rollback(savepoint) in AbstractConnectionProxy work unexpected

[caohdgege]

• I have searched the issues of this repository and believe that this is not a duplicate.

Ⅰ. Issue Description

rollback(savepoint) in AbstractConnectionProxy should not only call targetConnection.rollback(savepoint), but also need to delete the lockKeysBuffer and sqlUndoItemsBuffer of this savepoint life cycle.
If you want to fix it, please comment "Please assign it to me" in this issue.

rollback(savepoint) 除了要执行targetConnection.rollback(savepoint)，还要删除这个savepoint期间对应的lockKeysBuffer和sqlUndoItemsBuffer。
如果有靓仔靓女想要帮忙修复这个的话，请留言 "Please assign it to me"

Ⅱ. Describe what happened

Ⅲ. Describe what you expected to happen

能够正常删除这个savepoint期间对应的lockKeysBuffer和sqlUndoItemsBuffer
或者明确抛出异常说明不支持 savepoint

[neighbor-uncleWang]

My plan：Get the connection context of the dataSourceProxy and clear the cache directly from the context as shown in the figure.I'm not sure if I'm doing it right, please give me an idea of implementation.
我的计划：获得dataSourceProxy的ConnectionContext，然后直接清空ConnectionContext中的缓存，做法如图。我不敢确定我的做法是否正确，请给我一个实现思想。

[neighbor-uncleWang]

Please assign it to me

[caohdgege]

图裂了，能不能直接贴一下文字版？(最近github上面的图片都看不了。。。。)

[neighbor-uncleWang]

这个写法
@OverRide
public void rollback(Savepoint savepoint) throws SQLException {
targetConnection.rollback(savepoint);
try {
ConnectionContext connectionContext = dataSourceProxy.getConnection().getContext();
//Clear the cache
connectionContext.getUndoItems().clear();
connectionContext.getLockKeysBuffer().clear();
}catch (Exception e){
throw new UnsupportedOperationException("failed to empty sqlUndoItemsBuffer and lockKeysBuffer,does not support Savepoint."+e.getMessage());
}
}

[caohdgege]

不能这样删，你这样就相当于删除了整个分支事务的undo_item和lock_key_buffer了。
我的思路是要记录undo_item和lock_key_buffer对应的是哪个分支事务，然后rollback(savepoint)的时候把这些clear，如果是releaseSavepoint(savepoint)的时候，把后面的savepoint对应的undo_item和lock_key_buffer挪到上一个savepoint上。

[neighbor-uncleWang]

好的，了解

[neighbor-uncleWang]

抱歉，到年底了，开发工作繁重，没有时间完成这个issues。

[caohdgege]

抱歉，到年底了，开发工作繁重，没有时间完成这个issues。

OK，那我处理一下这个。