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).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).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());
}