Fix starter code for p1 (cmu-db#167)

jkosh44 · web-flow · commit 99f002c74e85 · 2021-09-05T21:39:48.000-04:00
diff --git a/src/buffer/buffer_pool_manager_instance.cpp b/src/buffer/buffer_pool_manager_instance.cpp
@@ -12,8 +12,6 @@
 
 #include "buffer/buffer_pool_manager_instance.h"
 
-#include <list>
-
 #include "common/macros.h"
 
 namespace bustub {
@@ -89,7 +87,8 @@ void BufferPoolManagerInstance::FlushAllPagesImpl() {
 }
 
 page_id_t BufferPoolManagerInstance::AllocatePage() {
-  const page_id_t next_page_id = next_page_id_ += num_instances_;
+  const page_id_t next_page_id = next_page_id_;
+  next_page_id_ += num_instances_;
   ValidatePageId(next_page_id);
   return next_page_id;
 }
diff --git a/src/buffer/parallel_ buffer_pool_manager.cpp b/src/buffer/parallel_ buffer_pool_manager.cpp
@@ -12,8 +12,6 @@
 
 #include "buffer/parallel_buffer_pool_manager.h"
 
-#include <list>
-
 namespace bustub {
 
 ParallelBufferPoolManager::ParallelBufferPoolManager(size_t num_instances, size_t pool_size, DiskManager *disk_manager,
diff --git a/src/include/storage/page/page.h b/src/include/storage/page/page.h
@@ -27,7 +27,7 @@ namespace bustub {
  */
 class Page {
   // There is book-keeping information inside the page that should only be relevant to the buffer pool manager.
-  friend class BufferPoolManager;
+  friend class BufferPoolManagerInstance;
 
  public:
   /** Constructor. Zeros out the page data. */
diff --git a/test/buffer/parallel_buffer_pool_manager_test.cpp b/test/buffer/parallel_buffer_pool_manager_test.cpp
@@ -117,24 +117,31 @@ TEST(ParallelBufferPoolManagerTest, DISABLED_SampleTest) {
     EXPECT_EQ(nullptr, bpm->NewPage(&page_id_temp));
   }
 
-  // Scenario: After unpinning pages {0, 1, 2, 3, 4} and pinning another 4 new pages,
-  // there would still be one buffer page left for reading page 0.
+  // Write world out to page 4
+  auto page4 = bpm->FetchPage(4);
+  snprintf(page4->GetData(), PAGE_SIZE, "World");
+  EXPECT_EQ(0, strcmp(page4->GetData(), "World"));
+  bpm->UnpinPage(4, true);
+
+  // Scenario: After unpinning pages {0, 1, 2, 3, 4} and pinning pages {0, 1, 2, 3},
+  // there would still be one buffer page left for reading page 4.
+
   for (int i = 0; i < 5; ++i) {
     EXPECT_EQ(true, bpm->UnpinPage(i, true));
   }
   for (int i = 0; i < 4; ++i) {
-    EXPECT_NE(nullptr, bpm->NewPage(&page_id_temp));
+    EXPECT_NE(nullptr, bpm->FetchPage(i));
   }
 
   // Scenario: We should be able to fetch the data we wrote a while ago.
-  page0 = bpm->FetchPage(0);
-  EXPECT_EQ(0, strcmp(page0->GetData(), "Hello"));
+  page4 = bpm->FetchPage(4);
+  EXPECT_EQ(0, strcmp(page4->GetData(), "World"));
 
-  // Scenario: If we unpin page 0 and then make a new page, all the buffer pages should
-  // now be pinned. Fetching page 0 should fail.
-  EXPECT_EQ(true, bpm->UnpinPage(0, true));
+  // Scenario: If we unpin page 4 and then make a new page, all the buffer pages should
+  // now be pinned. Fetching page 4 should fail.
+  EXPECT_EQ(true, bpm->UnpinPage(4, true));
   EXPECT_NE(nullptr, bpm->NewPage(&page_id_temp));
-  EXPECT_EQ(nullptr, bpm->FetchPage(0));
+  EXPECT_EQ(nullptr, bpm->FetchPage(4));
 
   // Shutdown the disk manager and remove the temporary file we created.
   disk_manager->ShutDown();

Original file line number	Diff line number	Diff line change
`@@ -12,8 +12,6 @@`
`12`	`12`
`13`	`13`	`#include "buffer/buffer_pool_manager_instance.h"`
`14`	`14`
`15`		`-#include <list>`
`16`		`-`
`17`	`15`	`#include "common/macros.h"`
`18`	`16`
`19`	`17`	`namespace bustub {`
`@@ -89,7 +87,8 @@ void BufferPoolManagerInstance::FlushAllPagesImpl() {`
`89`	`87`	`}`
`90`	`88`
`91`	`89`	`page_id_t BufferPoolManagerInstance::AllocatePage() {`
`92`		`- const page_id_t next_page_id = next_page_id_ += num_instances_;`
	`90`	`+ const page_id_t next_page_id = next_page_id_;`
	`91`	`+ next_page_id_ += num_instances_;`
`93`	`92`	`ValidatePageId(next_page_id);`
`94`	`93`	`return next_page_id;`
`95`	`94`	`}`