| 1 | //! File logging. The terminal belongs to the UI, so diagnostics go to a file. |
| 2 | |
| 3 | use std::{ |
| 4 | fs::OpenOptions, |
| 5 | io, |
| 6 | path::Path, |
| 7 | sync::{Arc, Mutex}, |
| 8 | }; |
| 9 | |
| 10 | use tracing_subscriber::{EnvFilter, fmt}; |
| 11 | |
| 12 | pub const LOG_PATH: &str = "/tmp/rmptui.log"; |
| 13 | |
| 14 | /// Appends logs to `path`. The level can be set with `RMPTUI_LOG` |
| 15 | /// (e.g. `RMPTUI_LOG=debug`); the default is `info`. |
| 16 | pub fn init(path: &Path) -> io::Result<()> { |
| 17 | let mut options = OpenOptions::new(); |
| 18 | options.create(true).append(true); |
| 19 | #[cfg(unix)] |
| 20 | { |
| 21 | use std::os::unix::fs::OpenOptionsExt; |
| 22 | options.mode(0o600); |
| 23 | } |
| 24 | let file = Arc::new(Mutex::new(options.open(path)?)); |
| 25 | let filter = EnvFilter::try_from_env("RMPTUI_LOG").unwrap_or_else(|_| EnvFilter::new("info")); |
| 26 | fmt() |
| 27 | .with_env_filter(filter) |
| 28 | .with_ansi(false) |
| 29 | .with_writer(move || MutexWriter(Arc::clone(&file))) |
| 30 | .try_init() |
| 31 | .map_err(io::Error::other)?; |
| 32 | |
| 33 | // Record panics in the log as well as on the (restored) terminal. |
| 34 | let previous = std::panic::take_hook(); |
| 35 | std::panic::set_hook(Box::new(move |info| { |
| 36 | tracing::error!("panic: {info}"); |
| 37 | previous(info); |
| 38 | })); |
| 39 | Ok(()) |
| 40 | } |
| 41 | |
| 42 | struct MutexWriter(Arc<Mutex<std::fs::File>>); |
| 43 | |
| 44 | impl io::Write for MutexWriter { |
| 45 | fn write(&mut self, buf: &[u8]) -> io::Result<usize> { |
| 46 | self.0 |
| 47 | .lock() |
| 48 | .unwrap_or_else(std::sync::PoisonError::into_inner) |
| 49 | .write(buf) |
| 50 | } |
| 51 | |
| 52 | fn flush(&mut self) -> io::Result<()> { |
| 53 | self.0 |
| 54 | .lock() |
| 55 | .unwrap_or_else(std::sync::PoisonError::into_inner) |
| 56 | .flush() |
| 57 | } |
| 58 | } |