Struct Watcher

pub struct Watcher<F, Fut>
where
    F: Fn(Snapshot) -> Fut,
    Fut: Future<Output = ()>,
{ /* private fields */ }

A file watcher that monitors changes in a list of files and triggers a callback when changes are detected.

Generics

• F: A closure or function that takes a Snapshot and produces a future.
• Fut: The type of the future returned by the callback.

Fields

• files: A list of FileInfo containing metadata about the monitored files.
• callback: A closure or function to execute when changes are detected.
• poll_interval: The interval (in milliseconds) at which files are polled for changes.

Implementations

impl<F, Fut> Watcher<F, Fut>

where F: Fn(Snapshot) -> Fut, Fut: Future<Output = ()>,

pub async fn new( paths: Vec<PathBuf>, poll_interval: u64, callback: F, ) -> Result<Self, Error>

Creates a new Watcher instance.

Parameters

• paths: A list of paths to the files to monitor.
• poll_interval: The interval (in milliseconds) at which files are polled for changes.
• callback: A closure or function to execute when changes are detected.

Returns

• Ok(Self): A new instance of Watcher if all files are successfully initialized.
• Err(Error): An error if any file cannot be initialized (e.g., failed to read metadata).

Errors

• Returns an error with ErrorKind::ErrorInitializingWatcher if a file’s metadata cannot be read.

pub async fn watch(&mut self) -> Result<(), Error>

Starts monitoring the files for changes.

Behavior

• Periodically checks the modification time of each file.
• If any file has been modified since the last check, triggers the callback with a Snapshot.
• Continues indefinitely until the task is canceled.

Returns

• Ok(()): This function only exits if the task is canceled or an error occurs.
• Err(Error): An error if reading a file’s metadata or content fails.

Errors

• Returns an error with ErrorKind::ErrorReadingFile if file metadata or content cannot be read.

pub async fn snapshot(&self) -> Result<Snapshot, Error>

Generates a snapshot of the current state of the monitored files.

Returns

• Ok(Snapshot): A snapshot containing the data of all monitored files.
• Err(Error): An error if any file cannot be read.

Errors

• Returns an error with ErrorKind::ErrorReadingFile if a file cannot be read.