Struct InMemoryProjection

pub struct InMemoryProjection<S, E> { /* private fields */ }

A simple in-memory projection for testing and development.

This projection maintains its state and checkpoint in memory only, making it suitable for testing but not for production use.

Implementations

impl<S, E> InMemoryProjection<S, E>

where S: Send + Sync + Debug + Clone + Default, E: Send + Sync + Debug + PartialEq + Eq,

pub fn new(config: ProjectionConfig) -> Self

Creates a new in-memory projection with the given configuration.

pub async fn set_status(&self, status: ProjectionStatus) -> ProjectionResult<()>

Sets the status of the projection.

Trait Implementations

impl<S: Debug, E: Debug> Debug for InMemoryProjection<S, E>

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

Formats the value using the given formatter.

impl<S, E> Projection for InMemoryProjection<S, E>

where S: Send + Sync + Debug + Clone + Default + 'static, E: Send + Sync + Debug + PartialEq + Eq + 'static,

type State = S

The type of the projection’s state.

type Event = E

The type of events this projection processes.

fn config(&self) -> &ProjectionConfig

Returns the configuration for this projection.

fn get_state<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = ProjectionResult<Self::State>> + Send + 'async_trait>>

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

Returns the current state of the projection.

fn get_status<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = ProjectionResult<ProjectionStatus>> + Send + 'async_trait>>

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

Returns the current status of the projection.

fn load_checkpoint<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = ProjectionResult<ProjectionCheckpoint>> + Send + 'async_trait>>

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

Loads the checkpoint from persistent storage.

fn save_checkpoint<'life0, 'async_trait>( &'life0 self, checkpoint: ProjectionCheckpoint, ) -> Pin<Box<dyn Future<Output = ProjectionResult<()>> + Send + 'async_trait>>

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

Saves the checkpoint to persistent storage.

fn apply_event<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, _state: &'life1 mut Self::State, _event: &'life2 Event<Self::Event>, ) -> Pin<Box<dyn Future<Output = ProjectionResult<()>> + Send + 'async_trait>>

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

Processes a single event, updating the projection state.

fn initialize_state<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = ProjectionResult<Self::State>> + Send + 'async_trait>>

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

Initializes the projection state.

fn apply_events<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, state: &'life1 mut Self::State, events: &'life2 [Event<Self::Event>], ) -> Pin<Box<dyn Future<Output = ProjectionResult<()>> + Send + 'async_trait>>

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

Processes a batch of events efficiently.

fn on_start<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = ProjectionResult<()>> + Send + 'async_trait>>

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

Called when the projection starts processing.

fn on_stop<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = ProjectionResult<()>> + Send + 'async_trait>>

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

Called when the projection stops processing.

fn on_pause<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = ProjectionResult<()>> + Send + 'async_trait>>

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

Called when the projection is paused.

fn on_resume<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = ProjectionResult<()>> + Send + 'async_trait>>

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

Called when the projection is resumed.

fn on_error<'life0, 'life1, 'async_trait>( &'life0 self, error: &'life1 ProjectionError, ) -> Pin<Box<dyn Future<Output = ProjectionResult<()>> + Send + 'async_trait>>

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

Called when an error occurs during processing.

fn should_process_event(&self, event: &Event<Self::Event>) -> bool

Determines if this projection should process the given event.

fn interested_streams(&self) -> Vec<StreamId>

Returns the streams this projection is interested in.