mocra-dag 0.4.1

Generic distributed DAG execution engine for the mocra crawler framework (zero crawler coupling).
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

//! Abstract traits for dag's runtime dependencies — the host crate injects the implementations,
//! so that mocra-dag does not depend back on the host.

use async_trait::async_trait;

use crate::types::DagNodeSyncState;

/// Distributed KV / atomic-operation backend (the host implements it with the embedded cluster
/// KV: `get`/`del`/`incr`).
///
/// Semantics: `get` reads bytes, `set` writes (with an optional TTL), `del` removes a key, and
/// `incr` atomically increments. Errors are uniformly `String` (the dag side is mostly
/// best-effort, either ignoring them or degrading gracefully).
#[async_trait]
pub trait DagStore: Send + Sync {
    async fn get(&self, key: &str) -> Result<Option<Vec<u8>>, String>;
    async fn set(
        &self,
        key: &str,
        value: &[u8],
        ttl: Option<std::time::Duration>,
    ) -> Result<(), String>;
    async fn del(&self, key: &str) -> Result<(), String>;
    async fn incr(&self, key: &str, delta: i64) -> Result<i64, String>;
}

/// Outlet for DAG node state events (the host implements it with distributed pub/sub). Optional:
/// if not injected, no events are emitted.
#[async_trait]
pub trait DagEventSink: Send + Sync {
    async fn emit(&self, event: &DagNodeSyncState) -> Result<(), String>;
}