[GitHub] [arrow] westonpace commented on a diff in pull request #13810: ARROW-17330: [C#] Extend ArrowBuffer.BitmapBuilder to improve performance of array concatenation

["westonpace (via GitHub)" <gi...@apache.org>]

westonpace commented on code in PR #13810:
URL: https://github.com/apache/arrow/pull/13810#discussion_r1162111150


##########
csharp/src/Apache.Arrow/Arrays/PrimitiveArrayBuilder.cs:
##########
@@ -141,15 +141,17 @@ public TBuilder Append(ReadOnlySpan<T> span)
         {
             int len = ValueBuffer.Length;
             ValueBuffer.Append(span);
-            ValidityBuffer.AppendRange(Enumerable.Repeat(true, ValueBuffer.Length - len));
+            int additionalBitsCount = ValueBuffer.Length - len;
+            ValidityBuffer.Reserve(additionalBitsCount).AppendRange(Enumerable.Repeat(true, additionalBitsCount));

Review Comment:
   I think the suggestion is to add a new `AppendRange` overload/method to BitmapBuilder...
   
   public BitmapBuilder AppendRange(bool value, int length) {
     // Set bits [Length:Length+length) to value
   }
   
   



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org