Update:更新有锁获取undologs

Author: Masttf

src/execution/execution_sort.h

@@ -75,7 +75,7 @@ class SortExecutor : public AbstractExecutor {
         }
 
         // 使用std::sort排序
-        parallel::sort(
+        std::sort(
             sorted_tuples_.begin(), sorted_tuples_.end(),
             [this](const std::unique_ptr<RmRecord>& a, const std::unique_ptr<RmRecord>& b) { return this->cmp(a, b); });
     }

src/transaction/transaction_manager.cpp

@@ -523,4 +523,35 @@ void TransactionManager::add_delete_undo_log(Transaction* txn, const int& fd, Ri
     log.prev_version_ = DeleteUpdateVersionLink(fd, rid, txn);
     auto undo_link = txn->AppendUndoLog(log);
     UpdateUndoLink(fd, rid, undo_link);
+}
+
+std::pair<std::vector<UndoLog>, bool> TransactionManager::get_undologs_with_lock(int fd, Rid rid, Transaction *txn) {
+    std::shared_lock<std::shared_mutex> lock(version_info_mutex_);
+    std::vector<UndoLog> undo_logs;
+    auto pre_undo_link = GetUndoLink(fd, rid);
+    
+    // 现在磁盘的是不是被标记删除
+    bool is_deleted = false;
+    if(pre_undo_link.has_value()) {
+        auto undo_log = GetUndoLog(pre_undo_link.value());
+        is_deleted = undo_log.is_deleted_;
+    }
+
+    while (pre_undo_link.has_value()) {
+        auto undo_log = GetUndoLog(pre_undo_link.value());
+        // 如果是自己修改的直接返回
+        if (pre_undo_link.value().prev_txn_ == txn->get_transaction_id()) {
+            break;
+        }
+        // 如果是已提交事物
+        if (undo_log.ts_ <= txn->get_read_ts()) {
+            break;
+        }
+        undo_logs.push_back(undo_log);
+        pre_undo_link = undo_log.prev_version_;
+        if (!pre_undo_link->IsValid()) {
+            break;
+        }
+    }
+    return {undo_logs, is_deleted};
 }

src/transaction/transaction_manager.h

@@ -213,6 +213,8 @@ class TransactionManager {
 
     void do_delete(Transaction *txn);
 
+    std::pair<std::vector<UndoLog>, bool> get_undologs_with_lock(int fd, Rid rid, Transaction *txn);
+
    private:
     /** @brief 检查事务是否可以被垃圾回收 */
     bool is_transaction_expired(Transaction *txn, timestamp_t watermark) const;