src/tools/rust-analyzer/crates/vfs-notify/src/lib.rs

   1 //! An implementation of `loader::Handle`, based on `walkdir` and `notify`.
   2 //!
   3 //! The file watching bits here are untested and quite probably buggy. For this
   4 //! reason, by default we don't watch files and rely on editor's file watching
   5 //! capabilities.
   6 //!
   7 //! Hopefully, one day a reliable file watching/walking crate appears on
   8 //! crates.io, and we can reduce this to trivial glue code.
   9
  10 #![warn(rust_2018_idioms, unused_lifetimes, semicolon_in_expressions_from_macros)]
  11
  12 use std::fs;
  13
  14 use crossbeam_channel::{never, select, unbounded, Receiver, Sender};
  15 use notify::{RecommendedWatcher, RecursiveMode, Watcher};
  16 use paths::{AbsPath, AbsPathBuf};
  17 use vfs::loader;
  18 use walkdir::WalkDir;
  19
  20 #[derive(Debug)]
  21 pub struct NotifyHandle {
  22     // Relative order of fields below is significant.
  23     sender: Sender<Message>,
  24     _thread: jod_thread::JoinHandle,
  25 }
  26
  27 #[derive(Debug)]
  28 enum Message {
  29     Config(loader::Config),
  30     Invalidate(AbsPathBuf),
  31 }
  32
  33 impl loader::Handle for NotifyHandle {
  34     fn spawn(sender: loader::Sender) -> NotifyHandle {
  35         let actor = NotifyActor::new(sender);
  36         let (sender, receiver) = unbounded::<Message>();
  37         let thread = jod_thread::Builder::new()
  38             .name("VfsLoader".to_owned())
  39             .spawn(move || actor.run(receiver))
  40             .expect("failed to spawn thread");
  41         NotifyHandle { sender, _thread: thread }
  42     }
  43
  44     fn set_config(&mut self, config: loader::Config) {
  45         self.sender.send(Message::Config(config)).unwrap();
  46     }
  47
  48     fn invalidate(&mut self, path: AbsPathBuf) {
  49         self.sender.send(Message::Invalidate(path)).unwrap();
  50     }
  51
  52     fn load_sync(&mut self, path: &AbsPath) -> Option<Vec<u8>> {
  53         read(path)
  54     }
  55 }
  56
  57 type NotifyEvent = notify::Result<notify::Event>;
  58
  59 struct NotifyActor {
  60     sender: loader::Sender,
  61     watched_entries: Vec<loader::Entry>,
  62     // Drop order is significant.
  63     watcher: Option<(RecommendedWatcher, Receiver<NotifyEvent>)>,
  64 }
  65
  66 #[derive(Debug)]
  67 enum Event {
  68     Message(Message),
  69     NotifyEvent(NotifyEvent),
  70 }
  71
  72 impl NotifyActor {
  73     fn new(sender: loader::Sender) -> NotifyActor {
  74         NotifyActor { sender, watched_entries: Vec::new(), watcher: None }
  75     }
  76
  77     fn next_event(&self, receiver: &Receiver<Message>) -> Option<Event> {
  78         let watcher_receiver = self.watcher.as_ref().map(|(_, receiver)| receiver);
  79         select! {
  80             recv(receiver) -> it => it.ok().map(Event::Message),
  81             recv(watcher_receiver.unwrap_or(&never())) -> it => Some(Event::NotifyEvent(it.unwrap())),
  82         }
  83     }
  84
  85     fn run(mut self, inbox: Receiver<Message>) {
  86         while let Some(event) = self.next_event(&inbox) {
  87             tracing::debug!(?event, "vfs-notify event");
  88             match event {
  89                 Event::Message(msg) => match msg {
  90                     Message::Config(config) => {
  91                         self.watcher = None;
  92                         if !config.watch.is_empty() {
  93                             let (watcher_sender, watcher_receiver) = unbounded();
  94                             let watcher = log_notify_error(RecommendedWatcher::new(move |event| {
  95                                 watcher_sender.send(event).unwrap();
  96                             }));
  97                             self.watcher = watcher.map(|it| (it, watcher_receiver));
  98                         }
  99
 100                         let config_version = config.version;
 101
 102                         let n_total = config.load.len();
 103                         self.send(loader::Message::Progress { n_total, n_done: 0, config_version });
 104
 105                         self.watched_entries.clear();
 106
 107                         for (i, entry) in config.load.into_iter().enumerate() {
 108                             let watch = config.watch.contains(&i);
 109                             if watch {
 110                                 self.watched_entries.push(entry.clone());
 111                             }
 112                             let files = self.load_entry(entry, watch);
 113                             self.send(loader::Message::Loaded { files });
 114                             self.send(loader::Message::Progress {
 115                                 n_total,
 116                                 n_done: i + 1,
 117                                 config_version,
 118                             });
 119                         }
 120                     }
 121                     Message::Invalidate(path) => {
 122                         let contents = read(path.as_path());
 123                         let files = vec![(path, contents)];
 124                         self.send(loader::Message::Loaded { files });
 125                     }
 126                 },
 127                 Event::NotifyEvent(event) => {
 128                     if let Some(event) = log_notify_error(event) {
 129                         let files = event
 130                             .paths
 131                             .into_iter()
 132                             .map(|path| AbsPathBuf::try_from(path).unwrap())
 133                             .filter_map(|path| {
 134                                 let meta = fs::metadata(&path).ok()?;
 135                                 if meta.file_type().is_dir()
 136                                     && self
 137                                         .watched_entries
 138                                         .iter()
 139                                         .any(|entry| entry.contains_dir(&path))
 140                                 {
 141                                     self.watch(path);
 142                                     return None;
 143                                 }
 144
 145                                 if !meta.file_type().is_file() {
 146                                     return None;
 147                                 }
 148                                 if !self
 149                                     .watched_entries
 150                                     .iter()
 151                                     .any(|entry| entry.contains_file(&path))
 152                                 {
 153                                     return None;
 154                                 }
 155
 156                                 let contents = read(&path);
 157                                 Some((path, contents))
 158                             })
 159                             .collect();
 160                         self.send(loader::Message::Loaded { files });
 161                     }
 162                 }
 163             }
 164         }
 165     }
 166     fn load_entry(
 167         &mut self,
 168         entry: loader::Entry,
 169         watch: bool,
 170     ) -> Vec<(AbsPathBuf, Option<Vec<u8>>)> {
 171         match entry {
 172             loader::Entry::Files(files) => files
 173                 .into_iter()
 174                 .map(|file| {
 175                     if watch {
 176                         self.watch(file.clone());
 177                     }
 178                     let contents = read(file.as_path());
 179                     (file, contents)
 180                 })
 181                 .collect::<Vec<_>>(),
 182             loader::Entry::Directories(dirs) => {
 183                 let mut res = Vec::new();
 184
 185                 for root in &dirs.include {
 186                     let walkdir =
 187                         WalkDir::new(root).follow_links(true).into_iter().filter_entry(|entry| {
 188                             if !entry.file_type().is_dir() {
 189                                 return true;
 190                             }
 191                             let path = AbsPath::assert(entry.path());
 192                             root == path
 193                                 || dirs.exclude.iter().chain(&dirs.include).all(|it| it != path)
 194                         });
 195
 196                     let files = walkdir.filter_map(|it| it.ok()).filter_map(|entry| {
 197                         let is_dir = entry.file_type().is_dir();
 198                         let is_file = entry.file_type().is_file();
 199                         let abs_path = AbsPathBuf::assert(entry.into_path());
 200                         if is_dir && watch {
 201                             self.watch(abs_path.clone());
 202                         }
 203                         if !is_file {
 204                             return None;
 205                         }
 206                         let ext = abs_path.extension().unwrap_or_default();
 207                         if dirs.extensions.iter().all(|it| it.as_str() != ext) {
 208                             return None;
 209                         }
 210                         Some(abs_path)
 211                     });
 212
 213                     res.extend(files.map(|file| {
 214                         let contents = read(file.as_path());
 215                         (file, contents)
 216                     }));
 217                 }
 218                 res
 219             }
 220         }
 221     }
 222
 223     fn watch(&mut self, path: AbsPathBuf) {
 224         if let Some((watcher, _)) = &mut self.watcher {
 225             log_notify_error(watcher.watch(path.as_ref(), RecursiveMode::NonRecursive));
 226         }
 227     }
 228     fn send(&mut self, msg: loader::Message) {
 229         (self.sender)(msg);
 230     }
 231 }
 232
 233 fn read(path: &AbsPath) -> Option<Vec<u8>> {
 234     std::fs::read(path).ok()
 235 }
 236
 237 fn log_notify_error<T>(res: notify::Result<T>) -> Option<T> {
 238     res.map_err(|err| tracing::warn!("notify error: {}", err)).ok()
 239 }