hypercall_db_diesel/
transaction.rs

1//! Transactional trait implementation for DatabaseHandler.
2//!
3//! Provides `DieselTransaction`, a scoped connection wrapper that issues
4//! BEGIN on construction and ROLLBACK on drop unless explicitly committed.
5
6use anyhow::Result;
7use diesel::connection::SimpleConnection;
8use diesel::r2d2;
9
10use crate::database_handler::{DatabaseHandler, DynConnectionManager};
11
12/// A scoped database transaction. Holds a pooled connection with an active
13/// BEGIN. Commits explicitly via `.commit()`, rolls back on drop otherwise.
14pub struct DieselTransaction {
15    conn: Option<r2d2::PooledConnection<DynConnectionManager>>,
16    committed: bool,
17}
18
19impl DieselTransaction {
20    pub(crate) fn new(mut conn: r2d2::PooledConnection<DynConnectionManager>) -> Result<Self> {
21        conn.batch_execute("BEGIN")?;
22        Ok(Self {
23            conn: Some(conn),
24            committed: false,
25        })
26    }
27}
28
29impl Drop for DieselTransaction {
30    fn drop(&mut self) {
31        if !self.committed {
32            if let Some(ref mut conn) = self.conn {
33                let _ = conn.batch_execute("ROLLBACK");
34            }
35        }
36    }
37}
38
39impl hypercall_db::Transaction for DieselTransaction {
40    fn commit(mut self) -> Result<()> {
41        if let Some(ref mut conn) = self.conn {
42            conn.batch_execute("COMMIT")?;
43        }
44        self.committed = true;
45        Ok(())
46    }
47
48    fn rollback(mut self) -> Result<()> {
49        if let Some(ref mut conn) = self.conn {
50            conn.batch_execute("ROLLBACK")?;
51        }
52        self.committed = true; // prevent double rollback in drop
53        Ok(())
54    }
55}
56
57impl hypercall_db::Transactional for DatabaseHandler {
58    type Tx = DieselTransaction;
59
60    fn begin_transaction(&self) -> Result<DieselTransaction> {
61        let conn = self.pool().get()?;
62        DieselTransaction::new(conn)
63    }
64}
65
66#[cfg(test)]
67mod tests {
68    use crate::test_helpers::TestDb;
69    use hypercall_db::*;
70    use hypercall_types::wallet_address::test_wallet;
71    use hypercall_types::MarginMode;
72
73    #[tokio::test]
74    async fn transaction_commit_persists() {
75        let test_db = TestDb::new().await.unwrap();
76        let db = test_db.handler.as_ref();
77        let wallet = test_wallet(8);
78
79        {
80            let tx = db.begin_transaction().unwrap();
81            // Transaction is created successfully -- the connection holds BEGIN
82            tx.commit().unwrap();
83        }
84
85        // Verify the connection was properly returned to pool
86        db.insert_margin_mode_if_missing_sync(&wallet, MarginMode::Standard)
87            .unwrap();
88        let mode = db.get_margin_mode_sync(&wallet).unwrap();
89        assert_eq!(mode, MarginMode::Standard);
90    }
91
92    #[tokio::test]
93    async fn transaction_rollback_on_drop() {
94        let test_db = TestDb::new().await.unwrap();
95        let db = test_db.handler.as_ref();
96
97        {
98            let _tx = db.begin_transaction().unwrap();
99            // Drop without commit -- should rollback
100        }
101
102        // Pool should still work after rollback
103        let all = db.get_all_user_tiers_sync().unwrap();
104        assert!(all.is_empty());
105    }
106}
hypercall_db_diesel/transaction.rs

hypercall_db_diesel/
transaction.rs
