opendal/services/hdfs/
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::io;
21use std::io::SeekFrom;
22use std::path::PathBuf;
23use std::sync::Arc;
24
25use log::debug;
26
27use super::delete::HdfsDeleter;
28use super::lister::HdfsLister;
29use super::reader::HdfsReader;
30use super::writer::HdfsWriter;
31use super::DEFAULT_SCHEME;
32use crate::raw::*;
33use crate::services::HdfsConfig;
34use crate::*;
35impl Configurator for HdfsConfig {
36    type Builder = HdfsBuilder;
37    fn into_builder(self) -> Self::Builder {
38        HdfsBuilder { config: self }
39    }
40}
41
42#[doc = include_str!("docs.md")]
43#[derive(Default)]
44pub struct HdfsBuilder {
45    config: HdfsConfig,
46}
47
48impl Debug for HdfsBuilder {
49    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
50        f.debug_struct("HdfsBuilder")
51            .field("config", &self.config)
52            .finish()
53    }
54}
55
56impl HdfsBuilder {
57    /// Set root of this backend.
58    ///
59    /// All operations will happen under this root.
60    pub fn root(mut self, root: &str) -> Self {
61        self.config.root = if root.is_empty() {
62            None
63        } else {
64            Some(root.to_string())
65        };
66
67        self
68    }
69
70    /// Set name_node of this backend.
71    ///
72    /// Valid format including:
73    ///
74    /// - `default`: using the default setting based on hadoop config.
75    /// - `hdfs://127.0.0.1:9000`: connect to hdfs cluster.
76    pub fn name_node(mut self, name_node: &str) -> Self {
77        if !name_node.is_empty() {
78            // Trim trailing `/` so that we can accept `http://127.0.0.1:9000/`
79            self.config.name_node = Some(name_node.trim_end_matches('/').to_string())
80        }
81
82        self
83    }
84
85    /// Set kerberos_ticket_cache_path of this backend
86    ///
87    /// This should be configured when kerberos is enabled.
88    pub fn kerberos_ticket_cache_path(mut self, kerberos_ticket_cache_path: &str) -> Self {
89        if !kerberos_ticket_cache_path.is_empty() {
90            self.config.kerberos_ticket_cache_path = Some(kerberos_ticket_cache_path.to_string())
91        }
92        self
93    }
94
95    /// Set user of this backend
96    pub fn user(mut self, user: &str) -> Self {
97        if !user.is_empty() {
98            self.config.user = Some(user.to_string())
99        }
100        self
101    }
102
103    /// Enable append capacity of this backend.
104    ///
105    /// This should be disabled when HDFS runs in non-distributed mode.
106    pub fn enable_append(mut self, enable_append: bool) -> Self {
107        self.config.enable_append = enable_append;
108        self
109    }
110
111    /// Set temp dir for atomic write.
112    ///
113    /// # Notes
114    ///
115    /// - When append is enabled, we will not use atomic write
116    ///   to avoid data loss and performance issue.
117    pub fn atomic_write_dir(mut self, dir: &str) -> Self {
118        self.config.atomic_write_dir = if dir.is_empty() {
119            None
120        } else {
121            Some(String::from(dir))
122        };
123        self
124    }
125}
126
127impl Builder for HdfsBuilder {
128    type Config = HdfsConfig;
129
130    fn build(self) -> Result<impl Access> {
131        debug!("backend build started: {:?}", &self);
132
133        let name_node = match &self.config.name_node {
134            Some(v) => v,
135            None => {
136                return Err(Error::new(ErrorKind::ConfigInvalid, "name node is empty")
137                    .with_context("service", Scheme::Hdfs))
138            }
139        };
140
141        let root = normalize_root(&self.config.root.unwrap_or_default());
142        debug!("backend use root {root}");
143
144        let mut builder = hdrs::ClientBuilder::new(name_node);
145        if let Some(ticket_cache_path) = &self.config.kerberos_ticket_cache_path {
146            builder = builder.with_kerberos_ticket_cache_path(ticket_cache_path.as_str());
147        }
148        if let Some(user) = &self.config.user {
149            builder = builder.with_user(user.as_str());
150        }
151
152        let client = builder.connect().map_err(new_std_io_error)?;
153
154        // Create root dir if not exist.
155        if let Err(e) = client.metadata(&root) {
156            if e.kind() == io::ErrorKind::NotFound {
157                debug!("root {root} is not exist, creating now");
158
159                client.create_dir(&root).map_err(new_std_io_error)?
160            }
161        }
162
163        let atomic_write_dir = self.config.atomic_write_dir;
164
165        // If atomic write dir is not exist, we must create it.
166        if let Some(d) = &atomic_write_dir {
167            if let Err(e) = client.metadata(d) {
168                if e.kind() == io::ErrorKind::NotFound {
169                    client.create_dir(d).map_err(new_std_io_error)?
170                }
171            }
172        }
173
174        Ok(HdfsBackend {
175            info: {
176                let am = AccessorInfo::default();
177                am.set_scheme(DEFAULT_SCHEME)
178                    .set_root(&root)
179                    .set_native_capability(Capability {
180                        stat: true,
181
182                        read: true,
183
184                        write: true,
185                        write_can_append: self.config.enable_append,
186
187                        create_dir: true,
188                        delete: true,
189
190                        list: true,
191
192                        rename: true,
193
194                        shared: true,
195
196                        ..Default::default()
197                    });
198
199                am.into()
200            },
201            root,
202            atomic_write_dir,
203            client: Arc::new(client),
204        })
205    }
206}
207
208/// Backend for hdfs services.
209#[derive(Debug, Clone)]
210pub struct HdfsBackend {
211    pub info: Arc<AccessorInfo>,
212    pub root: String,
213    atomic_write_dir: Option<String>,
214    pub client: Arc<hdrs::Client>,
215}
216
217/// hdrs::Client is thread-safe.
218unsafe impl Send for HdfsBackend {}
219unsafe impl Sync for HdfsBackend {}
220
221impl Access for HdfsBackend {
222    type Reader = HdfsReader<hdrs::AsyncFile>;
223    type Writer = HdfsWriter<hdrs::AsyncFile>;
224    type Lister = Option<HdfsLister>;
225    type Deleter = oio::OneShotDeleter<HdfsDeleter>;
226
227    fn info(&self) -> Arc<AccessorInfo> {
228        self.info.clone()
229    }
230
231    async fn create_dir(&self, path: &str, _: OpCreateDir) -> Result<RpCreateDir> {
232        let p = build_rooted_abs_path(&self.root, path);
233
234        self.client.create_dir(&p).map_err(new_std_io_error)?;
235
236        Ok(RpCreateDir::default())
237    }
238
239    async fn stat(&self, path: &str, _: OpStat) -> Result<RpStat> {
240        let p = build_rooted_abs_path(&self.root, path);
241
242        let meta = self.client.metadata(&p).map_err(new_std_io_error)?;
243
244        let mode = if meta.is_dir() {
245            EntryMode::DIR
246        } else if meta.is_file() {
247            EntryMode::FILE
248        } else {
249            EntryMode::Unknown
250        };
251        let mut m = Metadata::new(mode);
252        m.set_content_length(meta.len());
253        m.set_last_modified(meta.modified().into());
254
255        Ok(RpStat::new(m))
256    }
257
258    async fn read(&self, path: &str, args: OpRead) -> Result<(RpRead, Self::Reader)> {
259        let p = build_rooted_abs_path(&self.root, path);
260
261        let client = self.client.clone();
262        let mut f = client
263            .open_file()
264            .read(true)
265            .async_open(&p)
266            .await
267            .map_err(new_std_io_error)?;
268
269        if args.range().offset() != 0 {
270            use futures::AsyncSeekExt;
271
272            f.seek(SeekFrom::Start(args.range().offset()))
273                .await
274                .map_err(new_std_io_error)?;
275        }
276
277        Ok((
278            RpRead::new(),
279            HdfsReader::new(f, args.range().size().unwrap_or(u64::MAX) as _),
280        ))
281    }
282
283    async fn write(&self, path: &str, op: OpWrite) -> Result<(RpWrite, Self::Writer)> {
284        let target_path = build_rooted_abs_path(&self.root, path);
285        let mut initial_size = 0;
286        let target_exists = match self.client.metadata(&target_path) {
287            Ok(meta) => {
288                initial_size = meta.len();
289                true
290            }
291            Err(err) => {
292                if err.kind() != io::ErrorKind::NotFound {
293                    return Err(new_std_io_error(err));
294                }
295                false
296            }
297        };
298
299        let should_append = op.append() && target_exists;
300        let tmp_path = self.atomic_write_dir.as_ref().and_then(|atomic_write_dir| {
301            // If the target file exists, we should append to the end of it directly.
302            (!should_append).then_some(build_rooted_abs_path(
303                atomic_write_dir,
304                &build_tmp_path_of(path),
305            ))
306        });
307
308        if !target_exists {
309            let parent = get_parent(&target_path);
310            self.client.create_dir(parent).map_err(new_std_io_error)?;
311        }
312        if !should_append {
313            initial_size = 0;
314        }
315
316        let mut open_options = self.client.open_file();
317        open_options.create(true);
318        if should_append {
319            open_options.append(true);
320        } else {
321            open_options.write(true);
322        }
323
324        let f = open_options
325            .async_open(tmp_path.as_ref().unwrap_or(&target_path))
326            .await
327            .map_err(new_std_io_error)?;
328
329        Ok((
330            RpWrite::new(),
331            HdfsWriter::new(
332                target_path,
333                tmp_path,
334                f,
335                Arc::clone(&self.client),
336                target_exists,
337                initial_size,
338            ),
339        ))
340    }
341
342    async fn delete(&self) -> Result<(RpDelete, Self::Deleter)> {
343        Ok((
344            RpDelete::default(),
345            oio::OneShotDeleter::new(HdfsDeleter::new(Arc::new(self.clone()))),
346        ))
347    }
348
349    async fn list(&self, path: &str, _: OpList) -> Result<(RpList, Self::Lister)> {
350        let p = build_rooted_abs_path(&self.root, path);
351
352        let f = match self.client.read_dir(&p) {
353            Ok(f) => f,
354            Err(e) => {
355                return if e.kind() == io::ErrorKind::NotFound {
356                    Ok((RpList::default(), None))
357                } else {
358                    Err(new_std_io_error(e))
359                }
360            }
361        };
362
363        let rd = HdfsLister::new(&self.root, f, path);
364
365        Ok((RpList::default(), Some(rd)))
366    }
367
368    async fn rename(&self, from: &str, to: &str, _args: OpRename) -> Result<RpRename> {
369        let from_path = build_rooted_abs_path(&self.root, from);
370        self.client.metadata(&from_path).map_err(new_std_io_error)?;
371
372        let to_path = build_rooted_abs_path(&self.root, to);
373        let result = self.client.metadata(&to_path);
374        match result {
375            Err(err) => {
376                // Early return if other error happened.
377                if err.kind() != io::ErrorKind::NotFound {
378                    return Err(new_std_io_error(err));
379                }
380
381                let parent = PathBuf::from(&to_path)
382                    .parent()
383                    .ok_or_else(|| {
384                        Error::new(
385                            ErrorKind::Unexpected,
386                            "path should have parent but not, it must be malformed",
387                        )
388                        .with_context("input", &to_path)
389                    })?
390                    .to_path_buf();
391
392                self.client
393                    .create_dir(&parent.to_string_lossy())
394                    .map_err(new_std_io_error)?;
395            }
396            Ok(metadata) => {
397                if metadata.is_file() {
398                    self.client
399                        .remove_file(&to_path)
400                        .map_err(new_std_io_error)?;
401                } else {
402                    return Err(Error::new(ErrorKind::IsADirectory, "path should be a file")
403                        .with_context("input", &to_path));
404                }
405            }
406        }
407
408        self.client
409            .rename_file(&from_path, &to_path)
410            .map_err(new_std_io_error)?;
411
412        Ok(RpRename::new())
413    }
414}
opendal/services/hdfs/backend.rs

opendal/services/hdfs/
backend.rs
