p1: update cmake to include more submission files (#691)

* update cmake

* remove page.h from p1 make list

* tidy up files

* update cow_buffer comment

* fix format

* p2 -> p1

* sync with private

* remove unnecessary header

* rename CoW buffer to write back cache

* remove references to CoW buffer

* update header order

---------

Co-authored-by: Zixi An <[email protected]>
Co-authored-by: xx01cyx <[email protected]>

CMakeLists.txt

@@ -275,6 +275,8 @@ set(P1_FILES
         "src/buffer/buffer_pool_manager.cpp"
         "src/include/storage/disk/disk_scheduler.h"
         "src/storage/disk/disk_scheduler.cpp"
+        "src/storage/page/page_guard.cpp"
+        "src/include/storage/page/page_guard.h"
 )
 add_custom_target(check-clang-tidy-p1
         ${BUSTUB_BUILD_SUPPORT_DIR}/run_clang_tidy.py # run LLVM's clang-tidy script

src/include/buffer/buffer_pool_manager.h

@@ -20,8 +20,8 @@
 #include "buffer/lru_k_replacer.h"
 #include "common/config.h"
 #include "recovery/log_manager.h"
-#include "storage/disk/cow_buffer.h"
 #include "storage/disk/disk_scheduler.h"
+#include "storage/disk/write_back_cache.h"
 #include "storage/page/page.h"
 #include "storage/page/page_guard.h"
 
@@ -73,7 +73,7 @@ class BufferPoolManager {
   auto NewPage(page_id_t *page_id) -> Page *;
 
   /**
-   * TODO(P2): Add implementation
+   * TODO(P1): Add implementation
    *
    * @brief PageGuard wrapper for NewPage
    *
@@ -106,7 +106,7 @@ class BufferPoolManager {
   auto FetchPage(page_id_t page_id, AccessType access_type = AccessType::Unknown) -> Page *;
 
   /**
-   * TODO(P2): Add implementation
+   * TODO(P1): Add implementation
    *
    * @brief PageGuard wrappers for FetchPage
    *
@@ -194,7 +194,7 @@ class BufferPoolManager {
   /** This latch protects shared data structures. We recommend updating this comment to describe what it protects. */
   std::mutex latch_;
   /** This buffer is for the leaderboard task. You may want to use it to optimize the write requests. */
-  CoWBuffer cow_buffer_ __attribute__((__unused__));
+  WriteBackCache write_back_cache_ __attribute__((__unused__));
 
   /**
    * @brief Allocate a page on disk. Caller should acquire the latch before calling this function.

src/include/storage/disk/cow_buffer.h → src/include/storage/disk/write_back_cache.h

@@ -21,20 +21,20 @@
 namespace bustub {
 
 /**
- * CoWBuffer provides extra memory space other than the buffer pool to store the copy-on-write pages.
+ * WriteBackCache provides extra memory space other than the buffer pool to store the copy-on-write pages.
  * It's purpose is to gather the copy of pages that are about to be written back to disk, so that the bpm
  * doesn't have to incur IO penality and wait for the write to be completed when evicting.
  * Spring 24: The buffer is limited to store a constant number of pages in total (8).
  * !! ANY ATTEMPTS TO ADD ANOTHER IN-MEMORY CACHE WILL BE REVIEWED MANUALLY AS PER LEADERBOARD POLICY !!
  */
-class CoWBuffer {
+class WriteBackCache {
  public:
-  CoWBuffer() : cow_pages_{new Page[8]} {}
-  ~CoWBuffer() { delete[] cow_pages_; }
-  DISALLOW_COPY_AND_MOVE(CoWBuffer);
+  WriteBackCache() : write_back_pages_{new Page[8]} {}
+  ~WriteBackCache() { delete[] write_back_pages_; }
+  DISALLOW_COPY_AND_MOVE(WriteBackCache);
 
   /**
-   * @brief Adds a new page to the CoW buffer.
+   * @brief Adds a new page to the write back cache.
    * @param page the page pointer from the bpm that is about to be evicted.
    * @return pointer to the copied page in the buffer, or nullptr if the buffer is full.
    */
@@ -44,19 +44,19 @@ class CoWBuffer {
     }
 
     uint32_t slot = FindFreeSlot();
-    memcpy(cow_pages_[slot].GetData(), page->GetData(), BUSTUB_PAGE_SIZE);
+    memcpy(write_back_pages_[slot].GetData(), page->GetData(), BUSTUB_PAGE_SIZE);
     MarkSlotUsed(slot);
 
-    return cow_pages_ + slot;
+    return write_back_pages_ + slot;
   }
 
   /**
-   * @brief Removes a page from the CoW buffer.
+   * @brief Removes a page from the write back cache.
    * @param page the pointer previously returned by Add.
    */
   auto Remove(Page *page) -> void {
     if (page != nullptr) {
-      MarkSlotFree(page - cow_pages_);
+      MarkSlotFree(page - write_back_pages_);
     }
   }
 
@@ -66,7 +66,7 @@ class CoWBuffer {
 
   /** @brief Finds a free slot in the buffer, if not full. */
   auto FindFreeSlot() -> uint32_t {
-    BUSTUB_ASSERT(!IsFull(), "no free slot in cow buffer");
+    BUSTUB_ASSERT(!IsFull(), "no free slot in write back cache");
     uint32_t i = 0;
     uint8_t bitmap = free_slot_bitmap_;
     while ((bitmap & 1U) != 0) {
@@ -88,8 +88,8 @@ class CoWBuffer {
     free_slot_bitmap_ &= ~(1U << slot);
   }
 
-  /** The array of CoW buffer pages. */
-  Page *cow_pages_;
+  /** The array of write back cache pages. */
+  Page *write_back_pages_;
   /** The bitmap that records which slots are free. */
   uint8_t free_slot_bitmap_{0};
 };

test/storage/cow_buffer_test.cpp → test/storage/write_back_cache_test.cpp

@@ -10,46 +10,46 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "storage/disk/cow_buffer.h"
+#include "storage/disk/write_back_cache.h"
 #include "gtest/gtest.h"
 
 namespace bustub {
 
 // NOLINTNEXTLINE
-TEST(CoWBufferTest, ScheduleWriteReadPageTest) {
-  CoWBuffer cow{};
-  std::vector<Page *> cow_pages{};
+TEST(WriteBackCacheTest, ScheduleWriteReadPageTest) {
+  WriteBackCache wbc{};
+  std::vector<Page *> wbc_pages{};
   for (size_t i{0}; i < 8; i++) {
     Page bpm_page{};
     auto content{"Meuh!: " + std::to_string(i) + " 🐄🐄🐄🐄"};
     std::strncpy(bpm_page.GetData(), content.data(), BUSTUB_PAGE_SIZE);
 
-    Page *cow_page{cow.Add(&bpm_page)};
-    EXPECT_NE(cow_page, nullptr);
-    EXPECT_NE(cow_page, &bpm_page);
-    cow_pages.push_back(cow_page);
-    EXPECT_EQ(std::memcmp(cow_page->GetData(), bpm_page.GetData(), BUSTUB_PAGE_SIZE), 0);
+    Page *wbc_page{wbc.Add(&bpm_page)};
+    EXPECT_NE(wbc_page, nullptr);
+    EXPECT_NE(wbc_page, &bpm_page);
+    wbc_pages.push_back(wbc_page);
+    EXPECT_EQ(std::memcmp(wbc_page->GetData(), bpm_page.GetData(), BUSTUB_PAGE_SIZE), 0);
   }
 
   Page extra_page{};
-  Page *cow_extra_page{cow.Add(&extra_page)};
-  EXPECT_EQ(cow_extra_page, nullptr);
+  Page *wbc_extra_page{wbc.Add(&extra_page)};
+  EXPECT_EQ(wbc_extra_page, nullptr);
 
   for (size_t i{0}; i < 8; i++) {
     auto check{"Meuh!: " + std::to_string(i) + " 🐄🐄🐄🐄"};
-    EXPECT_EQ(std::memcmp(cow_pages[i]->GetData(), check.data(), check.size()), 0);
+    EXPECT_EQ(std::memcmp(wbc_pages[i]->GetData(), check.data(), check.size()), 0);
   }
 
-  cow.Remove(cow_pages[5]);
+  wbc.Remove(wbc_pages[5]);
   Page replace_page{};
-  cow_pages[5] = cow.Add(&replace_page);
-  EXPECT_NE(cow_pages[5], nullptr);
+  wbc_pages[5] = wbc.Add(&replace_page);
+  EXPECT_NE(wbc_pages[5], nullptr);
 
   for (size_t i{0}; i < 8; i++) {
-    cow.Remove(cow_pages[i]);  // Shouldn't crash.
+    wbc.Remove(wbc_pages[i]);  // Shouldn't crash.
   }
 
-  cow.Remove(nullptr);  // Shouldn't crash.
+  wbc.Remove(nullptr);  // Shouldn't crash.
 }
 
 }  // namespace bustub