add recover_max_pararelism configuration

include/limestone/api/configuration.h

@@ -47,11 +47,21 @@ class configuration {
      */
     configuration(const std::vector<boost::filesystem::path>&& data_locations, boost::filesystem::path metadata_location) noexcept;
 
+    /**
+     * @brief setter for recover_max_pararelism
+     * @param recover_max_pararelism  the number of recover_max_pararelism
+     */
+    void set_recover_max_pararelism(int recover_max_pararelism) {
+        recover_max_pararelism_ = recover_max_pararelism;
+    }
+
 private:
     std::vector<boost::filesystem::path> data_locations_{};
 
     boost::filesystem::path metadata_location_{};
 
+    int recover_max_pararelism_{8};
+
     friend class datastore;
 };
 

include/limestone/api/datastore.h

@@ -252,6 +252,8 @@ class datastore {
 
     std::mutex mtx_files_{};
 
+    int recover_max_pararelism_{};
+
     std::mutex mtx_epoch_file_{};
 
     state state_{};

src/limestone/datastore.cpp

@@ -64,7 +64,9 @@ datastore::datastore(configuration const& conf) {
         strm.close();
         add_file(epoch_file_path_);
     }
-
+
+    recover_max_pararelism_ = conf.recover_max_pararelism_;
+
     VLOG_LP(log_debug) << "datastore is created, location = " << location_.string();
 }
 

src/limestone/datastore_snapshot.cpp

@@ -174,7 +174,7 @@ void datastore::create_snapshot() noexcept {
         }
     };
 
-    int num_worker = 8;  // TODO: read from config recover_max_pararelism
+    int num_worker = recover_max_pararelism_;
     if (!works_with_multi_thread && num_worker > 1) {
         LOG_LP(ERROR) << "this sort method does not work correctly with multi-thread, so force num_worker = 1";
         num_worker = 1;