Struct InMemoryCheckpointer 

pub struct InMemoryCheckpointer<S>
where
    S: Clone + Send + Sync + 'static,
{ /* private fields */ }

In-process checkpointer backed by a HashMap<(tenant_id, thread_id), Vec<Checkpoint>>. The composite key encodes Invariant 11 (multi-tenant isolation): the same thread_id under two tenants resolves to two distinct histories.

Cheap to clone — internal state is Arc<Mutex<...>>-shared.

Implementations

impl<S> InMemoryCheckpointer<S>

where S: Clone + Send + Sync + 'static,

pub fn new() -> Self

Empty checkpointer.

pub fn total_checkpoints(&self) -> usize

Total number of checkpoints stored across all (tenant_id, thread_id) partitions. Test helper.

pub fn thread_count(&self) -> usize

Number of distinct (tenant_id, thread_id) partitions that have at least one checkpoint.

Trait Implementations

impl<S> Checkpointer<S> for InMemoryCheckpointer<S>

where S: Clone + Send + Sync + 'static,

fn put<'life0, 'async_trait>( &'life0 self, checkpoint: Checkpoint<S>, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Persist a checkpoint. The checkpoint’s own (tenant_id, thread_id) fields define its addressing.

fn get_latest<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 ThreadKey, ) -> Pin<Box<dyn Future<Output = Result<Option<Checkpoint<S>>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Load the most recent checkpoint for key. Verb-family get per .claude/rules/naming.md — single-item primary- key (most-recent) lookup, returns Option<Checkpoint<S>>.

fn get_by_id<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, key: &'life1 ThreadKey, id: &'life2 CheckpointId, ) -> Pin<Box<dyn Future<Output = Result<Option<Checkpoint<S>>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Look up a specific checkpoint by id within key’s scope. Verb-family get — primary-key lookup.

fn list_history<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 ThreadKey, limit: usize, ) -> Pin<Box<dyn Future<Output = Result<Vec<Checkpoint<S>>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Return the thread’s checkpoint history, most recent first. limit caps the result size (usize::MAX for “all”).

fn update_state<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, key: &'life1 ThreadKey, parent_id: &'life2 CheckpointId, new_state: S, ) -> Pin<Box<dyn Future<Output = Result<CheckpointId>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Time-travel write: create a fresh checkpoint that branches off parent_id, replacing only the state. The new checkpoint inherits next_node from its parent and records parent_id so history renders branches correctly.

impl<S> Clone for InMemoryCheckpointer<S>

where S: Clone + Send + Sync + 'static + Clone,

fn clone(&self) -> InMemoryCheckpointer<S>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<S> Default for InMemoryCheckpointer<S>

where S: Clone + Send + Sync + 'static,

fn default() -> Self

Returns the “default value” for a type.