buffer pool manager passed Memory River Test

bpt/include/bpt/bpt_page.hpp

@@ -2,9 +2,8 @@
 #define BPT_PAGE_HPP
 #include <utility>
 #include "bpt/config.h"
-#pragma pack(push, 1)
 template <typename KeyType, size_t kPageSize = 4096>
-class BPlusTreePage {
+struct ActualDataType {
   typedef std::pair<KeyType, default_numeric_index_t> value_type;
   page_id_t p_n;
   page_id_t p_parent;
@@ -13,8 +12,15 @@ class BPlusTreePage {
   const static size_t kMaxKeyCount =
       (kPageSize - sizeof(page_id_t) * 2 - sizeof(uint8_t) - sizeof(uint16_t)) / sizeof(value_type);
   value_type p_data[kMaxKeyCount];
-  char filler[kPageSize - sizeof(page_id_t) * 2 - sizeof(uint8_t) - sizeof(uint16_t) -
-              sizeof(value_type) * kMaxKeyCount];
 };
-#pragma pack(pop)
+template <typename KeyType, size_t kPageSize = 4096>
+union BPlusTreePage {
+  inline BPlusTreePage() {}
+  inline BPlusTreePage &operator=(const BPlusTreePage &that) {
+    memcpy(this, &that, sizeof(BPlusTreePage));
+    return *this;
+  }
+  ActualDataType<KeyType, kPageSize> data;
+  char filler[kPageSize];
+};
 #endif  // BPT_PAGE_H

bpt/include/bpt/buffer_pool_manager.h

@@ -362,6 +362,10 @@ class BufferPoolManager {
 
   /**
    * @brief Flush all the pages in the buffer pool to disk.
+   *
+   * @warning The buffer pool manager will automatically call FlushAllPages before being destroyed, but if the disk
+   * manager is closed, it will do nothing. And Page Guard should be destroyed before Buffer Pool Manager, Buffer Pool
+   * Manager should be destroyed before Disk Manager.
    */
   void FlushAllPages();
 

bpt/include/bpt/disk_manager.h

@@ -2,7 +2,7 @@
 #define DISK_MANAGER_H
 #include <cstdio>
 #include <string>
-#include "config.h"
+#include "bpt/config.h"
 class DiskManager {
   /**
    * The Data Structure on Disk: