Reorganize dataframe files (#6872)

* Increase performance of elementwise comparison operations

* Fix Perf Test

* Reorganize files in the DataFrame related projects

* Fix merge issues

Author: asmirnov82

src/Microsoft.Data.Analysis/ArrowStringDataFrameColumn.cs renamed to src/Microsoft.Data.Analysis/DataFrameColumns/ArrowStringDataFrameColumn.cs

@@ -0,0 +1,106 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Apache.Arrow;
+using Xunit;
+
+namespace Microsoft.Data.Analysis.Tests
+{
+    public class ArrowStringColumnTests
+    {
+
+        [Fact]
+        public void TestBasicArrowStringColumn()
+        {
+            StringArray strArray = new StringArray.Builder().Append("foo").Append("bar").Build();
+            Memory<byte> dataMemory = new byte[] { 102, 111, 111, 98, 97, 114 };
+            Memory<byte> nullMemory = new byte[] { 0, 0, 0, 0 };
+            Memory<byte> offsetMemory = new byte[] { 0, 0, 0, 0, 3, 0, 0, 0, 6, 0, 0, 0 };
+
+            ArrowStringDataFrameColumn stringColumn = new ArrowStringDataFrameColumn("String", dataMemory, offsetMemory, nullMemory, strArray.Length, strArray.NullCount);
+            Assert.Equal(2, stringColumn.Length);
+            Assert.Equal("foo", stringColumn[0]);
+            Assert.Equal("bar", stringColumn[1]);
+        }
+
+        [Fact]
+        public void TestArrowStringColumnWithNulls()
+        {
+            string data = "joemark";
+            byte[] bytes = Encoding.UTF8.GetBytes(data);
+            Memory<byte> dataMemory = new Memory<byte>(bytes);
+            Memory<byte> nullMemory = new byte[] { 0b1101 };
+            Memory<byte> offsetMemory = new byte[] { 0, 0, 0, 0, 3, 0, 0, 0, 3, 0, 0, 0, 7, 0, 0, 0, 7, 0, 0, 0 };
+            ArrowStringDataFrameColumn stringColumn = new ArrowStringDataFrameColumn("String", dataMemory, offsetMemory, nullMemory, 4, 1);
+
+            Assert.Equal(4, stringColumn.Length);
+            Assert.Equal("joe", stringColumn[0]);
+            Assert.Null(stringColumn[1]);
+            Assert.Equal("mark", stringColumn[2]);
+            Assert.Equal("", stringColumn[3]);
+
+            List<string> ret = stringColumn[0, 4];
+            Assert.Equal("joe", ret[0]);
+            Assert.Null(ret[1]);
+            Assert.Equal("mark", ret[2]);
+            Assert.Equal("", ret[3]);
+        }
+
+        [Fact]
+        public void TestArrowStringColumnClone()
+        {
+            StringArray strArray = new StringArray.Builder().Append("foo").Append("bar").Build();
+            Memory<byte> dataMemory = new byte[] { 102, 111, 111, 98, 97, 114 };
+            Memory<byte> nullMemory = new byte[] { 0, 0, 0, 0 };
+            Memory<byte> offsetMemory = new byte[] { 0, 0, 0, 0, 3, 0, 0, 0, 6, 0, 0, 0 };
+
+            ArrowStringDataFrameColumn stringColumn = new ArrowStringDataFrameColumn("String", dataMemory, offsetMemory, nullMemory, strArray.Length, strArray.NullCount);
+
+            DataFrameColumn clone = stringColumn.Clone(numberOfNullsToAppend: 5);
+            Assert.Equal(7, clone.Length);
+            Assert.Equal(stringColumn[0], clone[0]);
+            Assert.Equal(stringColumn[1], clone[1]);
+            for (int i = 2; i < 7; i++)
+                Assert.Null(clone[i]);
+        }
+
+        [Fact]
+        public void TestArrowStringApply()
+        {
+            ArrowStringDataFrameColumn column = DataFrameTests.CreateArrowStringColumn(10);
+            ArrowStringDataFrameColumn ret = column.Apply((string cur) =>
+            {
+                if (cur != null)
+                {
+                    return cur + "123";
+                }
+                return null;
+            });
+            for (long i = 0; i < column.Length; i++)
+            {
+                if (column[i] != null)
+                {
+                    Assert.Equal(column[i] + "123", ret[i]);
+                }
+                else
+                {
+                    Assert.Null(ret[i]);
+                }
+            }
+            Assert.Equal(1, ret.NullCount);
+
+            // Test null counts
+            ret = column.Apply((string cur) =>
+            {
+                return null;
+            });
+            Assert.Equal(column.Length, ret.NullCount);
+        }
+    }
+}

src/Microsoft.Data.Analysis/BooleanDataFrameColumn.cs renamed to src/Microsoft.Data.Analysis/DataFrameColumns/PrimitiveDataFrameColumns/BooleanDataFrameColumn.cs

@@ -8,10 +8,10 @@
 
 namespace Microsoft.Data.Analysis.Tests
 {
-    public class DataFrameJoinTests
+    public class DataFrameJoinExtensionsTests
     {
         [Fact]
-        public void DataFrameJoinTests_GetSortedListsIntersection_EmptyCollections_EmptyResult()
+        public void GetSortedListsIntersection_EmptyCollections_EmptyResult()
         {
             // Arrange
 
@@ -28,7 +28,7 @@ public void DataFrameJoinTests_GetSortedListsIntersection_EmptyCollections_Empty
         }
 
         [Fact]
-        public void DataFrameJoinTests_GetSortedListsIntersection_EmptyCollections_FirstIsNotEmpty_EmptyResult()
+        public void GetSortedListsIntersection_EmptyCollections_FirstIsNotEmpty_EmptyResult()
         {
             // Arrange
 
@@ -51,7 +51,7 @@ public void DataFrameJoinTests_GetSortedListsIntersection_EmptyCollections_First
         }
 
         [Fact]
-        public void DataFrameJoinTests_GetSortedListsIntersection_EmptyCollections_SecondIsNotEmpty_EmptyResult()
+        public void GetSortedListsIntersection_EmptyCollections_SecondIsNotEmpty_EmptyResult()
         {
             // Arrange
 
@@ -74,7 +74,7 @@ public void DataFrameJoinTests_GetSortedListsIntersection_EmptyCollections_Secon
         }
 
         [Fact]
-        public void DataFrameJoinTests_GetSortedListsIntersection_SortedCollections_WithoutIntersection_Success()
+        public void GetSortedListsIntersection_SortedCollections_WithoutIntersection_Success()
         {
             // Arrange
 
@@ -105,7 +105,7 @@ public void DataFrameJoinTests_GetSortedListsIntersection_SortedCollections_With
         }
 
         [Fact]
-        public void DataFrameJoinTests_GetSortedListsIntersection_SortedCollections_WithIntersection_Success()
+        public void GetSortedListsIntersection_SortedCollections_WithIntersection_Success()
         {
             // Arrange