fix: don't scale in shards when capacity is not enough, just warn (#769)

Signed-off-by: MrCroxx <[email protected]>

foyer-memory/src/cache.rs

@@ -401,14 +401,13 @@ where
  }
 
  /// Build in-memory cache with the given configuration.
- pub fn build(mut self) -> Cache<K, V, S> {
+ pub fn build(self) -> Cache<K, V, S> {
  if self.capacity < self.shards {
  tracing::warn!(
- "The in-memory cache capacity({}) < shards({})",
+ "The in-memory cache capacity({}) < shards({}).",
  self.capacity,
  self.shards
  );
- self.shards = 1;
  }
 
  match self.eviction_config {
@@ -889,12 +888,6 @@ mod tests {
  const OPS: usize = 10000;
  const CONCURRENCY: usize = 8;
 
- #[test]
- fn test_not_enough_capacity() {
- let cache: Cache<u64, u64> = CacheBuilder::new(4).with_shards(64).build();
- assert_eq!(cache.shards(), 1);
- }
-
  fn fifo() -> Cache<u64, u64> {
  CacheBuilder::new(CAPACITY)
  .with_shards(SHARDS)

foyer-memory/src/generic.rs

@@ -497,8 +497,6 @@ where
  S: HashBuilder,
 {
  pub fn new(config: GenericCacheConfig<K, V, E, S>) -> Self {
- assert!(config.capacity >= config.shards);
-
  let metrics = Arc::new(Metrics::new(&config.name));
 
  let usages = (0..config.shards).map(|_| Arc::new(AtomicUsize::new(0))).collect_vec();