Struct CacheStats 

pub struct CacheStats {
    pub hits: u64,
    pub misses: u64,
    pub evictions: u64,
    pub len: usize,
    pub capacity: usize,
}

A point-in-time snapshot of a CachedIndex’s cache.

Returned by CachedIndex::cache_stats. hits and misses are monotonic counters over the cache’s lifetime; len and capacity describe its current occupancy. Use hit_rate to turn the counters into a ratio for tuning.

Examples

use iqdb_cache::CacheStats;

let stats = CacheStats {
    hits: 75,
    misses: 25,
    evictions: 8,
    len: 64,
    capacity: 128,
};
assert_eq!(stats.lookups(), 100);
assert!((stats.hit_rate() - 0.75).abs() < f64::EPSILON);

Fields

hits: u64

Lookups served from the cache.

misses: u64

Lookups that missed and fell through to the wrapped index.

evictions: u64

Entries discarded by the eviction policy to make room over the cache’s lifetime.

len: usize

Entries currently held.

capacity: usize

Maximum entries the cache will hold; 0 means caching is disabled.

Implementations

impl CacheStats

pub fn lookups(&self) -> u64

Total lookups observed: hits + misses (saturating).

Examples

use iqdb_cache::CacheStats;

let stats = CacheStats { hits: 3, misses: 1, evictions: 0, len: 4, capacity: 8 };
assert_eq!(stats.lookups(), 4);

pub fn hit_rate(&self) -> f64

The fraction of lookups served from cache, in 0.0..=1.0.

Returns 0.0 when there have been no lookups, so the result is always finite and safe to display.

Examples

use iqdb_cache::CacheStats;

let warm = CacheStats { hits: 9, misses: 1, evictions: 0, len: 10, capacity: 16 };
assert!((warm.hit_rate() - 0.9).abs() < 1e-9);

let cold = CacheStats { hits: 0, misses: 0, evictions: 0, len: 0, capacity: 16 };
assert_eq!(cold.hit_rate(), 0.0);

Trait Implementations

impl Clone for CacheStats

fn clone(&self) -> CacheStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for CacheStats

impl Debug for CacheStats

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CacheStats

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for CacheStats

impl PartialEq for CacheStats

fn eq(&self, other: &CacheStats) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for CacheStats

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for CacheStats