parent
fa1979c2bb
commit
46c01c6c38
GPG Key ID:
2C5FD5035250423D
@ -0,0 +1,150 @@ |
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use failure::Error; |
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use inotify::{Inotify, WatchMask, EventMask}; |
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use serde::de::DeserializeOwned; |
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use std::fs::File; |
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use std::io::BufReader; |
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use std::path::Path; |
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use std::path::PathBuf; |
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|
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/// Reloadable config file
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pub struct ConfigFile<T> { |
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is_dummy : bool, |
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config: T, |
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path: PathBuf, |
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inotify: Option<Inotify>, |
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inotify_buffer: [u8; 1024], |
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} |
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|
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impl<T> ConfigFile<T> |
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where |
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T: Default + std::fmt::Debug + DeserializeOwned, |
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{ |
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pub fn borrow(&self) -> &T { |
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&self.config |
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} |
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|
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/// Create a new reloadable config file
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/// If loading fails, an error is printed and default values are be used
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pub fn new<P: AsRef<Path>>(path: P) -> Result<Self, Error> { |
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let loaded = Self::load(&path); |
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if let Err(e) = &loaded { |
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eprintln!("Config file failed to load/parse: {}", e); |
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} |
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|
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Ok(Self { |
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is_dummy: false, |
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config: loaded.unwrap_or(T::default()), |
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path: path.as_ref().to_owned(), |
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inotify: Self::setup_inotify(&path), |
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inotify_buffer: [0; 1024], |
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}) |
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} |
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|
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/// New without a backing file
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#[allow(dead_code)] |
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pub fn new_from_defaults() -> Self { |
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Self { |
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is_dummy: true, |
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config: T::default(), |
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path: "".into(), |
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inotify: None, |
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inotify_buffer: [0; 1024] |
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} |
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} |
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|
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/// Try to install inotify
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fn setup_inotify<P: AsRef<Path>>(path: P) -> Option<Inotify> { |
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let inotify = Inotify::init(); |
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if let Err(e) = inotify { |
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eprintln!("Failed to set up inotify for config file reload!\n{}", e); |
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return None; |
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} |
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let mut inotify = inotify.unwrap(); |
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let rv = inotify.add_watch(&path, WatchMask::MODIFY | WatchMask::CLOSE); |
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match rv { |
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Err(e) => { |
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eprintln!("Failed to add inotify watch for config!\n{}", e); |
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None |
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} |
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Ok(_) => Some(inotify), |
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} |
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} |
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|
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/// Update the config file if needed (there are inotify events)
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/// - if inotify failed to init, or an error occurs trying to get events from it,
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/// the 'def' value is used (true = reload if unsure)
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pub fn update_if_needed(&mut self, def: bool) -> Result<bool, Error> { |
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if self.is_dummy { |
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debug!("Config is dummy, no path to reload."); |
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return Ok(false); |
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} |
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|
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let needed = match self.inotify.as_mut() { |
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Some(ino) => { |
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let rv = ino.read_events(&mut self.inotify_buffer); |
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match rv { |
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Ok(evs) => { |
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let mut changed = false; |
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let mut need_reinstall = false; |
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for ev in evs { |
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if ev.mask.contains(EventMask::IGNORED) { |
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debug!("Inotify watcher got removed by OS??"); |
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changed = true; |
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need_reinstall = true; |
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} |
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if ev.mask.contains(EventMask::MODIFY) { |
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changed = true; |
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} |
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} |
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if changed { |
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info!("Config file changes detected, reloading"); |
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} |
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if need_reinstall { |
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debug!("Reinstalling inotify"); |
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self.inotify = Self::setup_inotify(&self.path); |
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} |
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changed |
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} |
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_ => { |
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error!("Failed to get inotify events."); |
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def |
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} |
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} |
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} |
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None => def, |
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}; |
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if needed { |
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self.update()?; |
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} else { |
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debug!("Config update not needed."); |
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} |
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Ok(needed) |
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} |
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/// load and parse the config file
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fn load<P: AsRef<Path>>(path: P) -> Result<T, Error> { |
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info!("Loading config file @ {}", path.as_ref().to_str().unwrap_or("???")); |
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let file = File::open(&path)?; |
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let reader = BufReader::new(file); |
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let val : T = serde_json::from_reader(reader)?; |
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debug!("Loaded config:\n{:#?}", val); |
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Ok(val) |
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} |
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/// Reload unconditionally
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pub fn update(&mut self) -> Result<(), Error> { |
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if self.is_dummy { |
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debug!("Config is dummy, no path to reload."); |
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return Ok(()); |
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} |
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self.config = Self::load(&self.path)?; |
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Ok(()) |
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} |
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} |
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