opendal_service_memcached/
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::borrow::Cow;
19use std::sync::Arc;
20use url::Url;
21
22use opendal_core::raw::*;
23use opendal_core::*;
24
25use super::MEMCACHED_SCHEME;
26use super::config::MemcachedConfig;
27use super::core::*;
28use super::deleter::MemcachedDeleter;
29use super::reader::*;
30use super::writer::MemcachedWriter;
31
32/// [Memcached](https://memcached.org/) service support.
33#[doc = include_str!("docs.md")]
34#[derive(Debug, Default)]
35pub struct MemcachedBuilder {
36    pub(super) config: MemcachedConfig,
37}
38
39impl MemcachedBuilder {
40    /// set the network address of memcached service.
41    ///
42    /// For example: "tcp://localhost:11211"
43    pub fn endpoint(mut self, endpoint: &str) -> Self {
44        if !endpoint.is_empty() {
45            self.config.endpoint = Some(endpoint.to_owned());
46        }
47        self
48    }
49
50    /// set the working directory, all operations will be performed under it.
51    ///
52    /// default: "/"
53    pub fn root(mut self, root: &str) -> Self {
54        self.config.root = if root.is_empty() {
55            None
56        } else {
57            Some(root.to_string())
58        };
59
60        self
61    }
62
63    /// set the username.
64    pub fn username(mut self, username: &str) -> Self {
65        self.config.username = Some(username.to_string());
66        self
67    }
68
69    /// set the password.
70    pub fn password(mut self, password: &str) -> Self {
71        self.config.password = Some(password.to_string());
72        self
73    }
74
75    /// Set the default ttl for memcached services.
76    pub fn default_ttl(mut self, ttl: Duration) -> Self {
77        self.config.default_ttl = Some(ttl);
78        self
79    }
80
81    /// Sets the maximum number of connections managed by the pool.
82    ///
83    /// Defaults to 10.
84    ///
85    /// # Panics
86    ///
87    /// Will panic if `max_size` is 0.
88    #[must_use]
89    pub fn connection_pool_max_size(mut self, max_size: usize) -> Self {
90        assert!(max_size > 0, "max_size must be greater than zero!");
91        self.config.connection_pool_max_size = Some(max_size);
92        self
93    }
94}
95
96impl Builder for MemcachedBuilder {
97    type Config = MemcachedConfig;
98
99    fn build(self) -> Result<impl Service> {
100        let endpoint_raw = self.config.endpoint.clone().ok_or_else(|| {
101            Error::new(ErrorKind::ConfigInvalid, "endpoint is empty")
102                .with_context("service", MEMCACHED_SCHEME)
103        })?;
104
105        let url_str = if !endpoint_raw.contains("://") {
106            Cow::Owned(format!("tcp://{}", endpoint_raw))
107        } else {
108            Cow::Borrowed(endpoint_raw.as_str())
109        };
110
111        let parsed = Url::parse(&url_str).map_err(|err| {
112            Error::new(ErrorKind::ConfigInvalid, "endpoint is invalid")
113                .with_context("service", MEMCACHED_SCHEME)
114                .with_context("endpoint", &endpoint_raw)
115                .set_source(err)
116        })?;
117
118        let endpoint = match parsed.scheme() {
119            "tcp" => {
120                let host = parsed.host_str().ok_or_else(|| {
121                    Error::new(ErrorKind::ConfigInvalid, "tcp endpoint doesn't have host")
122                        .with_context("service", MEMCACHED_SCHEME)
123                        .with_context("endpoint", &endpoint_raw)
124                })?;
125                let port = parsed.port().ok_or_else(|| {
126                    Error::new(ErrorKind::ConfigInvalid, "tcp endpoint doesn't have port")
127                        .with_context("service", MEMCACHED_SCHEME)
128                        .with_context("endpoint", &endpoint_raw)
129                })?;
130                Endpoint::Tcp(format!("{host}:{port}"))
131            }
132
133            #[cfg(unix)]
134            "unix" => {
135                let path = parsed.path();
136                if path.is_empty() {
137                    return Err(Error::new(
138                        ErrorKind::ConfigInvalid,
139                        "unix endpoint doesn't have path",
140                    )
141                    .with_context("service", MEMCACHED_SCHEME)
142                    .with_context("endpoint", &endpoint_raw));
143                }
144                Endpoint::Unix(path.to_string())
145            }
146
147            #[cfg(not(unix))]
148            "unix" => {
149                return Err(Error::new(
150                    ErrorKind::ConfigInvalid,
151                    "unix socket is not supported on this platform",
152                )
153                .with_context("service", MEMCACHED_SCHEME)
154                .with_context("endpoint", &endpoint_raw));
155            }
156
157            scheme => {
158                return Err(Error::new(
159                    ErrorKind::ConfigInvalid,
160                    "endpoint is using invalid scheme, only tcp and unix are supported",
161                )
162                .with_context("service", MEMCACHED_SCHEME)
163                .with_context("endpoint", &endpoint_raw)
164                .with_context("scheme", scheme));
165            }
166        };
167
168        let root = normalize_root(self.config.root.unwrap_or_else(|| "/".to_string()).as_str());
169
170        Ok(MemcachedBackend::new(MemcachedCore::new(
171            endpoint,
172            self.config.username,
173            self.config.password,
174            self.config.default_ttl,
175            self.config.connection_pool_max_size,
176        ))
177        .with_normalized_root(root))
178    }
179}
180
181/// Backend for memcached services.
182#[derive(Clone, Debug)]
183pub struct MemcachedBackend {
184    pub(crate) core: Arc<MemcachedCore>,
185    pub(crate) root: String,
186    pub(crate) info: ServiceInfo,
187    pub(crate) capability: Capability,
188}
189
190impl MemcachedBackend {
191    pub fn new(core: MemcachedCore) -> Self {
192        let info = ServiceInfo::new(MEMCACHED_SCHEME, "/", "memcached");
193        let capability = Capability {
194            read: true,
195            stat: true,
196            write: true,
197            write_can_empty: true,
198            delete: true,
199            shared: true,
200            ..Default::default()
201        };
202
203        Self {
204            core: Arc::new(core),
205            root: "/".to_string(),
206            info,
207            capability,
208        }
209    }
210
211    fn with_normalized_root(mut self, root: String) -> Self {
212        self.info = self.info.with_root(&root);
213        self.root = root;
214        self
215    }
216}
217
218impl Service for MemcachedBackend {
219    type Reader = oio::StreamReader<MemcachedReader>;
220    type Writer = MemcachedWriter;
221    type Lister = ();
222    type Deleter = oio::OneShotDeleter<MemcachedDeleter>;
223    type Copier = ();
224
225    fn info(&self) -> ServiceInfo {
226        self.info.clone()
227    }
228
229    fn capability(&self) -> Capability {
230        self.capability
231    }
232
233    async fn create_dir(
234        &self,
235        _ctx: &OperationContext,
236        _path: &str,
237        _args: OpCreateDir,
238    ) -> Result<RpCreateDir> {
239        Err(Error::new(
240            ErrorKind::Unsupported,
241            "operation is not supported",
242        ))
243    }
244
245    async fn stat(&self, _ctx: &OperationContext, path: &str, _: OpStat) -> Result<RpStat> {
246        let p = build_abs_path(&self.root, path);
247
248        if p == build_abs_path(&self.root, "") {
249            Ok(RpStat::new(Metadata::new(EntryMode::DIR)))
250        } else {
251            let bs = self.core.get(&p).await?;
252            match bs {
253                Some(bs) => Ok(RpStat::new(
254                    Metadata::new(EntryMode::FILE).with_content_length(bs.len() as u64),
255                )),
256                None => Err(Error::new(ErrorKind::NotFound, "kv not found in memcached")),
257            }
258        }
259    }
260    fn read(&self, _ctx: &OperationContext, path: &str, args: OpRead) -> Result<Self::Reader> {
261        let output: oio::StreamReader<MemcachedReader> = {
262            Ok(oio::StreamReader::new(MemcachedReader::new(
263                self.clone(),
264                path,
265                args,
266            )))
267        }?;
268
269        Ok(output)
270    }
271
272    fn write(&self, _ctx: &OperationContext, path: &str, _: OpWrite) -> Result<Self::Writer> {
273        let output: MemcachedWriter = {
274            let p = build_abs_path(&self.root, path);
275            Ok(MemcachedWriter::new(self.core.clone(), p))
276        }?;
277
278        Ok(output)
279    }
280
281    fn delete(&self, _ctx: &OperationContext) -> Result<Self::Deleter> {
282        let output: oio::OneShotDeleter<MemcachedDeleter> = {
283            Ok(oio::OneShotDeleter::new(MemcachedDeleter::new(
284                self.core.clone(),
285                self.root.clone(),
286            )))
287        }?;
288
289        Ok(output)
290    }
291
292    fn list(&self, _ctx: &OperationContext, _path: &str, _args: OpList) -> Result<Self::Lister> {
293        Err(Error::new(
294            ErrorKind::Unsupported,
295            "operation is not supported",
296        ))
297    }
298
299    fn copy(
300        &self,
301        _ctx: &OperationContext,
302        _from: &str,
303        _to: &str,
304        _args: OpCopy,
305        _opts: OpCopier,
306    ) -> Result<Self::Copier> {
307        Err(Error::new(
308            ErrorKind::Unsupported,
309            "operation is not supported",
310        ))
311    }
312
313    async fn rename(
314        &self,
315        _ctx: &OperationContext,
316        _from: &str,
317        _to: &str,
318        _args: OpRename,
319    ) -> Result<RpRename> {
320        Err(Error::new(
321            ErrorKind::Unsupported,
322            "operation is not supported",
323        ))
324    }
325
326    async fn presign(
327        &self,
328        _ctx: &OperationContext,
329        _path: &str,
330        _args: OpPresign,
331    ) -> Result<RpPresign> {
332        Err(Error::new(
333            ErrorKind::Unsupported,
334            "operation is not supported",
335        ))
336    }
337}
opendal_service_memcached/backend.rs

opendal_service_memcached/
backend.rs
