indexkv

Provides [Store], an on-disk storage bucket. Conceptually, this is not dissimilar to a map<u64, T> that provides fast (by persistent storage standards) key lookups, low memory complexity, and fast sequential writes at the expense of random writes; random writes are unsupported. See [Store::write] for details on writes.

While reading concurrently is safe, reading while a write is ongoing is a footgun.

Examples

Automatically keying values with [Iterator::enumerate]:

use indexkv::Store;

#[tokio::main]
async fn main() {
		let path = tempfile::NamedTempFile::new().unwrap().into_temp_path();
		let mut store: Store<u8, String> = Store::new(path).await.unwrap();

		let stream = futures::stream::iter(
			["zero", "one", "two", "three", "four", "five"]
				.into_iter()
				.enumerate()
				.map(|(i, v)| (i as u8, v.to_string()))
		);
		store.write_infallible(stream, 0).await.unwrap();

		let result = store.get(2).await.unwrap();
		assert_eq!(result, "two");
		let result = store.get_many(&[0, 4]).await.unwrap();
		assert_eq!(result.len(), 2);
		assert_eq!(result.get(&0), Some(&"zero".to_string()));
		assert_eq!(result.get(&2), None);
		assert_eq!(result.get(&4), Some(&"four".to_string()));
}

Manually keying values with an external "ID":

use indexkv::{Error, Store};

#[tokio::main]
async fn main() {
		let path = tempfile::NamedTempFile::new().unwrap().into_temp_path();
		let mut store: Store<u16, String> = Store::new(path).await.unwrap();

		let stream = futures::stream::iter([
			(200, "two hundred".to_string()),
			(1337, "thirteen hundred thirty-seven".to_string()),
			(75, "seventy-five".to_string()),
			(20, "twenty".to_string())
		]);
		store.write_infallible(stream, 4).await.unwrap();

		let result = store.get(2).await;
		assert!(matches!(result, Err(Error::NotFound(2))));
		let result = store.get(75).await.unwrap();
		assert_eq!(result, "seventy-five".to_string());
}