Change Graph.Import interface.

src/TensorFlowNET.Core/Framework/importer.py.cs

@@ -54,16 +54,17 @@ namespace Tensorflow
                 input_map = _ConvertInputMapValues(name, input_map);
             });
 
-            var scoped_options = c_api_util.ScopedTFImportGraphDefOptions();
-            _PopulateTFImportGraphDefOptions(scoped_options, prefix, input_map, return_elements);
-
             var bytes = graph_def.ToByteString().ToArray();
-            IntPtr buffer = c_api_util.tf_buffer(bytes);
-
-            var status = new Status();
-            // need to create a class ImportGraphDefWithResults with IDisposal
-            var results = c_api.TF_GraphImportGraphDefWithResults(graph, buffer, scoped_options, status);
-            status.Check(true);
+            using (var buffer = c_api_util.tf_buffer(bytes))
+            using (var scoped_options = c_api_util.ScopedTFImportGraphDefOptions())
+            using (var status = new Status())
+            {
+                _PopulateTFImportGraphDefOptions(scoped_options, prefix, input_map, return_elements);
+                // need to create a class ImportGraphDefWithResults with IDisposal
+                var results = c_api.TF_GraphImportGraphDefWithResults(graph, buffer, scoped_options, status);
+                status.Check(true);
+                c_api.TF_DeleteImportGraphDefResults(results);
+            }
 
             _ProcessNewOps(graph);
 

src/TensorFlowNET.Core/Graphs/Graph.Import.cs

@@ -23,6 +23,7 @@ namespace Tensorflow
     {
         public unsafe TF_Output[] ImportGraphDefWithReturnOutputs(Buffer graph_def, ImportGraphDefOptions opts, Status s)
         {
+            as_default();
             var num_return_outputs = opts.NumReturnOutputs;
             var return_outputs = new TF_Output[num_return_outputs];
             int size = Marshal.SizeOf<TF_Output>();
@@ -35,40 +36,37 @@ namespace Tensorflow
                 return_outputs[i] = Marshal.PtrToStructure<TF_Output>(handle);
             }
 
+            Marshal.FreeHGlobal(return_output_handle);
+
             return return_outputs;
         }
 
-        public Status Import(string file_path)
+        public bool Import(string file_path, string prefix = "")
         {
             var bytes = File.ReadAllBytes(file_path);
-            var graph_def = new Tensorflow.Buffer(bytes);
-            var opts = c_api.TF_NewImportGraphDefOptions();
-            var status = new Status();
-            c_api.TF_GraphImportGraphDef(_handle, graph_def, opts, status);
-            return status;
-        }
-
-        public Status Import(byte[] bytes, string prefix = "")
-        {
-            var graph_def = new Tensorflow.Buffer(bytes);
-            var opts = c_api.TF_NewImportGraphDefOptions();
-            c_api.TF_ImportGraphDefOptionsSetPrefix(opts, prefix);
-            var status = new Status();
-            c_api.TF_GraphImportGraphDef(_handle, graph_def, opts, status);
-            c_api.TF_DeleteImportGraphDefOptions(opts);
-            return status;
+            return Import(bytes, prefix: prefix);
         }
 
-        static object locker = new object();
-        public static Graph ImportFromPB(string file_path, string name = null)
+        public bool Import(byte[] bytes, string prefix = "")
         {
-            lock (locker)
+            using (var opts = new ImportGraphDefOptions())
+            using (var status = new Status())
+            using (var graph_def = new Buffer(bytes))
             {
-                var graph = tf.Graph().as_default();
-                var graph_def = GraphDef.Parser.ParseFrom(File.ReadAllBytes(file_path));
-                importer.import_graph_def(graph_def, name: name);
-                return graph;
+                as_default();
+                c_api.TF_ImportGraphDefOptionsSetPrefix(opts, prefix);
+                c_api.TF_GraphImportGraphDef(_handle, graph_def, opts, status);
+                status.Check(true);
+                return status.Code == TF_Code.TF_OK;
             }
         }
+
+        /*public Graph Import(string file_path, string name = null)
+        {
+            as_default();
+            var graph_def = GraphDef.Parser.ParseFrom(File.ReadAllBytes(file_path));
+            importer.import_graph_def(graph_def, name: name);
+            return this;
+        }*/
     }
 }

src/TensorFlowNET.Core/Graphs/ImportGraphDefOptions.cs

@@ -18,10 +18,8 @@ using System;
 
 namespace Tensorflow
 {
-    public class ImportGraphDefOptions : IDisposable
+    public class ImportGraphDefOptions : DisposableObject
     {
-        private IntPtr _handle;
-
         public int NumReturnOutputs => c_api.TF_ImportGraphDefOptionsNumReturnOutputs(_handle);
 
         public ImportGraphDefOptions()
@@ -39,10 +37,8 @@ namespace Tensorflow
             c_api.TF_ImportGraphDefOptionsAddReturnOutput(_handle, name, index);
         }
 
-        public void Dispose()
-        {
-            c_api.TF_DeleteImportGraphDefOptions(_handle);
-        }
+        protected override void DisposeUnManagedState(IntPtr handle)
+            => c_api.TF_DeleteImportGraphDefOptions(handle);
 
         public static implicit operator IntPtr(ImportGraphDefOptions opts) => opts._handle;
         public static implicit operator ImportGraphDefOptions(IntPtr handle) => new ImportGraphDefOptions(handle);

src/TensorFlowNET.Core/TensorFlowNET.Core.csproj

@@ -5,7 +5,7 @@
     <AssemblyName>TensorFlow.NET</AssemblyName>
     <RootNamespace>Tensorflow</RootNamespace>
     <TargetTensorFlow>1.14.0</TargetTensorFlow>
-    <Version>0.10.9</Version>
+    <Version>0.10.10</Version>
     <Authors>Haiping Chen, Meinrad Recheis</Authors>
     <Company>SciSharp STACK</Company>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
@@ -17,7 +17,7 @@
     <PackageTags>TensorFlow, NumSharp, SciSharp, MachineLearning, TensorFlow.NET, C#</PackageTags>
     <Description>Google's TensorFlow full binding in .NET Standard.
 Docs: https://tensorflownet.readthedocs.io</Description>
-    <AssemblyVersion>0.10.9.0</AssemblyVersion>
+    <AssemblyVersion>0.10.10.0</AssemblyVersion>
     <PackageReleaseNotes>Changes since v0.9.0:
 
 1. Added full connected Convolution Neural Network example.

test/TensorFlowNET.Examples/ImageProcessing/ImageRecognitionInception.cs

@@ -31,7 +31,7 @@ namespace TensorFlowNET.Examples
         {
             PrepareData();
            
-            var graph = new Graph().as_default();
+            var graph = new Graph();
             //import GraphDef from pb file
             graph.Import(Path.Join(dir, pbFile));
 

test/TensorFlowNET.Examples/ImageProcessing/InceptionArchGoogLeNet.cs

@@ -41,7 +41,8 @@ namespace TensorFlowNET.Examples
                 input_mean: input_mean,
                 input_std: input_std);
 
-            var graph = Graph.ImportFromPB(Path.Join(dir, pbFile));
+            var graph = new Graph();
+            graph.Import(Path.Join(dir, pbFile));
             var input_operation = graph.get_operation_by_name(input_name);
             var output_operation = graph.get_operation_by_name(output_name);
 

test/TensorFlowNET.Examples/ImageProcessing/RetrainImageClassifier.cs

@@ -738,7 +738,8 @@ namespace TensorFlowNET.Examples
             var fileBytes = ReadTensorFromImageFile(img_path);
 
             // import graph and variables
-            var graph = Graph.ImportFromPB(output_graph, "");
+            var graph = new Graph();
+            graph.Import(output_graph, "");
 
             Tensor input = graph.OperationByName("Placeholder");
             Tensor output = graph.OperationByName("final_result");
@@ -778,7 +779,8 @@ namespace TensorFlowNET.Examples
             if (!File.Exists(output_graph))
                 return;
 
-            var graph = Graph.ImportFromPB(output_graph);
+            var graph = new Graph();
+            graph.Import(output_graph);
             var (jpeg_data_tensor, decoded_image_tensor) = add_jpeg_decoding();
 
             tf_with(tf.Session(graph), sess =>