Skip to main content

bamboo_engine/runtime/execution/
runner_state.rs

1//! Runner state types for background agent execution.
2//!
3//! Provides the `AgentRunner` and `AgentStatus` types that track the lifecycle
4//! of an in-progress agent execution. These are used by the execution
5//! orchestration layer across all background paths (HTTP execute, spawn, schedule).
6
7use chrono::{DateTime, Utc};
8use tokio::sync::broadcast;
9use tokio_util::sync::CancellationToken;
10
11use bamboo_agent_core::AgentEvent;
12
13/// Status of an agent execution runner.
14///
15/// Represents the lifecycle state of an agent run from initialization
16/// through completion or error.
17#[derive(Debug, Clone)]
18pub enum AgentStatus {
19    /// Agent is initialized but not yet running.
20    Pending,
21
22    /// Agent is currently executing.
23    Running,
24
25    /// Agent completed successfully.
26    Completed,
27
28    /// Agent execution was cancelled by user.
29    Cancelled,
30
31    /// Agent execution failed with an error message.
32    Error(String),
33}
34
35/// Runner that manages agent execution for a session.
36///
37/// Each active agent run has an associated `AgentRunner` that coordinates
38/// event broadcasting, cancellation, and status tracking.
39///
40/// # Event Broadcasting
41///
42/// Uses a broadcast channel to support multiple subscribers watching
43/// the same agent run simultaneously.
44///
45/// # Cancellation
46///
47/// Provides a cancellation token that can be used to gracefully stop
48/// an in-progress agent execution.
49#[derive(Debug, Clone)]
50pub struct AgentRunner {
51    /// Broadcast sender for agent events.
52    ///
53    /// Allows multiple clients to subscribe to agent events
54    /// via `event_sender.subscribe()`.
55    pub event_sender: broadcast::Sender<AgentEvent>,
56
57    /// Cancellation token for graceful shutdown.
58    ///
59    /// When triggered, the agent should stop execution at the
60    /// next safe point.
61    pub cancel_token: CancellationToken,
62
63    /// Current status of the agent run.
64    pub status: AgentStatus,
65
66    /// Timestamp when the run was started.
67    pub started_at: DateTime<Utc>,
68
69    /// Timestamp when the run completed (if finished).
70    pub completed_at: Option<DateTime<Utc>>,
71
72    /// Last token budget event to replay for new subscribers.
73    ///
74    /// When a new client subscribes to an ongoing run, this
75    /// allows them to receive the most recent token usage info.
76    pub last_budget_event: Option<AgentEvent>,
77}
78
79impl Default for AgentRunner {
80    fn default() -> Self {
81        Self::new()
82    }
83}
84
85impl AgentRunner {
86    /// Broadcast channel capacity for agent events.
87    pub const EVENT_CHANNEL_CAPACITY: usize = 1000;
88
89    /// Create a new agent runner with default settings.
90    ///
91    /// Initializes a broadcast channel, a fresh cancellation token,
92    /// and `Pending` status.
93    pub fn new() -> Self {
94        let (event_sender, _) = broadcast::channel(Self::EVENT_CHANNEL_CAPACITY);
95        Self {
96            event_sender,
97            cancel_token: CancellationToken::new(),
98            status: AgentStatus::Pending,
99            started_at: Utc::now(),
100            completed_at: None,
101            last_budget_event: None,
102        }
103    }
104}