opendal/services/cacache/
backend.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use std::fmt::Debug;
19use std::fmt::Formatter;
20use std::str;
21
22use cacache;
23
24use crate::raw::adapters::kv;
25use crate::raw::Access;
26use crate::services::CacacheConfig;
27use crate::Builder;
28use crate::Error;
29use crate::ErrorKind;
30use crate::Scheme;
31use crate::*;
32
33impl Configurator for CacacheConfig {
34    type Builder = CacacheBuilder;
35    fn into_builder(self) -> Self::Builder {
36        CacacheBuilder { config: self }
37    }
38}
39
40/// cacache service support.
41#[doc = include_str!("docs.md")]
42#[derive(Default)]
43pub struct CacacheBuilder {
44    config: CacacheConfig,
45}
46
47impl CacacheBuilder {
48    /// Set the path to the cacache data directory. Will create if not exists.
49    pub fn datadir(mut self, path: &str) -> Self {
50        self.config.datadir = Some(path.into());
51        self
52    }
53}
54
55impl Builder for CacacheBuilder {
56    const SCHEME: Scheme = Scheme::Cacache;
57    type Config = CacacheConfig;
58
59    fn build(self) -> Result<impl Access> {
60        let datadir_path = self.config.datadir.ok_or_else(|| {
61            Error::new(ErrorKind::ConfigInvalid, "datadir is required but not set")
62                .with_context("service", Scheme::Cacache)
63        })?;
64
65        Ok(CacacheBackend::new(Adapter {
66            datadir: datadir_path,
67        }))
68    }
69}
70
71/// Backend for cacache services.
72pub type CacacheBackend = kv::Backend<Adapter>;
73
74#[derive(Clone)]
75pub struct Adapter {
76    datadir: String,
77}
78
79impl Debug for Adapter {
80    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
81        let mut ds = f.debug_struct("Adapter");
82        ds.field("path", &self.datadir);
83        ds.finish()
84    }
85}
86
87impl kv::Adapter for Adapter {
88    type Scanner = ();
89
90    fn info(&self) -> kv::Info {
91        kv::Info::new(
92            Scheme::Cacache,
93            &self.datadir,
94            Capability {
95                read: true,
96                write: true,
97                delete: true,
98                shared: false,
99                ..Default::default()
100            },
101        )
102    }
103
104    async fn get(&self, path: &str) -> Result<Option<Buffer>> {
105        let result = cacache::read(&self.datadir, path)
106            .await
107            .map_err(parse_error)?;
108        Ok(Some(Buffer::from(result)))
109    }
110
111    async fn set(&self, path: &str, value: Buffer) -> Result<()> {
112        cacache::write(&self.datadir, path, value.to_vec())
113            .await
114            .map_err(parse_error)?;
115        Ok(())
116    }
117
118    async fn delete(&self, path: &str) -> Result<()> {
119        cacache::remove(&self.datadir, path)
120            .await
121            .map_err(parse_error)?;
122
123        Ok(())
124    }
125}
126
127fn parse_error(err: cacache::Error) -> Error {
128    let kind = match err {
129        cacache::Error::EntryNotFound(_, _) => ErrorKind::NotFound,
130        _ => ErrorKind::Unexpected,
131    };
132
133    Error::new(kind, "error from cacache").set_source(err)
134}
opendal/services/cacache/backend.rs

opendal/services/cacache/
backend.rs
