risingwave_connector/sink/
trivial.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::marker::PhantomData;
16
17use async_trait::async_trait;
18use risingwave_common::session_config::sink_decouple::SinkDecouple;
19
20use crate::sink::log_store::{LogStoreReadItem, TruncateOffset};
21use crate::sink::{
22    DummySinkCommitCoordinator, LogSinker, Result, Sink, SinkError, SinkLogReader, SinkParam,
23    SinkWriterParam,
24};
25
26pub const BLACKHOLE_SINK: &str = "blackhole";
27pub const TABLE_SINK: &str = "table";
28
29pub trait TrivialSinkName: Send + 'static {
30    const SINK_NAME: &'static str;
31}
32
33#[derive(Debug)]
34pub struct BlackHoleSinkName;
35
36impl TrivialSinkName for BlackHoleSinkName {
37    const SINK_NAME: &'static str = BLACKHOLE_SINK;
38}
39
40pub type BlackHoleSink = TrivialSink<BlackHoleSinkName>;
41
42#[derive(Debug)]
43pub struct TableSinkName;
44
45impl TrivialSinkName for TableSinkName {
46    const SINK_NAME: &'static str = TABLE_SINK;
47}
48
49pub type TableSink = TrivialSink<TableSinkName>;
50
51#[derive(Debug)]
52pub struct TrivialSink<T: TrivialSinkName>(PhantomData<T>);
53
54impl<T: TrivialSinkName> TryFrom<SinkParam> for TrivialSink<T> {
55    type Error = SinkError;
56
57    fn try_from(_value: SinkParam) -> std::result::Result<Self, Self::Error> {
58        Ok(Self(PhantomData))
59    }
60}
61
62impl<T: TrivialSinkName> Sink for TrivialSink<T> {
63    type Coordinator = DummySinkCommitCoordinator;
64    type LogSinker = Self;
65
66    const SINK_NAME: &'static str = T::SINK_NAME;
67
68    // Disable sink decoupling for all trivial sinks because it introduces overhead without any benefit
69    fn is_sink_decouple(_user_specified: &SinkDecouple) -> Result<bool> {
70        Ok(false)
71    }
72
73    async fn new_log_sinker(&self, _writer_env: SinkWriterParam) -> Result<Self::LogSinker> {
74        Ok(Self(PhantomData))
75    }
76
77    async fn validate(&self) -> Result<()> {
78        Ok(())
79    }
80}
81
82#[async_trait]
83impl<T: TrivialSinkName> LogSinker for TrivialSink<T> {
84    async fn consume_log_and_sink(self, mut log_reader: impl SinkLogReader) -> Result<!> {
85        log_reader.start_from(None).await?;
86        loop {
87            let (epoch, item) = log_reader.next_item().await?;
88            match item {
89                LogStoreReadItem::StreamChunk { chunk_id, .. } => {
90                    log_reader.truncate(TruncateOffset::Chunk { epoch, chunk_id })?;
91                }
92                LogStoreReadItem::Barrier { .. } => {
93                    log_reader.truncate(TruncateOffset::Barrier { epoch })?;
94                }
95            }
96        }
97    }
98}
risingwave_connector/sink/trivial.rs

risingwave_connector/sink/
trivial.rs
