fix(tools): flush when draw to file, stop when cin is invalid (#425)

Signed-off-by: Alex Chi <[email protected]>

Author: skyzh

src/storage/index/b_plus_tree.cpp

@@ -166,6 +166,7 @@ void BPLUSTREE_TYPE::Draw(BufferPoolManager *bpm, const std::string &outf) {
   out << "digraph G {" << std::endl;
   ToGraph(reinterpret_cast<BPlusTreePage *>(bpm->FetchPage(root_page_id_)->GetData()), bpm, out);
   out << "}" << std::endl;
+  out.flush();
   out.close();
 }
 

tools/b_plus_tree_printer/b_plus_tree_printer.cpp

@@ -25,10 +25,10 @@ using bustub::DiskManager;
 using bustub::Exception;
 using bustub::GenericComparator;
 using bustub::GenericKey;
-using bustub::RID;
-using bustub::Transaction;
 using bustub::page_id_t;
 using bustub::ParseCreateStatement;
+using bustub::RID;
+using bustub::Transaction;
 
 auto UsageMessage() -> std::string {
   std::string message =
@@ -84,6 +84,9 @@ auto main(int argc, char **argv) -> int {
   while (!quit) {
     std::cout << "> ";
     std::cin >> instruction;
+    if (!std::cin) {
+      break;
+    }
     switch (instruction) {
       case 'c':
         std::cin >> filename;