risingwave_frontend/optimizer/plan_node/generic/
limit.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 std::hash::Hash;
16
17use pretty_xmlish::{Pretty, Str, XmlNode};
18use risingwave_common::catalog::Schema;
19
20use super::{DistillUnit, GenericPlanNode, GenericPlanRef};
21use crate::OptimizerContextRef;
22use crate::optimizer::plan_node::utils::childless_record;
23use crate::optimizer::property::FunctionalDependencySet;
24
25#[derive(Debug, Clone, PartialEq, Eq, Hash)]
26pub struct Limit<PlanRef> {
27    pub input: PlanRef,
28    pub limit: u64,
29    pub offset: u64,
30}
31
32impl<PlanRef: GenericPlanRef> GenericPlanNode for Limit<PlanRef> {
33    fn ctx(&self) -> OptimizerContextRef {
34        self.input.ctx()
35    }
36
37    fn schema(&self) -> Schema {
38        self.input.schema().clone()
39    }
40
41    fn functional_dependency(&self) -> FunctionalDependencySet {
42        self.input.functional_dependency().clone()
43    }
44
45    fn stream_key(&self) -> Option<Vec<usize>> {
46        Some(self.input.stream_key()?.to_vec())
47    }
48}
49impl<PlanRef> Limit<PlanRef> {
50    pub fn new(input: PlanRef, limit: u64, offset: u64) -> Self {
51        Limit {
52            input,
53            limit,
54            offset,
55        }
56    }
57}
58
59impl<PlanRef> DistillUnit for Limit<PlanRef> {
60    fn distill_with_name<'a>(&self, name: impl Into<Str<'a>>) -> XmlNode<'a> {
61        childless_record(
62            name,
63            vec![
64                ("limit", Pretty::debug(&self.limit)),
65                ("offset", Pretty::debug(&self.offset)),
66            ],
67        )
68    }
69}
risingwave_frontend/optimizer/plan_node/generic/limit.rs

risingwave_frontend/optimizer/plan_node/generic/
limit.rs
