[GitHub] [arrow] eerhardt commented on a change in pull request #7671: ARROW-8344: [C#] Bug-fixes to binary array plus other improvements

[GitBox <gi...@apache.org>]

eerhardt commented on a change in pull request #7671:
URL: https://github.com/apache/arrow/pull/7671#discussion_r453038089



##########
File path: csharp/src/Apache.Arrow/Arrays/BinaryArray.cs
##########
@@ -66,87 +66,158 @@ protected BuilderBase(IArrowType dataType)
                 ValueOffsets = new ArrowBuffer.Builder<int>();
                 ValueBuffer = new ArrowBuffer.Builder<byte>();
                 ValidityBuffer = new ArrowBuffer.BitmapBuilder();
+
+                // From the docs:
+                //
+                // The offsets buffer contains length + 1 signed integers (either 32-bit or 64-bit, depending on the
+                // logical type), which encode the start position of each slot in the data buffer. The length of the
+                // value in each slot is computed using the difference between the offset at that slot’s index and the
+                // subsequent offset.
+                //
+                // In this builder, we choose to append the first offset (zero) upon construction, and each trailing
+                // offset is then added after each individual item has been appended.
+                ValueOffsets.Append(this.Offset);

Review comment:
       Nice fix.




----------------------------------------------------------------
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.

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