Merge pull request pingcap#901 from pingcap/coocood/simple

executor, optimizer: add simple plan and executor, implement UseStmt.

executor/builder.go

@@ -78,6 +78,8 @@ func (b *executorBuilder) build(p plan.Plan) Executor {
 		return b.buildSelectLock(v)
 	case *plan.ShowDDL:
 		return b.buildShowDDL(v)
+	case *plan.Simple:
+		return b.buildSimple(v)
 	case *plan.Sort:
 		return b.buildSort(v)
 	case *plan.TableScan:
@@ -327,3 +329,7 @@ func (b *executorBuilder) buildDelete(v *plan.Delete) Executor {
 		IsMultiTable: v.IsMultiTable,
 	}
 }
+
+func (b *executorBuilder) buildSimple(v *plan.Simple) Executor {
+	return &SimpleExec{Statement: v.Statement, ctx: b.ctx}
+}

executor/converter/convert_stmt.go

@@ -868,51 +868,6 @@ func convertRollback(converter *expressionConverter, v *ast.RollbackStmt) (*stmt
 	}, nil
 }
 
-func convertUse(converter *expressionConverter, v *ast.UseStmt) (*stmts.UseStmt, error) {
-	return &stmts.UseStmt{
-		DBName: v.DBName,
-		Text:   v.Text(),
-	}, nil
-}
-
-func convertVariableAssignment(converter *expressionConverter, v *ast.VariableAssignment) (*stmts.VariableAssignment, error) {
-	oldValue, err := convertExpr(converter, v.Value)
-	if err != nil {
-		return nil, errors.Trace(err)
-	}
-
-	return &stmts.VariableAssignment{
-		IsGlobal: v.IsGlobal,
-		IsSystem: v.IsSystem,
-		Name:     v.Name,
-		Value:    oldValue,
-		Text:     v.Text(),
-	}, nil
-}
-
-func convertSet(converter *expressionConverter, v *ast.SetStmt) (*stmts.SetStmt, error) {
-	oldSet := &stmts.SetStmt{
-		Text:      v.Text(),
-		Variables: make([]*stmts.VariableAssignment, len(v.Variables)),
-	}
-	for i, val := range v.Variables {
-		oldAssign, err := convertVariableAssignment(converter, val)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		oldSet.Variables[i] = oldAssign
-	}
-	return oldSet, nil
-}
-
-func convertSetCharset(converter *expressionConverter, v *ast.SetCharsetStmt) (*stmts.SetCharsetStmt, error) {
-	return &stmts.SetCharsetStmt{
-		Charset: v.Charset,
-		Collate: v.Collate,
-		Text:    v.Text(),
-	}, nil
-}
-
 func convertSetPwd(converter *expressionConverter, v *ast.SetPwdStmt) (*stmts.SetPwdStmt, error) {
 	return &stmts.SetPwdStmt{
 		User:     v.User,

executor/converter/converter.go

@@ -62,12 +62,8 @@ func (con *Converter) Convert(node ast.Node) (stmt.Statement, error) {
 		return convertRollback(c, v)
 	case *ast.SelectStmt:
 		return convertSelect(c, v)
-	case *ast.SetCharsetStmt:
-		return convertSetCharset(c, v)
 	case *ast.SetPwdStmt:
 		return convertSetPwd(c, v)
-	case *ast.SetStmt:
-		return convertSet(c, v)
 	case *ast.ShowStmt:
 		return convertShow(c, v)
 	case *ast.TruncateTableStmt:
@@ -76,8 +72,6 @@ func (con *Converter) Convert(node ast.Node) (stmt.Statement, error) {
 		return convertUnion(c, v)
 	case *ast.UpdateStmt:
 		return convertUpdate(c, v)
-	case *ast.UseStmt:
-		return convertUse(c, v)
 	}
 	return nil, nil
 }

executor/executor_simple.go

@@ -0,0 +1,165 @@
+// Copyright 2016 PingCAP, 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,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package executor
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/juju/errors"
+	"github.com/pingcap/tidb/ast"
+	"github.com/pingcap/tidb/context"
+	"github.com/pingcap/tidb/infoschema"
+	"github.com/pingcap/tidb/model"
+	"github.com/pingcap/tidb/optimizer/evaluator"
+	"github.com/pingcap/tidb/sessionctx"
+	"github.com/pingcap/tidb/sessionctx/db"
+	"github.com/pingcap/tidb/sessionctx/variable"
+	"github.com/pingcap/tidb/util/charset"
+	"github.com/pingcap/tidb/util/types"
+)
+
+// SimpleExec represents simple statement executor.
+// For statements do simple execution.
+// includes `UseStmt`, 'SetStmt`, `SetCharsetStmt`.
+// TODO: list all simple statements.
+type SimpleExec struct {
+	Statement ast.StmtNode
+	ctx       context.Context
+	done      bool
+}
+
+// Fields implements Executor Fields interface.
+func (e *SimpleExec) Fields() []*ast.ResultField {
+	return nil
+}
+
+// Next implements Execution Next interface.
+func (e *SimpleExec) Next() (*Row, error) {
+	if e.done {
+		return nil, nil
+	}
+	var err error
+	switch x := e.Statement.(type) {
+	case *ast.UseStmt:
+		err = e.executeUse(x)
+	case *ast.SetStmt:
+		err = e.executeSet(x)
+	case *ast.SetCharsetStmt:
+		err = e.executeSetCharset(x)
+	}
+	if err != nil {
+		return nil, errors.Trace(err)
+	}
+	e.done = true
+	return nil, nil
+}
+
+// Close implements Executor Close interface.
+func (e *SimpleExec) Close() error {
+	return nil
+}
+
+func (e *SimpleExec) executeUse(s *ast.UseStmt) error {
+	dbname := model.NewCIStr(s.DBName)
+	dbinfo, exists := sessionctx.GetDomain(e.ctx).InfoSchema().SchemaByName(dbname)
+	if !exists {
+		return infoschema.DatabaseNotExists.Gen("database %s not exists", dbname)
+	}
+	db.BindCurrentSchema(e.ctx, dbname.O)
+	// character_set_database is the character set used by the default database.
+	// The server sets this variable whenever the default database changes.
+	// See: http://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_character_set_database
+	sessionVars := variable.GetSessionVars(e.ctx)
+	sessionVars.Systems[variable.CharsetDatabase] = dbinfo.Charset
+	sessionVars.Systems[variable.CollationDatabase] = dbinfo.Collate
+	return nil
+}
+
+func (e *SimpleExec) executeSet(s *ast.SetStmt) error {
+	sessionVars := variable.GetSessionVars(e.ctx)
+	globalVars := variable.GetGlobalVarAccessor(e.ctx)
+	for _, v := range s.Variables {
+		// Variable is case insensitive, we use lower case.
+		name := strings.ToLower(v.Name)
+		if !v.IsSystem {
+			// User variable.
+			value, err := evaluator.Eval(e.ctx, v.Value)
+			if err != nil {
+				return errors.Trace(err)
+			}
+
+			if value == nil {
+				delete(sessionVars.Users, name)
+			} else {
+				sessionVars.Users[name] = fmt.Sprintf("%v", value)
+			}
+			return nil
+		}
+		sysVar := variable.GetSysVar(name)
+		if sysVar == nil {
+			return variable.UnknownSystemVar.Gen("Unknown system variable '%s'", name)
+		}
+		if sysVar.Scope == variable.ScopeNone {
+			return errors.Errorf("Variable '%s' is a read only variable", name)
+		}
+		if v.IsGlobal {
+			if sysVar.Scope&variable.ScopeGlobal > 0 {
+				value, err := evaluator.Eval(e.ctx, v.Value)
+				if err != nil {
+					return errors.Trace(err)
+				}
+				if value == nil {
+					value = ""
+				}
+				svalue, err := types.ToString(value)
+				if err != nil {
+					return errors.Trace(err)
+				}
+				err = globalVars.SetGlobalSysVar(e.ctx, name, svalue)
+				return errors.Trace(err)
+			}
+			return errors.Errorf("Variable '%s' is a SESSION variable and can't be used with SET GLOBAL", name)
+		}
+		if sysVar.Scope&variable.ScopeSession > 0 {
+			if value, err := evaluator.Eval(e.ctx, v.Value); err != nil {
+				return errors.Trace(err)
+			} else if value == nil {
+				sessionVars.Systems[name] = ""
+			} else {
+				sessionVars.Systems[name] = fmt.Sprintf("%v", value)
+			}
+			return nil
+		}
+		return errors.Errorf("Variable '%s' is a GLOBAL variable and should be set with SET GLOBAL", name)
+	}
+	return nil
+}
+
+func (e *SimpleExec) executeSetCharset(s *ast.SetCharsetStmt) error {
+	collation := s.Collate
+	if len(collation) == 0 {
+		var err error
+		collation, err = charset.GetDefaultCollation(s.Charset)
+		if err != nil {
+			return errors.Trace(err)
+		}
+	}
+	sessionVars := variable.GetSessionVars(e.ctx)
+	for _, v := range variable.SetNamesVariables {
+		sessionVars.Systems[v] = s.Charset
+	}
+	sessionVars.Systems[variable.CollationConnection] = collation
+	return nil
+}

executor/executor_simple_test.go

@@ -0,0 +1,100 @@
+// Copyright 2016 PingCAP, 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,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package executor_test
+
+import (
+	. "github.com/pingcap/check"
+	"github.com/pingcap/tidb/context"
+	"github.com/pingcap/tidb/sessionctx/variable"
+	"github.com/pingcap/tidb/util/testkit"
+)
+
+func (s *testSuite) TestCharsetDatabase(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	testSQL := `create database if not exists cd_test_utf8 CHARACTER SET utf8 COLLATE utf8_bin;`
+	tk.MustExec(testSQL)
+
+	testSQL = `create database if not exists cd_test_latin1 CHARACTER SET latin1 COLLATE latin1_swedish_ci;`
+	tk.MustExec(testSQL)
+
+	testSQL = `use cd_test_utf8;`
+	tk.MustExec(testSQL)
+	tk.MustQuery(`select @@character_set_database;`).Check(testkit.Rows("utf8"))
+	tk.MustQuery(`select @@collation_database;`).Check(testkit.Rows("utf8_bin"))
+
+	testSQL = `use cd_test_latin1;`
+	tk.MustExec(testSQL)
+	tk.MustQuery(`select @@character_set_database;`).Check(testkit.Rows("latin1"))
+	tk.MustQuery(`select @@collation_database;`).Check(testkit.Rows("latin1_swedish_ci"))
+}
+
+func (s *testSuite) TestSet(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	testSQL := "SET @a = 1;"
+	tk.MustExec(testSQL)
+
+	testSQL = `SET @a = "1";`
+	tk.MustExec(testSQL)
+
+	testSQL = "SET @a = null;"
+	tk.MustExec(testSQL)
+
+	testSQL = "SET @@global.autocommit = 1;"
+	tk.MustExec(testSQL)
+
+	testSQL = "SET @@global.autocommit = null;"
+	tk.MustExec(testSQL)
+
+	testSQL = "SET @@autocommit = 1;"
+	tk.MustExec(testSQL)
+
+	testSQL = "SET @@autocommit = null;"
+	tk.MustExec(testSQL)
+
+	errTestSql := "SET @@date_format = 1;"
+	_, err := tk.Exec(errTestSql)
+	c.Assert(err, NotNil)
+
+	errTestSql = "SET @@rewriter_enabled = 1;"
+	_, err = tk.Exec(errTestSql)
+	c.Assert(err, NotNil)
+
+	errTestSql = "SET xxx = abcd;"
+	_, err = tk.Exec(errTestSql)
+	c.Assert(err, NotNil)
+
+	errTestSql = "SET @@global.a = 1;"
+	_, err = tk.Exec(errTestSql)
+	c.Assert(err, NotNil)
+
+	errTestSql = "SET @@global.timestamp = 1;"
+	_, err = tk.Exec(errTestSql)
+	c.Assert(err, NotNil)
+}
+
+func (s *testSuite) TestSetCharset(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec(`SET NAMES latin1`)
+
+	ctx := tk.Se.(context.Context)
+	sessionVars := variable.GetSessionVars(ctx)
+	for _, v := range variable.SetNamesVariables {
+		c.Assert(sessionVars.Systems[v] != "utf8", IsTrue)
+	}
+	tk.MustExec(`SET NAMES utf8`)
+	for _, v := range variable.SetNamesVariables {
+		c.Assert(sessionVars.Systems[v], Equals, "utf8")
+	}
+	c.Assert(sessionVars.Systems[variable.CollationConnection], Equals, "utf8_general_ci")
+}

optimizer/optimizer.go

@@ -88,6 +88,7 @@ func IsSupported(node ast.Node) bool {
 	switch node.(type) {
 	case *ast.SelectStmt, *ast.PrepareStmt, *ast.ExecuteStmt, *ast.DeallocateStmt,
 		*ast.AdminStmt, *ast.UpdateStmt, *ast.DeleteStmt, *ast.UnionStmt:
+	case *ast.UseStmt, *ast.SetStmt, *ast.SetCharsetStmt:
 	default:
 		return false
 	}

optimizer/plan/planbuilder.go

@@ -71,6 +71,12 @@ func (b *planBuilder) build(node ast.Node) Plan {
 		return b.buildUnion(x)
 	case *ast.UpdateStmt:
 		return b.buildUpdate(x)
+	case *ast.UseStmt:
+		return b.buildSimple(x)
+	case *ast.SetCharsetStmt:
+		return b.buildSimple(x)
+	case *ast.SetStmt:
+		return b.buildSimple(x)
 	}
 	b.err = ErrUnsupportedType.Gen("Unsupported type %T", node)
 	return nil
@@ -790,3 +796,7 @@ func columnOffsetInFields(cn *ast.ColumnName, fields []*ast.ResultField) (int, e
 	}
 	return offset, nil
 }
+
+func (b *planBuilder) buildSimple(node ast.StmtNode) Plan {
+	return &Simple{Statement: node}
+}