Actually enable io-uring (#751)

librocksdb-sys/build_version.cc

@@ -23,6 +23,10 @@ static const std::string rocksdb_build_date = "rocksdb_build_date:2023-02-19 21:
 
 std::unordered_map<std::string, ROCKSDB_NAMESPACE::RegistrarFunc> ROCKSDB_NAMESPACE::ObjectRegistry::builtins_ = {};
 
+extern "C" bool RocksDbIOUringEnable() {
+  return true;
+}
+
 namespace ROCKSDB_NAMESPACE {
 static void AddProperty(std::unordered_map<std::string, std::string> *props, const std::string& name) {
   size_t colon = name.find(":");

src/db_options.rs

@@ -3417,6 +3417,17 @@ impl ReadOptions {
             ffi::rocksdb_readoptions_set_pin_data(self.inner, c_uchar::from(v));
         }
     }
+
+    /// Asynchronously prefetch some data.
+    ///
+    /// Used for sequential reads and internal automatic prefetching.
+    ///
+    /// Default: `false`
+    pub fn set_async_io(&mut self, v: bool) {
+        unsafe {
+            ffi::rocksdb_readoptions_set_async_io(self.inner, c_uchar::from(v));
+        }
+    }
 }
 
 impl Default for ReadOptions {