Implement ISpanAppendable in CharBlockArray and CharTermAttributeImpl (…

…#1028)

* Implement ISpanAppendable in CharBlockArray and CharTermAttributeImpl

* Add tests for ReadOnlySpan overloads of CharBlockArray.Append and CharTermAttributeImpl.Append

src/Lucene.Net.Facet/Taxonomy/WriterCache/CharBlockArray.cs

@@ -35,10 +35,11 @@ namespace Lucene.Net.Facet.Taxonomy.WriterCache
     /// @lucene.experimental
     /// </summary>
     // LUCENENET NOTE: The serialization features here are strictly for testing purposes,
-    // therefore it doesn't make any difference what type of serialization is used. 
-    // To make things simpler, we are using BinaryReader and BinaryWriter since 
+    // therefore it doesn't make any difference what type of serialization is used.
+    // To make things simpler, we are using BinaryReader and BinaryWriter since
     // BinaryFormatter is not implemented in .NET Standard 1.x.
-    internal class CharBlockArray : IAppendable, ICharSequence
+    internal class CharBlockArray : IAppendable, ICharSequence,
+        ISpanAppendable /* LUCENENET specific */
     {
         private const long serialVersionUID = 1L;
 
@@ -65,8 +66,6 @@ public object Clone()
                 return clone;
             }
 
-
-
             // LUCENENET specific
             public void Serialize(Stream writer)
             {
@@ -235,7 +234,6 @@ public virtual CharBlockArray Append(char[]? value, int startIndex, int length)
             if (startIndex > value.Length - length)
                 throw new ArgumentOutOfRangeException(nameof(startIndex), $"Index and length must refer to a location within the string. For example {nameof(startIndex)} + {nameof(length)} <= {nameof(Length)}.");
 
-
             int offset = startIndex;
             int remain = length;
             while (remain > 0)
@@ -310,7 +308,6 @@ public virtual CharBlockArray Append(string? value, int startIndex, int length)
             if (startIndex > value.Length - length)
                 throw new ArgumentOutOfRangeException(nameof(startIndex), $"Index and length must refer to a location within the string. For example {nameof(startIndex)} + {nameof(length)} <= {nameof(Length)}.");
 
-
             int offset = startIndex;
             int remain = length;
             while (remain > 0)
@@ -409,6 +406,32 @@ public virtual CharBlockArray Append(StringBuilder? value, int startIndex, int l
             return this;
         }
 
+        public virtual CharBlockArray Append(ReadOnlySpan<char> value)
+        {
+            int offset = 0;
+            int remain = value.Length;
+            while (remain > 0)
+            {
+                if (this.current.length == this.blockSize)
+                {
+                    AddBlock();
+                }
+                int toCopy = remain;
+                int remainingInBlock = this.blockSize - this.current.length;
+                if (remainingInBlock < toCopy)
+                {
+                    toCopy = remainingInBlock;
+                }
+                value.Slice(offset, toCopy).CopyTo(this.current.chars.AsSpan(this.current.length));
+                offset += toCopy;
+                remain -= toCopy;
+                this.current.length += toCopy;
+            }
+
+            this.length += value.Length;
+            return this;
+        }
+
 #nullable restore
 
         #region IAppendable Members
@@ -431,6 +454,11 @@ public virtual CharBlockArray Append(StringBuilder? value, int startIndex, int l
 
         IAppendable IAppendable.Append(ICharSequence value, int startIndex, int count) => Append(value, startIndex, count);
 
+        #endregion
+
+        #region ISpanAppendable Members
+
+        ISpanAppendable ISpanAppendable.Append(ReadOnlySpan<char> value) => Append(value);
 
         #endregion
 
@@ -612,4 +640,4 @@ internal bool Equals(int startIndex, int length, ReadOnlySpan<char> other)
             return true;
         }
     }
-}
+}

src/Lucene.Net.Tests.Facet/Taxonomy/WriterCache/TestCharBlockArray.cs

@@ -44,9 +44,9 @@ public virtual void TestArray()
             // CharsetDecoder decoder = StandardCharsets.UTF_8.newDecoder()
             //     .onUnmappableCharacter(CodingErrorAction.REPLACE)
             //     .onMalformedInput(CodingErrorAction.REPLACE);
-            // 
-            // Encoding decoder = Encoding.GetEncoding(Encoding.UTF8.CodePage, 
-            //     new EncoderReplacementFallback("?"), 
+            //
+            // Encoding decoder = Encoding.GetEncoding(Encoding.UTF8.CodePage,
+            //     new EncoderReplacementFallback("?"),
             //     new DecoderReplacementFallback("?"));
 
             for (int i = 0; i < n; i++)
@@ -287,6 +287,30 @@ public virtual void TestAppendableInterfaceWithLongSequences()
             Assert.AreEqual("4567890123456" + longTestString, t.ToString());
         }
 
+        [Test]
+        [LuceneNetSpecific]
+        public virtual void TestSpanAppendableInterface()
+        {
+            CharBlockArray t = new CharBlockArray();
+
+            // Test with a span
+            t.Append("12345678".AsSpan());
+            Assert.AreEqual("12345678", t.ToString());
+
+            // test with a span slice
+            t.Append("0123456789".AsSpan(3, 5 - 3));
+            Assert.AreEqual("1234567834", t.ToString());
+
+            // test with a long span
+            t = new CharBlockArray();
+            t.Append("01234567890123456789012345678901234567890123456789".AsSpan());
+            Assert.AreEqual("01234567890123456789012345678901234567890123456789", t.ToString());
+
+            // test with a long span slice
+            t.Append("01234567890123456789012345678901234567890123456789".AsSpan(3, 50 - 3));
+            Assert.AreEqual("0123456789012345678901234567890123456789012345678934567890123456789012345678901234567890123456789", t.ToString());
+        }
+
         private sealed class CharSequenceAnonymousClass : ICharSequence
         {
             private string longTestString;
@@ -319,4 +343,4 @@ public override string ToString()
             }
         }
     }
-}
+}

src/Lucene.Net.Tests/Analysis/TokenAttributes/TestCharTermAttributeImpl.cs

@@ -1,5 +1,6 @@
 using J2N.IO;
 using J2N.Text;
+using Lucene.Net.Attributes;
 using NUnit.Framework;
 using System;
 using System.Collections.Generic;
@@ -328,6 +329,29 @@ public virtual void TestAppendableInterfaceWithLongSequences()
             Assert.AreEqual("4567890123456" + longTestString, t.ToString());
         }
 
+        [Test]
+        [LuceneNetSpecific]
+        public virtual void TestSpanAppendableInterface()
+        {
+            CharTermAttribute t = new CharTermAttribute();
+
+            // Test with a span
+            t.Append("12345678".AsSpan());
+            Assert.AreEqual("12345678", t.ToString());
+
+            // test with a span slice
+            t.Append("0123456789".AsSpan(3, 5 - 3));
+            Assert.AreEqual("1234567834", t.ToString());
+
+            // test with a long span
+            t.SetEmpty().Append("01234567890123456789012345678901234567890123456789".AsSpan());
+            Assert.AreEqual("01234567890123456789012345678901234567890123456789", t.ToString());
+
+            // test with a long span slice
+            t.Append("01234567890123456789012345678901234567890123456789".AsSpan(3, 50 - 3));
+            Assert.AreEqual("0123456789012345678901234567890123456789012345678934567890123456789012345678901234567890123456789", t.ToString());
+        }
+
         private sealed class CharSequenceAnonymousClass : ICharSequence
         {
             private readonly string longTestString;

src/Lucene.Net/Analysis/TokenAttributes/CharTermAttribute.cs

@@ -43,7 +43,7 @@ public interface ICharTermAttribute : IAttribute, ICharSequence, IAppendable
         /// you can then directly alter.  If the array is too
         /// small for your token, use <see cref="ResizeBuffer(int)"/>
         /// to increase it.  After
-        /// altering the buffer be sure to call <see cref="SetLength(int)"/> 
+        /// altering the buffer be sure to call <see cref="SetLength(int)"/>
         /// to record the number of valid
         /// characters that were placed into the termBuffer.
         /// <para>
@@ -76,15 +76,15 @@ public interface ICharTermAttribute : IAttribute, ICharSequence, IAppendable
         /// the termBuffer array. Use this to truncate the termBuffer
         /// or to synchronize with external manipulation of the termBuffer.
         /// Note: to grow the size of the array,
-        /// use <see cref="ResizeBuffer(int)"/> first. 
-        /// NOTE: This is exactly the same operation as calling the <see cref="Length"/> setter, the primary 
+        /// use <see cref="ResizeBuffer(int)"/> first.
+        /// NOTE: This is exactly the same operation as calling the <see cref="Length"/> setter, the primary
         /// difference is that this method returns a reference to the current object so it can be chained.
         /// <code>
         /// obj.SetLength(30).Append("hey you");
         /// </code>
         /// </summary>
         /// <param name="length"> the truncated length </param>
-        ICharTermAttribute SetLength(int length); 
+        ICharTermAttribute SetLength(int length);
 
         /// <summary>
         /// Sets the length of the termBuffer to zero.
@@ -197,8 +197,8 @@ public interface ICharTermAttribute : IAttribute, ICharSequence, IAppendable
         /// </summary>
         /// <param name="value">The sequence of characters to append.</param>
         /// <remarks>
-        /// LUCENENET specific method, added because the .NET <see cref="string"/> data type 
-        /// doesn't implement <see cref="ICharSequence"/>. 
+        /// LUCENENET specific method, added because the .NET <see cref="string"/> data type
+        /// doesn't implement <see cref="ICharSequence"/>.
         /// </remarks>
         new ICharTermAttribute Append(string value);
 
@@ -228,8 +228,8 @@ public interface ICharTermAttribute : IAttribute, ICharSequence, IAppendable
         /// <paramref name="startIndex"/> + <paramref name="count"/> is greater than the length of <paramref name="value"/>.
         /// </exception>
         /// <remarks>
-        /// LUCENENET specific method, added because the .NET <see cref="string"/> data type 
-        /// doesn't implement <see cref="ICharSequence"/>. 
+        /// LUCENENET specific method, added because the .NET <see cref="string"/> data type
+        /// doesn't implement <see cref="ICharSequence"/>.
         /// </remarks>
         new ICharTermAttribute Append(string value, int startIndex, int count); // LUCENENET TODO: API - change to startIndex/length to match .NET
 
@@ -270,7 +270,7 @@ public interface ICharTermAttribute : IAttribute, ICharSequence, IAppendable
         /// <paramref name="startIndex"/> + <paramref name="count"/> is greater than the length of <paramref name="value"/>.
         /// </exception>
         /// <remarks>
-        /// LUCENENET specific method, added because the .NET <see cref="StringBuilder"/> data type 
+        /// LUCENENET specific method, added because the .NET <see cref="StringBuilder"/> data type
         /// doesn't implement <see cref="ICharSequence"/>.
         /// </remarks>
         new ICharTermAttribute Append(StringBuilder value, int startIndex, int count);

src/Lucene.Net/Analysis/TokenAttributes/CharTermAttributeImpl.cs

@@ -34,7 +34,8 @@ namespace Lucene.Net.Analysis.TokenAttributes
 
     /// <summary>
     /// Default implementation of <see cref="ICharTermAttribute"/>. </summary>
-    public class CharTermAttribute : Attribute, ICharTermAttribute, ITermToBytesRefAttribute, IAppendable // LUCENENET specific: Not implementing ICloneable per Microsoft's recommendation
+    public class CharTermAttribute : Attribute, ICharTermAttribute, ITermToBytesRefAttribute, IAppendable, // LUCENENET specific: Not implementing ICloneable per Microsoft's recommendation
+        ISpanAppendable /* LUCENENET specific */
     {
         private const int MIN_BUFFER_SIZE = 10;
 
@@ -85,7 +86,7 @@ public char[] ResizeBuffer(int newSize)
             {
                 // Not big enough; create a new array with slight
                 // over allocation and preserve content
-                
+
                 // LUCENENET: Resize rather than copy
                 Array.Resize(ref termBuffer, ArrayUtil.Oversize(newSize, RamUsageEstimator.NUM_BYTES_CHAR));
             }
@@ -196,7 +197,6 @@ public ICharSequence Subsequence(int startIndex, int length)
 
         // *** Appendable interface ***
 
-
         public CharTermAttribute Append(string value, int startIndex, int charCount)
         {
             // LUCENENET: Changed semantics to be the same as the StringBuilder in .NET
@@ -358,6 +358,17 @@ public CharTermAttribute Append(ICharSequence value, int startIndex, int charCou
             return this;
         }
 
+        public CharTermAttribute Append(ReadOnlySpan<char> value)
+        {
+            if (value.Length == 0)
+                return this;
+
+            value.CopyTo(InternalResizeBuffer(termLength + value.Length).AsSpan(termLength));
+            Length += value.Length;
+
+            return this;
+        }
+
         private char[] InternalResizeBuffer(int length)
         {
             if (termBuffer.Length < length)
@@ -524,7 +535,12 @@ public override void CopyTo(IAttribute target) // LUCENENET specific - intention
 
         IAppendable IAppendable.Append(ICharSequence value, int startIndex, int count) => Append(value, startIndex, count);
 
+        #endregion
+
+        #region ISpanAppendable Members
+
+        ISpanAppendable ISpanAppendable.Append(ReadOnlySpan<char> value) => Append(value);
 
         #endregion
     }
-}
+}