Struct SharedState 

pub struct SharedState { /* private fields */ }

Shared state: a heterogeneous container accessed by type.

Type is the key: a second insert of the same type overwrites; retrieval takes a type parameter (compile-time type safety). Unlike Box<dyn Any>’s “store anything”, this container holds multiple values side by side, distinguished by type.

An internal RwLock (read-heavy) provides cross-thread safety; Clone is cheap (Arc), so tools and agents — several agents — share the same instance.

Example

use molo::SharedState;

#[derive(Debug, Clone, PartialEq)]
struct Session { user: String }

let state = SharedState::new();
state.insert(Session { user: "alice".into() });
state.with::<Session>(|s| assert_eq!(s.user, "alice"));
state.with_mut::<Session>(|s| s.user = "bob".into());
assert_eq!(state.get::<Session>(), Some(Session { user: "bob".into() }));

Implementations

impl SharedState

pub fn new() -> SharedState

An empty shared state.

pub fn insert<T>(&self, value: T)

where T: Any + Send + Sync,

Store a custom value; storing the same type again overwrites.

pub fn get<T>(&self) -> Option<T>

where T: Any + Clone,

Retrieve (clone) a custom value; returns None when the type is absent (the type must implement Clone; a clone is returned and the original value in the container is unchanged).

pub fn with<T>(&self, f: impl FnOnce(&T))

where T: Any,

Read an existing value under the lock; the closure does not run when the type is absent.

Panics

A panic inside the closure propagates outward; the lock gets poisoned as a result, but the container recovers from poisoning and later access works as usual (the closure returns nothing; for an in-place read use get).

Deadlock red line

The underlying RwLock is not reentrant, and the closure runs while the lock is held: the closure must not access the same SharedState again (e.g. with(|a| ... state.get::<B>() ...)), or it hangs with no error. To access several values at once, call get sequentially / combine them into one struct, or move reads and writes outside the closure.

pub fn with_mut<T>(&self, f: impl FnOnce(&mut T))

where T: Any,

Update an existing value in place under the lock; the closure does not run when the type is absent.

Panics

A panic inside the closure propagates outward; the lock gets poisoned as a result, but the container recovers from poisoning and later access works as usual.

Deadlock red line

Same as with: the underlying lock is not reentrant, and the closure must not access the same SharedState again.

Trait Implementations

impl Clone for SharedState

fn clone(&self) -> SharedState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SharedState

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

Formats the value using the given formatter.

impl Default for SharedState

fn default() -> SharedState

Returns the “default value” for a type.