Struct ResourceSubscriptions 

pub struct ResourceSubscriptions(/* private fields */);

Tracks which MCP resource URIs the client has subscribed to.

The hot read path (pump tasks checking before sending notifications) uses a RwLock so concurrent readers do not block each other.

Implementations

impl ResourceSubscriptions

pub fn new() -> Self

Create an empty subscription set.

pub async fn subscribe(&self, uri: String) -> Result<bool, String>

Add a URI to the subscription set.

Returns Ok(true) if newly inserted, Ok(false) if already present. Returns Err if the subscription set has reached MAX_SUBSCRIPTIONS.

Errors

Returns an error string when the cap is exceeded.

pub async fn is_empty(&self) -> bool

Check whether the subscription set is empty.

Used as a fast path in the diagnostics pump to skip URI construction when no client has subscribed yet.

pub async fn unsubscribe(&self, uri: &str) -> bool

Remove a URI from the subscription set.

Returns true if the URI was present and removed.

pub async fn contains(&self, uri: &str) -> bool

Check if a URI is currently subscribed.

pub async fn snapshot(&self) -> Vec<String>

Return a snapshot of all subscribed URIs (primarily for tests).

Trait Implementations

impl Debug for ResourceSubscriptions

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

Formats the value using the given formatter.

impl Default for ResourceSubscriptions

fn default() -> Self

Returns the “default value” for a type.