### What problem were solved in this pull request?

Issue Number: close #151 

Problem:
当前在发送消息到客户端时，每个数据都会刷新socket buffer，效率很低

### What is changed and how it works?
实现BufferedWriter，通过buffered
writer将消息缓存在内存中，结果写完时或者buffer满时，才将结果真正的发送到客户端。

### Other information

### What problem were solved in this pull request?

Problem:
当前生成的github pages不太整洁方便，可以优化一下

### What is changed and how it works?
改用mdbook生成文档，并整理文档目录，调整链接

### What problem were solved in this pull request?

Issue Number: close #173 close #136 

ref #174 
ref #165 

Problem:
这个PR修改了多个问题，可以参考各个issue。包括observer编译两次、代码目录规划不合理、command executor未全部实现等

### What is changed and how it works?
做一些重构优化，包括CMakelist、一些代码目录、command executor

### What problem were solved in this pull request?

close issue: #186 

Problem:
实现MVCC代码后没有将持久化代码合并进来

### What is changed and how it works?
支持并发模式下落日志，并在异常停机后回复。

持久化是事务模块中最复杂的功能（没有之一），当前miniob实现的持久化简化了非常多，因此不能依赖持久化能力，仅仅作为一个学习测试的工具，在实际测试时也有一些限制。

### Other information

### What problem were solved in this pull request?

Issue Number: close #192 

Problem:
clang 14编译失败

### What is changed and how it works?
修复编译错误

### Other information

### What problem were solved in this pull request?

Issue Number: ref #165 

Problem:
record_manager 没有比较详细的注释

### What is changed and how it works?
加一些注释

### Other information

### What problem were solved in this pull request?

Issue Number: close #149 

Problem:
RC return code ，定义的东西太多，不太简洁，并且有很多错误码当前没有使用

### What is changed and how it works?
仅使用enum RC 定义错误码，删掉其它枚举定义。
删除当前没有使用的错误码。

### Other information

### What problem were solved in this pull request?

Issue Number: close #91 close #1 

Problem:
编译时编译器抛出的一些告警信息可以帮我们避免很多问题，但是现在并没有利用这个特性

### What is changed and how it works?
CMake中增加-Werror编译选项

### Other information

fix unittest;
add unittest to github action

### What problem were solved in this pull request?

Issue Number: close #176 close #163 

Problem:
单元测试执行失败；
github action 没有单元测试检查

### What problem were solved in this pull request?

Issue Number: close #155 close #135 

Problem:
实现了简单的事务处理。
当前支持并发事务数据.

### What is changed and how it works?
- 支持两种事务模式：Vacuous和MVCC。
  Vacuous 事务模式算是没有事务，它的事务接口什么都不做。
MVCC 是多版本并发控制(Multi-Version Concurrency
Control)，使用多个版本保留记录数据。启动miniob时增加运行时选项 -t mvcc可以选择mvcc。

- MVCC：简单模式的多版本并发控制。
  当前miniob仅包含insert和delete操作，因此数据最多包含两个版本，并且不需要在record中保留版本链表信息；
  不支持持久化；
  没有做垃圾回收；
  遗留一个BUG：在提交时没有保证提交的数据一次性对外可见；
  使用简单的写写冲突策略：检测到要修改的数据当前有人在修改，就回退

- 编译MINIOB时使用 -DCONCURRENCY=ON 才会支持并发
支持各个模块并发处理，包括buffer pool、bplus、record
manager。如果编译时没有使用CONCURRENCY选项，则保持原样，不支持并发，保持系统的简单性。

- 编译时增加 -DDEBUG=ON 还会增加并发调试日志与严格的运行时检测(ASSERT语句)
- 当前版本代码中包含了bplus tree和record manager的并发测试，参考benchmark目录下的代码。

### Other information

Fix problem:
1. the buffer pool and b tree is not thread safe;
2. github/workflow/build does not work

### What is changed and how it works?
1. thread-safe buffer pool
- I use a mutex in buffer pool and take a lock in buffer pool operations
such as allocate frame, dispose frame;
- The frame is locked while updating/reading the content of frame;
- Frame manager take a lock when allocate/free pages.

2. thread-safe b+tree
- Crabing protocol is used to support concurrent

3. github/workflow/build
- update the submodules;
- create a build script and run build.sh in build.yaml

logical plan & physical plan;
explain;
yacc rewrite;
join operator(nested loop join);
simple rewrite rules;
fix some issues of mysql protocol;

tested by mariadb ( Ver 15.1 Distrib 5.5.65-MariaDB, for Linux (x86_64) using readline 5.1)
but failed with obclient

2022 oceanbase competition

* support build with address sanitizer

using cmake options `-DENALBE_ASAN=ON` to enable address sanitizer

* fix some memory leaks detected by asan

* fix -Wunused-function

* 调整文档格式

优化load data效率

format lex file

Docker 中安装gdb；
删除handler.h 文件；
BplusTree中的比较函数使用deps下公用接口；

修复进程退出时，libevent 无法正常结束循环的BUG

remove unused variable

set response to failure while resolve failed