diff options
| -rw-r--r-- | src/watcher.rs | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/src/watcher.rs b/src/watcher.rs index 16e65b4d..ac35b5b5 100644 --- a/src/watcher.rs +++ b/src/watcher.rs @@ -27,7 +27,18 @@ impl Watcher { thread::Builder::new() .name(format!("Filesystem Watcher for {}", path.to_string_lossy())) .spawn(move || { - let mut last_mtime = path.metadata().and_then(|meta| meta.modified()).ok(); + // this "should" be as simple as mtime, but it does not quite work in practice; + // it doesn't work if the config is a symlink, and its target changes but the + // new target and old target have identical mtimes. + // + // in practice, this does not occur on any systems other than nix. + // because, on nix practically everything is a symlink to /nix/store + // and due to reproducibility, /nix/store keeps no mtime (= 1970-01-01) + // so, symlink targets change frequently when mtime doesn't. + let mut last_props = path + .canonicalize() + .and_then(|canon| Ok((canon.metadata()?.modified()?, canon))) + .ok(); loop { thread::sleep(Duration::from_millis(500)); @@ -36,8 +47,11 @@ impl Watcher { break; } - if let Ok(mtime) = path.metadata().and_then(|meta| meta.modified()) { - if last_mtime != Some(mtime) { + if let Ok(new_props) = path + .canonicalize() + .and_then(|canon| Ok((canon.metadata()?.modified()?, canon))) + { + if last_props.as_ref() != Some(&new_props) { trace!("file changed: {}", path.to_string_lossy()); if let Err(err) = changed.send(()) { @@ -45,7 +59,7 @@ impl Watcher { break; } - last_mtime = Some(mtime); + last_props = Some(new_props); } } } |