fakecloud_support/
persistence.rs

1//! Snapshot save/load for AWS Support state.
2
3use std::sync::Arc;
4
5use tokio::sync::Mutex as AsyncMutex;
6
7use fakecloud_persistence::SnapshotStore;
8
9use crate::state::{SharedSupportState, SupportSnapshot, SUPPORT_SNAPSHOT_SCHEMA_VERSION};
10
11#[derive(Debug, PartialEq, Eq)]
12pub enum LoadOutcome {
13    Empty,
14    Loaded(usize),
15}
16
17#[derive(Debug, thiserror::Error)]
18pub enum LoadError {
19    #[error("failed to read support persistence snapshot: {0}")]
20    Io(String),
21    #[error("failed to parse support persistence snapshot: {0}")]
22    Parse(String),
23    #[error("support persistence schema too new: on-disk={on_disk}, max supported={supported}")]
24    SchemaTooNew { on_disk: u32, supported: u32 },
25}
26
27pub fn load_into(
28    store: &dyn SnapshotStore,
29    state: &SharedSupportState,
30) -> Result<LoadOutcome, LoadError> {
31    let Some(bytes) = store.load().map_err(|e| LoadError::Io(e.to_string()))? else {
32        return Ok(LoadOutcome::Empty);
33    };
34    let mut snapshot: SupportSnapshot =
35        serde_json::from_slice(&bytes).map_err(|e| LoadError::Parse(e.to_string()))?;
36    if snapshot.schema_version > SUPPORT_SNAPSHOT_SCHEMA_VERSION {
37        return Err(LoadError::SchemaTooNew {
38            on_disk: snapshot.schema_version,
39            supported: SUPPORT_SNAPSHOT_SCHEMA_VERSION,
40        });
41    }
42    // There is no timer-driven lifecycle to resume, but keep the reconcile call
43    // for symmetry with the other services (it is a no-op).
44    for (_account_id, account) in snapshot.accounts.iter_mut() {
45        account.reconcile();
46    }
47    let accounts = snapshot.accounts.account_count();
48    *state.write() = snapshot.accounts;
49    Ok(LoadOutcome::Loaded(accounts))
50}
51
52pub async fn save_snapshot(
53    state: &SharedSupportState,
54    store: Option<Arc<dyn SnapshotStore>>,
55    lock: &AsyncMutex<()>,
56) {
57    let Some(store) = store else {
58        return;
59    };
60    let _guard = lock.lock().await;
61    let snapshot = SupportSnapshot {
62        schema_version: SUPPORT_SNAPSHOT_SCHEMA_VERSION,
63        accounts: state.read().clone(),
64    };
65    let join = tokio::task::spawn_blocking(move || -> std::io::Result<()> {
66        let bytes = serde_json::to_vec(&snapshot)
67            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e.to_string()))?;
68        store.save(&bytes)
69    })
70    .await;
71    match join {
72        Ok(Ok(())) => {}
73        Ok(Err(err)) => tracing::error!(%err, "failed to write support snapshot"),
74        Err(err) => tracing::error!(%err, "support snapshot task panicked"),
75    }
76}
77
78#[cfg(test)]
79mod tests {
80    use super::*;
81    use crate::state::SupportData;
82    use fakecloud_core::multi_account::MultiAccountState;
83    use parking_lot::RwLock;
84    use serde_json::json;
85    use std::sync::Mutex;
86
87    struct MemStore(Mutex<Option<Vec<u8>>>);
88    impl SnapshotStore for MemStore {
89        fn load(&self) -> std::io::Result<Option<Vec<u8>>> {
90            Ok(self.0.lock().unwrap().clone())
91        }
92        fn save(&self, bytes: &[u8]) -> std::io::Result<()> {
93            *self.0.lock().unwrap() = Some(bytes.to_vec());
94            Ok(())
95        }
96    }
97
98    fn state() -> SharedSupportState {
99        Arc::new(RwLock::new(MultiAccountState::new(
100            "000000000000",
101            "us-east-1",
102            "",
103        )))
104    }
105
106    #[test]
107    fn empty_store_is_empty() {
108        assert_eq!(
109            load_into(&MemStore(Mutex::new(None)), &state()).unwrap(),
110            LoadOutcome::Empty
111        );
112    }
113
114    #[test]
115    fn round_trip_restores_cases() {
116        let mut accounts: MultiAccountState<SupportData> =
117            MultiAccountState::new("000000000000", "us-east-1", "");
118        let data = accounts.get_or_create("111122223333");
119        data.cases.insert(
120            "case-111122223333-2026-abc".into(),
121            json!({ "caseId": "case-111122223333-2026-abc", "status": "opened" }),
122        );
123        let snap = SupportSnapshot {
124            schema_version: SUPPORT_SNAPSHOT_SCHEMA_VERSION,
125            accounts,
126        };
127        let store = MemStore(Mutex::new(Some(serde_json::to_vec(&snap).unwrap())));
128        let restored = state();
129        assert_eq!(
130            load_into(&store, &restored).unwrap(),
131            LoadOutcome::Loaded(2)
132        );
133        let guard = restored.read();
134        let case = &guard.get("111122223333").unwrap().cases["case-111122223333-2026-abc"];
135        assert_eq!(case["status"], "opened");
136    }
137
138    #[test]
139    fn rejects_future_schema() {
140        let accounts: MultiAccountState<SupportData> =
141            MultiAccountState::new("000000000000", "us-east-1", "");
142        let bytes = serde_json::to_vec(&serde_json::json!({
143            "schema_version": SUPPORT_SNAPSHOT_SCHEMA_VERSION + 1,
144            "accounts": accounts,
145        }))
146        .unwrap();
147        let store = MemStore(Mutex::new(Some(bytes)));
148        assert!(matches!(
149            load_into(&store, &state()),
150            Err(LoadError::SchemaTooNew { .. })
151        ));
152    }
153}
fakecloud_support/persistence.rs

fakecloud_support/
persistence.rs
