Struct CacheBuilder 

pub struct CacheBuilder { /* private fields */ }

Builder for configuring a Cache.

Example

use priority_lfu::CacheBuilder;

let cache = CacheBuilder::new(1024 * 1024 * 512) // 512 MB
    .shards(128)
    .build();

Automatic Shard Scaling

By default, the cache uses up to 64 shards, but automatically scales down for smaller caches to ensure each shard has at least 4KB capacity. This prevents premature eviction due to uneven hash distribution.

• 256KB+ capacity: 64 shards (4KB+ per shard)
• 64KB capacity: 16 shards (4KB per shard)
• 4KB capacity: 1 shard (4KB per shard)

You can override this with [shards()], but the count may still be reduced if the capacity is too small to support the requested number.

Implementations

impl CacheBuilder

pub fn new(max_size_bytes: usize) -> Self

Create a new builder with the given maximum size in bytes.

pub fn shards(self, count: usize) -> Self

Set the number of shards.

More shards reduce contention but increase memory overhead. Will be rounded up to the next power of 2.

Note: The shard count may be reduced if the capacity is too small to support the requested number of shards (minimum 4KB per shard). This prevents premature eviction due to uneven hash distribution.

Default: up to 64 shards, scaled based on capacity

pub fn build(self) -> Cache

Build the cache with the configured settings.

Trait Implementations

impl Default for CacheBuilder

fn default() -> Self

Create a builder with default settings and 1GB capacity.