Add missing trackable class but not implemented.

src/TensorFlowNET.Core/Operations/SafeOperationHandle.cs

@@ -0,0 +1,40 @@
+/*****************************************************************************
+   Copyright 2018 The TensorFlow.NET Authors. All Rights Reserved.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+******************************************************************************/
+
+using Tensorflow.Util;
+
+namespace Tensorflow;
+
+public sealed class SafeOperationHandle : SafeTensorflowHandle
+{
+    private SafeOperationHandle()
+    {
+    }
+
+    public SafeOperationHandle(IntPtr handle)
+        : base(handle)
+    {
+    }
+
+    protected override bool ReleaseHandle()
+    {
+        var status = new Status();
+        // c_api.TF_CloseSession(handle, status);
+        c_api.TF_DeleteSession(handle, status);
+        SetHandle(IntPtr.Zero);
+        return true;
+    }
+}

src/TensorFlowNET.Core/Tensors/Tensors.cs

@@ -65,6 +65,18 @@ namespace Tensorflow
         IEnumerator IEnumerable.GetEnumerator()
             => GetEnumerator();
 
+        public string[] StringData()
+        {
+            EnsureSingleTensor(this, "nnumpy");
+            return this[0].StringData();
+        }
+
+        public string StringData(int index)
+        {
+            EnsureSingleTensor(this, "nnumpy");
+            return this[0].StringData(index);
+        }
+
         public NDArray numpy()
         {
             EnsureSingleTensor(this, "nnumpy");

src/TensorFlowNET.Core/Trackables/Asset.cs

@@ -0,0 +1,11 @@
+using Tensorflow.Train;
+
+namespace Tensorflow.Trackables;
+
+public class Asset : Trackable
+{
+    public static (Trackable, Action<object, object, object>) deserialize_from_proto()
+    {
+        return (null, null);
+    }
+}

src/TensorFlowNET.Core/Trackables/CapturableResource.cs

@@ -0,0 +1,7 @@
+using Tensorflow.Train;
+
+namespace Tensorflow.Trackables;
+
+public class CapturableResource : Trackable
+{
+}

src/TensorFlowNET.Core/Trackables/RestoredResource.cs

@@ -0,0 +1,12 @@
+using System.Runtime.CompilerServices;
+using Tensorflow.Train;
+
+namespace Tensorflow.Trackables;
+
+public class RestoredResource : TrackableResource
+{
+    public static (Trackable, Action<object, object, object>) deserialize_from_proto()
+    {
+        return (null, null);
+    }
+}

src/TensorFlowNET.Core/Trackables/TrackableConstant.cs

@@ -0,0 +1,11 @@
+using Tensorflow.Train;
+
+namespace Tensorflow.Trackables;
+
+public class TrackableConstant : Trackable
+{
+    public static (Trackable, Action<object, object, object>) deserialize_from_proto()
+    {
+        return (null, null);
+    }
+}

src/TensorFlowNET.Core/Trackables/TrackableResource.cs

@@ -0,0 +1,5 @@
+namespace Tensorflow.Trackables;
+
+public class TrackableResource : CapturableResource
+{
+}

src/TensorFlowNET.Core/Training/Saving/SavedModel/loader.cs

@@ -13,6 +13,7 @@ using System.Runtime.CompilerServices;
 using Tensorflow.Variables;
 using Tensorflow.Functions;
 using Tensorflow.Training.Saving.SavedModel;
+using Tensorflow.Trackables;
 
 namespace Tensorflow
 {
@@ -51,9 +52,13 @@ namespace Tensorflow
             _node_filters = filters;
             _node_path_to_id = _convert_node_paths_to_ints();
             _loaded_nodes = new Dictionary<int, (Trackable, Action<object, object, object>)>();
-            foreach(var filter in filters)
+
+            if (filters != null)
             {
-                _loaded_nodes[_node_path_to_id[filter.Key]] = filter.Value;
+                foreach (var filter in filters)
+                {
+                    _loaded_nodes[_node_path_to_id[filter.Key]] = filter.Value;
+                }
             }
 
             _filtered_nodes = _retrieve_all_filtered_nodes();
@@ -535,7 +540,13 @@ namespace Tensorflow
                 dependencies[item.Key] = nodes[item.Value];
             }
 
-            return _recreate_default(proto, node_id, dependencies);
+            return proto.KindCase switch
+            {
+                SavedObject.KindOneofCase.Resource => RestoredResource.deserialize_from_proto(),
+                SavedObject.KindOneofCase.Asset => Asset.deserialize_from_proto(),
+                SavedObject.KindOneofCase.Constant => TrackableConstant.deserialize_from_proto(),
+                _ => _recreate_default(proto, node_id, dependencies)
+            };
         }
 
         /// <summary>
@@ -549,7 +560,7 @@ namespace Tensorflow
             return proto.KindCase switch
             {
                 SavedObject.KindOneofCase.UserObject => _recreate_user_object(proto.UserObject, node_id),
-                SavedObject.KindOneofCase.Function => throw new NotImplementedException(),
+                SavedObject.KindOneofCase.Function => _recreate_function(proto.Function, null),
                 SavedObject.KindOneofCase.BareConcreteFunction => throw new NotImplementedException(),
                 SavedObject.KindOneofCase.Variable => _recreate_variable(proto.Variable),
                 SavedObject.KindOneofCase.CapturedTensor => throw new NotImplementedException()
@@ -609,6 +620,13 @@ namespace Tensorflow
             }
         }
 
+        private (ConcreteFunction, Action<object, object, object>) _recreate_function(SavedFunction proto,
+            Dictionary<Maybe<string, int>, Trackable> dependencies)
+        {
+            throw new NotImplementedException();
+            //var fn = function_deserialization.setup_bare_concrete_function(proto, )
+        }
+
         private (ConcreteFunction, Action<object, object, object>) _recreate_bare_concrete_function(SavedBareConcreteFunction proto,
             Dictionary<Maybe<string, int>, Trackable> dependencies)
         {