Dandandan commented on code in PR #6904:
URL: https://github.com/apache/arrow-datafusion/pull/6904#discussion_r1258780386
##########
datafusion/physical-expr/src/aggregate/count.rs:
##########
@@ -76,6 +85,109 @@ impl Count {
}
}
+/// An accumulator to compute the counts of [`PrimitiveArray<T>`].
+/// Stores values as native types, and does overflow checking
+///
+/// Unlike most other accumulators, COUNT never produces NULLs. If no
+/// non-null values are seen in any group the output is 0. Thus, this
+/// accumulator has no additional null or seen filter tracking.
+#[derive(Debug)]
+struct CountGroupsAccumulator {
+ /// Count per group (use i64 to make Int64Array)
+ counts: Vec<i64>,
+}
+
+impl CountGroupsAccumulator {
+ pub fn new() -> Self {
+ Self { counts: vec![] }
+ }
+}
+
+impl GroupsAccumulator for CountGroupsAccumulator {
+ fn update_batch(
+ &mut self,
+ values: &[ArrayRef],
+ group_indices: &[usize],
+ opt_filter: Option<&arrow_array::BooleanArray>,
+ total_num_groups: usize,
+ ) -> Result<()> {
+ assert_eq!(values.len(), 1, "single argument to update_batch");
+ let values = values.get(0).unwrap();
+
+ // Add one to each group's counter for each non null, non
+ // filtered value
+ self.counts.resize(total_num_groups, 0);
+ accumulate_indices(
+ group_indices,
+ values.nulls(), // ignore values
+ opt_filter,
+ |group_index| {
Review Comment:
I suggested it mainly for consistency.
AFAIK `wrapping_add` doesn't check for overflow but wraps, which is the
default already, but in debug mode it causes an exception.
Maybe we should remove the `wrapping_add` in the other places and "just" use
`+` etc.
--
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: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
