feat(db): Add mdbx-rs apache licenced code 55e234 (#132)

crates/libmdbx-rs/benches/utils.rs

@@ -0,0 +1,26 @@
+use libmdbx::{Environment, NoWriteMap, WriteFlags};
+use tempfile::{tempdir, TempDir};
+
+pub fn get_key(n: u32) -> String {
+    format!("key{}", n)
+}
+
+pub fn get_data(n: u32) -> String {
+    format!("data{}", n)
+}
+
+pub fn setup_bench_db(num_rows: u32) -> (TempDir, Environment<NoWriteMap>) {
+    let dir = tempdir().unwrap();
+    let env = Environment::new().open(dir.path()).unwrap();
+
+    {
+        let txn = env.begin_rw_txn().unwrap();
+        let db = txn.open_db(None).unwrap();
+        for i in 0..num_rows {
+            txn.put(&db, &get_key(i), &get_data(i), WriteFlags::empty())
+                .unwrap();
+        }
+        txn.commit().unwrap();
+    }
+    (dir, env)
+}