community: every ledger takes its write lock, so the inbox check can no longer land on top of a friend accept

src-tauri/src/proposals.rs

@@ -30,6 +30,7 @@ use crate::persona;
 use crate::pipeline::LibraryState;
 use crate::playlists;
 use crate::shared_playlists::{self, Published};
+use crate::ledger;
 use crate::slsk_link;
 use crate::spaces;
 use crate::state::AppState;
@@ -192,8 +193,11 @@ fn board_id(owner: &[u8; 32], uuid: &[u8; 16]) -> String {
     format!("{}/{}", b58(owner), b58(uuid))
 }
 
+/// Both the file the ledger lives in and the key its write lock is taken on.
+const LEDGER_FILE: &str = "boards.json";
+
 fn path(app: &tauri::AppHandle) -> Result<PathBuf, String> {
-    Ok(app.path().app_data_dir().map_err(|e| e.to_string())?.join("freenet").join("boards.json"))
+    Ok(app.path().app_data_dir().map_err(|e| e.to_string())?.join("freenet").join(LEDGER_FILE))
 }
 fn load(app: &tauri::AppHandle) -> Ledger {
     path(app)
@@ -392,6 +396,7 @@ pub async fn open(app: &tauri::AppHandle, space_owner_b58: &str, space_b58: &str
         let have: Vec<[u8; 32]> = board.authority.as_ref().map(|a| a.contributors.clone()).unwrap_or_default();
         let same = want.iter().collect::<BTreeSet<_>>() == have.iter().collect::<BTreeSet<_>>();
         if !same {
+            let _ledger = ledger::hold(LEDGER_FILE).await;
             let bid = board_id(&pin.owner, &pin.uuid);
             let mut l = load(app);
             let rec = l.boards.get(&bid).cloned().unwrap_or_default();
@@ -517,6 +522,7 @@ pub async fn decide(app: &tauri::AppHandle, space_owner_b58: &str, space_b58: &s
         return Err("the board has not reached this node".into());
     }
     let p = board.proposals.iter().find(|p| p.proposal_id == pid).cloned().ok_or("that proposal is no longer pending")?;
+    let ledger = ledger::hold(LEDGER_FILE).await;
     let bid = board_id(&pin.owner, &pin.uuid);
     let mut l = load(app);
     let rec = l.boards.get(&bid).cloned().unwrap_or_default();
@@ -544,6 +550,8 @@ pub async fn decide(app: &tauri::AppHandle, space_owner_b58: &str, space_b58: &s
     l.boards.insert(bid, BoardRecord { last_seq: seq, ..rec });
     save(app, &l)?;
     log::info!("proposals: decision {} ({}) on board {}", seq, if accept { "accept" } else { "reject" }, b58(&pin.uuid));
+    // open() takes this same ledger; the write is done, so let go first.
+    drop(ledger);
     open(app, space_owner_b58, space_b58).await
 }