Module asyncdb 

Async-safe access to DejaDB.

Use AsyncDejaDB whenever the calling code is async. It is the supported entry point for Tokio-based hosts, which is where most agent code lives.

Why a separate handle

DejaDB is a blocking store: it owns a Tokio runtime internally and drives each operation with Runtime::block_on. Tokio does not permit a runtime to be started from within another runtime, so a DejaDB driven directly from async code panics — in two distinct places:

• when an operation is called (Cannot start a runtime from within a runtime);
• when the handle is dropped, because dropping it drops the runtime it owns.

The second is the easier one to miss: code can look correct and still panic at teardown.

What this handle does

• Every operation runs on Tokio’s blocking pool, where blocking is permitted.
• Concurrent callers queue asynchronously, so a burst of operations cannot exhaust the host’s blocking pool with threads that are only waiting their turn.
• Drop moves the store to a dedicated OS thread, so teardown never blocks an async worker.

Callers simply .await. The blocking DejaDB API is unchanged, and sync callers pay nothing for this module.

Example

use dejadb_store::AsyncDejaDB;
use dejadb_core::types::Fact;

let db = AsyncDejaDB::open("agent.db").await?;
db.add(Fact::new("john", "prefers", "dark mode")).await?;
let latest = db.latest("caller", "john", "prefers").await?;

Structs

AsyncDejaDB

A DejaDB that is safe to use from async code.