speccoder_runtime/resume.rs
1//! Resuming an attempt a killed process left behind.
2//!
3//! Before an attempt, a marker records its admission key, the checkpoint it
4//! started from and the acceptance tests it is judged by. A run that ends in
5//! any ordinary way removes it ([`Guard`]); a killed process cannot, so a
6//! marker on disk means an attempt was interrupted. The next run then keeps
7//! the worktree as the attempt left it and admits the attempt under the same
8//! key: agentplane finds the interrupted run and resumes it from its journal
9//! — model calls and tool calls that finished are read back, not repeated —
10//! and a run that had already finished is read back whole and judged again
11//! (a task that passed just before the kill is ticked now).
12
13use std::path::{Path, PathBuf};
14
15use serde::{Deserialize, Serialize};
16use sha2::{Digest as _, Sha256};
17
18/// An attempt in progress.
19#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
20pub struct Marker {
21 /// The agentplane admission key.
22 pub key: String,
23 /// The checkpoint the attempt started from.
24 pub before: String,
25 /// The worktree's HEAD then; a different HEAD means the marker is stale.
26 pub head: String,
27 /// Which attempt of the task run.
28 pub attempt: u32,
29 /// Which best-of-n sample (0-based).
30 pub sample: usize,
31 /// The acceptance tests prepared for the task run.
32 pub acceptance: Option<serde_json::Value>,
33 /// The run the attempt belongs to: an invocation resuming it adopts it.
34 #[serde(default)]
35 pub run_id: Option<String>,
36 /// The run's prompts when the attempt started.
37 #[serde(default)]
38 pub asked: u32,
39 /// The run's grants when it started.
40 #[serde(default)]
41 pub run_grants: Vec<crate::tools::policy::Object>,
42}
43
44/// Where the marker of `feature/task` lives.
45#[must_use]
46pub fn path(plane_dir: &Path, feature: &str, task: &str) -> PathBuf {
47 plane_dir
48 .join("resume")
49 .join(feature)
50 .join(format!("{task}.json"))
51}
52
53/// The marker, if an attempt was interrupted.
54#[must_use]
55pub fn load(path: &Path) -> Option<Marker> {
56 serde_json::from_str(&std::fs::read_to_string(path).ok()?).ok()
57}
58
59/// Records `marker` (written whole, then renamed: never half a marker).
60pub fn save(path: &Path, marker: &Marker) -> std::io::Result<()> {
61 if let Some(dir) = path.parent() {
62 std::fs::create_dir_all(dir)?;
63 }
64 let tmp = path.with_extension("json.tmp");
65 std::fs::write(
66 &tmp,
67 serde_json::to_vec(marker).map_err(std::io::Error::other)?,
68 )?;
69 std::fs::rename(tmp, path)
70}
71
72/// A fresh admission key: unique per attempt, so an ordinary rerun never
73/// meets an old attempt's run.
74#[must_use]
75pub fn new_key(feature: &str, task: &str) -> String {
76 static COUNTER: std::sync::atomic::AtomicU64 = std::sync::atomic::AtomicU64::new(0);
77 let nanos = std::time::SystemTime::now()
78 .duration_since(std::time::UNIX_EPOCH)
79 .map_or(0, |d| d.as_nanos());
80 let n = COUNTER.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
81 let digest = Sha256::digest(format!(
82 "{feature}/{task}/{nanos}/{}/{n}",
83 std::process::id()
84 ));
85 let hex: String = digest.iter().take(16).map(|b| format!("{b:02x}")).collect();
86 format!("attempt-{hex}")
87}
88
89/// Removes the marker when a task run that started an attempt ends in any
90/// ordinary way. A run refused before its attempt starts (a session check,
91/// a worktree held by a waiting call) leaves an interrupted or waiting
92/// attempt's marker alone: that attempt still resumes.
93#[derive(Debug)]
94pub struct Guard {
95 path: PathBuf,
96 armed: std::cell::Cell<bool>,
97}
98
99impl Guard {
100 /// A guard for the marker at `path`, not yet armed.
101 #[must_use]
102 pub fn new(path: PathBuf) -> Self {
103 Self {
104 path,
105 armed: std::cell::Cell::new(false),
106 }
107 }
108
109 /// An attempt is starting: the marker goes when the run ends.
110 pub fn arm(&self) {
111 self.armed.set(true);
112 }
113
114 /// Leaves the marker in place: the attempt waits for a person and the
115 /// next run resumes it.
116 pub fn keep(self) {
117 self.armed.set(false);
118 }
119}
120
121impl Drop for Guard {
122 fn drop(&mut self) {
123 if self.armed.get() {
124 let _ = std::fs::remove_file(&self.path);
125 }
126 }
127}