From 2dabd8189e1bc70b5e9ad340b925bb1915e062d3 Mon Sep 17 00:00:00 2001
From: Connor Tsui <connor.tsui20@gmail.com>
Date: Tue, 3 Sep 2024 20:36:15 -0400
Subject: [PATCH] no default values and clean up some docs

---
 src/buffer/buffer_pool_manager.cpp       | 26 +++++++++++++++++-------
 src/include/buffer/buffer_pool_manager.h | 21 ++++++-------------
 2 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/src/buffer/buffer_pool_manager.cpp b/src/buffer/buffer_pool_manager.cpp
index f0c1fc899..ae1f717f4 100644
--- a/src/buffer/buffer_pool_manager.cpp
+++ b/src/buffer/buffer_pool_manager.cpp
@@ -30,7 +30,10 @@ namespace bustub {
  */
 BufferPoolManager::BufferPoolManager(size_t pool_size, DiskManager *disk_manager, size_t replacer_k,
                                      LogManager *log_manager)
-    : pool_size_(pool_size), disk_scheduler_(std::make_unique<DiskScheduler>(disk_manager)), log_manager_(log_manager) {
+    : next_page_id_(0),
+      pool_size_(pool_size),
+      disk_scheduler_(std::make_unique<DiskScheduler>(disk_manager)),
+      log_manager_(log_manager) {
   // TODO(students): remove this line after you have implemented the buffer pool manager
   throw NotImplementedException(
       "BufferPoolManager is not implemented yet. If you have finished implementing BPM, please remove the throw "
@@ -180,11 +183,25 @@ auto BufferPoolManager::FlushPage(page_id_t page_id) -> bool { return false; }
  */
 void BufferPoolManager::FlushAllPages() {}
 
+/**
+ * @brief Deallocates a page on disk. The caller should acquire the `BufferPoolManager` latch before calling this
+ * function.
+ *
+ * Note: You should look at the documentation for `DeletePage` before using this method.
+ * Also note: This is a no-op without a more complex data structure to track deallocated pages.
+ *
+ * @param page_id The page ID of the page to deallocate from disk.
+ */
+void BufferPoolManager::DeallocatePage(page_id_t page_id) {}
+
 /**********************************************************************************************************************/
 /**********************************************************************************************************************/
 /**********************************************************************************************************************/
 
-// TODO(2024 tas) Remove this function from the rest of the BusTub.
+// Below there be dragons...
+
+// TODO(2024 tas) Remove these function from the rest of the BusTub.
+
 auto BufferPoolManager::FetchPageRead(page_id_t page_id, AccessType access_type) -> ReadPageGuard {
   auto guard_opt = ReadPage(page_id, access_type);
   BUSTUB_ASSERT(guard_opt.has_value(), "TODO(2024 tas) Using deprecated `FetchPageRead`");
@@ -193,7 +210,6 @@ auto BufferPoolManager::FetchPageRead(page_id_t page_id, AccessType access_type)
   return std::move(guard_opt).value();
 }
 
-// TODO(2024 tas) Remove this function from the rest of the BusTub.
 auto BufferPoolManager::FetchPageWrite(page_id_t page_id, AccessType access_type) -> WritePageGuard {
   auto guard_opt = WritePage(page_id, access_type);
   BUSTUB_ASSERT(guard_opt.has_value(), "TODO(2024 tas) Using deprecated `FetchPageWrite`");
@@ -203,8 +219,6 @@ auto BufferPoolManager::FetchPageWrite(page_id_t page_id, AccessType access_type
 }
 
 /**
- * TODO(cjtsui): This entire function should probably be removed.
- *
  * @brief Fetch the requested page from the buffer pool. Return nullptr if page_id needs to be fetched from the disk
  * but all frames are currently in use and not evictable (in another word, pinned).
  *
@@ -224,8 +238,6 @@ auto BufferPoolManager::FetchPage(page_id_t page_id, [[maybe_unused]] AccessType
 }
 
 /**
- * TODO(cjtsui): This entire function should probably be removed.
- *
  * @brief Unpin the target page from the buffer pool. If page_id is not in the buffer pool or its pin count is already
  * 0, return false.
  *
diff --git a/src/include/buffer/buffer_pool_manager.h b/src/include/buffer/buffer_pool_manager.h
index ec1d5b7d8..82287f1dc 100644
--- a/src/include/buffer/buffer_pool_manager.h
+++ b/src/include/buffer/buffer_pool_manager.h
@@ -50,12 +50,12 @@ class BufferPoolManager {
   auto UnpinPage(page_id_t page_id, bool is_dirty, AccessType access_type = AccessType::Unknown) -> bool;
 
  private:
+  /** @brief The next page ID to be allocated.  */
+  std::atomic<page_id_t> next_page_id_;
+
   /** @brief The number of frames in the buffer pool. */
   const size_t pool_size_;
 
-  /** @brief The next page ID to be allocated.  */
-  std::atomic<page_id_t> next_page_id_ = 0;
-
   /**
    * @brief The latch protecting most of the `BufferPoolManager`'s shared data structures.
    *
@@ -96,18 +96,9 @@ class BufferPoolManager {
    */
   LogManager *log_manager_ __attribute__((__unused__));
 
-  /**
-   * @brief Deallocates a page on disk. The caller should acquire the `BufferPoolManager` latch before calling this
-   * function.
-   *
-   * Note: You should look at the documentation for `DeletePage` before using this method.
-   *
-   * @param page_id The page ID of the page to deallocate from disk.
-   */
-  void DeallocatePage(__attribute__((unused)) page_id_t page_id) {
-    // Note that this is a no-op without a more complex data structure to track deallocated pages.
-  }
+  // TODO(cjtsui) this should probably be a method on the disk scheduler.
+  void DeallocatePage(page_id_t page_id);
 
-  /** TODO(student): You may add additional private members and helper functions */
+  /** TODO(student): You may add additional private members and helper functions. */
 };
 }  // namespace bustub