| /** |
| * Copyright 2011-2015 Quickstep Technologies LLC. |
| * Copyright 2015-2016 Pivotal Software, Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| **/ |
| |
| #ifndef QUICKSTEP_STORAGE_STORAGE_BLOCK_BASE_HPP_ |
| #define QUICKSTEP_STORAGE_STORAGE_BLOCK_BASE_HPP_ |
| |
| #include <atomic> |
| #include <cstddef> |
| |
| #include "storage/StorageBlockInfo.hpp" |
| #include "utility/Macros.hpp" |
| |
| #include "glog/logging.h" |
| |
| namespace quickstep { |
| |
| /** |
| * @brief Abstract base class which encompasses functionality common to |
| * StorageBlock and StorageBlob. |
| **/ |
| class StorageBlockBase { |
| public: |
| /** |
| * @brief Virtual destructor. |
| **/ |
| virtual ~StorageBlockBase() { |
| #ifdef QUICKSTEP_DEBUG |
| CHECK_EQ(0, getRefCount()) |
| << "Nonzero ref_count_ when deleting block (" |
| << BlockIdUtil::Domain(id_) << ", " |
| << BlockIdUtil::Counter(id_) << ")"; |
| #endif |
| } |
| |
| /** |
| * @brief Determine if this is a StorageBlob or StorageBlock. |
| * |
| * @return true if this is a StorageBlob, false if it is a StorageBlock. |
| **/ |
| virtual bool isBlob() const = 0; |
| |
| /** |
| * @brief Get this block's block_id. |
| * |
| * @return This block's ID. |
| **/ |
| inline block_id getID() const { |
| return id_; |
| } |
| |
| /** |
| * @brief Check whether this block is dirty (whether it has been changed |
| * since being written to disk). |
| * |
| * @return Whether the block is dirty. |
| **/ |
| inline bool isDirty() const { |
| return dirty_; |
| } |
| |
| /** |
| * @brief Clear the dirty bit for this block, marking it as clean. |
| **/ |
| inline void markClean() { |
| dirty_ = false; |
| } |
| |
| #ifdef QUICKSTEP_DEBUG |
| /** |
| * @brief Atomically increment the reference count for this StorageBlockBase. |
| **/ |
| void ref() const { |
| ++ref_count_; |
| } |
| |
| /** |
| * @brief Atomically decrement the reference count for this StorageBlockBase. |
| **/ |
| void unref() const { |
| CHECK_GE(--ref_count_, 0) |
| << "unref() of block (" |
| << BlockIdUtil::Domain(id_) << ", " |
| << BlockIdUtil::Counter(id_) << ") " |
| << "caused reference count to become negative."; |
| } |
| |
| /** |
| * @brief Atomically get the reference count of this block. |
| * @return This block's reference count. |
| **/ |
| int getRefCount() const { |
| return ref_count_.load(); |
| } |
| #endif |
| |
| protected: |
| StorageBlockBase(const block_id id, |
| void *block_memory, |
| const std::size_t block_memory_size) |
| : id_(id), |
| dirty_(false), |
| block_memory_(block_memory), |
| block_memory_size_(block_memory_size) |
| #ifdef QUICKSTEP_DEBUG |
| , ref_count_(0) // Initialize the atomic using direct initialization. |
| #endif |
| { // We are breaking the style guidelines to call direct initialization |
| // on the atomic variable only when compiled with QUICKSTEP_DEBUG defined. |
| } |
| |
| const block_id id_; |
| bool dirty_; |
| |
| void *block_memory_; |
| const std::size_t block_memory_size_; |
| |
| private: |
| #ifdef QUICKSTEP_DEBUG |
| mutable std::atomic_int ref_count_; |
| #endif |
| |
| DISALLOW_COPY_AND_ASSIGN(StorageBlockBase); |
| }; |
| |
| } // namespace quickstep |
| |
| #endif // QUICKSTEP_STORAGE_STORAGE_BLOCK_BASE_HPP_ |