Struct DnsblCache 

pub struct DnsblCache { /* private fields */ }

TTL-cached DNSBL lookup. Avoids repeated DNS queries for IPs we’ve seen recently.

Caches both positive results (listed → known bad) and negative results (not listed → known good). The TTL applies uniformly; if you want different positive vs negative TTLs, run two caches.

Storage is Mutex<HashMap> — fine for sub-1k entries with moderate throughput. For higher contention, wrap your own DashMap and call check_dnsbl directly.

Implementations

impl DnsblCache

pub fn new(ttl: Duration) -> Self

Construct an empty cache with the given per-entry TTL.

pub async fn check( &self, resolver: &TokioResolver, ip: IpAddr, zones: &[String], ) -> Option<(String, DnsblResult)>

check with cache: return cached result if fresh, otherwise query DNS

pub fn cleanup(&self)

remove expired entries

pub fn len(&self) -> usize

number of cached entries (for testing)

pub fn is_empty(&self) -> bool

check if cache is empty