Struct Cache 

pub struct Cache { /* private fields */ }

Event ID deduplication cache using std::sync::Mutex with LRU eviction

This is the winning strategy from benchmarks - fastest under realistic multi-threaded relay pool scenarios (10-20 concurrent connections).

Pros:

• Automatic LRU eviction, bounded memory
• Excellent performance under realistic concurrency
• Zero external dependencies beyond lru crate
• Simple, predictable behavior

Implementations

impl Cache

pub fn new(capacity: usize) -> Self

Create a new cache with the specified capacity

Arguments

• capacity - Maximum number of event IDs to cache

Example

use nostro2_cache::Cache;

let cache = Cache::new(10_000);

pub fn insert(&self, id: String) -> bool

Insert an event ID into the cache

Returns true if this is a new event (not seen before), false if the event was already in the cache (duplicate).

Example

use nostro2_cache::Cache;

let cache = Cache::new(10_000);

if cache.insert("event_id_123".to_string()) {
    println!("New event!");
} else {
    println!("Duplicate, skip");
}

pub fn contains(&self, id: &str) -> bool

Check if the cache contains an event ID

pub fn len(&self) -> usize

Get the current number of cached event IDs

pub fn is_empty(&self) -> bool

Check if the cache is empty

Trait Implementations

impl Clone for Cache

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.