Revert:优化hash

Author: Masttf

src/common/config.h

@@ -37,7 +37,7 @@ static constexpr int HEADER_PAGE_ID = 0;                 // the header page id
 static constexpr int PAGE_SIZE = 4096;                   // size of a data page in byte  4KB
 static constexpr int BUFFER_POOL_SIZE = 1024 * 256 / 8;  // size of buffer pool 256MB
 // static constexpr int BUFFER_POOL_SIZE = 1024 * 256 / 4;  // size of buffer pool 4GB
-static constexpr int BUFFER_POOL_INSTANCE_SIZE = 8;         // size of buffer pool instance
+static constexpr int BUFFER_POOL_INSTANCE_SIZE = 1;         // size of buffer pool instance
 static constexpr int LOG_BUFFER_SIZE = (1024 * PAGE_SIZE);  // size of a log buffer in byte
 static constexpr int BUCKET_SIZE = 50;                      // size of extendible hash bucket
 

src/storage/buffer_pool_manager.cpp

@@ -13,9 +13,7 @@ See the Mulan PSL v2 for more details. */
 extern DiskManager disk_manager;
 
 size_t BufferPoolManager::get_instance_no(const PageId& page_id) const {
-    // return hasher_(page_id) % BUFFER_POOL_INSTANCE_SIZE;
-    //! 八个缓冲区的
-    return hasher_(page_id) & 0x7;
+    return std::hash<PageId>{}(page_id) % BUFFER_POOL_INSTANCE_SIZE;
 }
 
 /**

src/storage/buffer_pool_manager.h

@@ -32,13 +32,6 @@ class BufferPoolManager {
    private:
     size_t pool_size_;                                                      // 缓冲池大小（帧数）
     BufferPoolInstance* buffer_pool_instances_[BUFFER_POOL_INSTANCE_SIZE];  // 缓冲池实例数组
-    
-    struct PageIdHash {
-        size_t operator()(const PageId &pid) const {
-            return static_cast<size_t>(pid.fd) * 131 + static_cast<size_t>(pid.page_no);
-        }
-    };
-    PageIdHash hasher_;  // 哈希函数，用于计算PageId的哈希值
 
    public:
     BufferPoolManager(size_t pool_size) : pool_size_(pool_size) {

src/transaction/transaction_manager.cpp

@@ -177,9 +177,7 @@ void TransactionManager::abort(Context* context) {
 }
 
 auto TransactionManager::GetVersionInfoShard(const PageId& page_id) -> PageVersionInfoShard& {
-    // return version_info_shards_[hasher_(page_id) % VERSION_INFO_SHARDS];
-    //256个分片，使用哈希函数计算页ID的哈希值并取模
-    return version_info_shards_[hasher_(page_id) & 0xFF];
+    return version_info_shards_[std::hash<PageId>{}(page_id) % VERSION_INFO_SHARDS];
 }
 
 /**

src/transaction/transaction_manager.h

@@ -42,13 +42,6 @@ class TransactionManager {
     // 保护事务表的读写锁
     std::shared_mutex txn_map_mutex_;
 
-    struct PageIdHash {
-        size_t operator()(const PageId &pid) const {
-            return static_cast<size_t>(pid.fd) * 131 + static_cast<size_t>(pid.page_no);
-        }
-    };
-    PageIdHash hasher_;  // 哈希函数，用于计算PageId的哈希值
-
     // std::mutex commit_mutex_;  // 用于提交事务时的互斥锁
 
     /**