Crate deduplicate
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Provides a safe, asynchronous (tokio based), caching request deduplicator.
If you have a slow or expensive data retrieving operation data, Deduplicate will help avoid
work duplication. Furthermore, if your retrieval operation is “flaky”, failures will be handled
cleanly and Deduplicate will continue to function.
An example will probably make usage clear.
Let’s imagine we have a mechanism for retrieving data that is arbitrarily slow. Our data is
keyed by usize and consists of a String. In this case we are simply going to sleep for a
while and then return a value which consists of the supplied key and the duration for which we
slept. We represent this by implementing the Retriever trait.
Once we have a retriever, we can create a Deduplicate instance to manage delegate access to
data efficiently.
Example 1
use deduplicate::Deduplicate;
use deduplicate::DeduplicateError;
use deduplicate::Retriever;
use rand::Rng;
struct MyRetriever;
#[async_trait::async_trait]
impl Retriever for MyRetriever {
type Key = usize;
type Value = String;
async fn get(&self, key: &Self::Key) -> Option<Self::Value> {
let num = rand::thread_rng().gen_range(4000..5000);
let duration = tokio::time::Duration::from_millis(num);
tokio::time::sleep(duration).await;
Some(format!("key: {}, duration: {}", key, num))
}
}