[Feature] Support Spark bitmap_count

[zhangxffff]

Feature Category

SQL Function / Operator

Problem / Use Case

Apache Spark 3.5 provides bitmap_count, but Bolt has no native Spark SQL implementation. Queries currently retain Spark's BitmapExpressionUtils.bitmapCount invocation and fall back instead of running in Bolt.

Proposed Solution

Implement Spark-compatible bitmap_count:

bitmap_count(bitmap: BINARY) -> BIGINT

The function should return the population count across every input byte and preserve Spark null and binary input-type behavior. It must accept output produced by bitmap_construct_agg and bitmap_or_agg.

Add the Gluten/Substrait expression mapping and register the function for Spark-compatible Bolt builds.

References / Prior Art

• Apache Spark 3.5 BitmapCount
• Apache Spark 3.5 BitmapExpressionUtils.bitmapCount
• Spark BitmapExpressionsQuerySuite case bitmap_count

Acceptance Criteria

• Add native Bolt tests for empty binary input, all-zero/all-one bytes, mixed bits, null, and invalid input types.
• Match Spark 3.5 results.
• Execute the corresponding Gluten query with a native project transformer.

Importance

Medium