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TaskStore

a2a_protocol_sdk::server::store

Trait TaskStore 

Source 
pub trait TaskStore:
    Send
    + Sync
    + 'static {
    // Required methods
    fn save<'a>(
        &'a self,
        task: &'a Task,
    ) -> Pin<Box<dyn Future<Output = Result<(), A2aError>> + Send + 'a>>;
    fn get<'a>(
        &'a self,
        id: &'a TaskId,
    ) -> Pin<Box<dyn Future<Output = Result<Option<Task>, A2aError>> + Send + 'a>>;
    fn list<'a>(
        &'a self,
        params: &'a ListTasksParams,
    ) -> Pin<Box<dyn Future<Output = Result<TaskListResponse, A2aError>> + Send + 'a>>;
    fn insert_if_absent<'a>(
        &'a self,
        task: &'a Task,
    ) -> Pin<Box<dyn Future<Output = Result<bool, A2aError>> + Send + 'a>>;
    fn delete<'a>(
        &'a self,
        id: &'a TaskId,
    ) -> Pin<Box<dyn Future<Output = Result<(), A2aError>> + Send + 'a>>;

    // Provided method
    fn count<'a>(
        &'a self,
    ) -> Pin<Box<dyn Future<Output = Result<u64, A2aError>> + 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: &'a 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: &'a 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: &'a Task, ) -> Pin<Box<dyn Future<Output = Result<(), A2aError>> + 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 = Result<Option<Task>, A2aError>> + 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 = Result<TaskListResponse, A2aError>> + 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: &'a Task, ) -> Pin<Box<dyn Future<Output = Result<bool, A2aError>> + 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 = Result<(), A2aError>> + 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 = Result<u64, A2aError>> + 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.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§