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48 lines
1.8 KiB
Markdown
48 lines
1.8 KiB
Markdown
# `treacle`
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A generic event debouncer for Rust, for grouping events which occur close together in time into a
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single event.
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For example, you may have some
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[templates](https://www.arewewebyet.org/topics/templating/)
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which you want to reload whenever a template file changes. However, if many small changes are made
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to the template files in quick succession, it would be wasteful to reload the templates for every
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change; instead, a debouncer could be used to group the changes that occur at a similar time into
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a single change, so the templates are only reloaded once.
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A new debouncer can be created with the
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`debouncer`
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function, which returns the debouncer in two halves: a tx (send) half and rx (receive) half. The
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tx sends raw un-debounced events to the debouncer, and the rx receives the debounced events from
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the debouncer. Both halves can be cloned to allow for multiple senders and receivers.
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```rust
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use std::{thread, time::Duration};
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// Create a new debouncer which takes raw events of type `u32` and outputs
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// debounced events of type `Vec<u32>`.
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let (tx, rx) = treacle::debouncer::<u32, Vec<u32>, _>(
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// Group events which occur in the same 500ms window.
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Duration::from_millis(500),
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// Combine raw events by pushing them to a vector.
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|acc, raw_event| {
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let mut events_vector = acc.unwrap_or_default();
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events_vector.push(raw_event);
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events_vector
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});
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thread::spawn(move || {
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// Send two raw events in quick succession.
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tx.send(10).unwrap();
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tx.send(20).unwrap();
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// Wait, then send more raw events.
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thread::sleep(Duration::from_millis(500));
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tx.send(30).unwrap();
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tx.send(40).unwrap();
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tx.send(50).unwrap();
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});
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assert_eq!(rx.recv().unwrap(), &[10, 20]);
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assert_eq!(rx.recv().unwrap(), &[30, 40, 50]);
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```
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