Struct MetricsCache 

pub struct MetricsCache { /* private fields */ }

Shared read/write handle to a cached ConsoleMetricsReport.

Why: The route handler must never block on an MCP call. The background poller writes to this cache; route handlers read from it. What: Wraps Arc<RwLock<Option<ConsoleMetricsReport>>>. None means no successful poll has completed yet (first boot or service absent). Test: test_metrics_cache_initialises_empty and test_metrics_cache_write_read_roundtrip.

Implementations

impl MetricsCache

pub fn new() -> Self

Create a new, empty MetricsCache.

Why: Start empty so the route can distinguish “not yet polled” from a successful but trivially empty report. What: Allocates Arc<RwLock<None>>. Test: test_metrics_cache_initialises_empty.

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

Read the latest cached report (may be None before the first poll).

Why: Route handlers call this to serve the report without blocking. What: Acquires a read lock, clones the value, releases the lock. Test: test_metrics_cache_write_read_roundtrip.

pub async fn set(&self, report: ConsoleMetricsReport)

Write a new report into the cache.

Why: The poller calls this after each successful poll. What: Acquires a write lock, replaces the inner value. Test: test_metrics_cache_write_read_roundtrip.

Trait Implementations

impl Clone for MetricsCache

fn clone(&self) -> MetricsCache

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MetricsCache

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

Formats the value using the given formatter.

impl Default for MetricsCache

fn default() -> Self

Why: Required by clippy’s new_without_default lint. What: Delegates to MetricsCache::new(). Test: Implicitly tested wherever MetricsCache::new() is called.