说明:

  • parser 模块

https://docs.qq.com/sheet/DSlBwS3VCb01kTnZw?tab=BB08J2&confirmed=1

https://docs.qq.com/sheet/DSlBwS3VCb01kTnZw?tab=BB08J2

https://github.com/pingcap/blog

https://github.com/pingcap/tidb/issues/20804

https://github.com/pingcap/tidb/issues/20804#sig/DDL

基本操作parser

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https://github.com/watchpoints/parser
https://github.com/pingcap/parser
git reset --hard origin/master // git 放弃本地修改 强制更新
git remote add upstream //https://github.com/pingcap/parser.git
#切换到主分支
git checkout master
git fetch upstream
git merge upstream/master
git push origin master
git checkout dev_study

git@github.com:watchpoints/parser.git	
git remote -v 
git checkout -b wangchuanyi

使用tiup 部署集群

vpn 环境

准备

  1. 使用tiup 部署集群
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cd /data/tidb/tiup
tiup cluster deploy tidb-test  v5.0.2 ./topology1.yaml --user root -p ##部署

root@money:/data/tidb/tiup# cat topology1.yaml
# # Global variables are applied to all deployments and used as the default value of
# # the deployments if a specific deployment value is missing.
global:
 user: "tidb"
 ssh_port: 29761
 deploy_dir: "/data/tidb/tiup/tidb-deploy"
 data_dir: "/data/tidb/tiup/tidb-data"

# # Monitored variables are applied to all the machines.
monitored:
 node_exporter_port: 9100
 blackbox_exporter_port: 9115

server_configs:
 tidb:
   log.slow-threshold: 300
 tikv:
   readpool.storage.use-unified-pool: false
   readpool.coprocessor.use-unified-pool: true
 pd:
   replication.enable-placement-rules: true
 tiflash:
   logger.level: "info"

pd_servers:
 - host: 127.0.0.1

tidb_servers:
 - host: 127.0.0.1

tikv_servers:
 - host: 127.0.0.1
   port: 20170
   status_port: 20180




monitoring_servers:
 - host: 127.0.0.1

grafana_servers:
 - host: 127.0.0.1
 
 
tiup cluster list ##查询

tiup cluster display tidb-test  ##查询
tiup cluster start tidb-test ##启动
tiup cluster stop tidb-test


cd /data/tidb/tiup/tidb-deploy/tidb-4000/bin


## 对之前部署tidb-test集群进行参数 
tiup cluster edit-config  tidb-test
tiup cluster reload  tidb-test

# TiDB 集群可以在不中断线上服务的情况下进行扩容和缩容。
## 执行扩容命令  https://docs.pingcap.com/zh/tidb/dev/scale-tidb-using-tiup
tiup cluster scale-out tidb-test scale-out.yaml
ssh-keygen //设置 SSH 通过密钥登录

## 缩容 TiDB/PD/TiKV 节点 
画外音:配置太低,需要缩容

tiup cluster display  tidb-test
tiup cluster scale-in tidb-test --node 127.0.0.1:4001
提示:Scaled cluster `tidb-test` in successfully
查看 /data/tidb/tiup/tidb-deploy 目录 tidb-4001 已经被删除

https://asktug.com/t/topic/36950
  1. 编译源码

tidb

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## go 
https://golang.google.cn/dl/
cd /Users/wangchuanyi/local


### tidb
git clone https://github.com/pingcap/tidb.git
cd /Users/wangchuanyi/code/src/github.com/watchpoints/tidb
make

./tidb-server -V 
Release Version: v4.0.0-beta.2-949-g3f38fa5d0-dirty
Edition: Community
Git Commit Hash: 3f38fa5d02b618666efce714be129b1afacd582d
Git Branch: master



 git remote add  wangchuanyi https://github.com/pingcap/tidb.git
 git remote -v
 

//切换到本地分支


git checkout -b wangchuanyi

//下载远程代码
git fetch wangchuanyi
//合并master到自己分支

git merge wangchuanyi/master
//合并upstream的master
// 提交远程master分支代码
 git push origin master
 
 http://senzhangai.github.io/programming/build-tidb-by-source
  git remote -v
  
 
 
 取代默认tidb:
 
 data/tidb/tiup/tidb-deploy/tidb-4000/bin
 
 

## vpn环境

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# vpn环境
## go环境
cd /root/local
https://golang.google.cn/dl/go1.16.5.linux-amd64.tar.gz
tar -xvf go1.16.5.linux-amd64.tar.gz 

## tidb
cd /data/tidb/src/github.com/watchpoints/tidb
git clone https://github.com/pingcap/tidb.git

git remote add  wangchuanyi https://github.com/pingcap/tidb.git


git fetch wangchuanyi
git merge wangchuanyi/master
git push origin master
 

make 

替换成自己编译

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### tidb 
cp /data/tidb/src/github.com/watchpoints/tidb/bin/tidb-server  /data/tidb/tiup/tidb-deploy/tidb-4000/bin/tidb-server 

tiup cluster destroy tidb-test
tiup cluster stop tidb-test
tiup cluster start tidb-test 
tiup cluster display tidb-test 


https://asktug.com/t/topic/34904/22

5 步:查看 TiUP 管理的集群情况

tiup cluster deploy tidb-test v5.0.2 ./topology1.yaml --user root -p 


tiup cluster list
tiup cluster display tidb-test

连接:

mysql -h 127.0.0.1 -P 4000 -u root -D test

Cdmysql

设置密码: mysql -h 127.0.0.1 -P 4000 -u root

SET PASSWORD FOR ‘root’@’%’ = ‘123456’

mysql -h 127.0.0.1 -P 4000 -u root -p

如何单元测试

go test -check.f $TEST_NAME 来指定测试用例

## Q1之前根本没接触过parser,该从哪里开始呀?

步骤1 : 阅读 三十分钟成为Contributor | 提升TiDB Parser对MySQL 8.0语法兼容性

步骤2: CreateTableStmt为例子tiDB是如何新建一张表的。

2.1 修改 parser.y 文件

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/*******************************************************************
 *
 *  Create Table Statement
 *
 *  Example:
 *      CREATE TABLE Persons
 *      (
 *          P_Id int NOT NULL,
 *          LastName varchar(255) NOT NULL,
 *          FirstName varchar(255),
 *          Address varchar(255),
 *          City varchar(255),
 *          PRIMARY KEY (P_Id)
 *      )
 // https://dev.mysql.com/doc/refman/5.7/en/create-table.html
 *******************************************************************/
CreateTableStmt:
	"CREATE" OptTemporary "TABLE" IfNotExists TableName TableElementListOpt CreateTableOptionListOpt PartitionOpt DuplicateOpt AsOpt CreateTableSelectOpt OnCommitOpt
	{
		stmt := $6.(*ast.CreateTableStmt)
		stmt.Table = $5.(*ast.TableName)
		stmt.IfNotExists = $4.(bool)
		stmt.TemporaryKeyword = $2.(ast.TemporaryKeyword)
		stmt.Options = $7.([]*ast.TableOption)
		if $8 != nil {
			stmt.Partition = $8.(*ast.PartitionOptions)
		}
		stmt.OnDuplicate = $9.(ast.OnDuplicateKeyHandlingType)
		stmt.Select = $11.(*ast.CreateTableStmt).Select
		if ($12 != nil && stmt.TemporaryKeyword != ast.TemporaryGlobal) || (stmt.TemporaryKeyword == ast.TemporaryGlobal && $12 == nil) {
			yylex.AppendError(yylex.Errorf("GLOBAL TEMPORARY and ON COMMIT DELETE|PRESERVE ROWS must appear together"))
		} else {
			if stmt.TemporaryKeyword == ast.TemporaryGlobal {
				stmt.OnCommitDelete = $12.(bool)
			}
		}
		$$ = stmt
	}

2.2 ddl.go

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// CreateTableStmt is a statement to create a table.
// See https://dev.mysql.com/doc/refman/5.7/en/create-table.html
type CreateTableStmt struct {
	ddlNode

	IfNotExists bool
	TemporaryKeyword
	// Meanless when TemporaryKeyword is not TemporaryGlobal.
	// ON COMMIT DELETE ROWS => true
	// ON COMMIT PRESERVE ROW => false
	OnCommitDelete bool
	Table          *TableName
	ReferTable     *TableName
	Cols           []*ColumnDef
	Constraints    []*Constraint
	Options        []*TableOption
	Partition      *PartitionOptions
	OnDuplicate    OnDuplicateKeyHandlingType
	Select         ResultSetNode
}

// Restore implements Node interface.
func (n *CreateTableStmt) Restore(ctx *format.RestoreCtx) error {
	switch n.TemporaryKeyword {
	case TemporaryNone:
		ctx.WriteKeyWord("CREATE TABLE ")
	case TemporaryGlobal:
		ctx.WriteKeyWord("CREATE GLOBAL TEMPORARY TABLE ")
	case TemporaryLocal:
		ctx.WriteKeyWord("CREATE TEMPORARY TABLE ")
	}
	if n.IfNotExists {
		ctx.WriteKeyWord("IF NOT EXISTS ")
	}

	if err := n.Table.Restore(ctx); err != nil {
		return errors.Annotate(err, "An error occurred while splicing CreateTableStmt Table")
	}

	if n.ReferTable != nil {
		ctx.WriteKeyWord(" LIKE ")
		if err := n.ReferTable.Restore(ctx); err != nil {
			return errors.Annotate(err, "An error occurred while splicing CreateTableStmt ReferTable")
		}
	}
	lenCols := len(n.Cols)
	lenConstraints := len(n.Constraints)
	if lenCols+lenConstraints > 0 {
		ctx.WritePlain(" (")
		for i, col := range n.Cols {
			if i > 0 {
				ctx.WritePlain(",")
			}
			if err := col.Restore(ctx); err != nil {
				return errors.Annotatef(err, "An error occurred while splicing CreateTableStmt ColumnDef: [%v]", i)
			}
		}
		for i, constraint := range n.Constraints {
			if i > 0 || lenCols >= 1 {
				ctx.WritePlain(",")
			}
			if err := constraint.Restore(ctx); err != nil {
				return errors.Annotatef(err, "An error occurred while splicing CreateTableStmt Constraints: [%v]", i)
			}
		}
		ctx.WritePlain(")")
	}

	for i, option := range n.Options {
		ctx.WritePlain(" ")
		if err := option.Restore(ctx); err != nil {
			return errors.Annotatef(err, "An error occurred while splicing CreateTableStmt TableOption: [%v]", i)
		}
	}

	if n.Partition != nil {
		ctx.WritePlain(" ")
		if err := n.Partition.Restore(ctx); err != nil {
			return errors.Annotate(err, "An error occurred while splicing CreateTableStmt Partition")
		}
	}

	if n.Select != nil {
		switch n.OnDuplicate {
		case OnDuplicateKeyHandlingError:
			ctx.WriteKeyWord(" AS ")
		case OnDuplicateKeyHandlingIgnore:
			ctx.WriteKeyWord(" IGNORE AS ")
		case OnDuplicateKeyHandlingReplace:
			ctx.WriteKeyWord(" REPLACE AS ")
		}

		if err := n.Select.Restore(ctx); err != nil {
			return errors.Annotate(err, "An error occurred while splicing CreateTableStmt Select")
		}
	}

	if n.TemporaryKeyword == TemporaryGlobal {
		if n.OnCommitDelete {
			ctx.WriteKeyWord(" ON COMMIT DELETE ROWS")
		} else {
			ctx.WriteKeyWord(" ON COMMIT PRESERVE ROWS")
		}
	}

	return nil
}

// Accept implements Node Accept interface.
func (n *CreateTableStmt) Accept(v Visitor) (Node, bool) {
	newNode, skipChildren := v.Enter(n)
	if skipChildren {
		return v.Leave(newNode)
	}
	n = newNode.(*CreateTableStmt)
	node, ok := n.Table.Accept(v)
	if !ok {
		return n, false
	}
	n.Table = node.(*TableName)
	if n.ReferTable != nil {
		node, ok = n.ReferTable.Accept(v)
		if !ok {
			return n, false
		}
		n.ReferTable = node.(*TableName)
	}
	for i, val := range n.Cols {
		node, ok = val.Accept(v)
		if !ok {
			return n, false
		}
		n.Cols[i] = node.(*ColumnDef)
	}
	for i, val := range n.Constraints {
		node, ok = val.Accept(v)
		if !ok {
			return n, false
		}
		n.Constraints[i] = node.(*Constraint)
	}
	if n.Select != nil {
		node, ok := n.Select.Accept(v)
		if !ok {
			return n, false
		}
		n.Select = node.(ResultSetNode)
	}
	if n.Partition != nil {
		node, ok := n.Partition.Accept(v)
		if !ok {
			return n, false
		}
		n.Partition = node.(*PartitionOptions)
	}

	return v.Leave(n)
}

2.3 parser_test.go

  • TestDMLStmt

步骤2.4 查看历史 issue

Q2:如何了解 planner模块

https://github.com/watchpoints/tidb

步骤2 查看代码

  • lanner/core/preprocess_test.go

planner/core/preprocess.go

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// preprocessor is an ast.Visitor that preprocess
// ast Nodes parsed from parser.
type preprocessor struct {
	ctx    sessionctx.Context
	flag   preprocessorFlag
	stmtTp byte

	// tableAliasInJoin is a stack that keeps the table alias names for joins.
	// len(tableAliasInJoin) may bigger than 1 because the left/right child of join may be subquery that contains `JOIN`
	tableAliasInJoin []map[string]interface{}
	withName         map[string]interface{}

	// values that may be returned
	*PreprocessorReturn
	err error
}

func (p *preprocessor) Enter(in ast.Node) 

 func (p *preprocessor) checkCreateTableGrammar(

   
   
   planner/core/preprocess_test.go
   

Q3:如何了解DDL 模块

步骤1 阅读文档。了解整个处理过程

  • TiDB 源码阅读系列文章(十七)DDL 源码解析

https://pingcap.com/blog-cn/tidb-source-code-reading-17/

步骤2 根据文档看代码

https://github.com/pingcap/tidb/blob/source-code/ddl/ddl_api.go#L739

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func (e *DDLExec) Next:
	case *ast.CreateTableStmt:-->func (e *DDLExec) executeCreateTable -->func (d *ddl) CreateTable(
    
  
    
func (d *ddl) CreateTableWithInfo(
  buildTableInfo 获取 global table ID,生成 tableInfo ,  table 的元信息,然后封装成一个 DDL job
  这个 job 包含了 table ID  tableInfo
  并将这个 job  type 标记为
  ActionCreateTable

 checkTableInfoValidExtra
d.doDDLJob(ctx, job) 函数中的 d.addDDLJob(ctx, job) 会先给 job 获取一个 global job ID 然后放到 job queue 中去。
  

我的issue

issue 18149 [合并]

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if constraint.IsEmptyIndex {
				p.err = ddl.ErrWrongNameForIndex.GenWithStackByArgs(constraint.Name)
				return
			}
// issue 18149
func (s *testValidatorSuite) TestValidator(c *C) 

func (s *testValidatorSuite) runSQL(c *C, sql string, inPrepare bool, terr error) {
	stmts, err1 := session.Parse(s.ctx, sql)
	c.Assert(err1, IsNil, Commentf("sql: %s", sql))
	c.Assert(stmts, HasLen, 1)
	stmt := stmts[0]
	var opts []core.PreprocessOpt
	if inPrepare {
		opts = append(opts, core.InPrepare)
	}
	err := core.Preprocess(s.ctx, stmt, append(opts, core.WithPreprocessorReturn(&core.PreprocessorReturn{InfoSchema: s.is}))...)
	c.Assert(terror.ErrorEqual(err, terr), IsTrue, Commentf("sql: %s, err:%v", sql, err))
}

ssues/9815

进展

输出

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What did you expect to see?
mysql [localhost:8015] {msandbox} (test) > use test;
Database changed
mysql [localhost:8015] {msandbox} (test) > DROP VIEW IF EXISTS v1;
Query OK, 0 rows affected (0.01 sec)

mysql [localhost:8015] {msandbox} (test) > CREATE VIEW v1 AS SELECT 1;
Query OK, 0 rows affected (0.01 sec)

mysql [localhost:8015] {msandbox} (test) > SELECT * FROM v1;
+---+
| 1 |
+---+
| 1 |
+---+
1 row in set (0.00 sec)

mysql [localhost:8015] {msandbox} (test) > ALTER VIEW v1 AS SELECT 2;
Query OK, 0 rows affected (0.01 sec)

mysql [localhost:8015] {msandbox} (test) > SELECT * FROM v1;
+---+
| 2 |
+---+
| 2 |
+---+
1 row in set (0.00 sec)

// DropTableStmt is a statement to drop one or more tables.
// See https://dev.mysql.com/doc/refman/5.7/en/drop-table.html
type DropTableStmt struct {
	ddlNode

	IfExists         bool
	Tables           []*TableName
	IsView           bool
	TemporaryKeyword // make sense ONLY if/when IsView == false
}

DropViewStmt:
	"DROP" "VIEW" TableNameList RestrictOrCascadeOpt
	{
		$$ = &ast.DropTableStmt{Tables: $3.([]*ast.TableName), IsView: true}
	}
|	"DROP" "VIEW" "IF" "EXISTS" TableNameList RestrictOrCascadeOpt
	{
		$$ = &ast.DropTableStmt{IfExists: true, Tables: $5.([]*ast.TableName), IsView: true}
	}

看代码过程

第一天:

https://zhuanlan.zhihu.com/p/24564238