feat(batch,agg): support array_agg for batch mode

e2e_test/batch/aggregate/array_agg.slt.part

@@ -0,0 +1,29 @@
+statement ok
+SET RW_IMPLICIT_FLUSH TO true;
+
+statement ok
+create table t(v1 varchar, v2 int, v3 int)
+
+statement ok
+insert into t values ('aaa', 1, 1), ('bbb', 0, 2), ('ccc', 0, 5), ('ddd', 1, 4)
+
+query T
+select b from (select unnest(a) from (select array_agg(v3) as v3_arr from t) g(a)) p(b) order by b;
+----
+1
+2
+4
+5
+
+query T
+select array_agg(v1 order by v3 desc) from t
+----
+{ccc,ddd,bbb,aaa}
+
+query T
+select array_agg(v1 order by v2 asc, v3 desc) from t
+----
+{ccc,bbb,ddd,aaa}
+
+statement ok
+drop table t

src/expr/src/vector_op/agg/aggregator.rs

@@ -22,6 +22,7 @@ use risingwave_common::util::sort_util::{OrderPair, OrderType};
 use risingwave_pb::expr::AggCall;
 use risingwave_pb::plan_common::OrderType as ProstOrderType;
 
+use super::array_agg::create_array_agg_state;
 use super::string_agg::StringAgg;
 use crate::expr::{
     build_from_prost, AggKind, Expression, ExpressionRef, InputRefExpression, LiteralExpression,
@@ -123,6 +124,10 @@ impl AggStateFactory {
                     order_col_types,
                 ))
             }
+            (AggKind::ArrayAgg, [arg]) => {
+                let agg_col_idx = arg.get_input()?.get_column_idx() as usize;
+                create_array_agg_state(return_type.clone(), agg_col_idx, order_pairs)?
+            }
             (agg_kind, [arg]) => {
                 // other unary agg call
                 let input_type = DataType::from(arg.get_type()?);

src/expr/src/vector_op/agg/array_agg.rs

@@ -0,0 +1,262 @@
+// Copyright 2022 Singularity Data
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use risingwave_common::array::{ArrayBuilder, ArrayBuilderImpl, DataChunk, ListValue, RowRef};
+use risingwave_common::error::{ErrorCode, Result};
+use risingwave_common::types::{DataType, Datum, Scalar};
+use risingwave_common::util::ordered::OrderedRow;
+use risingwave_common::util::sort_util::{OrderPair, OrderType};
+
+use crate::vector_op::agg::aggregator::Aggregator;
+
+#[derive(Clone)]
+struct ArrayAggUnordered {
+    return_type: DataType,
+    agg_col_idx: usize,
+    values: Vec<Datum>,
+}
+
+impl ArrayAggUnordered {
+    fn new(return_type: DataType, agg_col_idx: usize) -> Self {
+        debug_assert!(matches!(return_type, DataType::List { datatype: _ }));
+        ArrayAggUnordered {
+            return_type,
+            agg_col_idx,
+            values: vec![],
+        }
+    }
+
+    fn push(&mut self, datum: Datum) {
+        self.values.push(datum);
+    }
+
+    fn get_result_and_reset(&mut self) -> ListValue {
+        ListValue::new(std::mem::take(&mut self.values))
+    }
+}
+
+impl Aggregator for ArrayAggUnordered {
+    fn return_type(&self) -> DataType {
+        self.return_type.clone()
+    }
+
+    fn update_single(&mut self, input: &DataChunk, row_id: usize) -> Result<()> {
+        let array = input.column_at(self.agg_col_idx).array_ref();
+        self.push(array.datum_at(row_id));
+        Ok(())
+    }
+
+    fn update_multi(
+        &mut self,
+        input: &DataChunk,
+        start_row_id: usize,
+        end_row_id: usize,
+    ) -> Result<()> {
+        for row_id in start_row_id..end_row_id {
+            self.update_single(input, row_id)?;
+        }
+        Ok(())
+    }
+
+    fn output(&mut self, builder: &mut ArrayBuilderImpl) -> Result<()> {
+        if let ArrayBuilderImpl::List(builder) = builder {
+            builder
+                .append(Some(self.get_result_and_reset().as_scalar_ref()))
+                .map_err(Into::into)
+        } else {
+            Err(
+                ErrorCode::InternalError(format!("Builder fail to match {}.", stringify!(Utf8)))
+                    .into(),
+            )
+        }
+    }
+}
+
+#[derive(Clone)]
+struct ArrayAggOrdered {
+    return_type: DataType,
+    agg_col_idx: usize,
+    order_col_indices: Vec<usize>,
+    order_types: Vec<OrderType>,
+    unordered_values: Vec<(OrderedRow, Datum)>,
+}
+
+impl ArrayAggOrdered {
+    fn new(return_type: DataType, agg_col_idx: usize, order_pairs: Vec<OrderPair>) -> Self {
+        debug_assert!(matches!(return_type, DataType::List { datatype: _ }));
+        let (order_col_indices, order_types) = order_pairs
+            .into_iter()
+            .map(|p| (p.column_idx, p.order_type))
+            .unzip();
+        ArrayAggOrdered {
+            return_type,
+            agg_col_idx,
+            order_col_indices,
+            order_types,
+            unordered_values: vec![],
+        }
+    }
+
+    fn push_row(&mut self, row: RowRef) {
+        let key = OrderedRow::new(
+            row.row_by_indices(&self.order_col_indices),
+            &self.order_types,
+        );
+        let datum = row.value_at(self.agg_col_idx).map(|x| x.into_scalar_impl());
+        self.unordered_values.push((key, datum));
+    }
+
+    fn get_result_and_reset(&mut self) -> ListValue {
+        let mut rows = std::mem::take(&mut self.unordered_values);
+        rows.sort_unstable_by(|a, b| a.0.cmp(&b.0));
+        ListValue::new(rows.into_iter().map(|(_, datum)| datum).collect())
+    }
+}
+
+impl Aggregator for ArrayAggOrdered {
+    fn return_type(&self) -> DataType {
+        self.return_type.clone()
+    }
+
+    fn update_single(&mut self, input: &DataChunk, row_id: usize) -> Result<()> {
+        let (row, vis) = input.row_at(row_id)?;
+        assert!(vis);
+        self.push_row(row);
+        Ok(())
+    }
+
+    fn update_multi(
+        &mut self,
+        input: &DataChunk,
+        start_row_id: usize,
+        end_row_id: usize,
+    ) -> Result<()> {
+        for row_id in start_row_id..end_row_id {
+            self.update_single(input, row_id)?;
+        }
+        Ok(())
+    }
+
+    fn output(&mut self, builder: &mut ArrayBuilderImpl) -> Result<()> {
+        if let ArrayBuilderImpl::List(builder) = builder {
+            builder
+                .append(Some(self.get_result_and_reset().as_scalar_ref()))
+                .map_err(Into::into)
+        } else {
+            Err(
+                ErrorCode::InternalError(format!("Builder fail to match {}.", stringify!(Utf8)))
+                    .into(),
+            )
+        }
+    }
+}
+
+pub fn create_array_agg_state(
+    return_type: DataType,
+    agg_col_idx: usize,
+    order_pairs: Vec<OrderPair>,
+) -> Result<Box<dyn Aggregator>> {
+    if order_pairs.is_empty() {
+        Ok(Box::new(ArrayAggUnordered::new(return_type, agg_col_idx)))
+    } else {
+        Ok(Box::new(ArrayAggOrdered::new(
+            return_type,
+            agg_col_idx,
+            order_pairs,
+        )))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use itertools::Itertools;
+    use risingwave_common::array::Array;
+    use risingwave_common::test_prelude::DataChunkTestExt;
+    use risingwave_common::types::ScalarRef;
+
+    use super::*;
+
+    #[test]
+    fn test_array_agg_basic() -> Result<()> {
+        let chunk = DataChunk::from_pretty(
+            "i
+             123
+             456
+             789",
+        );
+        let return_type = DataType::List {
+            datatype: Box::new(DataType::Int32),
+        };
+        let mut agg = create_array_agg_state(return_type.clone(), 0, vec![])?;
+        let mut builder = return_type.create_array_builder(0);
+        agg.update_multi(&chunk, 0, chunk.cardinality())?;
+        agg.output(&mut builder)?;
+        let output = builder.finish()?;
+        let actual = output.into_list();
+        let actual = actual
+            .iter()
+            .map(|v| v.map(|s| s.to_owned_scalar()))
+            .collect_vec();
+        assert_eq!(
+            actual,
+            vec![Some(ListValue::new(vec![
+                Some(123.into()),
+                Some(456.into()),
+                Some(789.into())
+            ]))]
+        );
+        Ok(())
+    }
+
+    #[test]
+    fn test_array_agg_with_order() -> Result<()> {
+        let chunk = DataChunk::from_pretty(
+            "i    i
+             123  3
+             456  2
+             789  2
+             321  9",
+        );
+        let return_type = DataType::List {
+            datatype: Box::new(DataType::Int32),
+        };
+        let mut agg = create_array_agg_state(
+            return_type.clone(),
+            0,
+            vec![
+                OrderPair::new(1, OrderType::Ascending),
+                OrderPair::new(0, OrderType::Descending),
+            ],
+        )?;
+        let mut builder = return_type.create_array_builder(0);
+        agg.update_multi(&chunk, 0, chunk.cardinality())?;
+        agg.output(&mut builder)?;
+        let output = builder.finish()?;
+        let actual = output.into_list();
+        let actual = actual
+            .iter()
+            .map(|v| v.map(|s| s.to_owned_scalar()))
+            .collect_vec();
+        assert_eq!(
+            actual,
+            vec![Some(ListValue::new(vec![
+                Some(789.into()),
+                Some(456.into()),
+                Some(123.into()),
+                Some(321.into())
+            ]))]
+        );
+        Ok(())
+    }
+}

src/expr/src/vector_op/agg/mod.rs

@@ -14,6 +14,7 @@
 
 mod aggregator;
 mod approx_count_distinct;
+mod array_agg;
 mod count_star;
 mod functions;
 mod general_agg;