risingwave_connector/source/
data_gen_util.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::sync::LazyLock;
16
17use futures::{Stream, StreamExt, pin_mut};
18use tokio::runtime::Runtime;
19use tokio::sync::mpsc;
20
21/// Spawn the data generator to a dedicated runtime, returns a channel receiver
22/// for acquiring the generated data. This is used for the [`DatagenSplitReader`]
23/// and [`NexmarkSplitReader`] in case that they are CPU intensive
24/// and may block the streaming actors.
25///
26/// [`DatagenSplitReader`]: super::datagen::DatagenSplitReader
27/// [`NexmarkSplitReader`]: super::nexmark::source::reader::NexmarkSplitReader
28pub fn spawn_data_generation_stream<T: Send + 'static>(
29    stream: impl Stream<Item = T> + Send + 'static,
30    buffer_size: usize,
31) -> impl Stream<Item = T> + Send + 'static {
32    static RUNTIME: LazyLock<Runtime> = LazyLock::new(|| {
33        tokio::runtime::Builder::new_multi_thread()
34            .thread_name("rw-datagen")
35            .enable_all()
36            .build()
37            .expect("failed to build data-generation runtime")
38    });
39
40    let (generation_tx, generation_rx) = mpsc::channel(buffer_size);
41    RUNTIME.spawn(async move {
42        pin_mut!(stream);
43        while let Some(result) = stream.next().await {
44            if generation_tx.send(result).await.is_err() {
45                tracing::warn!("failed to send next event to reader, exit");
46                break;
47            }
48        }
49    });
50
51    tokio_stream::wrappers::ReceiverStream::new(generation_rx)
52}
risingwave_connector/source/data_gen_util.rs

risingwave_connector/source/
data_gen_util.rs
