Add support for getting txn id

meilisearch · Dec 19, 2024 · 874e9e3 · 874e9e3
1 parent c219133
commit 874e9e3
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Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/heed/src/mdb/lmdb_ffi.rs b/heed/src/mdb/lmdb_ffi.rs
@@ -6,9 +6,9 @@ pub use ffi::{
     mdb_env_get_fd, mdb_env_get_flags, mdb_env_get_maxkeysize, mdb_env_info, mdb_env_open,
     mdb_env_set_flags, mdb_env_set_mapsize, mdb_env_set_maxdbs, mdb_env_set_maxreaders,
     mdb_env_stat, mdb_env_sync, mdb_filehandle_t, mdb_get, mdb_put, mdb_reader_check,
-    mdb_set_compare, mdb_stat, mdb_txn_abort, mdb_txn_begin, mdb_txn_commit, mdb_version,
-    MDB_cursor, MDB_dbi, MDB_env, MDB_stat, MDB_txn, MDB_val, MDB_CP_COMPACT, MDB_CURRENT,
-    MDB_RDONLY, MDB_RESERVE,
+    mdb_set_compare, mdb_stat, mdb_txn_abort, mdb_txn_begin, mdb_txn_commit, mdb_txn_id,
+    mdb_version, MDB_cursor, MDB_dbi, MDB_env, MDB_stat, MDB_txn, MDB_val, MDB_CP_COMPACT,
+    MDB_CURRENT, MDB_RDONLY, MDB_RESERVE,
 };
 #[cfg(master3)]
 pub use ffi::{mdb_env_set_encrypt, MDB_enc_func};

diff --git a/heed/src/txn.rs b/heed/src/txn.rs
@@ -86,6 +86,15 @@ impl<'e> RoTxn<'e> {
         self.env.env_mut_ptr()
     }
 
+    /// Return the transaction's ID.
+    ///
+    /// This returns the identifier associated with this transaction. For a
+    /// [`RoTxn`], this corresponds to the snapshot being read;
+    /// concurrent readers will frequently have the same transaction ID.
+    pub fn id(&self) -> usize {
+        unsafe { ffi::mdb_txn_id(self.txn.unwrap().as_ptr()) }
+    }
+
     /// Commit a read transaction.
     ///
     /// Synchronizing some [`Env`] metadata with the global handle.