Merge pull request #4 from XiaoMi/master

merge by xiaomi

CHANGES.md

 # CHANGELOG
 
 ## 2018-12
+
 - DOING: english translation
 
 ## 2018-11
+
 - add all third-party lib into vendor
 - support `-report-type chardet`
 - add more heuristic rules: TBL.008, KEY.010, ARG.012, KWR.004
@@ -21,33 +23,36 @@
 - fix #112 multi-line comment will cause line counter error, when -report-type=lint
 - fix #110 remove bom before auditing
 - fix #104 case insensitive regex @ CLA.009
-- fix #87 RuleImplicitConversion value type mistach check bug
+- fix #87 RuleImplicitConversion value type mismatch check bug
 - fix #38 always true where condition check
 - abandon stdin terminal interactive mod, which may seems like hangup
 
 ## 2018-10
-- Fix SplitStatement mulitstatement eof bug #66
+
+- Fix SplitStatement multistatement eof bug #66
 - Fix pretty func hangup issue #47
 - Fix some foolish code spell error
 - Use travis for CI
-- Fix Go 1.8 defapth GOPATH compatible issue BUG #5
+- Fix Go 1.8 default GOPATH compatible issue BUG #5
 - 2018-10-20 开源先锋日(OSCAR)对外正式开源发布代码
 
 ## 2018-09
+
 - 修复多个启发式建议不准确BUG，优化部分建议文案使得建议更清晰
-- 基于TiDB Parser完善多个DDL类型语句的建议
+- 基于 TiDB Parser 完善多个 DDL 类型语句的建议
 - 新增lint report-type类型，支持Vim Plugin优化建议输出
 - 更新整理项目文档，开源准备
 - 2018-09-21 Gdevops SOAR首次对外进行技术分享宣传
 
 ## 2018-08
-- 利用docker临时容器进行daily测试
+
+- 利用 docker 临时容器进行 daily 测试
 - 添加main_test全功能回归测试
 - 修复在测试中发现的问题
-- mymysql合并MySQL8.0相关PR，修改vendor依赖
+- mymysql 合并 MySQL8.0 相关PR，修改vendor依赖
 - 改善HeuristicRule中的文案
 - 持续集成Vitess Parser的改进
-- NewQuery4Audit结构体中引入TiDB Parser
+- NewQuery4Audit 结构体中引入 TiDB Parser
 - 通过TiAST完成大量与 DDL 相关的TODO
 - 修改heuristic rules检查的返回值，提升拓展性
 - 建议中引入Position，用于表示建议产生于SQL的位置
@@ -58,22 +63,25 @@
 - 优化 doc 文档
 
 ## 2018-07
+
 - 补充文档，添加项目LOGO
 - 改善代码质量提升测试覆盖度
 - mymysql升级，支持MySQL 8.0
 - 提供remove-comment小工具
 - 提供索引重复检查小工具
-- HeuristicRule新增RuleSpaceAfterDot
+- HeuristicRule 新增 RuleSpaceAfterDot
 - 支持字符集和Collation不相同时的隐式数据类型转换的检查
 
 ## 2018-06
+
 - 支持更多的SQL Rewrite规则
 - 添加SQL执行超时限制
 - 索引优化建议支持对约束的检查
-- 修复数据采样中null值处理不正确的问题
-- Explain支持last_query_cost
+- 修复数据采样中 NULL 值处理不正确的问题
+- Explain 支持 last_query_cost
 
 ## 2018-05
+
 - 添加数据采样功能
 - 添加语句执行安全检查
 - 支持DDL语法检查
@@ -84,6 +92,7 @@
 - 支持SQL Pretty输出
 
 ## 2018-04
+
 - 支持语法检查
 - 支持测试环境
 - 支持MySQL原数据的获取
@@ -93,7 +102,8 @@
 - 引入配置文件
 
 ## 2018-03
+
 - 基本架构设计
 - 添加大量底层函数用于处理AST
-- 添加Insert、Delete、Update转写成Select的基本函数
+- 添加Insert、Delete、Update 转写成 Select 的基本函数
 - 支持MySQL Explain信息输出

Makefile

@@ -18,6 +18,7 @@ BUILD_TIME=`date +%Y%m%d%H%M`
 COMMIT_VERSION=`git rev-parse HEAD`
 
 # Add mysql version for testing `MYSQL_RELEASE=percona MYSQL_VERSION=5.7 make docker`
+# MySQL 5.1 `MYSQL_RELEASE=vsamov/mysql-5.1.73 make docker`
 # MYSQL_RELEASE: mysql, percona, mariadb ...
 # MYSQL_VERSION: latest, 8.0, 5.7, 5.6, 5.5 ...
 # use mysql:latest as default
@@ -169,6 +170,7 @@ release: build
 docker:
 	@echo "\033[92mBuild mysql test enviorment\033[0m"
 	@docker stop soar-mysql 2>/dev/null || true
+	@docker wait soar-mysql 2>/dev/null || true
 	@echo "docker run --name soar-mysql $(MYSQL_RELEASE):$(MYSQL_VERSION)"
 	@docker run --name soar-mysql --rm -d \
 	-e MYSQL_ROOT_PASSWORD=1tIsB1g3rt \
@@ -178,16 +180,21 @@ docker:
 	$(MYSQL_RELEASE):$(MYSQL_VERSION)
 
 	@echo "waiting for sakila database initializing "
-	@while ! mysql -h 127.0.0.1 -u root sakila -p1tIsB1g3rt -NBe "do 1;" 2>/dev/null; do \
+	@while ! docker exec soar-mysql mysql --user=root --password=1tIsB1g3rt --host "127.0.0.1" --silent -NBe "do 1" >/dev/null 2>&1 ; do \
 	printf '.' ; \
 	sleep 1 ; \
 	done ; \
 	echo '.'
 	@echo "mysql test enviorment is ready!"
 
-.PHONY: connect
-connect:
-	mysql -h 127.0.0.1 -u root -p1tIsB1g3rt -c
+.PHONY: docker-connect
+docker-connect:
+	docker exec -it soar-mysql mysql --user=root --password=1tIsB1g3rt --host "127.0.0.1"
+
+# attach docker container with bash interactive mode
+.PHONY: docker-it
+docker-it:
+	docker exec -it soar-mysql /bin/bash
 
 .PHONY: main_test
 main_test: install

advisor/heuristic.go

@@ -1319,28 +1319,34 @@ func (q *Query4Audit) RuleMultiCompare() Rule {
 				case *tidb.BinaryOperationExpr:
 					switch where.L.(type) {
 					case *tidb.BinaryOperationExpr:
+						if where.Op.String() == "eq" {
 							rule = HeuristicRules["RES.009"]
 						}
 					}
+				}
 			case *tidb.UpdateStmt:
 				switch where := node.Where.(type) {
 				case *tidb.BinaryOperationExpr:
 					switch where.L.(type) {
 					case *tidb.BinaryOperationExpr:
+						if where.Op.String() == "eq" {
 							rule = HeuristicRules["RES.009"]
 						}
 					}
+				}
 			case *tidb.DeleteStmt:
 				switch where := node.Where.(type) {
 				case *tidb.BinaryOperationExpr:
 					switch where.L.(type) {
 					case *tidb.BinaryOperationExpr:
+						if where.Op.String() == "eq" {
 							rule = HeuristicRules["RES.009"]
 						}
 					}
 				}
 			}
 		}
+	}
 	return rule
 }
 

advisor/heuristic_test.go

@@ -952,6 +952,10 @@ func TestRuleMultiCompare(t *testing.T) {
 		},
 		{
 			"SELECT * FROM tbl WHERE col = 'abc'",
+			// https://github.com/XiaoMi/soar/issues/169
+			"SELECT * FROM tbl WHERE col = 'abc' and c = 1",
+			"update tb set c = 1 where a = 2 and b = 3",
+			"delete from tb where a = 2 and b = 3",
 		},
 	}
 

ast/pretty_test.go

@@ -22,8 +22,6 @@ import (
 	"testing"
 
 	"github.com/XiaoMi/soar/common"
-
-	"vitess.io/vitess/go/vt/sqlparser"
 )
 
 var update = flag.Bool("update", false, "update .golden files")
@@ -157,16 +155,6 @@ func TestIsKeyword(t *testing.T) {
 	}
 }
 
-func TestRemoveComments(t *testing.T) {
-	for _, sql := range TestSqlsPretty {
-		stmt, _ := sqlparser.Parse(sql)
-		newSQL := sqlparser.String(stmt)
-		if newSQL != sql {
-			fmt.Print(newSQL)
-		}
-	}
-}
-
 func TestMysqlEscapeString(t *testing.T) {
 	var strs = []map[string]string{
 		{

ast/tidb.go

@@ -17,11 +17,14 @@
 package ast
 
 import (
+	"encoding/json"
+
 	"github.com/XiaoMi/soar/common"
 
 	"github.com/kr/pretty"
 	"github.com/pingcap/parser"
 	"github.com/pingcap/parser/ast"
+
 	// for pincap parser
 	_ "github.com/pingcap/tidb/types/parser_driver"
 )
@@ -29,7 +32,12 @@ import (
 // TiParse TiDB 语法解析
 func TiParse(sql, charset, collation string) ([]ast.StmtNode, error) {
 	p := parser.New()
-	return p.Parse(sql, charset, collation)
+	stmt, warn, err := p.Parse(sql, charset, collation)
+	// TODO: bypass warning info
+	for _, w := range warn {
+		common.Log.Warn(w.Error())
+	}
+	return stmt, err
 }
 
 // PrintPrettyStmtNode 打印TiParse语法树
@@ -43,20 +51,19 @@ func PrintPrettyStmtNode(sql, charset, collation string) {
 	}
 }
 
-// TiVisitor TODO:
-type TiVisitor struct {
-	EnterFunc func(node ast.Node) bool
-	LeaveFunc func(node ast.Node) bool
-}
-
-// Enter TODO:
-func (visitor *TiVisitor) Enter(n ast.Node) (node ast.Node, skip bool) {
-	skip = visitor.EnterFunc(n)
-	return
-}
-
-// Leave TODO:
-func (visitor *TiVisitor) Leave(n ast.Node) (node ast.Node, ok bool) {
-	ok = visitor.LeaveFunc(n)
-	return
+// StmtNode2JSON TiParse AST tree into json format
+func StmtNode2JSON(sql, charset, collation string) string {
+	var str string
+	tree, err := TiParse(sql, charset, collation)
+	if err != nil {
+		common.Log.Warning(err.Error())
+	} else {
+		b, err := json.MarshalIndent(tree, "", "  ")
+		if err != nil {
+			common.Log.Error(err.Error())
+		} else {
+			str = string(b)
+		}
+	}
+	return str
 }

ast/vitess.go

+/*
+ * Copyright 2018 Xiaomi, 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.
+ */
+
+package ast
+
+import (
+	"encoding/json"
+
+	"github.com/XiaoMi/soar/common"
+
+	"github.com/kr/pretty"
+	"vitess.io/vitess/go/vt/sqlparser"
+)
+
+// PrintPrettyVitessStmtNode print vitess AST struct data
+func PrintPrettyVitessStmtNode(sql string) {
+	tree, err := sqlparser.Parse(sql)
+	if err != nil {
+		common.Log.Warning(err.Error())
+	} else {
+		_, err = pretty.Println(tree)
+		common.LogIfWarn(err, "")
+	}
+}
+
+// VitessStmtNode2JSON vitess AST tree into json format
+func VitessStmtNode2JSON(sql string) string {
+	var str string
+	tree, err := sqlparser.Parse(sql)
+	if err != nil {
+		common.Log.Warning(err.Error())
+	} else {
+		b, err := json.MarshalIndent(tree, "", "  ")
+		if err != nil {
+			common.Log.Error(err.Error())
+		} else {
+			str = string(b)
+		}
+	}
+	return str
+}

cmd/soar/soar.go

@@ -31,7 +31,6 @@ import (
 	"github.com/kr/pretty"
 	"github.com/percona/go-mysql/query"
 	"github.com/ziutek/mymysql/mysql"
-	"vitess.io/vitess/go/vt/sqlparser"
 )
 
 func main() {
@@ -143,20 +142,21 @@ func main() {
 			fmt.Println(ast.Compress(sql) + common.Config.Delimiter)
 			continue
 		case "ast":
-			// SQL 抽象语法树
-			var tree sqlparser.Statement
-			tree, err = sqlparser.Parse(sql)
-			if err != nil {
-				fmt.Println(err)
-			} else {
-				_, err = pretty.Println(tree)
-				common.LogIfWarn(err, "")
-			}
+			// print vitess AST data struct
+			ast.PrintPrettyVitessStmtNode(sql)
+			continue
+		case "ast-json":
+			// print vitess SQL AST into json format
+			fmt.Println(ast.VitessStmtNode2JSON(sql))
 			continue
 		case "tiast":
-			// TiDB SQL 抽象语法树
+			// print TiDB AST data struct
 			ast.PrintPrettyStmtNode(sql, "", "")
 			continue
+		case "tiast-json":
+			// print TiDB SQL AST into json format
+			fmt.Println(ast.StmtNode2JSON(sql, "", ""))
+			continue
 		case "tokenize":
 			// SQL 切词
 			_, err = pretty.Println(ast.Tokenize(sql))
@@ -185,7 +185,7 @@ func main() {
 		if syntaxErr != nil {
 			errContent := fmt.Sprintf("At SQL %d : %v", sqlCounter, syntaxErr)
 			common.Log.Warning(errContent)
-			if common.Config.OnlySyntaxCheck {
+			if common.Config.OnlySyntaxCheck || common.Config.ReportType == "rewrite" {
 				fmt.Println(errContent)
 				os.Exit(1)
 			}
@@ -424,4 +424,9 @@ func main() {
 		}
 		return
 	}
+
+	// syntax check verbose mode, add output for success!
+	if common.Config.OnlySyntaxCheck && common.Config.Verbose {
+		fmt.Println("Syntax check OK!")
+	}
 }

common/config.go

@@ -257,7 +257,7 @@ func parseDSN(odbc string, d *dsn) *dsn {
 
 	if d != nil {
 		// 原来有个判断，后来判断条件被删除了就导致第一次addr无论如何都会被修改。所以这边先注释掉
-		//addr = d.Addr
+		// addr = d.Addr
 		user = d.User
 		password = d.Password
 		schema = d.Schema
@@ -273,27 +273,24 @@ func parseDSN(odbc string, d *dsn) *dsn {
 	var userInfo, hostInfo, query string
 
 	// DSN 格式匹配
+	if res := regexp.MustCompile(`^(.*)@(.*?)/(.*?)($|\?)(.*)`).FindStringSubmatch(odbc); len(res) > 5 {
 		// userInfo@hostInfo/database
-	if res := regexp.MustCompile( `^(.*)@(.*?)/(.*?)($|\?)(.*)`).FindStringSubmatch(odbc); len(res)  > 5 {
 		userInfo = res[1]
 		hostInfo = res[2]
 		schema = res[3]
 		query = res[5]
-
-	// hostInfo/database
 	} else if res := regexp.MustCompile(`^(.*)/(.*?)($|\?)(.*)`).FindStringSubmatch(odbc); len(res) > 4 {
+		// hostInfo/database
 		hostInfo = res[1]
 		schema = res[2]
 		query = res[4]
-
-	// userInfo@hostInfo
 	} else if res := regexp.MustCompile(`^(.*)@(.*?)($|\?)(.*)`).FindStringSubmatch(odbc); len(res) > 4 {
+		// userInfo@hostInfo
 		userInfo = res[1]
 		hostInfo = res[2]
 		query = res[4]
-		
-	// hostInfo
 	} else {
+		// hostInfo
 		hostInfo = odbc
 	}
 
@@ -301,7 +298,7 @@ func parseDSN(odbc string, d *dsn) *dsn {
 	if userInfo != "" {
 		user = strings.Split(userInfo, ":")[0]
 		// 防止密码中含有与用户名相同的字符, 所以用正则替换, 剩下的就是密码
-		password = strings.TrimLeft(regexp.MustCompile("^" + user).ReplaceAllString(userInfo, ""), ":")
+		password = strings.TrimLeft(regexp.MustCompile("^"+user).ReplaceAllString(userInfo, ""), ":")
 	}
 
 	// 解析主机信息
@@ -310,13 +307,13 @@ func parseDSN(odbc string, d *dsn) *dsn {
 	if host == "" {
 		host = "127.0.0.1"
 	}
-	if port == ""{
+	if port == "" {
 		port = "3306"
 	}
 	addr = host + ":" + port
 
 	// 解析查询字符串
-	if (query != "") {
+	if query != "" {
 		params := strings.Split(query, "&")
 		for _, f := range params {
 			attr := strings.Split(f, "=")
@@ -515,7 +512,7 @@ func readCmdFlags() error {
 	maxGroupByColsCount := flag.Int("max-group-by-cols-count", Config.MaxGroupByColsCount, "MaxGroupByColsCount, 单条 SQL 中 GroupBy 包含列的最大数量")
 	maxDistinctCount := flag.Int("max-distinct-count", Config.MaxDistinctCount, "MaxDistinctCount, 单条 SQL 中 Distinct 的最大数量")
 	maxIdxColsCount := flag.Int("max-index-cols-count", Config.MaxIdxColsCount, "MaxIdxColsCount, 复合索引中包含列的最大数量")
-	maxTextColsCount := flag.Int("max-texst-cols-count", Config.MaxTextColsCount, "MaxTextColsCount, 表中含有的 text/blob 列的最大数量")
+	maxTextColsCount := flag.Int("max-text-cols-count", Config.MaxTextColsCount, "MaxTextColsCount, 表中含有的 text/blob 列的最大数量")
 	maxTotalRows := flag.Int64("max-total-rows", Config.MaxTotalRows, "MaxTotalRows, 计算散粒度时，当数据行数大于MaxTotalRows即开启数据库保护模式，不计算散粒度")
 	maxQueryCost := flag.Int64("max-query-cost", Config.MaxQueryCost, "MaxQueryCost, last_query_cost 超过该值时将给予警告")
 	spaghettiQueryLength := flag.Int("spaghetti-query-length", Config.SpaghettiQueryLength, "SpaghettiQueryLength, SQL最大长度警告，超过该长度会给警告")

database/show.go

@@ -222,7 +222,6 @@ func (db *Connector) ShowIndex(tableName string) (*TableIndexInfo, error) {
 	null := res.Result.Map("Null")
 	idxType := res.Result.Map("Index_type")
 	comment := res.Result.Map("Comment")
-	idxComment := res.Result.Map("Index_comment")
 
 	// 获取值
 	for _, row := range res.Rows {
@@ -239,7 +238,6 @@ func (db *Connector) ShowIndex(tableName string) (*TableIndexInfo, error) {
 			Null:        row.Str(null),
 			IndexType:   row.Str(idxType),
 			Comment:     row.Str(comment),
-			IndexComment: row.Str(idxComment),
 		}
 		tbIndex.IdxRows = append(tbIndex.IdxRows, value)
 	}

deps.sh

 #!/bin/bash
 
-NEEDED_COMMANDS="mysql docker git go govendor retool"
+NEEDED_COMMANDS="docker git go govendor retool"
 
 for cmd in ${NEEDED_COMMANDS} ; do
     if ! command -v "${cmd}" &> /dev/null ; then
@@ -11,10 +11,6 @@ for cmd in ${NEEDED_COMMANDS} ; do
     fi
 done
 
-# MySQL client
-## Mac OS: brew install mysql
-## Ubuntu: apt-get install mysql-client
-
 # Docker
 ## https://www.docker.com
 

vendor/github.com/pingcap/parser/ast/ast.go

@@ -17,7 +17,6 @@ package ast
 
 import (
 	"io"
-	"strings"
 
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/parser/types"
@@ -27,7 +26,7 @@ import (
 // Interfaces embed Node should have 'Node' name suffix.
 type Node interface {
 	// Restore returns the sql text from ast tree
-	Restore(sb *strings.Builder) error
+	Restore(ctx *RestoreCtx) error
 	// Accept accepts Visitor to visit itself.
 	// The returned node should replace original node.
 	// ok returns false to stop visiting.

vendor/github.com/pingcap/parser/ast/ddl.go

@@ -14,8 +14,6 @@
 package ast
 
 import (
-	"strings"
-
 	"github.com/pingcap/errors"
 	"github.com/pingcap/parser/auth"
 	"github.com/pingcap/parser/model"
@@ -65,15 +63,17 @@ type DatabaseOption struct {
 	Value string
 }
 
-// Restore implements Recoverable interface.
-func (n *DatabaseOption) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *DatabaseOption) Restore(ctx *RestoreCtx) error {
 	switch n.Tp {
 	case DatabaseOptionCharset:
-		sb.WriteString("CHARACTER SET = ")
-		sb.WriteString(n.Value)
+		ctx.WriteKeyWord("CHARACTER SET")
+		ctx.WritePlain(" = ")
+		ctx.WritePlain(n.Value)
 	case DatabaseOptionCollate:
-		sb.WriteString("COLLATE = ")
-		sb.WriteString(n.Value)
+		ctx.WriteKeyWord("COLLATE")
+		ctx.WritePlain(" = ")
+		ctx.WritePlain(n.Value)
 	default:
 		return errors.Errorf("invalid DatabaseOptionType: %d", n.Tp)
 	}
@@ -90,16 +90,16 @@ type CreateDatabaseStmt struct {
 	Options     []*DatabaseOption
 }
 
-// Restore implements Recoverable interface.
-func (n *CreateDatabaseStmt) Restore(sb *strings.Builder) error {
-	sb.WriteString("CREATE DATABASE ")
+// Restore implements Node interface.
+func (n *CreateDatabaseStmt) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("CREATE DATABASE ")
 	if n.IfNotExists {
-		sb.WriteString("IF NOT EXISTS ")
+		ctx.WriteKeyWord("IF NOT EXISTS ")
 	}
-	WriteName(sb, n.Name)
+	ctx.WriteName(n.Name)
 	for _, option := range n.Options {
-		sb.WriteString(" ")
-		err := option.Restore(sb)
+		ctx.WritePlain(" ")
+		err := option.Restore(ctx)
 		if err != nil {
 			return errors.Trace(err)
 		}
@@ -126,13 +126,13 @@ type DropDatabaseStmt struct {
 	Name     string
 }
 
-// Restore implements Recoverable interface.
-func (n *DropDatabaseStmt) Restore(sb *strings.Builder) error {
-	sb.WriteString("DROP DATABASE ")
+// Restore implements Node interface.
+func (n *DropDatabaseStmt) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("DROP DATABASE ")
 	if n.IfExists {
-		sb.WriteString("IF EXISTS ")
+		ctx.WriteKeyWord("IF EXISTS ")
 	}
-	WriteName(sb, n.Name)
+	ctx.WriteName(n.Name)
 	return nil
 }
 
@@ -154,8 +154,8 @@ type IndexColName struct {
 	Length int
 }
 
-// Restore implements Recoverable interface.
-func (n *IndexColName) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *IndexColName) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -185,8 +185,8 @@ type ReferenceDef struct {
 	OnUpdate      *OnUpdateOpt
 }
 
-// Restore implements Recoverable interface.
-func (n *ReferenceDef) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ReferenceDef) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -255,8 +255,8 @@ type OnDeleteOpt struct {
 	ReferOpt ReferOptionType
 }
 
-// Restore implements Recoverable interface.
-func (n *OnDeleteOpt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *OnDeleteOpt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -276,8 +276,8 @@ type OnUpdateOpt struct {
 	ReferOpt ReferOptionType
 }
 
-// Restore implements Recoverable interface.
-func (n *OnUpdateOpt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *OnUpdateOpt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -325,8 +325,8 @@ type ColumnOption struct {
 	Refer *ReferenceDef
 }
 
-// Restore implements Recoverable interface.
-func (n *ColumnOption) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ColumnOption) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -361,9 +361,32 @@ type IndexOption struct {
 	Comment      string
 }
 
-// Restore implements Recoverable interface.
-func (n *IndexOption) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *IndexOption) Restore(ctx *RestoreCtx) error {
+	hasPrevOption := false
+	if n.KeyBlockSize > 0 {
+		ctx.WriteKeyWord("KEY_BLOCK_SIZE")
+		ctx.WritePlainf("=%d", n.KeyBlockSize)
+		hasPrevOption = true
+	}
+
+	if n.Tp != model.IndexTypeInvalid {
+		if hasPrevOption {
+			ctx.WritePlain(" ")
+		}
+		ctx.WriteKeyWord("USING ")
+		ctx.WritePlain(n.Tp.String())
+		hasPrevOption = true
+	}
+
+	if n.Comment != "" {
+		if hasPrevOption {
+			ctx.WritePlain(" ")
+		}
+		ctx.WriteKeyWord("COMMENT ")
+		ctx.WriteString(n.Comment)
+	}
+	return nil
 }
 
 // Accept implements Node Accept interface.
@@ -406,8 +429,8 @@ type Constraint struct {
 	Option *IndexOption // Index Options
 }
 
-// Restore implements Recoverable interface.
-func (n *Constraint) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *Constraint) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -451,8 +474,8 @@ type ColumnDef struct {
 	Options []*ColumnOption
 }
 
-// Restore implements Recoverable interface.
-func (n *ColumnDef) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ColumnDef) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -494,8 +517,8 @@ type CreateTableStmt struct {
 	Select      ResultSetNode
 }
 
-// Restore implements Recoverable interface.
-func (n *CreateTableStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *CreateTableStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -553,8 +576,8 @@ type DropTableStmt struct {
 	IsView   bool
 }
 
-// Restore implements Recoverable interface.
-func (n *DropTableStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *DropTableStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -588,8 +611,8 @@ type RenameTableStmt struct {
 	TableToTables []*TableToTable
 }
 
-// Restore implements Recoverable interface.
-func (n *RenameTableStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *RenameTableStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -629,8 +652,8 @@ type TableToTable struct {
 	NewTable *TableName
 }
 
-// Restore implements Recoverable interface.
-func (n *TableToTable) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *TableToTable) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -669,8 +692,8 @@ type CreateViewStmt struct {
 	CheckOption model.ViewCheckOption
 }
 
-// Restore implements Recoverable interface.
-func (n *CreateViewStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *CreateViewStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -706,8 +729,8 @@ type CreateIndexStmt struct {
 	IndexOption   *IndexOption
 }
 
-// Restore implements Recoverable interface.
-func (n *CreateIndexStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *CreateIndexStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -750,9 +773,20 @@ type DropIndexStmt struct {
 	Table     *TableName
 }
 
-// Restore implements Recoverable interface.
-func (n *DropIndexStmt) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *DropIndexStmt) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("DROP INDEX ")
+	if n.IfExists {
+		ctx.WriteKeyWord("IF EXISTS ")
+	}
+	ctx.WriteName(n.IndexName)
+	ctx.WriteKeyWord(" ON ")
+
+	if err := n.Table.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while add index")
+	}
+
+	return nil
 }
 
 // Accept implements Node Accept interface.
@@ -843,8 +877,8 @@ type ColumnPosition struct {
 	RelativeColumn *ColumnName
 }
 
-// Restore implements Recoverable interface.
-func (n *ColumnPosition) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ColumnPosition) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -925,8 +959,8 @@ type AlterTableSpec struct {
 	Num             uint64
 }
 
-// Restore implements Recoverable interface.
-func (n *AlterTableSpec) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *AlterTableSpec) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -984,8 +1018,8 @@ type AlterTableStmt struct {
 	Specs []*AlterTableSpec
 }
 
-// Restore implements Recoverable interface.
-func (n *AlterTableStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *AlterTableStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -1019,8 +1053,8 @@ type TruncateTableStmt struct {
 	Table *TableName
 }
 
-// Restore implements Recoverable interface.
-func (n *TruncateTableStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *TruncateTableStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 

vendor/github.com/pingcap/parser/ast/dml.go

@@ -14,8 +14,6 @@
 package ast
 
 import (
-	"strings"
-
 	"github.com/pingcap/errors"
 	"github.com/pingcap/parser/auth"
 	"github.com/pingcap/parser/model"
@@ -85,8 +83,8 @@ type Join struct {
 	StraightJoin bool
 }
 
-// Restore implements Recoverable interface.
-func (n *Join) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *Join) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -133,16 +131,16 @@ type TableName struct {
 	IndexHints []*IndexHint
 }
 
-// Restore implements Recoverable interface.
-func (n *TableName) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *TableName) Restore(ctx *RestoreCtx) error {
 	if n.Schema.String() != "" {
-		WriteName(sb, n.Schema.String())
-		sb.WriteString(".")
+		ctx.WriteName(n.Schema.String())
+		ctx.WritePlain(".")
 	}
-	WriteName(sb, n.Name.String())
+	ctx.WriteName(n.Name.String())
 	for _, value := range n.IndexHints {
-		sb.WriteString(" ")
-		if err := value.Restore(sb); err != nil {
+		ctx.WritePlain(" ")
+		if err := value.Restore(ctx); err != nil {
 			return errors.Annotate(err, "An error occurred while splicing IndexHints")
 		}
 	}
@@ -178,7 +176,7 @@ type IndexHint struct {
 }
 
 // IndexHint Restore (The const field uses switch to facilitate understanding)
-func (n *IndexHint) Restore(sb *strings.Builder) error {
+func (n *IndexHint) Restore(ctx *RestoreCtx) error {
 	indexHintType := ""
 	switch n.HintType {
 	case 1:
@@ -204,17 +202,16 @@ func (n *IndexHint) Restore(sb *strings.Builder) error {
 	default: // Prevent accidents
 		return errors.New("IndexHintScope has an error while matching")
 	}
-
-	sb.WriteString(indexHintType)
-	sb.WriteString(indexHintScope)
-	sb.WriteString(" (")
+	ctx.WriteKeyWord(indexHintType)
+	ctx.WriteKeyWord(indexHintScope)
+	ctx.WritePlain(" (")
 	for i, value := range n.IndexNames {
 		if i > 0 {
-			sb.WriteString(", ")
+			ctx.WritePlain(", ")
 		}
-		WriteName(sb, value.O)
+		ctx.WriteName(value.O)
 	}
-	sb.WriteString(")")
+	ctx.WritePlain(")")
 
 	return nil
 }
@@ -235,8 +232,8 @@ type DeleteTableList struct {
 	Tables []*TableName
 }
 
-// Restore implements Recoverable interface.
-func (n *DeleteTableList) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *DeleteTableList) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -266,8 +263,8 @@ type OnCondition struct {
 	Expr ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *OnCondition) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *OnCondition) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -298,8 +295,8 @@ type TableSource struct {
 	AsName model.CIStr
 }
 
-// Restore implements Recoverable interface.
-func (n *TableSource) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *TableSource) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -349,8 +346,8 @@ type WildCardField struct {
 	Schema model.CIStr
 }
 
-// Restore implements Recoverable interface.
-func (n *WildCardField) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *WildCardField) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -384,8 +381,8 @@ type SelectField struct {
 	Auxiliary bool
 }
 
-// Restore implements Recoverable interface.
-func (n *SelectField) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *SelectField) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -413,8 +410,8 @@ type FieldList struct {
 	Fields []*SelectField
 }
 
-// Restore implements Recoverable interface.
-func (n *FieldList) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *FieldList) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -442,8 +439,8 @@ type TableRefsClause struct {
 	TableRefs *Join
 }
 
-// Restore implements Recoverable interface.
-func (n *TableRefsClause) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *TableRefsClause) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -470,8 +467,8 @@ type ByItem struct {
 	Desc bool
 }
 
-// Restore implements Recoverable interface.
-func (n *ByItem) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ByItem) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -496,8 +493,8 @@ type GroupByClause struct {
 	Items []*ByItem
 }
 
-// Restore implements Recoverable interface.
-func (n *GroupByClause) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *GroupByClause) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -524,8 +521,8 @@ type HavingClause struct {
 	Expr ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *HavingClause) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *HavingClause) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -551,8 +548,8 @@ type OrderByClause struct {
 	ForUnion bool
 }
 
-// Restore implements Recoverable interface.
-func (n *OrderByClause) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *OrderByClause) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -609,8 +606,8 @@ type SelectStmt struct {
 	IsInBraces bool
 }
 
-// Restore implements Recoverable interface.
-func (n *SelectStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *SelectStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -708,8 +705,8 @@ type UnionSelectList struct {
 	Selects []*SelectStmt
 }
 
-// Restore implements Recoverable interface.
-func (n *UnionSelectList) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *UnionSelectList) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -741,8 +738,8 @@ type UnionStmt struct {
 	Limit      *Limit
 }
 
-// Restore implements Recoverable interface.
-func (n *UnionStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *UnionStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -786,8 +783,8 @@ type Assignment struct {
 	Expr ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *Assignment) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *Assignment) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -825,8 +822,8 @@ type LoadDataStmt struct {
 	IgnoreLines uint64
 }
 
-// Restore implements Recoverable interface.
-func (n *LoadDataStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *LoadDataStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -883,8 +880,8 @@ type InsertStmt struct {
 	Select      ResultSetNode
 }
 
-// Restore implements Recoverable interface.
-func (n *InsertStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *InsertStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -964,8 +961,8 @@ type DeleteStmt struct {
 	TableHints []*TableOptimizerHint
 }
 
-// Restore implements Recoverable interface.
-func (n *DeleteStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *DeleteStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -1029,8 +1026,8 @@ type UpdateStmt struct {
 	TableHints    []*TableOptimizerHint
 }
 
-// Restore implements Recoverable interface.
-func (n *UpdateStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *UpdateStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -1085,9 +1082,19 @@ type Limit struct {
 	Offset ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *Limit) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *Limit) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("LIMIT ")
+	if n.Offset != nil {
+		if err := n.Offset.Restore(ctx); err != nil {
+			return errors.Annotate(err, "An error occurred while restore Limit.Offset")
+		}
+		ctx.WritePlain(",")
+	}
+	if err := n.Count.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore Limit.Count")
+	}
+	return nil
 }
 
 // Accept implements Node Accept interface.
@@ -1170,8 +1177,8 @@ type ShowStmt struct {
 	Where       ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *ShowStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ShowStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -1235,8 +1242,8 @@ type WindowSpec struct {
 	Frame       *FrameClause
 }
 
-// Restore implements Recoverable interface.
-func (n *WindowSpec) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *WindowSpec) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -1278,8 +1285,8 @@ type PartitionByClause struct {
 	Items []*ByItem
 }
 
-// Restore implements Recoverable interface.
-func (n *PartitionByClause) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *PartitionByClause) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -1319,8 +1326,8 @@ type FrameClause struct {
 	Extent FrameExtent
 }
 
-// Restore implements Recoverable interface.
-func (n *FrameClause) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *FrameClause) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -1372,8 +1379,8 @@ type FrameBound struct {
 	Unit ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *FrameBound) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *FrameBound) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 

vendor/github.com/pingcap/parser/ast/expressions.go

@@ -79,9 +79,24 @@ type BetweenExpr struct {
 	Not bool
 }
 
-// Restore implements Recoverable interface.
-func (n *BetweenExpr) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *BetweenExpr) Restore(ctx *RestoreCtx) error {
+	if err := n.Expr.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore BetweenExpr.Expr")
+	}
+	if n.Not {
+		ctx.WriteKeyWord(" NOT BETWEEN ")
+	} else {
+		ctx.WriteKeyWord(" BETWEEN ")
+	}
+	if err := n.Left.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore BetweenExpr.Left")
+	}
+	ctx.WriteKeyWord(" AND ")
+	if err := n.Right.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore BetweenExpr.Right ")
+	}
+	return nil
 }
 
 // Format the ExprNode into a Writer.
@@ -137,9 +152,19 @@ type BinaryOperationExpr struct {
 	R ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *BinaryOperationExpr) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *BinaryOperationExpr) Restore(ctx *RestoreCtx) error {
+	if err := n.L.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred when restore BinaryOperationExpr.L")
+	}
+	if err := n.Op.Restore(ctx.In); err != nil {
+		return errors.Annotate(err, "An error occurred when restore BinaryOperationExpr.Op")
+	}
+	if err := n.R.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred when restore BinaryOperationExpr.R")
+	}
+
+	return nil
 }
 
 // Format the ExprNode into a Writer.
@@ -183,9 +208,17 @@ type WhenClause struct {
 	Result ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *WhenClause) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *WhenClause) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("WHEN ")
+	if err := n.Expr.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore WhenClauses.Expr")
+	}
+	ctx.WriteKeyWord(" THEN ")
+	if err := n.Result.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore WhenClauses.Result")
+	}
+	return nil
 }
 
 // Accept implements Node Accept interface.
@@ -221,9 +254,30 @@ type CaseExpr struct {
 	ElseClause ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *CaseExpr) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *CaseExpr) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("CASE")
+	if n.Value != nil {
+		ctx.WritePlain(" ")
+		if err := n.Value.Restore(ctx); err != nil {
+			return errors.Annotate(err, "An error occurred while restore CaseExpr.Value")
+		}
+	}
+	for _, clause := range n.WhenClauses {
+		ctx.WritePlain(" ")
+		if err := clause.Restore(ctx); err != nil {
+			return errors.Annotate(err, "An error occurred while restore CaseExpr.WhenClauses")
+		}
+	}
+	if n.ElseClause != nil {
+		ctx.WriteKeyWord(" ELSE ")
+		if err := n.ElseClause.Restore(ctx); err != nil {
+			return errors.Annotate(err, "An error occurred while restore CaseExpr.ElseClause")
+		}
+	}
+	ctx.WriteKeyWord(" END")
+
+	return nil
 }
 
 // Format the ExprNode into a Writer.
@@ -290,8 +344,8 @@ type SubqueryExpr struct {
 	Exists     bool
 }
 
-// Restore implements Recoverable interface.
-func (n *SubqueryExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *SubqueryExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -331,8 +385,8 @@ type CompareSubqueryExpr struct {
 	All bool
 }
 
-// Restore implements Recoverable interface.
-func (n *CompareSubqueryExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *CompareSubqueryExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -369,17 +423,17 @@ type ColumnName struct {
 	Name   model.CIStr
 }
 
-// Restore implements Recoverable interface.
-func (n *ColumnName) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ColumnName) Restore(ctx *RestoreCtx) error {
 	if n.Schema.O != "" {
-		WriteName(sb, n.Schema.O)
-		sb.WriteString(".")
+		ctx.WriteName(n.Schema.O)
+		ctx.WritePlain(".")
 	}
 	if n.Table.O != "" {
-		WriteName(sb, n.Table.O)
-		sb.WriteString(".")
+		ctx.WriteName(n.Table.O)
+		ctx.WritePlain(".")
 	}
-	WriteName(sb, n.Name.O)
+	ctx.WriteName(n.Name.O)
 	return nil
 }
 
@@ -431,10 +485,9 @@ type ColumnNameExpr struct {
 	Refer *ResultField
 }
 
-// Restore implements Recoverable interface.
-func (n *ColumnNameExpr) Restore(sb *strings.Builder) error {
-	err := n.Name.Restore(sb)
-	if err != nil {
+// Restore implements Node interface.
+func (n *ColumnNameExpr) Restore(ctx *RestoreCtx) error {
+	if err := n.Name.Restore(ctx); err != nil {
 		return errors.Trace(err)
 	}
 	return nil
@@ -468,9 +521,17 @@ type DefaultExpr struct {
 	Name *ColumnName
 }
 
-// Restore implements Recoverable interface.
-func (n *DefaultExpr) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *DefaultExpr) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("DEFAULT")
+	if n.Name != nil {
+		ctx.WritePlain("(")
+		if err := n.Name.Restore(ctx); err != nil {
+			return errors.Annotate(err, "An error occurred while restore DefaultExpr.Name")
+		}
+		ctx.WritePlain(")")
+	}
+	return nil
 }
 
 // Format the ExprNode into a Writer.
@@ -505,8 +566,8 @@ type ExistsSubqueryExpr struct {
 	Not bool
 }
 
-// Restore implements Recoverable interface.
-func (n *ExistsSubqueryExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ExistsSubqueryExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -543,8 +604,8 @@ type PatternInExpr struct {
 	Sel ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *PatternInExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *PatternInExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -603,9 +664,16 @@ type IsNullExpr struct {
 	Not bool
 }
 
-// Restore implements Recoverable interface.
-func (n *IsNullExpr) Restore(sb *strings.Builder) error {
-	n.Format(sb)
+// Restore implements Node interface.
+func (n *IsNullExpr) Restore(ctx *RestoreCtx) error {
+	if err := n.Expr.Restore(ctx); err != nil {
+		return errors.Trace(err)
+	}
+	if n.Not {
+		ctx.WriteKeyWord(" IS NOT NULL")
+	} else {
+		ctx.WriteKeyWord(" IS NULL")
+	}
 	return nil
 }
 
@@ -645,9 +713,22 @@ type IsTruthExpr struct {
 	True int64
 }
 
-// Restore implements Recoverable interface.
-func (n *IsTruthExpr) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *IsTruthExpr) Restore(ctx *RestoreCtx) error {
+	if err := n.Expr.Restore(ctx); err != nil {
+		return errors.Trace(err)
+	}
+	if n.Not {
+		ctx.WriteKeyWord(" IS NOT")
+	} else {
+		ctx.WriteKeyWord(" IS")
+	}
+	if n.True > 0 {
+		ctx.WriteKeyWord(" TRUE")
+	} else {
+		ctx.WriteKeyWord(" FALSE")
+	}
+	return nil
 }
 
 // Format the ExprNode into a Writer.
@@ -696,9 +777,23 @@ type PatternLikeExpr struct {
 	PatTypes []byte
 }
 
-// Restore implements Recoverable interface.
-func (n *PatternLikeExpr) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *PatternLikeExpr) Restore(ctx *RestoreCtx) error {
+	if err := n.Expr.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore PatternLikeExpr.Expr")
+	}
+
+	if n.Not {
+		ctx.WriteKeyWord(" NOT LIKE ")
+	} else {
+		ctx.WriteKeyWord(" LIKE ")
+	}
+
+	if err := n.Pattern.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore PatternLikeExpr.Pattern")
+	}
+
+	return nil
 }
 
 // Format the ExprNode into a Writer.
@@ -754,9 +849,14 @@ type ParenthesesExpr struct {
 	Expr ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *ParenthesesExpr) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *ParenthesesExpr) Restore(ctx *RestoreCtx) error {
+	ctx.WritePlain("(")
+	if err := n.Expr.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred when restore ParenthesesExpr.Expr")
+	}
+	ctx.WritePlain(")")
+	return nil
 }
 
 // Format the ExprNode into a Writer.
@@ -796,8 +896,8 @@ type PositionExpr struct {
 	Refer *ResultField
 }
 
-// Restore implements Recoverable interface.
-func (n *PositionExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *PositionExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -839,9 +939,23 @@ type PatternRegexpExpr struct {
 	Sexpr *string
 }
 
-// Restore implements Recoverable interface.
-func (n *PatternRegexpExpr) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *PatternRegexpExpr) Restore(ctx *RestoreCtx) error {
+	if err := n.Expr.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore PatternRegexpExpr.Expr")
+	}
+
+	if n.Not {
+		ctx.WriteKeyWord(" NOT REGEXP ")
+	} else {
+		ctx.WriteKeyWord(" REGEXP ")
+	}
+
+	if err := n.Pattern.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore PatternRegexpExpr.Pattern")
+	}
+
+	return nil
 }
 
 // Format the ExprNode into a Writer.
@@ -883,8 +997,8 @@ type RowExpr struct {
 	Values []ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *RowExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *RowExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -919,9 +1033,14 @@ type UnaryOperationExpr struct {
 	V ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *UnaryOperationExpr) Restore(sb *strings.Builder) error {
-	n.Format(sb)
+// Restore implements Node interface.
+func (n *UnaryOperationExpr) Restore(ctx *RestoreCtx) error {
+	if err := n.Op.Restore(ctx.In); err != nil {
+		return errors.Trace(err)
+	}
+	if err := n.V.Restore(ctx); err != nil {
+		return errors.Trace(err)
+	}
 	return nil
 }
 
@@ -953,9 +1072,16 @@ type ValuesExpr struct {
 	Column *ColumnNameExpr
 }
 
-// Restore implements Recoverable interface.
-func (n *ValuesExpr) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *ValuesExpr) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("VALUES")
+	ctx.WritePlain("(")
+	if err := n.Column.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while restore ValuesExpr.Column")
+	}
+	ctx.WritePlain(")")
+
+	return nil
 }
 
 // Format the ExprNode into a Writer.
@@ -995,8 +1121,8 @@ type VariableExpr struct {
 	Value ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *VariableExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *VariableExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -1029,8 +1155,8 @@ type MaxValueExpr struct {
 	exprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *MaxValueExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *MaxValueExpr) Restore(ctx *RestoreCtx) error {
 	panic("Not implemented")
 }
 

vendor/github.com/pingcap/parser/ast/functions.go

@@ -16,7 +16,6 @@ package ast
 import (
 	"fmt"
 	"io"
-	"strings"
 
 	"github.com/pingcap/errors"
 	"github.com/pingcap/parser/model"
@@ -329,8 +328,8 @@ type FuncCallExpr struct {
 	Args []ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *FuncCallExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *FuncCallExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -406,8 +405,8 @@ type FuncCastExpr struct {
 	FunctionType CastFunctionType
 }
 
-// Restore implements Recoverable interface.
-func (n *FuncCastExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *FuncCastExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -519,8 +518,8 @@ type AggregateFuncExpr struct {
 	Distinct bool
 }
 
-// Restore implements Recoverable interface.
-func (n *AggregateFuncExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *AggregateFuncExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -592,8 +591,8 @@ type WindowFuncExpr struct {
 	Spec WindowSpec
 }
 
-// Restore implements Recoverable interface.
-func (n *WindowFuncExpr) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *WindowFuncExpr) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 

vendor/github.com/pingcap/parser/ast/misc.go

@@ -98,8 +98,8 @@ type TraceStmt struct {
 	Format string
 }
 
-// Restore implements Recoverable interface.
-func (n *TraceStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *TraceStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -129,8 +129,8 @@ type ExplainStmt struct {
 	Analyze bool
 }
 
-// Restore implements Recoverable interface.
-func (n *ExplainStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ExplainStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -160,8 +160,8 @@ type PrepareStmt struct {
 	SQLVar  *VariableExpr
 }
 
-// Restore implements Recoverable interface.
-func (n *PrepareStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *PrepareStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -190,8 +190,8 @@ type DeallocateStmt struct {
 	Name string
 }
 
-// Restore implements Recoverable interface.
-func (n *DeallocateStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *DeallocateStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -223,8 +223,8 @@ type ExecuteStmt struct {
 	ExecID    uint32
 }
 
-// Restore implements Recoverable interface.
-func (n *ExecuteStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *ExecuteStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -251,8 +251,8 @@ type BeginStmt struct {
 	stmtNode
 }
 
-// Restore implements Recoverable interface.
-func (n *BeginStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *BeginStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -274,8 +274,8 @@ type BinlogStmt struct {
 	Str string
 }
 
-// Restore implements Recoverable interface.
-func (n *BinlogStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *BinlogStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -295,8 +295,8 @@ type CommitStmt struct {
 	stmtNode
 }
 
-// Restore implements Recoverable interface.
-func (n *CommitStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *CommitStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -316,8 +316,8 @@ type RollbackStmt struct {
 	stmtNode
 }
 
-// Restore implements Recoverable interface.
-func (n *RollbackStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *RollbackStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -339,10 +339,10 @@ type UseStmt struct {
 	DBName string
 }
 
-// Restore implements Recoverable interface.
-func (n *UseStmt) Restore(sb *strings.Builder) error {
-	sb.WriteString("USE ")
-	WriteName(sb, n.DBName)
+// Restore implements Node interface.
+func (n *UseStmt) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("USE ")
+	ctx.WriteName(n.DBName)
 	return nil
 }
 
@@ -377,8 +377,8 @@ type VariableAssignment struct {
 	ExtendValue ValueExpr
 }
 
-// Restore implements Recoverable interface.
-func (n *VariableAssignment) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *VariableAssignment) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -418,8 +418,8 @@ type FlushStmt struct {
 	ReadLock        bool
 }
 
-// Restore implements Recoverable interface.
-func (n *FlushStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *FlushStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -453,8 +453,8 @@ type KillStmt struct {
 	TiDBExtension bool
 }
 
-// Restore implements Recoverable interface.
-func (n *KillStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *KillStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -475,8 +475,8 @@ type SetStmt struct {
 	Variables []*VariableAssignment
 }
 
-// Restore implements Recoverable interface.
-func (n *SetStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *SetStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -527,8 +527,8 @@ type SetPwdStmt struct {
 	Password string
 }
 
-// Restore implements Recoverable interface.
-func (n *SetPwdStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *SetPwdStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -595,8 +595,8 @@ type CreateUserStmt struct {
 	Specs       []*UserSpec
 }
 
-// Restore implements Recoverable interface.
-func (n *CreateUserStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *CreateUserStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -631,8 +631,8 @@ type AlterUserStmt struct {
 	Specs       []*UserSpec
 }
 
-// Restore implements Recoverable interface.
-func (n *AlterUserStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *AlterUserStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -666,8 +666,8 @@ type DropUserStmt struct {
 	UserList []*auth.UserIdentity
 }
 
-// Restore implements Recoverable interface.
-func (n *DropUserStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *DropUserStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -688,8 +688,8 @@ type DoStmt struct {
 	Exprs []ExprNode
 }
 
-// Restore implements Recoverable interface.
-func (n *DoStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *DoStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -780,8 +780,8 @@ type AdminStmt struct {
 	ShowSlow     *ShowSlow
 }
 
-// Restore implements Recoverable interface.
-func (n *AdminStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *AdminStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -812,8 +812,8 @@ type PrivElem struct {
 	Cols []*ColumnName
 }
 
-// Restore implements Recoverable interface.
-func (n *PrivElem) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *PrivElem) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -875,8 +875,8 @@ type RevokeStmt struct {
 	Users      []*UserSpec
 }
 
-// Restore implements Recoverable interface.
-func (n *RevokeStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *RevokeStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -908,8 +908,8 @@ type GrantStmt struct {
 	WithGrant  bool
 }
 
-// Restore implements Recoverable interface.
-func (n *GrantStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *GrantStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -978,8 +978,8 @@ type TableOptimizerHint struct {
 	MaxExecutionTime uint64
 }
 
-// Restore implements Recoverable interface.
-func (n *TableOptimizerHint) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *TableOptimizerHint) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 

vendor/github.com/pingcap/parser/ast/stats.go

@@ -14,8 +14,6 @@
 package ast
 
 import (
-	"strings"
-
 	"github.com/pingcap/errors"
 	"github.com/pingcap/parser/model"
 )
@@ -39,8 +37,8 @@ type AnalyzeTableStmt struct {
 	IndexFlag bool
 }
 
-// Restore implements Recoverable interface.
-func (n *AnalyzeTableStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *AnalyzeTableStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 
@@ -68,9 +66,14 @@ type DropStatsStmt struct {
 	Table *TableName
 }
 
-// Restore implements Recoverable interface.
-func (n *DropStatsStmt) Restore(sb *strings.Builder) error {
-	return errors.New("Not implemented")
+// Restore implements Node interface.
+func (n *DropStatsStmt) Restore(ctx *RestoreCtx) error {
+	ctx.WriteKeyWord("DROP STATS ")
+	if err := n.Table.Restore(ctx); err != nil {
+		return errors.Annotate(err, "An error occurred while add table")
+	}
+
+	return nil
 }
 
 // Accept implements Node Accept interface.
@@ -95,8 +98,8 @@ type LoadStatsStmt struct {
 	Path string
 }
 
-// Restore implements Recoverable interface.
-func (n *LoadStatsStmt) Restore(sb *strings.Builder) error {
+// Restore implements Node interface.
+func (n *LoadStatsStmt) Restore(ctx *RestoreCtx) error {
 	return errors.New("Not implemented")
 }
 

vendor/github.com/pingcap/parser/ast/util.go

@@ -13,7 +13,11 @@
 
 package ast
 
-import "strings"
+import (
+	"fmt"
+	"io"
+	"strings"
+)
 
 // IsReadOnly checks whether the input ast is readOnly.
 func IsReadOnly(node Node) bool {
@@ -62,14 +66,150 @@ func (checker *readOnlyChecker) Leave(in Node) (out Node, ok bool) {
 	return in, checker.readOnly
 }
 
-// WriteName append escaped `name` with back quote to `sb`.
-func WriteName(sb *strings.Builder, name string) {
-	sb.WriteString("`")
-	sb.WriteString(EscapeName(name))
-	sb.WriteString("`")
+//RestoreFlag mark the Restore format
+type RestoreFlags uint64
+
+// Mutually exclusive group of `RestoreFlags`:
+// [RestoreStringSingleQuotes, RestoreStringDoubleQuotes]
+// [RestoreKeyWordUppercase, RestoreKeyWordLowercase]
+// [RestoreNameUppercase, RestoreNameLowercase]
+// [RestoreNameDoubleQuotes, RestoreNameBackQuotes]
+// The flag with the left position in each group has a higher priority.
+const (
+	RestoreStringSingleQuotes RestoreFlags = 1 << iota
+	RestoreStringDoubleQuotes
+	RestoreStringEscapeBackslash
+
+	RestoreKeyWordUppercase
+	RestoreKeyWordLowercase
+
+	RestoreNameUppercase
+	RestoreNameLowercase
+	RestoreNameDoubleQuotes
+	RestoreNameBackQuotes
+)
+
+const (
+	DefaultRestoreFlags = RestoreStringSingleQuotes | RestoreKeyWordUppercase | RestoreNameBackQuotes
+)
+
+func (rf RestoreFlags) has(flag RestoreFlags) bool {
+	return rf&flag != 0
+}
+
+// HasStringSingleQuotesFlag returns a boolean indicating when `rf` has `RestoreStringSingleQuotes` flag.
+func (rf RestoreFlags) HasStringSingleQuotesFlag() bool {
+	return rf.has(RestoreStringSingleQuotes)
+}
+
+// HasStringDoubleQuotesFlag returns a boolean indicating whether `rf` has `RestoreStringDoubleQuotes` flag.
+func (rf RestoreFlags) HasStringDoubleQuotesFlag() bool {
+	return rf.has(RestoreStringDoubleQuotes)
+}
+
+// HasStringEscapeBackslashFlag returns a boolean indicating whether `rf` has `RestoreStringEscapeBackslash` flag.
+func (rf RestoreFlags) HasStringEscapeBackslashFlag() bool {
+	return rf.has(RestoreStringEscapeBackslash)
+}
+
+// HasKeyWordUppercaseFlag returns a boolean indicating whether `rf` has `RestoreKeyWordUppercase` flag.
+func (rf RestoreFlags) HasKeyWordUppercaseFlag() bool {
+	return rf.has(RestoreKeyWordUppercase)
+}
+
+// HasKeyWordLowercaseFlag returns a boolean indicating whether `rf` has `RestoreKeyWordLowercase` flag.
+func (rf RestoreFlags) HasKeyWordLowercaseFlag() bool {
+	return rf.has(RestoreKeyWordLowercase)
+}
+
+// HasNameUppercaseFlag returns a boolean indicating whether `rf` has `RestoreNameUppercase` flag.
+func (rf RestoreFlags) HasNameUppercaseFlag() bool {
+	return rf.has(RestoreNameUppercase)
+}
+
+// HasNameLowercaseFlag returns a boolean indicating whether `rf` has `RestoreNameLowercase` flag.
+func (rf RestoreFlags) HasNameLowercaseFlag() bool {
+	return rf.has(RestoreNameLowercase)
+}
+
+// HasNameDoubleQuotesFlag returns a boolean indicating whether `rf` has `RestoreNameDoubleQuotes` flag.
+func (rf RestoreFlags) HasNameDoubleQuotesFlag() bool {
+	return rf.has(RestoreNameDoubleQuotes)
+}
+
+// HasNameBackQuotesFlag returns a boolean indicating whether `rf` has `RestoreNameBackQuotes` flag.
+func (rf RestoreFlags) HasNameBackQuotesFlag() bool {
+	return rf.has(RestoreNameBackQuotes)
+}
+
+// RestoreCtx is `Restore` context to hold flags and writer.
+type RestoreCtx struct {
+	Flags RestoreFlags
+	In    io.Writer
+}
+
+// NewRestoreCtx returns a new `RestoreCtx`.
+func NewRestoreCtx(flags RestoreFlags, in io.Writer) *RestoreCtx {
+	return &RestoreCtx{flags, in}
+}
+
+// WriteKeyWord writes the `keyWord` into writer.
+// `keyWord` will be converted format(uppercase and lowercase for now) according to `RestoreFlags`.
+func (ctx *RestoreCtx) WriteKeyWord(keyWord string) {
+	switch {
+	case ctx.Flags.HasKeyWordUppercaseFlag():
+		keyWord = strings.ToUpper(keyWord)
+	case ctx.Flags.HasKeyWordLowercaseFlag():
+		keyWord = strings.ToLower(keyWord)
+	}
+	fmt.Fprint(ctx.In, keyWord)
+}
+
+// WriteString writes the string into writer
+// `str` may be wrapped in quotes and escaped according to RestoreFlags.
+func (ctx *RestoreCtx) WriteString(str string) {
+	if ctx.Flags.HasStringEscapeBackslashFlag() {
+		str = strings.Replace(str, `\`, `\\`, -1)
+	}
+	quotes := ""
+	switch {
+	case ctx.Flags.HasStringSingleQuotesFlag():
+		str = strings.Replace(str, `'`, `''`, -1)
+		quotes = `'`
+	case ctx.Flags.HasStringDoubleQuotesFlag():
+		str = strings.Replace(str, `"`, `""`, -1)
+		quotes = `"`
+	}
+	fmt.Fprint(ctx.In, quotes, str, quotes)
+}
+
+// WriteName writes the name into writer
+// `name` maybe wrapped in quotes and escaped according to RestoreFlags.
+func (ctx *RestoreCtx) WriteName(name string) {
+	switch {
+	case ctx.Flags.HasNameUppercaseFlag():
+		name = strings.ToUpper(name)
+	case ctx.Flags.HasNameLowercaseFlag():
+		name = strings.ToLower(name)
+	}
+	quotes := ""
+	switch {
+	case ctx.Flags.HasNameDoubleQuotesFlag():
+		name = strings.Replace(name, `"`, `""`, -1)
+		quotes = `"`
+	case ctx.Flags.HasNameBackQuotesFlag():
+		name = strings.Replace(name, "`", "``", -1)
+		quotes = "`"
+	}
+	fmt.Fprint(ctx.In, quotes, name, quotes)
+}
+
+// WritePlain writes the plain text into writer without any handling.
+func (ctx *RestoreCtx) WritePlain(plainText string) {
+	fmt.Fprint(ctx.In, plainText)
 }
 
-// EscapeName escape the `name`
-func EscapeName(name string) string {
-	return strings.Replace(name, "`", "``", -1)
+// WritePlainf write the plain text into writer without any handling.
+func (ctx *RestoreCtx) WritePlainf(format string, a ...interface{}) {
+	fmt.Fprintf(ctx.In, format, a...)
 }

vendor/github.com/pingcap/parser/go.mod1

@@ -7,11 +7,10 @@ require (
 	github.com/cznic/sortutil v0.0.0-20150617083342-4c7342852e65
 	github.com/cznic/strutil v0.0.0-20171016134553-529a34b1c186
 	github.com/cznic/y v0.0.0-20170802143616-045f81c6662a
-	github.com/pingcap/check v0.0.0-20171206051426-1c287c953996
+	github.com/pingcap/check v0.0.0-20181213055612-5c2b07721bdb
 	github.com/pingcap/errors v0.11.0
-	github.com/pingcap/tidb v0.0.0-20181203021530-741adcee43e2
+	github.com/pingcap/tidb v0.0.0-20181217070741-096bb68e6bef
 	github.com/pingcap/tipb v0.0.0-20181012112600-11e33c750323
 	github.com/sirupsen/logrus v1.2.0
-	golang.org/x/net v0.0.0-20181029044818-c44066c5c816
 	golang.org/x/text v0.3.0
 )

vendor/github.com/pingcap/parser/lexer.go

@@ -38,6 +38,7 @@ type Scanner struct {
 	buf bytes.Buffer
 
 	errs         []error
+	warns        []error
 	stmtStartPos int
 
 	// For scanning such kind of comment: /*! MySQL-specific code */ or /*+ optimizer hint */
@@ -88,9 +89,9 @@ func (s *optimizerHintScanner) scan() (tok int, pos Pos, lit string) {
 	return
 }
 
-// Errors returns the errors during a scan.
-func (s *Scanner) Errors() []error {
-	return s.errs
+// Errors returns the errors and warns during a scan.
+func (s *Scanner) Errors() (warns []error, errs []error) {
+	return s.warns, s.errs
 }
 
 // reset resets the sql string to be scanned.
@@ -98,6 +99,7 @@ func (s *Scanner) reset(sql string) {
 	s.r = reader{s: sql, p: Pos{Line: 1}}
 	s.buf.Reset()
 	s.errs = s.errs[:0]
+	s.warns = s.warns[:0]
 	s.stmtStartPos = 0
 	s.specialComment = nil
 }

vendor/github.com/pingcap/parser/model/model.go

@@ -250,6 +250,14 @@ func (t *TableInfo) GetAutoIncrementColInfo() *ColumnInfo {
 	return nil
 }
 
+func (t *TableInfo) IsAutoIncColUnsigned() bool {
+	col := t.GetAutoIncrementColInfo()
+	if col == nil {
+		return false
+	}
+	return mysql.HasUnsignedFlag(col.Flag)
+}
+
 // Cols returns the columns of the table in public state.
 func (t *TableInfo) Cols() []*ColumnInfo {
 	publicColumns := make([]*ColumnInfo, len(t.Columns))

vendor/github.com/pingcap/parser/opcode/opcode.go

@@ -16,6 +16,8 @@ package opcode
 import (
 	"fmt"
 	"io"
+
+	"github.com/pingcap/errors"
 )
 
 // Op is opcode type.
@@ -136,3 +138,12 @@ var opsLiteral = map[Op]string{
 func (o Op) Format(w io.Writer) {
 	fmt.Fprintf(w, "%s", opsLiteral[o])
 }
+
+// Restore the Op into a Writer
+func (o Op) Restore(w io.Writer) error {
+	if v, ok := opsLiteral[o]; ok {
+		fmt.Fprint(w, v)
+		return nil
+	}
+	return errors.Errorf("Invalid opcode type %d during restoring AST to SQL text", o)
+}

vendor/github.com/pingcap/parser/parser.y

@@ -2926,6 +2926,8 @@ IndexOptionList:
 				opt1.Comment = opt2.Comment
 			} else if opt2.Tp != 0 {
 				opt1.Tp = opt2.Tp
+			} else if opt2.KeyBlockSize > 0 {
+			    opt1.KeyBlockSize = opt2.KeyBlockSize
 			}
 			$$ = opt1
 		}
@@ -2936,8 +2938,7 @@ IndexOption:
 	"KEY_BLOCK_SIZE" EqOpt LengthNum
 	{
 		$$ = &ast.IndexOption{
-			// TODO bug should be fix here!
-			// KeyBlockSize: $1.(uint64),
+			KeyBlockSize: $3.(uint64),
 		}
 	}
 |	IndexType
@@ -5190,6 +5191,11 @@ TableOptimizerHints:
 	{
 		$$ = $2
 	}
+|	hintBegin error hintEnd
+	{
+		yyerrok()
+		parser.lastErrorAsWarn()
+	}
 
 HintTableList:
 	Identifier

vendor/github.com/pingcap/parser/yy_parser.go

@@ -90,7 +90,7 @@ func New() *Parser {
 
 // Parse parses a query string to raw ast.StmtNode.
 // If charset or collation is "", default charset and collation will be used.
-func (parser *Parser) Parse(sql, charset, collation string) ([]ast.StmtNode, error) {
+func (parser *Parser) Parse(sql, charset, collation string) (stmt []ast.StmtNode, warns []error, err error) {
 	if charset == "" {
 		charset = mysql.DefaultCharset
 	}
@@ -107,19 +107,33 @@ func (parser *Parser) Parse(sql, charset, collation string) ([]ast.StmtNode, err
 	l = &parser.lexer
 	yyParse(l, parser)
 
-	if len(l.Errors()) != 0 {
-		return nil, errors.Trace(l.Errors()[0])
+	warns, errs := l.Errors()
+	if len(warns) > 0 {
+		warns = append([]error(nil), warns...)
+	} else {
+		warns = nil
+	}
+	if len(errs) != 0 {
+		return nil, warns, errors.Trace(errs[0])
 	}
 	for _, stmt := range parser.result {
 		ast.SetFlag(stmt)
 	}
-	return parser.result, nil
+	return parser.result, warns, nil
+}
+
+func (parser *Parser) lastErrorAsWarn() {
+	if len(parser.lexer.errs) == 0 {
+		return
+	}
+	parser.lexer.warns = append(parser.lexer.warns, parser.lexer.errs[len(parser.lexer.errs)-1])
+	parser.lexer.errs = parser.lexer.errs[:len(parser.lexer.errs)-1]
 }
 
 // ParseOneStmt parses a query and returns an ast.StmtNode.
 // The query must have one statement, otherwise ErrSyntax is returned.
 func (parser *Parser) ParseOneStmt(sql, charset, collation string) (ast.StmtNode, error) {
-	stmts, err := parser.Parse(sql, charset, collation)
+	stmts, _, err := parser.Parse(sql, charset, collation)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}

vendor/github.com/pingcap/tidb/sessionctx/stmtctx/stmtctx.go

@@ -65,8 +65,29 @@ type StatementContext struct {
 	// mu struct holds variables that change during execution.
 	mu struct {
 		sync.Mutex
+
 		affectedRows uint64
 		foundRows    uint64
+
+		/*
+			following variables are ported from 'COPY_INFO' struct of MySQL server source,
+			they are used to count rows for INSERT/REPLACE/UPDATE queries:
+			  If a row is inserted then the copied variable is incremented.
+			  If a row is updated by the INSERT ... ON DUPLICATE KEY UPDATE and the
+			     new data differs from the old one then the copied and the updated
+			     variables are incremented.
+			  The touched variable is incremented if a row was touched by the update part
+			     of the INSERT ... ON DUPLICATE KEY UPDATE no matter whether the row
+			     was actually changed or not.
+
+			see https://github.com/mysql/mysql-server/blob/d2029238d6d9f648077664e4cdd611e231a6dc14/sql/sql_data_change.h#L60 for more details
+		*/
+		records uint64
+		updated uint64
+		copied  uint64
+		touched uint64
+
+		message           string
 		warnings          []SQLWarn
 		histogramsNotLoad bool
 		execDetails       execdetails.ExecDetails
@@ -122,6 +143,81 @@ func (sc *StatementContext) AddFoundRows(rows uint64) {
 	sc.mu.Unlock()
 }
 
+// RecordRows is used to generate info message
+func (sc *StatementContext) RecordRows() uint64 {
+	sc.mu.Lock()
+	rows := sc.mu.records
+	sc.mu.Unlock()
+	return rows
+}
+
+// AddRecordRows adds record rows.
+func (sc *StatementContext) AddRecordRows(rows uint64) {
+	sc.mu.Lock()
+	sc.mu.records += rows
+	sc.mu.Unlock()
+}
+
+// UpdatedRows is used to generate info message
+func (sc *StatementContext) UpdatedRows() uint64 {
+	sc.mu.Lock()
+	rows := sc.mu.updated
+	sc.mu.Unlock()
+	return rows
+}
+
+// AddUpdatedRows adds updated rows.
+func (sc *StatementContext) AddUpdatedRows(rows uint64) {
+	sc.mu.Lock()
+	sc.mu.updated += rows
+	sc.mu.Unlock()
+}
+
+// CopiedRows is used to generate info message
+func (sc *StatementContext) CopiedRows() uint64 {
+	sc.mu.Lock()
+	rows := sc.mu.copied
+	sc.mu.Unlock()
+	return rows
+}
+
+// AddCopiedRows adds copied rows.
+func (sc *StatementContext) AddCopiedRows(rows uint64) {
+	sc.mu.Lock()
+	sc.mu.copied += rows
+	sc.mu.Unlock()
+}
+
+// TouchedRows is used to generate info message
+func (sc *StatementContext) TouchedRows() uint64 {
+	sc.mu.Lock()
+	rows := sc.mu.touched
+	sc.mu.Unlock()
+	return rows
+}
+
+// AddTouchedRows adds touched rows.
+func (sc *StatementContext) AddTouchedRows(rows uint64) {
+	sc.mu.Lock()
+	sc.mu.touched += rows
+	sc.mu.Unlock()
+}
+
+// GetMessage returns the extra message of the last executed command, if there is no message, it returns empty string
+func (sc *StatementContext) GetMessage() string {
+	sc.mu.Lock()
+	msg := sc.mu.message
+	sc.mu.Unlock()
+	return msg
+}
+
+// SetMessage sets the info message generated by some commands
+func (sc *StatementContext) SetMessage(msg string) {
+	sc.mu.Lock()
+	sc.mu.message = msg
+	sc.mu.Unlock()
+}
+
 // GetWarnings gets warnings.
 func (sc *StatementContext) GetWarnings() []SQLWarn {
 	sc.mu.Lock()
@@ -247,6 +343,11 @@ func (sc *StatementContext) ResetForRetry() {
 	sc.mu.Lock()
 	sc.mu.affectedRows = 0
 	sc.mu.foundRows = 0
+	sc.mu.records = 0
+	sc.mu.updated = 0
+	sc.mu.copied = 0
+	sc.mu.touched = 0
+	sc.mu.message = ""
 	sc.mu.warnings = nil
 	sc.mu.Unlock()
 	sc.TableIDs = sc.TableIDs[:0]

vendor/github.com/pingcap/tidb/types/field_type.go

@@ -128,12 +128,24 @@ func DefaultParamTypeForValue(value interface{}, tp *FieldType) {
 		tp.Decimal = UnspecifiedLength
 	default:
 		DefaultTypeForValue(value, tp)
+		if hasVariantFieldLength(tp) {
+			tp.Flen = UnspecifiedLength
+		}
 		if tp.Tp == mysql.TypeUnspecified {
 			tp.Tp = mysql.TypeVarString
 		}
 	}
 }
 
+func hasVariantFieldLength(tp *FieldType) bool {
+	switch tp.Tp {
+	case mysql.TypeLonglong, mysql.TypeVarString, mysql.TypeDouble, mysql.TypeBlob,
+		mysql.TypeBit, mysql.TypeDuration, mysql.TypeNewDecimal, mysql.TypeEnum, mysql.TypeSet:
+		return true
+	}
+	return false
+}
+
 // DefaultTypeForValue returns the default FieldType for the value.
 func DefaultTypeForValue(value interface{}, tp *FieldType) {
 	switch x := value.(type) {

vendor/github.com/pingcap/tidb/types/parser_driver/value_expr.go

@@ -17,7 +17,6 @@ import (
 	"fmt"
 	"io"
 	"strconv"
-	"strings"
 
 	"github.com/pingcap/errors"
 	"github.com/pingcap/parser/ast"
@@ -69,11 +68,45 @@ type ValueExpr struct {
 	projectionOffset int
 }
 
-// Restore implements Recoverable interface.
-func (n *ValueExpr) Restore(sb *strings.Builder) error {
-	err := n.format(sb)
-	if err != nil {
-		return errors.Trace(err)
+// Restore implements Node interface.
+func (n *ValueExpr) Restore(ctx *ast.RestoreCtx) error {
+	switch n.Kind() {
+	case types.KindNull:
+		ctx.WriteKeyWord("NULL")
+	case types.KindInt64:
+		if n.Type.Flag&mysql.IsBooleanFlag != 0 {
+			if n.GetInt64() > 0 {
+				ctx.WriteKeyWord("TRUE")
+			} else {
+				ctx.WriteKeyWord("FALSE")
+			}
+		} else {
+			ctx.WritePlain(strconv.FormatInt(n.GetInt64(), 10))
+		}
+	case types.KindUint64:
+		ctx.WritePlain(strconv.FormatUint(n.GetUint64(), 10))
+	case types.KindFloat32:
+		ctx.WritePlain(strconv.FormatFloat(n.GetFloat64(), 'e', -1, 32))
+	case types.KindFloat64:
+		ctx.WritePlain(strconv.FormatFloat(n.GetFloat64(), 'e', -1, 64))
+	case types.KindString, types.KindBytes:
+		ctx.WriteString(n.GetString())
+	case types.KindMysqlDecimal:
+		ctx.WritePlain(n.GetMysqlDecimal().String())
+	case types.KindBinaryLiteral:
+		if n.Type.Flag&mysql.UnsignedFlag != 0 {
+			ctx.WritePlainf("x'%x'", n.GetBytes())
+		} else {
+			ctx.WritePlain(n.GetBinaryLiteral().ToBitLiteralString(true))
+		}
+	case types.KindMysqlDuration, types.KindMysqlEnum,
+		types.KindMysqlBit, types.KindMysqlSet, types.KindMysqlTime,
+		types.KindInterface, types.KindMinNotNull, types.KindMaxValue,
+		types.KindRaw, types.KindMysqlJSON:
+		// TODO implement Restore function
+		return errors.New("Not implemented")
+	default:
+		return errors.New("can't format to string")
 	}
 	return nil
 }
@@ -84,7 +117,7 @@ func (n *ValueExpr) GetDatumString() string {
 }
 
 // Format the ExprNode into a Writer.
-func (n *ValueExpr) format(w io.Writer) error {
+func (n *ValueExpr) Format(w io.Writer) {
 	var s string
 	switch n.Kind() {
 	case types.KindNull:
@@ -116,18 +149,9 @@ func (n *ValueExpr) format(w io.Writer) error {
 			s = n.GetBinaryLiteral().ToBitLiteralString(true)
 		}
 	default:
-		return errors.New("can't format to string")
-	}
-	fmt.Fprint(w, s)
-	return nil
-}
-
-// Format the ExprNode into a Writer.
-func (n *ValueExpr) Format(w io.Writer) {
-	err := n.format(w)
-	if err != nil {
 		panic("Can't format to string")
 	}
+	fmt.Fprint(w, s)
 }
 
 // newValueExpr creates a ValueExpr with value, and sets default field type.
@@ -170,9 +194,9 @@ type ParamMarkerExpr struct {
 	Order  int
 }
 
-// Restore implements Recoverable interface.
-func (n *ParamMarkerExpr) Restore(sb *strings.Builder) error {
-	sb.WriteString("?")
+// Restore implements Node interface.
+func (n *ParamMarkerExpr) Restore(ctx *ast.RestoreCtx) error {
+	ctx.WritePlain("?")
 	return nil
 }
 

vendor/vendor.json

@@ -105,106 +105,106 @@
 			"revisionTime": "2018-10-24T15:10:47Z"
 		},
 		{
-			"checksumSHA1": "xbV0lm0Qw8rFC82Dttxbf5ypBjA=",
+			"checksumSHA1": "cbEXJvrHC69taa1/5o/VlbkZy/g=",
 			"path": "github.com/pingcap/parser",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
-			"checksumSHA1": "RosqMriA/39ZEtqGgNU+bOfRBVc=",
+			"checksumSHA1": "9pUt2OvfLX8RpWG8gq4efJ33eQw=",
 			"path": "github.com/pingcap/parser/ast",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
 			"checksumSHA1": "skWGV4FNvD3vr+5olepaPPnylUw=",
 			"path": "github.com/pingcap/parser/auth",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
 			"checksumSHA1": "t4UHo966WzU9Z0IJkyGHRp0loOk=",
 			"path": "github.com/pingcap/parser/charset",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
 			"checksumSHA1": "SInoXbsRe0tnBwmatmtZYfSFbdk=",
 			"path": "github.com/pingcap/parser/format",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
-			"checksumSHA1": "reRV2qecd6NpB7tIW3JeK46K/sk=",
+			"checksumSHA1": "WZYTGDMnc1UfTdjdZoBbISsnpRY=",
 			"path": "github.com/pingcap/parser/model",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
 			"checksumSHA1": "QBa9yiMDQNl2cLLwqlRoNTpCPNg=",
 			"path": "github.com/pingcap/parser/mysql",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
-			"checksumSHA1": "oNBCSwJRykKuzIKgPCttatB9hAo=",
+			"checksumSHA1": "+O6CYIE0jT8pIDxWRP9FtKwFZjI=",
 			"path": "github.com/pingcap/parser/opcode",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
 			"checksumSHA1": "XvnUllvwMYd6HrMvMiKnn4cGN2M=",
 			"path": "github.com/pingcap/parser/terror",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
 			"checksumSHA1": "YoDiJ3sniNqxkP5X/BDkx6efteA=",
 			"path": "github.com/pingcap/parser/types",
-			"revision": "f20218bc290343c2752c4926c1bf4264343bbef4",
-			"revisionTime": "2018-12-12T04:21:31Z"
+			"revision": "651ad7108326d8bc3991288d749bb6c778135216",
+			"revisionTime": "2018-12-21T12:21:43Z"
 		},
 		{
-			"checksumSHA1": "fWqL/7jTYOiqDNmiUcQi3u45Hw0=",
+			"checksumSHA1": "+0bf1l46m6GG7JtACNufnZG0OUw=",
 			"path": "github.com/pingcap/tidb/sessionctx/stmtctx",
-			"revision": "4ccd7456fcdc5e62e68f49a0a542cbcf88e38343",
-			"revisionTime": "2018-12-13T09:52:39Z"
+			"revision": "ef7082da1cb2da10bee4ad70eb6ec9412bc96a90",
+			"revisionTime": "2018-12-22T14:19:41Z"
 		},
 		{
-			"checksumSHA1": "0CCq+3fAyaXs9XU+xWaRvbbtSOQ=",
+			"checksumSHA1": "kXyszfR2fQ6bHvuCCFlHRkt1mF0=",
 			"path": "github.com/pingcap/tidb/types",
-			"revision": "4ccd7456fcdc5e62e68f49a0a542cbcf88e38343",
-			"revisionTime": "2018-12-13T09:52:39Z"
+			"revision": "ef7082da1cb2da10bee4ad70eb6ec9412bc96a90",
+			"revisionTime": "2018-12-22T14:19:41Z"
 		},
 		{
 			"checksumSHA1": "DWVD7+ygtT66IQ+cqXmMJ5OVqUk=",
 			"path": "github.com/pingcap/tidb/types/json",
-			"revision": "4ccd7456fcdc5e62e68f49a0a542cbcf88e38343",
-			"revisionTime": "2018-12-13T09:52:39Z"
+			"revision": "ef7082da1cb2da10bee4ad70eb6ec9412bc96a90",
+			"revisionTime": "2018-12-22T14:19:41Z"
 		},
 		{
-			"checksumSHA1": "Zp5ME8OXNTmHnYTwJJUZlydN4/U=",
+			"checksumSHA1": "6vi/eCZXqNTa5eAUpxDZet4LPlY=",
 			"path": "github.com/pingcap/tidb/types/parser_driver",
-			"revision": "4ccd7456fcdc5e62e68f49a0a542cbcf88e38343",
-			"revisionTime": "2018-12-13T09:52:39Z"
+			"revision": "ef7082da1cb2da10bee4ad70eb6ec9412bc96a90",
+			"revisionTime": "2018-12-22T14:19:41Z"
 		},
 		{
 			"checksumSHA1": "s709bhSrG2Ec35406mGtrySid4s=",
 			"path": "github.com/pingcap/tidb/util/execdetails",
-			"revision": "4ccd7456fcdc5e62e68f49a0a542cbcf88e38343",
-			"revisionTime": "2018-12-13T09:52:39Z"
+			"revision": "ef7082da1cb2da10bee4ad70eb6ec9412bc96a90",
+			"revisionTime": "2018-12-22T14:19:41Z"
 		},
 		{
 			"checksumSHA1": "nUC7zVoAMNR2a+z2iGqHoN2AkFE=",
 			"path": "github.com/pingcap/tidb/util/hack",
-			"revision": "4ccd7456fcdc5e62e68f49a0a542cbcf88e38343",
-			"revisionTime": "2018-12-13T09:52:39Z"
+			"revision": "ef7082da1cb2da10bee4ad70eb6ec9412bc96a90",
+			"revisionTime": "2018-12-22T14:19:41Z"
 		},
 		{
 			"checksumSHA1": "xSyepiuqsoaaeDch7cXeumvVHKM=",
 			"path": "github.com/pingcap/tidb/util/memory",
-			"revision": "4ccd7456fcdc5e62e68f49a0a542cbcf88e38343",
-			"revisionTime": "2018-12-13T09:52:39Z"
+			"revision": "ef7082da1cb2da10bee4ad70eb6ec9412bc96a90",
+			"revisionTime": "2018-12-22T14:19:41Z"
 		},
 		{
 			"checksumSHA1": "SmYeIK/fIYXNu8IKxD6HOVQVTuU=",
@@ -401,62 +401,62 @@
 		{
 			"checksumSHA1": "aKn1oKcY74N8TRLm3Ayt7Q4bbI4=",
 			"path": "vitess.io/vitess/go/bytes2",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		},
 		{
 			"checksumSHA1": "JVCEN4UGRmg3TofIBdzZMZ3G0Ww=",
 			"path": "vitess.io/vitess/go/hack",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		},
 		{
-			"checksumSHA1": "e1WJ7vCnVrlQQQlc6n/FewCDMso=",
+			"checksumSHA1": "F5pcGq+2W1FHEjgktTdKOE6W8mk=",
 			"path": "vitess.io/vitess/go/sqltypes",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		},
 		{
 			"checksumSHA1": "ntFIQYkBS51G6y+FEkjFW40+HOU=",
 			"path": "vitess.io/vitess/go/vt/log",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		},
 		{
 			"checksumSHA1": "tPQFPwbMdjuX0qjNl4Zl8zc37JQ=",
 			"path": "vitess.io/vitess/go/vt/proto/query",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		},
 		{
 			"checksumSHA1": "o0tR/c7lgr0pLkxk7CdvjiNDAKU=",
 			"path": "vitess.io/vitess/go/vt/proto/topodata",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		},
 		{
 			"checksumSHA1": "77UojBqi0yyeQvR70j7C3kcKclQ=",
 			"path": "vitess.io/vitess/go/vt/proto/vtgate",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		},
 		{
 			"checksumSHA1": "QpWGhoVDwM+8+sgYLI/YU+95iGU=",
 			"path": "vitess.io/vitess/go/vt/proto/vtrpc",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		},
 		{
-			"checksumSHA1": "lENrUY/YyxwYFHYN+21TBH92P3U=",
+			"checksumSHA1": "IDe+9Bn42lZVsuoYO/epdguiErk=",
 			"path": "vitess.io/vitess/go/vt/sqlparser",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		},
 		{
-			"checksumSHA1": "oF4XzuOzwvj1iduX/lYqNSyY/HM=",
+			"checksumSHA1": "Jx+gOh/kiBDSZxEIWHyYn9brjdo=",
 			"path": "vitess.io/vitess/go/vt/vterrors",
-			"revision": "eb5a5e0e435db30856600b794d8cff235fdf24b7",
-			"revisionTime": "2018-12-13T22:28:01Z"
+			"revision": "23f135ea6e773f3cc7c43c3d10c482b2221e9db9",
+			"revisionTime": "2018-12-22T19:18:51Z"
 		}
 	],
 	"rootPath": "github.com/XiaoMi/soar"

vendor/vitess.io/vitess/go/sqltypes/query_response.go

@@ -16,7 +16,9 @@ limitations under the License.
 
 package sqltypes
 
-import "reflect"
+import (
+	"vitess.io/vitess/go/vt/vterrors"
+)
 
 // QueryResponse represents a query response for ExecuteBatch.
 type QueryResponse struct {
@@ -34,7 +36,7 @@ func QueryResponsesEqual(r1, r2 []QueryResponse) bool {
 		if !r.QueryResult.Equal(r2[i].QueryResult) {
 			return false
 		}
-		if !reflect.DeepEqual(r.QueryError, r2[i].QueryError) {
+		if !vterrors.Equals(r.QueryError, r2[i].QueryError) {
 			return false
 		}
 	}

vendor/vitess.io/vitess/go/vt/sqlparser/ast.go

@@ -3691,7 +3691,7 @@ mustEscape:
 }
 
 func compliantName(in string) string {
-	var buf bytes.Buffer
+	var buf strings.Builder
 	for i, c := range in {
 		if !isLetter(uint16(c)) {
 			if i == 0 || !isDigit(uint16(c)) {

vendor/vitess.io/vitess/go/vt/vterrors/LICENSE

+Copyright (c) 2015, Dave Cheney <dave@cheney.net>
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/vitess.io/vitess/go/vt/vterrors/doc.go

-/*
-Copyright 2017 Google 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 agreedto 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.
-*/
-
-// Package vterrors provides helpers for propagating internal errors
-// through the Vitess system (including across RPC boundaries) in a
-// structured way.
-package vterrors
-
-/*
-
-Vitess uses canonical error codes for error reporting. This is based
-on years of industry experience with error reporting. This idea is
-that errors should be classified into a small set of errors (10 or so)
-with very specific meaning. Each error has a code, and a message. When
-errors are passed around (even through RPCs), the code is
-propagated. To handle errors, only the code should be looked at (and
-not string-matching on the error message).
-
-Vitess defines the error codes in /proto/vtrpc.proto. Along with an
-RPCError message that can be used to transmit errors through RPCs, in
-the message payloads. These codes match the names and numbers defined
-by gRPC.
-
-Vitess also defines a standardized error implementation that allows
-you to build an error with an associated canonical code.
-
-While sending an error through gRPC, these codes are transmitted
-using gRPC's error propagation mechanism and decoded back to
-the original code on the other end.
-
-*/

vendor/vitess.io/vitess/go/vt/vterrors/stack.go

+package vterrors
+
+/* This file is copied from https://github.com/pkg/errors/blob/v0.8.0/stack.go */
+
+import (
+	"fmt"
+	"io"
+	"path"
+	"runtime"
+	"strings"
+)
+
+// Frame represents a program counter inside a stack frame.
+type Frame uintptr
+
+// pc returns the program counter for this frame;
+// multiple frames may have the same PC value.
+func (f Frame) pc() uintptr { return uintptr(f) - 1 }
+
+// file returns the full path to the file that contains the
+// function for this Frame's pc.
+func (f Frame) file() string {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return "unknown"
+	}
+	file, _ := fn.FileLine(f.pc())
+	return file
+}
+
+// line returns the line number of source code of the
+// function for this Frame's pc.
+func (f Frame) line() int {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return 0
+	}
+	_, line := fn.FileLine(f.pc())
+	return line
+}
+
+// Format formats the frame according to the fmt.Formatter interface.
+//
+//    %s    source file
+//    %d    source line
+//    %n    function name
+//    %v    equivalent to %s:%d
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//    %+s   path of source file relative to the compile time GOPATH
+//    %+v   equivalent to %+s:%d
+func (f Frame) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 's':
+		switch {
+		case s.Flag('+'):
+			pc := f.pc()
+			fn := runtime.FuncForPC(pc)
+			if fn == nil {
+				io.WriteString(s, "unknown")
+			} else {
+				file, _ := fn.FileLine(pc)
+				fmt.Fprintf(s, "%s\n\t%s", fn.Name(), file)
+			}
+		default:
+			io.WriteString(s, path.Base(f.file()))
+		}
+	case 'd':
+		fmt.Fprintf(s, "%d", f.line())
+	case 'n':
+		name := runtime.FuncForPC(f.pc()).Name()
+		io.WriteString(s, funcname(name))
+	case 'v':
+		f.Format(s, 's')
+		io.WriteString(s, ":")
+		f.Format(s, 'd')
+	}
+}
+
+// StackTrace is stack of Frames from innermost (newest) to outermost (oldest).
+type StackTrace []Frame
+
+// Format format the stacktrace according to the fmt.Formatter interface.
+//
+//    %s    source file
+//    %d    source line
+//    %n    function name
+//    %v    equivalent to %s:%d
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//    %+s   path of source file relative to the compile time GOPATH
+//    %+v   equivalent to %+s:%d
+func (st StackTrace) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case s.Flag('+'):
+			for _, f := range st {
+				fmt.Fprintf(s, "\n%+v", f)
+			}
+		case s.Flag('#'):
+			fmt.Fprintf(s, "%#v", []Frame(st))
+		default:
+			fmt.Fprintf(s, "%v", []Frame(st))
+		}
+	case 's':
+		fmt.Fprintf(s, "%s", []Frame(st))
+	}
+}
+
+// stack represents a stack of program counters.
+type stack []uintptr
+
+func (s *stack) Format(st fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case st.Flag('+'):
+			for _, pc := range *s {
+				f := Frame(pc)
+				fmt.Fprintf(st, "\n%+v", f)
+			}
+		}
+	}
+}
+
+func (s *stack) StackTrace() StackTrace {
+	f := make([]Frame, len(*s))
+	for i := 0; i < len(f); i++ {
+		f[i] = Frame((*s)[i])
+	}
+	return f
+}
+
+func callers() *stack {
+	const depth = 32
+	var pcs [depth]uintptr
+	n := runtime.Callers(3, pcs[:])
+	var st stack = pcs[0:n]
+	return &st
+}
+
+// funcname removes the path prefix component of a function's name reported by func.Name().
+func funcname(name string) string {
+	i := strings.LastIndex(name, "/")
+	name = name[i+1:]
+	i = strings.Index(name, ".")
+	return name[i+1:]
+}
+
+func trimGOPATH(name, file string) string {
+	// Here we want to get the source file path relative to the compile time
+	// GOPATH. As of Go 1.6.x there is no direct way to know the compiled
+	// GOPATH at runtime, but we can infer the number of path segments in the
+	// GOPATH. We note that fn.Name() returns the function name qualified by
+	// the import path, which does not include the GOPATH. Thus we can trim
+	// segments from the beginning of the file path until the number of path
+	// separators remaining is one more than the number of path separators in
+	// the function name. For example, given:
+	//
+	//    GOPATH     /home/user
+	//    file       /home/user/src/pkg/sub/file.go
+	//    fn.Name()  pkg/sub.Type.Method
+	//
+	// We want to produce:
+	//
+	//    pkg/sub/file.go
+	//
+	// From this we can easily see that fn.Name() has one less path separator
+	// than our desired output. We count separators from the end of the file
+	// path until it finds two more than in the function name and then move
+	// one character forward to preserve the initial path segment without a
+	// leading separator.
+	const sep = "/"
+	goal := strings.Count(name, sep) + 2
+	i := len(file)
+	for n := 0; n < goal; n++ {
+		i = strings.LastIndex(file[:i], sep)
+		if i == -1 {
+			// not enough separators found, set i so that the slice expression
+			// below leaves file unmodified
+			i = -len(sep)
+			break
+		}
+	}
+	// get back to 0 or trim the leading separator
+	file = file[i+len(sep):]
+	return file
+}

vendor/vitess.io/vitess/go/vt/vterrors/vterrors.go

-/*
-Copyright 2017 Google 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 agreedto 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.
-*/
-
+// Package vterrors provides simple error handling primitives for Vitess
+//
+// In all Vitess code, errors should be propagated using vterrors.Wrapf()
+// and not fmt.Errorf().
+//
+// New errors should be created using vterrors.New
+//
+// Vitess uses canonical error codes for error reporting. This is based
+// on years of industry experience with error reporting. This idea is
+// that errors should be classified into a small set of errors (10 or so)
+// with very specific meaning. Each error has a code, and a message. When
+// errors are passed around (even through RPCs), the code is
+// propagated. To handle errors, only the code should be looked at (and
+// not string-matching on the error message).
+//
+// Error codes are defined in /proto/vtrpc.proto. Along with an
+// RPCError message that can be used to transmit errors through RPCs, in
+// the message payloads. These codes match the names and numbers defined
+// by gRPC.
+//
+// A standardized error implementation that allows you to build an error
+// with an associated canonical code is also defined.
+// While sending an error through gRPC, these codes are transmitted
+// using gRPC's error propagation mechanism and decoded back to
+// the original code on the other end.
+//
+// Retrieving the cause of an error
+//
+// Using vterrors.Wrap constructs a stack of errors, adding context to the
+// preceding error. Depending on the nature of the error it may be necessary
+// to reverse the operation of errors.Wrap to retrieve the original error
+// for inspection. Any error value which implements this interface
+//
+//     type causer interface {
+//             Cause() error
+//     }
+//
+// can be inspected by vterrors.Cause and vterrors.RootCause.
+//
+// * vterrors.Cause will find the immediate cause if one is available, or nil
+//   if the error is not a `causer` or if no cause is available.
+// * vterrors.RootCause will recursively retrieve
+//   the topmost error which does not implement causer, which is assumed to be
+//   the original cause. For example:
+//
+//     switch err := errors.RootCause(err).(type) {
+//     case *MyError:
+//             // handle specifically
+//     default:
+//             // unknown error
+//     }
+//
+// causer interface is not exported by this package, but is considered a part
+// of stable public API.
+//
+// Formatted printing of errors
+//
+// All error values returned from this package implement fmt.Formatter and can
+// be formatted by the fmt package. The following verbs are supported
+//
+//     %s    print the error. If the error has a Cause it will be
+//           printed recursively
+//     %v    see %s
+//     %+v   extended format. Each Frame of the error's StackTrace will
+//           be printed in detail.
+//
+// Most but not all of the code in this file was originally copied from
+// https://github.com/pkg/errors/blob/v0.8.0/errors.go
 package vterrors
 
 import (
 	"fmt"
-
 	"golang.org/x/net/context"
-
+	"io"
 	vtrpcpb "vitess.io/vitess/go/vt/proto/vtrpc"
 )
 
-type vtError struct {
-	code vtrpcpb.Code
-	err  string
-}
-
-// New creates a new error using the code and input string.
-func New(code vtrpcpb.Code, in string) error {
-	if code == vtrpcpb.Code_OK {
-		panic("OK is an invalid error code; use INTERNAL instead")
-	}
-	return &vtError{
+// New returns an error with the supplied message.
+// New also records the stack trace at the point it was called.
+func New(code vtrpcpb.Code, message string) error {
+	return &fundamental{
+		msg:   message,
 		code:  code,
-		err:  in,
+		stack: callers(),
 	}
 }
 
-// Wrap wraps the given error, returning a new error with the given message as a prefix but with the same error code (if err was a vterror) and message of the passed error.
-func Wrap(err error, message string) error {
-	return New(Code(err), fmt.Sprintf("%v: %v", message, err.Error()))
+// NewWithoutCode returns an error when no applicable error code is available
+// It will record the stack trace when creating the error
+func NewWithoutCode(message string) error {
+	return &fundamental{
+		msg:   message,
+		code:  vtrpcpb.Code_UNKNOWN,
+		stack: callers(),
+	}
 }
 
-// Wrapf wraps the given error, returning a new error with the given format string as a prefix but with the same error code (if err was a vterror) and message of the passed error.
-func Wrapf(err error, format string, args ...interface{}) error {
-	return Wrap(err, fmt.Sprintf(format, args...))
+// Errorf formats according to a format specifier and returns the string
+// as a value that satisfies error.
+// Errorf also records the stack trace at the point it was called.
+func Errorf(code vtrpcpb.Code, format string, args ...interface{}) error {
+	return &fundamental{
+		msg:   fmt.Sprintf(format, args...),
+		code:  code,
+		stack: callers(),
+	}
 }
 
-// Errorf returns a new error built using Printf style arguments.
-func Errorf(code vtrpcpb.Code, format string, args ...interface{}) error {
-	return New(code, fmt.Sprintf(format, args...))
+// fundamental is an error that has a message and a stack, but no caller.
+type fundamental struct {
+	msg  string
+	code vtrpcpb.Code
+	*stack
 }
 
-func (e *vtError) Error() string {
-	return e.err
+func (f *fundamental) Error() string { return f.msg }
+
+func (f *fundamental) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			io.WriteString(s, "Code: "+f.code.String()+"\n")
+			io.WriteString(s, f.msg+"\n")
+			f.stack.Format(s, verb)
+			return
+		}
+		fallthrough
+	case 's':
+		io.WriteString(s, f.msg)
+	case 'q':
+		fmt.Fprintf(s, "%q", f.msg)
+	}
 }
 
 // Code returns the error code if it's a vtError.
-// If err is nil, it returns ok. Otherwise, it returns unknown.
+// If err is nil, it returns ok.
 func Code(err error) vtrpcpb.Code {
 	if err == nil {
 		return vtrpcpb.Code_OK
 	}
-	if err, ok := err.(*vtError); ok {
+	if err, ok := err.(*fundamental); ok {
 		return err.code
 	}
+
+	cause := Cause(err)
+	if cause != err && cause != nil {
+		// If we did not find an error code at the outer level, let's find the cause and check it's code
+		return Code(cause)
+	}
+
 	// Handle some special cases.
 	switch err {
 	case context.Canceled:
@@ -78,16 +158,111 @@ func Code(err error) vtrpcpb.Code {
 	return vtrpcpb.Code_UNKNOWN
 }
 
+// Wrap returns an error annotating err with a stack trace
+// at the point Wrap is called, and the supplied message.
+// If err is nil, Wrap returns nil.
+func Wrap(err error, message string) error {
+	if err == nil {
+		return nil
+	}
+	return &wrapping{
+		cause: err,
+		msg:   message,
+		stack: callers(),
+	}
+}
+
+// Wrapf returns an error annotating err with a stack trace
+// at the point Wrapf is call, and the format specifier.
+// If err is nil, Wrapf returns nil.
+func Wrapf(err error, format string, args ...interface{}) error {
+	if err == nil {
+		return nil
+	}
+	return &wrapping{
+		cause: err,
+		msg:   fmt.Sprintf(format, args...),
+		stack: callers(),
+	}
+}
+
+type wrapping struct {
+	cause error
+	msg   string
+	stack *stack
+}
+
+func (w *wrapping) Error() string { return w.msg + ": " + w.cause.Error() }
+func (w *wrapping) Cause() error  { return w.cause }
+
+func (w *wrapping) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprintf(s, "%+v\n", w.Cause())
+			io.WriteString(s, w.msg)
+			w.stack.Format(s, verb)
+			return
+		}
+		fallthrough
+	case 's', 'q':
+		io.WriteString(s, w.Error())
+	}
+}
+
+// RootCause returns the underlying cause of the error, if possible.
+// An error value has a cause if it implements the following
+// interface:
+//
+//     type causer interface {
+//            Cause() error
+//     }
+//
+// If the error does not implement Cause, the original error will
+// be returned. If the error is nil, nil will be returned without further
+// investigation.
+func RootCause(err error) error {
+	for {
+		cause := Cause(err)
+		if cause == nil {
+			return err
+		}
+		err = cause
+	}
+}
+
+//
+// Cause will return the immediate cause, if possible.
+// An error value has a cause if it implements the following
+// interface:
+//
+//     type causer interface {
+//            Cause() error
+//     }
+// If the error does not implement Cause, nil will be returned
+func Cause(err error) error {
+	type causer interface {
+		Cause() error
+	}
+
+	causerObj, ok := err.(causer)
+	if !ok {
+		return nil
+	}
+
+	return causerObj.Cause()
+}
+
 // Equals returns true iff the error message and the code returned by Code()
-// is equal.
+// are equal.
 func Equals(a, b error) bool {
 	if a == nil && b == nil {
 		// Both are nil.
 		return true
 	}
 
-	if a == nil && b != nil || a != nil && b == nil {
-		// One of the two is nil.
+	if a == nil || b == nil {
+		// One of the two is nil, since we know both are not nil.
 		return false
 	}
 
@@ -97,5 +272,5 @@ func Equals(a, b error) bool {
 // Print is meant to print the vtError object in test failures.
 // For comparing two vterrors, use Equals() instead.
 func Print(err error) string {
-	return fmt.Sprintf("%v: %v", Code(err), err.Error())
+	return fmt.Sprintf("%v: %v\n", Code(err), err.Error())
 }