risingwave_stream/executor/join/
row.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use risingwave_common::row::{self, CompactedRow, OwnedRow, Row, RowExt};
16use risingwave_common::types::{DataType, ScalarImpl};
17use risingwave_common_estimate_size::EstimateSize;
18
19use crate::executor::StreamExecutorResult;
20
21pub trait JoinEncoding: 'static + Send + Sync + Default {
22    type EncodedRow: CachedJoinRow<DecodedRow = Self::DecodedRow> + Default;
23    type DecodedRow: Row;
24
25    fn encode<R: Row>(row: &JoinRow<R>) -> Self::EncodedRow;
26}
27
28#[derive(Default)]
29pub struct CpuEncoding {}
30
31impl JoinEncoding for CpuEncoding {
32    type DecodedRow = OwnedRow;
33    type EncodedRow = JoinRow<OwnedRow>;
34
35    fn encode<R: Row>(row: &JoinRow<R>) -> JoinRow<OwnedRow> {
36        JoinRow::new(row.row.to_owned_row(), row.degree)
37    }
38}
39
40#[derive(Default)]
41pub struct MemoryEncoding {}
42
43impl JoinEncoding for MemoryEncoding {
44    type DecodedRow = OwnedRow;
45    type EncodedRow = EncodedJoinRow;
46
47    fn encode<R: Row>(row: &JoinRow<R>) -> EncodedJoinRow {
48        EncodedJoinRow {
49            compacted_row: (&row.row).into(),
50            degree: row.degree,
51        }
52    }
53}
54
55/// This is a row with a match degree
56#[derive(Clone, Debug)]
57pub struct JoinRow<R: Row> {
58    pub row: R,
59    pub degree: DegreeType,
60}
61
62impl<R: Row> JoinRow<R> {
63    pub fn new(row: R, degree: DegreeType) -> Self {
64        Self { row, degree }
65    }
66
67    pub fn is_zero_degree(&self) -> bool {
68        self.degree == 0
69    }
70
71    /// Return row and degree in `Row` format. The degree part will be inserted in degree table
72    /// later, so a pk prefix will be added.
73    ///
74    /// * `state_order_key_indices` - the order key of `row`
75    pub fn to_table_rows<'a>(
76        &'a self,
77        state_order_key_indices: &'a [usize],
78    ) -> (&'a R, impl Row + 'a) {
79        let order_key = (&self.row).project(state_order_key_indices);
80        let degree = build_degree_row(order_key, self.degree);
81        (&self.row, degree)
82    }
83
84    /// Map the row to another row.
85    pub fn map<R2: Row>(self, f: impl FnOnce(R) -> R2) -> JoinRow<R2> {
86        JoinRow::new(f(self.row), self.degree)
87    }
88}
89
90pub type DegreeType = u64;
91
92fn build_degree_row(order_key: impl Row, degree: DegreeType) -> impl Row {
93    order_key.chain(row::once(Some(ScalarImpl::Int64(degree as i64))))
94}
95
96pub trait CachedJoinRow: EstimateSize + Default + Send + Sync {
97    type DecodedRow: Row;
98
99    fn decode(&self, data_types: &[DataType]) -> StreamExecutorResult<JoinRow<Self::DecodedRow>>;
100
101    fn increase_degree(&mut self);
102
103    fn decrease_degree(&mut self);
104}
105
106#[derive(Clone, Debug, EstimateSize, Default)]
107pub struct EncodedJoinRow {
108    pub compacted_row: CompactedRow,
109    pub degree: DegreeType,
110}
111
112impl CachedJoinRow for EncodedJoinRow {
113    type DecodedRow = OwnedRow;
114
115    fn decode(&self, data_types: &[DataType]) -> StreamExecutorResult<JoinRow<OwnedRow>> {
116        let row = self.compacted_row.deserialize(data_types)?;
117        Ok(JoinRow::new(row, self.degree))
118    }
119
120    fn increase_degree(&mut self) {
121        self.degree += 1;
122    }
123
124    fn decrease_degree(&mut self) {
125        self.degree -= 1;
126    }
127}
128
129impl Default for JoinRow<OwnedRow> {
130    fn default() -> JoinRow<OwnedRow> {
131        Self {
132            row: OwnedRow::default(),
133            degree: DegreeType::default(),
134        }
135    }
136}
137
138impl EstimateSize for JoinRow<OwnedRow> {
139    fn estimated_heap_size(&self) -> usize {
140        self.row.estimated_heap_size()
141    }
142}
143
144impl CachedJoinRow for JoinRow<OwnedRow> {
145    type DecodedRow = OwnedRow;
146
147    fn decode(&self, _data_types: &[DataType]) -> StreamExecutorResult<JoinRow<OwnedRow>> {
148        Ok(self.clone())
149    }
150
151    fn increase_degree(&mut self) {
152        self.degree += 1;
153    }
154
155    fn decrease_degree(&mut self) {
156        self.degree -= 1;
157    }
158}
159
160#[cfg(test)]
161mod tests {
162    use super::*;
163
164    #[test]
165    fn test_cached_join_row_sizes() {
166        let encoded_size = size_of::<EncodedJoinRow>();
167        let unencoded_size = size_of::<JoinRow<OwnedRow>>();
168
169        assert_eq!(encoded_size, 40);
170        assert_eq!(unencoded_size, 24);
171    }
172}
risingwave_stream/executor/join/row.rs

risingwave_stream/executor/join/
row.rs
