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TaskStore

a2a_protocol_server::store::task_store

Trait TaskStore 

Source 
pub trait TaskStore:
    Send
    + Sync
    + 'static {
    // Required methods
    fn save<'a>(
        &'a self,
        task: Task,
    ) -> Pin<Box<dyn Future<Output = A2aResult<()>> + Send + 'a>>;
    fn get<'a>(
        &'a self,
        id: &'a TaskId,
    ) -> Pin<Box<dyn Future<Output = A2aResult<Option<Task>>> + Send + 'a>>;
    fn list<'a>(
        &'a self,
        params: &'a ListTasksParams,
    ) -> Pin<Box<dyn Future<Output = A2aResult<TaskListResponse>> + Send + 'a>>;
    fn insert_if_absent<'a>(
        &'a self,
        task: Task,
    ) -> Pin<Box<dyn Future<Output = A2aResult<bool>> + Send + 'a>>;
    fn delete<'a>(
        &'a self,
        id: &'a TaskId,
    ) -> Pin<Box<dyn Future<Output = A2aResult<()>> + Send + 'a>>;

    // Provided method
    fn count<'a>(
        &'a self,
    ) -> Pin<Box<dyn Future<Output = A2aResult<u64>> + Send + 'a>> { ... }
}
Expand description

Trait for persisting and retrieving Task objects.

All methods return Pin<Box<dyn Future>> for object safety — this trait is used as Box<dyn TaskStore>.

§Object safety

Do not add async fn methods; use the explicit Pin<Box<...>> form.

§Example

use std::future::Future;
use std::pin::Pin;
use a2a_protocol_types::error::A2aResult;
use a2a_protocol_types::params::ListTasksParams;
use a2a_protocol_types::responses::TaskListResponse;
use a2a_protocol_types::task::{Task, TaskId};
use a2a_protocol_server::store::TaskStore;

/// A no-op store that rejects all operations (for illustration).
struct NullStore;

impl TaskStore for NullStore {
    fn save<'a>(&'a self, _task: Task)
        -> Pin<Box<dyn Future<Output = A2aResult<()>> + Send + 'a>>
    {
        Box::pin(async { Ok(()) })
    }

    fn get<'a>(&'a self, _id: &'a TaskId)
        -> Pin<Box<dyn Future<Output = A2aResult<Option<Task>>> + Send + 'a>>
    {
        Box::pin(async { Ok(None) })
    }

    fn list<'a>(&'a self, _params: &'a ListTasksParams)
        -> Pin<Box<dyn Future<Output = A2aResult<TaskListResponse>> + Send + 'a>>
    {
        Box::pin(async { Ok(TaskListResponse::new(vec![])) })
    }

    fn insert_if_absent<'a>(&'a self, _task: Task)
        -> Pin<Box<dyn Future<Output = A2aResult<bool>> + Send + 'a>>
    {
        Box::pin(async { Ok(true) })
    }

    fn delete<'a>(&'a self, _id: &'a TaskId)
        -> Pin<Box<dyn Future<Output = A2aResult<()>> + Send + 'a>>
    {
        Box::pin(async { Ok(()) })
    }
}

Required Methods§

Source

fn save<'a>( &'a self, task: Task, ) -> Pin<Box<dyn Future<Output = A2aResult<()>> + Send + 'a>>

Saves (creates or updates) a task.

§Errors

Returns an A2aError if the store operation fails.

Source

fn get<'a>( &'a self, id: &'a TaskId, ) -> Pin<Box<dyn Future<Output = A2aResult<Option<Task>>> + Send + 'a>>

Retrieves a task by its ID, returning None if not found.

§Errors

Returns an A2aError if the store operation fails.

Source

fn list<'a>( &'a self, params: &'a ListTasksParams, ) -> Pin<Box<dyn Future<Output = A2aResult<TaskListResponse>> + Send + 'a>>

Lists tasks matching the given filter parameters.

§Errors

Returns an A2aError if the store operation fails.

Source

fn insert_if_absent<'a>( &'a self, task: Task, ) -> Pin<Box<dyn Future<Output = A2aResult<bool>> + Send + 'a>>

Atomically inserts a task only if no task with the same ID exists.

Returns Ok(true) if the task was inserted, Ok(false) if a task with the same ID already exists (no modification made).

§Errors

Returns an A2aError if the store operation fails.

Source

fn delete<'a>( &'a self, id: &'a TaskId, ) -> Pin<Box<dyn Future<Output = A2aResult<()>> + Send + 'a>>

Deletes a task by its ID.

§Errors

Returns an A2aError if the store operation fails.

Provided Methods§

Source

fn count<'a>( &'a self, ) -> Pin<Box<dyn Future<Output = A2aResult<u64>> + Send + 'a>>

Returns the total number of tasks in the store.

Useful for monitoring, metrics, and capacity management. Has a default implementation that returns 0 so existing implementations are not broken when this method is added.

§Errors

Returns an A2aError if the store operation fails.

Implementors§