cacheflight 0.2.0

Cache-backed deduplication for async Rust services with stale-while-revalidate support
Documentation 
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use crate::Result;
use async_trait::async_trait;
use std::time::Duration;

/// The only cache abstraction the library depends on.
///
/// Implement this trait for whatever backing store you already use. The
/// library only reads and writes raw bytes plus a TTL, so callers remain in
/// control of serialization and the actual cache technology.
#[async_trait]
pub trait CacheBackend: Send + Sync + 'static {
    /// Returns the raw cached bytes for `key`, if they are still available.
    ///
    /// Backends should return `Ok(None)` for a normal cache miss and use
    /// [`crate::Error::cache_read`] when the cache itself cannot be queried.
    async fn get(&self, key: &str) -> Result<Option<Vec<u8>>>;

    /// Stores raw cached bytes for `key` with the provided TTL.
    async fn set(&self, key: &str, value: Vec<u8>, ttl: Duration) -> Result<()>;

    /// Removes the cached entry for `key` from the backend.
    async fn delete(&self, key: &str) -> Result<()>;

    /// Removes all cached entries whose key starts with `prefix`.
    ///
    /// Returns the number of entries that were removed.
    async fn delete_by_prefix(&self, prefix: &str) -> Result<u64>;
}