Fast TensorAccessor

.gitignore

@@ -273,3 +273,5 @@ packages/
 /.idea
 /test/TorchSharpTest/exportsd.py
 .vscode/settings.json
+/TestClear
+TestClear/

TorchSharp.sln

@@ -34,7 +34,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "TorchSharp", "TorchSharp",
 		pkg\TorchSharp\TorchSharp.symbols.nupkgproj = pkg\TorchSharp\TorchSharp.symbols.nupkgproj
 	EndProjectSection
 EndProject
-Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "LibTorchSharp", "bin\obj\x64.Debug\Native\LibTorchSharp\LibTorchSharp.vcxproj", "{2B359162-062E-3C52-91D3-027A8542A58C}"
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "LibTorchSharp", "bin\obj\x64.Debug\Native\LibTorchSharp\LibTorchSharp.vcxproj", "{265C2E6F-04E6-37A8-B504-E3DD4A3FEE06}"
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "LibTorchSharp", "bin\obj\x64.Release\Native\LibTorchSharp\LibTorchSharp.vcxproj", "{E4C0DBEE-0815-311B-9065-137BB50BD793}"
 EndProject
@@ -66,9 +66,9 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		azure-pipelines.yml = azure-pipelines.yml
 		build\BranchInfo.props = build\BranchInfo.props
 		DEVGUIDE.md = DEVGUIDE.md
+		global.json = global.json
 		README.md = README.md
 		RELEASENOTES.md = RELEASENOTES.md
-		global.json = global.json
 	EndProjectSection
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TorchVision", "src\TorchVision\TorchVision.csproj", "{DCF01EE5-6431-4115-85E0-1FC4C3DE86A2}"
@@ -107,10 +107,10 @@ Global
 		{42B45168-476D-4BFA-87B8-81A34E6295CD}.Release|Any CPU.Build.0 = Release|Any CPU
 		{42B45168-476D-4BFA-87B8-81A34E6295CD}.Release|x64.ActiveCfg = Release|Any CPU
 		{42B45168-476D-4BFA-87B8-81A34E6295CD}.Release|x64.Build.0 = Release|Any CPU
-		{2B359162-062E-3C52-91D3-027A8542A58C}.Debug|Any CPU.ActiveCfg = Debug|x64
-		{2B359162-062E-3C52-91D3-027A8542A58C}.Debug|x64.ActiveCfg = Debug|x64
-		{2B359162-062E-3C52-91D3-027A8542A58C}.Release|Any CPU.ActiveCfg = Release|x64
-		{2B359162-062E-3C52-91D3-027A8542A58C}.Release|x64.ActiveCfg = Release|x64
+		{265C2E6F-04E6-37A8-B504-E3DD4A3FEE06}.Debug|Any CPU.ActiveCfg = Debug|x64
+		{265C2E6F-04E6-37A8-B504-E3DD4A3FEE06}.Debug|x64.ActiveCfg = Debug|x64
+		{265C2E6F-04E6-37A8-B504-E3DD4A3FEE06}.Release|Any CPU.ActiveCfg = Release|x64
+		{265C2E6F-04E6-37A8-B504-E3DD4A3FEE06}.Release|x64.ActiveCfg = Release|x64
 		{E4C0DBEE-0815-311B-9065-137BB50BD793}.Debug|Any CPU.ActiveCfg = Debug|x64
 		{E4C0DBEE-0815-311B-9065-137BB50BD793}.Debug|x64.ActiveCfg = Debug|x64
 		{E4C0DBEE-0815-311B-9065-137BB50BD793}.Release|Any CPU.ActiveCfg = Release|x64
@@ -181,7 +181,7 @@ Global
 		{6C323B05-9028-4B09-911C-3C03AE058BEE} = {AED9C836-31E3-4F3F-8ABC-929555D3F3C4}
 		{42B45168-476D-4BFA-87B8-81A34E6295CD} = {09EADF06-BE25-4228-AB53-95AE3E15B530}
 		{567456AD-B026-4CB6-B98D-4FC930C90223} = {D3D38B03-B557-484D-8348-8BADEE4DF592}
-		{2B359162-062E-3C52-91D3-027A8542A58C} = {CF2C1A9E-3A8A-4329-8A6E-7880C15AAC3D}
+		{265C2E6F-04E6-37A8-B504-E3DD4A3FEE06} = {CF2C1A9E-3A8A-4329-8A6E-7880C15AAC3D}
 		{E4C0DBEE-0815-311B-9065-137BB50BD793} = {4DB9E84D-324C-408F-87A6-246E86205540}
 		{CF2C1A9E-3A8A-4329-8A6E-7880C15AAC3D} = {09EADF06-BE25-4228-AB53-95AE3E15B530}
 		{D8C60CD8-8429-45F2-A755-47B6CD10FDF8} = {09EADF06-BE25-4228-AB53-95AE3E15B530}

src/TorchSharp/Utils/TensorAccessor.cs

@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Runtime.InteropServices;
 using static TorchSharp.PInvoke.NativeMethods;
 
 namespace TorchSharp.Utils
@@ -47,6 +48,16 @@ public T[] ToArray()
             if (_tensor.ndim < 2)
                 return (T[])ToNDArray();
 
+            if (_tensor.is_contiguous()) {
+                //This is very fast. And work VERY WELL
+                var shps = _tensor.shape;
+                long TempCount = 1;
+                for (int i = 0; i < shps.Length; i++)
+                    TempCount *= shps[i]; //Theorically the numel is simple as product of each element shape
+                unsafe {
+                    return new Span<T>(_tensor_data_ptr.ToPointer(), Convert.ToInt32(TempCount)).ToArray();
+                }
+            }
             var result = new T[Count];
             CopyTo(result);
             return result;
@@ -231,8 +242,38 @@ private void validate(long index)
             if (index >= Count) throw new IndexOutOfRangeException();
         }
 
+        private void CopyContiguous(T[] array, int index=0, int count=0)
+        {
+             if (!_tensor.is_contiguous())
+                 throw new Exception("The tensor is not contiguous");
+             var shps = _tensor.shape;
+             long TempCount = 1;
+             for (int i = 0; i < shps.Length; i++)
+                 TempCount *= shps[i]; //Theorically the numel is simple as product of each element shape
+             if (count > TempCount || count == 0)
+                 count = (int)TempCount;
+             if (array is byte[] ba)
+                 Marshal.Copy(_tensor_data_ptr, ba, index, count);
+             if (array is short[] sa)
+                 Marshal.Copy(_tensor_data_ptr, sa, index, count);
+             if(array is char[] ca)
+                 Marshal.Copy(_tensor_data_ptr, ca, index, count);
+             if (array is long[] la)
+                 Marshal.Copy(_tensor_data_ptr, la, index, count);
+             if (array is float[] fa)
+                 Marshal.Copy(_tensor_data_ptr, fa, index, count);
+             if (array is int[] ia)
+                 Marshal.Copy(_tensor_data_ptr, ia, index, count);
+             if (array is double[] da)
+                 Marshal.Copy(_tensor_data_ptr, da, index, count);
+        }
         public void CopyTo(T[] array, int arrayIndex = 0, long tensorIndex = 0)
         {
+            if (_tensor.is_contiguous()) {
+                CopyContiguous(array, arrayIndex, array.Length);
+                return;
+            }
+
             int idx = arrayIndex;
             foreach (int offset in GetSubsequentIndices(tensorIndex)) {
                 if (idx >= array.Length) break;
@@ -243,6 +284,11 @@ public void CopyTo(T[] array, int arrayIndex = 0, long tensorIndex = 0)
 
         public void CopyTo(Span<T> array, int arrayIndex = 0, long tensorIndex = 0)
         {
+            if (_tensor.is_contiguous()) {
+                ToArray().CopyTo(array);
+                return;
+            }
+
             int idx = arrayIndex;
             foreach (int offset in GetSubsequentIndices(tensorIndex)) {
                 if (idx >= array.Length) break;