Added DBMain::RecoverSystem() for loading the database back in from t…

…he WAL. This is currently broken because it tries to recreate the catalogs from the WAL but the catalog obviously already exists...

src/include/main/db_main.h

@@ -61,6 +61,11 @@ class DBMain {
    */
   void Run();
 
+  /**
+   * Attempt to recover the system from the WAL.
+   */
+  void RecoverSystem();
+
   /**
    * Shuts down the server.
    * It is worth noting that in normal cases, noisepage will shut down and return from Run().

src/main/db_main.cpp

@@ -5,6 +5,7 @@
 #undef __SETTING_GFLAGS_DEFINE__     // NOLINT
 
 #include "execution/execution_util.h"
+#include "storage/recovery/disk_log_provider.h"
 #include "storage/recovery/replication_log_provider.h"
 
 namespace noisepage {
@@ -30,6 +31,31 @@ void DBMain::Run() {
   }
 }
 
+void DBMain::RecoverSystem() {
+  NOISEPAGE_ASSERT(settings_manager_ != DISABLED, "Trying to recover system without SettingsManager.");
+
+  // Skip if logging is disabled
+  if (settings_manager_->GetBool(settings::Param::wal_enable) == false) {
+    return;
+  }
+
+  // Skip if the file does not exist
+  auto wal_file_path = settings_manager_->GetString(settings::Param::wal_file_path);
+  if (std::filesystem::exists(wal_file_path) == false) {
+    return;
+  }
+
+  // Instantiate recovery manager and recover the tables
+  storage::DiskLogProvider log_provider(wal_file_path);
+  storage::RecoveryManager recovery_manager(common::ManagedPointer<storage::AbstractLogProvider>(&log_provider),
+                                            catalog_layer_->GetCatalog(), txn_layer_->GetTransactionManager(),
+                                            txn_layer_->GetDeferredActionManager(), GetReplicationManager(),
+                                            GetThreadRegistry(), storage_layer_->GetBlockStore());
+
+  recovery_manager.StartRecovery();
+  recovery_manager.WaitForRecoveryToFinish();
+}
+
 void DBMain::ForceShutdown() {
   if (replication_manager_ != DISABLED) {
     GetLogManager()->EndReplication();

src/main/noisepage.cpp

@@ -84,6 +84,7 @@ int main(int argc, char *argv[]) {
 
   db_main_handler_ptr = db_main.get();
 
+  db_main->RecoverSystem();
   db_main->Run();
 
   noisepage::LoggersUtil::ShutDown();