Struct Envelope 

pub struct Envelope { /* private fields */ }

The process-wide envelope state: the global query semaphore and one index-operation semaphore per key.

The per-key semaphores are created on first use with the key’s plan cap and kept for the process lifetime. The map grows by one entry per key that ever indexes — bounded by the number of keys the operator has issued, which is the same order as the key store itself.

Implementations

impl Envelope

pub fn new() -> Self

An envelope with the production global query cap.

pub fn with_query_permits(permits: usize) -> Self

An envelope with a chosen global query cap — the seam tests use to exercise exhaustion without four real graph loads.

pub async fn acquire_query(&self) -> OwnedSemaphorePermit

Waits for a global query slot. The semaphore is never closed, so acquisition cannot fail.

pub fn try_acquire_query(&self) -> Option<OwnedSemaphorePermit>

Takes a global query slot without waiting, if one is free.

pub fn try_acquire_index_op( &self, key_id: &str, max_concurrent: usize, ) -> Option<OwnedSemaphorePermit>

Takes this key’s index-operation slot without waiting.

None means the key already runs max_concurrent index operations (or the permit map’s lock was poisoned, in which case refusing is again the safe direction). Index operations refuse rather than queue: a queued creation would hold a connection open for the length of someone else’s clone, and a client can retry a 429 the moment its own first build ends.

Trait Implementations

impl Debug for Envelope

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

Formats the value using the given formatter.

impl Default for Envelope

fn default() -> Self

Returns the “default value” for a type.