Struct HostMetricsCache 

pub struct HostMetricsCache { /* private fields */ }

Shared read/write handle to the latest HostMetrics snapshot.

Why: the machine-status route reads without blocking; the background task writes. None means no sample has completed yet (first boot). What: wraps Arc<RwLock<Option<HostMetrics>>>. Test: cache_initialises_empty, cache_write_read_roundtrip.

Implementations

impl HostMetricsCache

pub fn new() -> Self

Create a new, empty cache.

Why: start empty so the route can distinguish “not yet sampled” (503) from a real snapshot. What: allocates Arc<RwLock<None>>. Test: cache_initialises_empty.

pub async fn get(&self) -> Option<HostMetrics>

Read the latest snapshot (None before the first sample).

Why: the machine-status route calls this to serve without blocking. What: acquires a read lock, clones the value, releases the lock. Test: cache_write_read_roundtrip.

pub async fn set(&self, metrics: HostMetrics)

Write a new snapshot into the cache.

Why: the background task calls this after each sample. What: acquires a write lock, replaces the inner value. Test: cache_write_read_roundtrip.

Trait Implementations

impl Clone for HostMetricsCache

fn clone(&self) -> HostMetricsCache

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HostMetricsCache

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

Formats the value using the given formatter.

impl Default for HostMetricsCache

fn default() -> Self

Returns the “default value” for a type.