.Count, stream);
+                foreach (var item in value)
+                    PrimitiveSerializer.Int32.WriteTo(item, stream);
+            }
+        }
+        */
+    }
+}