engula_journal/mem/
journal.rs

1// Copyright 2021 The Engula Authors.
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::{
16    collections::{hash_map, HashMap},
17    sync::Arc,
18};
19
20use tokio::sync::Mutex;
21
22use super::stream::Stream;
23use crate::{async_trait, Error, Result};
24
25#[derive(Clone)]
26pub struct Journal {
27    streams: Arc<Mutex<HashMap<String, Stream>>>,
28}
29
30impl Default for Journal {
31    fn default() -> Self {
32        Self {
33            streams: Arc::new(Mutex::new(HashMap::new())),
34        }
35    }
36}
37
38#[async_trait]
39impl crate::Journal for Journal {
40    type Stream = Stream;
41
42    async fn stream(&self, name: &str) -> Result<Self::Stream> {
43        let streams = self.streams.lock().await;
44        match streams.get(name) {
45            Some(stream) => Ok(stream.clone()),
46            None => Err(Error::NotFound(format!("stream '{}'", name))),
47        }
48    }
49
50    async fn create_stream(&self, name: &str) -> Result<Self::Stream> {
51        let stream = Stream::default();
52        let mut streams = self.streams.lock().await;
53        match streams.entry(name.to_owned()) {
54            hash_map::Entry::Vacant(ent) => {
55                ent.insert(stream.clone());
56                Ok(stream)
57            }
58            hash_map::Entry::Occupied(ent) => {
59                Err(Error::AlreadyExists(format!("stream '{}'", ent.key())))
60            }
61        }
62    }
63
64    async fn delete_stream(&self, name: &str) -> Result<()> {
65        let mut streams = self.streams.lock().await;
66        match streams.remove(name) {
67            Some(_) => Ok(()),
68            None => Err(Error::NotFound(format!("stream '{}'", name))),
69        }
70    }
71}
engula_journal/mem/journal.rs

engula_journal/mem/
journal.rs
