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tansu_storage/service/
metadata.rs

1// Copyright ⓒ 2024-2025 Peter Morgan <peter.james.morgan@gmail.com>
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 rama::{Context, Service};
16use tansu_sans_io::{ApiKey, MetadataRequest, MetadataResponse};
17use tracing::{error, instrument};
18
19use crate::{Error, Result, Storage, TopicId};
20
21/// A [`Service`] using [`Storage`] as [`Context`] taking [`MetadataRequest`] returning [`MetadataRequest`].
22/// ```
23/// use rama::{Context, Layer as _, Service, layer::MapStateLayer};
24/// use tansu_sans_io::MetadataRequest;
25/// use tansu_storage::{Error, MetadataService, StorageContainer};
26/// use url::Url;
27///
28/// # #[tokio::main]
29/// # async fn main() -> Result<(), Error> {
30/// const HOST: &str = "localhost";
31/// const PORT: i32 = 9092;
32/// const NODE_ID: i32 = 111;
33///
34/// let storage = StorageContainer::builder()
35///     .cluster_id("tansu")
36///     .node_id(NODE_ID)
37///     .advertised_listener(Url::parse(&format!("tcp://{HOST}:{PORT}"))?)
38///     .storage(Url::parse("memory://tansu/")?)
39///     .build()
40///     .await?;
41///
42/// let service = MapStateLayer::new(|_| storage).into_layer(MetadataService);
43///
44/// let response = service
45///     .serve(
46///         Context::default(),
47///         MetadataRequest::default()
48///             .allow_auto_topic_creation(Some(false))
49///             .include_cluster_authorized_operations(Some(false))
50///             .include_topic_authorized_operations(Some(false))
51///             .topics(Some([].into())),
52///     )
53///     .await?;
54///
55/// let brokers = response.brokers.as_deref().unwrap_or_default();
56/// assert_eq!(1, brokers.len());
57/// assert_eq!(HOST, brokers[0].host);
58/// assert_eq!(PORT, brokers[0].port);
59/// assert_eq!(NODE_ID, brokers[0].node_id);
60/// assert!(brokers[0].rack.is_none());
61/// # Ok(())
62/// # }
63/// ```
64#[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
65pub struct MetadataService;
66
67impl ApiKey for MetadataService {
68    const KEY: i16 = MetadataRequest::KEY;
69}
70
71impl<G> Service<G, MetadataRequest> for MetadataService
72where
73    G: Storage,
74{
75    type Response = MetadataResponse;
76    type Error = Error;
77
78    #[instrument(skip(ctx, req))]
79    async fn serve(
80        &self,
81        ctx: Context<G>,
82        req: MetadataRequest,
83    ) -> Result<Self::Response, Self::Error> {
84        let topics = req
85            .topics
86            .map(|topics| topics.iter().map(TopicId::from).collect::<Vec<_>>());
87
88        let response = ctx
89            .state()
90            .metadata(topics.as_deref())
91            .await
92            .inspect_err(|err| error!(?err))?;
93        let brokers = Some(response.brokers().to_owned());
94        let cluster_id = response.cluster().map(|s| s.into());
95        let controller_id = response.controller();
96        let topics = Some(response.topics().to_owned());
97        let cluster_authorized_operations = Some(-1);
98
99        let throttle_time_ms = Some(0);
100
101        Ok(MetadataResponse::default()
102            .throttle_time_ms(throttle_time_ms)
103            .brokers(brokers)
104            .cluster_id(cluster_id)
105            .controller_id(controller_id)
106            .topics(topics)
107            .cluster_authorized_operations(cluster_authorized_operations))
108    }
109}