opendal/services/redb/
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::sync::Arc;
21
22use tokio::task;
23
24use crate::raw::adapters::kv;
25use crate::raw::*;
26use crate::services::RedbConfig;
27use crate::Builder;
28use crate::Error;
29use crate::ErrorKind;
30use crate::Scheme;
31use crate::*;
32
33impl Configurator for RedbConfig {
34    type Builder = RedbBuilder;
35    fn into_builder(self) -> Self::Builder {
36        RedbBuilder { config: self }
37    }
38}
39
40/// Redb service support.
41#[doc = include_str!("docs.md")]
42#[derive(Default, Debug)]
43pub struct RedbBuilder {
44    config: RedbConfig,
45}
46
47impl RedbBuilder {
48    /// Set the path to the redb 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    /// Set the table name for Redb.
55    pub fn table(mut self, table: &str) -> Self {
56        self.config.table = Some(table.into());
57        self
58    }
59
60    /// Set the root for Redb.
61    pub fn root(mut self, path: &str) -> Self {
62        self.config.root = Some(path.into());
63        self
64    }
65}
66
67impl Builder for RedbBuilder {
68    const SCHEME: Scheme = Scheme::Redb;
69    type Config = RedbConfig;
70
71    fn build(self) -> Result<impl Access> {
72        let datadir_path = self.config.datadir.ok_or_else(|| {
73            Error::new(ErrorKind::ConfigInvalid, "datadir is required but not set")
74                .with_context("service", Scheme::Redb)
75        })?;
76
77        let table_name = self.config.table.ok_or_else(|| {
78            Error::new(ErrorKind::ConfigInvalid, "table is required but not set")
79                .with_context("service", Scheme::Redb)
80        })?;
81
82        let db = redb::Database::create(&datadir_path).map_err(parse_database_error)?;
83
84        let db = Arc::new(db);
85
86        Ok(RedbBackend::new(Adapter {
87            datadir: datadir_path,
88            table: table_name,
89            db,
90        })
91        .with_root(self.config.root.as_deref().unwrap_or_default()))
92    }
93}
94
95/// Backend for Redb services.
96pub type RedbBackend = kv::Backend<Adapter>;
97
98#[derive(Clone)]
99pub struct Adapter {
100    datadir: String,
101    table: String,
102    db: Arc<redb::Database>,
103}
104
105impl Debug for Adapter {
106    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
107        let mut ds = f.debug_struct("Adapter");
108        ds.field("path", &self.datadir);
109        ds.finish()
110    }
111}
112
113impl kv::Adapter for Adapter {
114    type Scanner = ();
115
116    fn info(&self) -> kv::Info {
117        kv::Info::new(
118            Scheme::Redb,
119            &self.datadir,
120            Capability {
121                read: true,
122                write: true,
123                blocking: true,
124                shared: false,
125                ..Default::default()
126            },
127        )
128    }
129
130    async fn get(&self, path: &str) -> Result<Option<Buffer>> {
131        let cloned_self = self.clone();
132        let cloned_path = path.to_string();
133
134        task::spawn_blocking(move || cloned_self.blocking_get(cloned_path.as_str()))
135            .await
136            .map_err(new_task_join_error)
137            .and_then(|inner_result| inner_result)
138    }
139
140    fn blocking_get(&self, path: &str) -> Result<Option<Buffer>> {
141        let read_txn = self.db.begin_read().map_err(parse_transaction_error)?;
142
143        let table_define: redb::TableDefinition<&str, &[u8]> =
144            redb::TableDefinition::new(&self.table);
145
146        let table = read_txn
147            .open_table(table_define)
148            .map_err(parse_table_error)?;
149
150        let result = match table.get(path) {
151            Ok(Some(v)) => Ok(Some(v.value().to_vec())),
152            Ok(None) => Ok(None),
153            Err(e) => Err(parse_storage_error(e)),
154        }?;
155        Ok(result.map(Buffer::from))
156    }
157
158    async fn set(&self, path: &str, value: Buffer) -> Result<()> {
159        let cloned_self = self.clone();
160        let cloned_path = path.to_string();
161
162        task::spawn_blocking(move || cloned_self.blocking_set(cloned_path.as_str(), value))
163            .await
164            .map_err(new_task_join_error)
165            .and_then(|inner_result| inner_result)
166    }
167
168    fn blocking_set(&self, path: &str, value: Buffer) -> Result<()> {
169        let write_txn = self.db.begin_write().map_err(parse_transaction_error)?;
170
171        let table_define: redb::TableDefinition<&str, &[u8]> =
172            redb::TableDefinition::new(&self.table);
173
174        {
175            let mut table = write_txn
176                .open_table(table_define)
177                .map_err(parse_table_error)?;
178
179            table
180                .insert(path, &*value.to_vec())
181                .map_err(parse_storage_error)?;
182        }
183
184        write_txn.commit().map_err(parse_commit_error)?;
185        Ok(())
186    }
187
188    async fn delete(&self, path: &str) -> Result<()> {
189        let cloned_self = self.clone();
190        let cloned_path = path.to_string();
191
192        task::spawn_blocking(move || cloned_self.blocking_delete(cloned_path.as_str()))
193            .await
194            .map_err(new_task_join_error)
195            .and_then(|inner_result| inner_result)
196    }
197
198    fn blocking_delete(&self, path: &str) -> Result<()> {
199        let write_txn = self.db.begin_write().map_err(parse_transaction_error)?;
200
201        let table_define: redb::TableDefinition<&str, &[u8]> =
202            redb::TableDefinition::new(&self.table);
203
204        {
205            let mut table = write_txn
206                .open_table(table_define)
207                .map_err(parse_table_error)?;
208
209            table.remove(path).map_err(parse_storage_error)?;
210        }
211
212        write_txn.commit().map_err(parse_commit_error)?;
213        Ok(())
214    }
215}
216
217fn parse_transaction_error(e: redb::TransactionError) -> Error {
218    Error::new(ErrorKind::Unexpected, "error from redb").set_source(e)
219}
220
221fn parse_table_error(e: redb::TableError) -> Error {
222    match e {
223        redb::TableError::TableDoesNotExist(_) => {
224            Error::new(ErrorKind::NotFound, "error from redb").set_source(e)
225        }
226        _ => Error::new(ErrorKind::Unexpected, "error from redb").set_source(e),
227    }
228}
229
230fn parse_storage_error(e: redb::StorageError) -> Error {
231    Error::new(ErrorKind::Unexpected, "error from redb").set_source(e)
232}
233
234fn parse_database_error(e: redb::DatabaseError) -> Error {
235    Error::new(ErrorKind::Unexpected, "error from redb").set_source(e)
236}
237
238fn parse_commit_error(e: redb::CommitError) -> Error {
239    Error::new(ErrorKind::Unexpected, "error from redb").set_source(e)
240}
opendal/services/redb/backend.rs

opendal/services/redb/
backend.rs
