planner: provide a unified interface to set and get user variables and types

executor/load_data.go

@@ -625,13 +625,11 @@ func (e *LoadDataInfo) colsToRow(ctx context.Context, cols []field) []types.Datu
 	row := make([]types.Datum, 0, len(e.insertColumns))
 	sessionVars := e.Ctx.GetSessionVars()
 	setVar := func(name string, col *field) {
-		sessionVars.UsersLock.Lock()
 		if col == nil || col.isNull() {
 			sessionVars.UnsetUserVar(name)
 		} else {
 			sessionVars.SetUserVar(name, string(col.str), mysql.DefaultCollationName)
 		}
-		sessionVars.UsersLock.Unlock()
 	}
 
 	for i := 0; i < len(e.FieldMappings); i++ {

executor/set.go

@@ -87,14 +87,12 @@ func (e *SetExecutor) Next(ctx context.Context, req *chunk.Chunk) error {
 			if err != nil {
 				return err
 			}
-			sessionVars.UsersLock.Lock()
 			if value.IsNull() {
 				sessionVars.UnsetUserVar(name)
 			} else {
-				sessionVars.Users[name] = value
-				sessionVars.UserVarTypes[name] = v.Expr.GetType()
+				sessionVars.SetUserVarVal(name, value)
+				sessionVars.SetUserVarType(name, v.Expr.GetType())
 			}
-			sessionVars.UsersLock.Unlock()
 			continue
 		}
 

expression/builtin_other.go

@@ -776,9 +776,7 @@ func (b *builtinSetStringVarSig) evalString(row chunk.Row) (res string, isNull b
 	if err != nil {
 		return "", isNull, err
 	}
-	sessionVars.UsersLock.Lock()
 	sessionVars.SetUserVar(varName, stringutil.Copy(res), datum.Collation())
-	sessionVars.UsersLock.Unlock()
 	return res, false, nil
 }
 
@@ -806,9 +804,7 @@ func (b *builtinSetRealVarSig) evalReal(row chunk.Row) (res float64, isNull bool
 	}
 	res = datum.GetFloat64()
 	varName = strings.ToLower(varName)
-	sessionVars.UsersLock.Lock()
-	sessionVars.Users[varName] = datum
-	sessionVars.UsersLock.Unlock()
+	sessionVars.SetUserVarVal(varName, datum)
 	return res, false, nil
 }
 
@@ -835,9 +831,7 @@ func (b *builtinSetDecimalVarSig) evalDecimal(row chunk.Row) (*types.MyDecimal,
 	}
 	res := datum.GetMysqlDecimal()
 	varName = strings.ToLower(varName)
-	sessionVars.UsersLock.Lock()
-	sessionVars.Users[varName] = datum
-	sessionVars.UsersLock.Unlock()
+	sessionVars.SetUserVarVal(varName, datum)
 	return res, false, nil
 }
 
@@ -864,9 +858,7 @@ func (b *builtinSetIntVarSig) evalInt(row chunk.Row) (int64, bool, error) {
 	}
 	res := datum.GetInt64()
 	varName = strings.ToLower(varName)
-	sessionVars.UsersLock.Lock()
-	sessionVars.Users[varName] = datum
-	sessionVars.UsersLock.Unlock()
+	sessionVars.SetUserVarVal(varName, datum)
 	return res, false, nil
 }
 
@@ -892,9 +884,7 @@ func (b *builtinSetTimeVarSig) evalTime(row chunk.Row) (types.Time, bool, error)
 	}
 	res := datum.GetMysqlTime()
 	varName = strings.ToLower(varName)
-	sessionVars.UsersLock.Lock()
-	sessionVars.Users[varName] = datum
-	sessionVars.UsersLock.Unlock()
+	sessionVars.SetUserVarVal(varName, datum)
 	return res, false, nil
 }
 
@@ -971,9 +961,7 @@ func (b *builtinGetStringVarSig) evalString(row chunk.Row) (string, bool, error)
 		return "", isNull, err
 	}
 	varName = strings.ToLower(varName)
-	sessionVars.UsersLock.RLock()
-	defer sessionVars.UsersLock.RUnlock()
-	if v, ok := sessionVars.Users[varName]; ok {
+	if v, ok := sessionVars.GetUserVarVal(varName); ok {
 		// We cannot use v.GetString() here, because the datum may be in KindMysqlTime, which
 		// stores the data in datum.x.
 		// This seems controversial with https://dev.mysql.com/doc/refman/8.0/en/user-variables.html:
@@ -1025,9 +1013,7 @@ func (b *builtinGetIntVarSig) evalInt(row chunk.Row) (int64, bool, error) {
 		return 0, isNull, err
 	}
 	varName = strings.ToLower(varName)
-	sessionVars.UsersLock.RLock()
-	defer sessionVars.UsersLock.RUnlock()
-	if v, ok := sessionVars.Users[varName]; ok {
+	if v, ok := sessionVars.GetUserVarVal(varName); ok {
 		return v.GetInt64(), false, nil
 	}
 	return 0, true, nil
@@ -1067,9 +1053,7 @@ func (b *builtinGetRealVarSig) evalReal(row chunk.Row) (float64, bool, error) {
 		return 0, isNull, err
 	}
 	varName = strings.ToLower(varName)
-	sessionVars.UsersLock.RLock()
-	defer sessionVars.UsersLock.RUnlock()
-	if v, ok := sessionVars.Users[varName]; ok {
+	if v, ok := sessionVars.GetUserVarVal(varName); ok {
 		return v.GetFloat64(), false, nil
 	}
 	return 0, true, nil
@@ -1109,9 +1093,7 @@ func (b *builtinGetDecimalVarSig) evalDecimal(row chunk.Row) (*types.MyDecimal,
 		return nil, isNull, err
 	}
 	varName = strings.ToLower(varName)
-	sessionVars.UsersLock.RLock()
-	defer sessionVars.UsersLock.RUnlock()
-	if v, ok := sessionVars.Users[varName]; ok {
+	if v, ok := sessionVars.GetUserVarVal(varName); ok {
 		return v.GetMysqlDecimal(), false, nil
 	}
 	return nil, true, nil
@@ -1159,9 +1141,7 @@ func (b *builtinGetTimeVarSig) evalTime(row chunk.Row) (types.Time, bool, error)
 		return types.ZeroTime, isNull, err
 	}
 	varName = strings.ToLower(varName)
-	sessionVars.UsersLock.RLock()
-	defer sessionVars.UsersLock.RUnlock()
-	if v, ok := sessionVars.Users[varName]; ok {
+	if v, ok := sessionVars.GetUserVarVal(varName); ok {
 		return v.GetMysqlTime(), false, nil
 	}
 	return types.ZeroTime, true, nil

expression/builtin_other_test.go

@@ -111,7 +111,7 @@ func TestSetVar(t *testing.T) {
 		if tc.args[1] != nil {
 			key, ok := tc.args[0].(string)
 			require.Equal(t, true, ok)
-			sessionVar, ok := ctx.GetSessionVars().Users[key]
+			sessionVar, ok := ctx.GetSessionVars().GetUserVarVal(key)
 			require.Equal(t, true, ok)
 			require.Equal(t, tc.res, sessionVar.GetValue())
 		}
@@ -135,15 +135,15 @@ func TestGetVar(t *testing.T) {
 		{"h", timeDec},
 	}
 	for _, kv := range sessionVars {
-		ctx.GetSessionVars().Users[kv.key] = types.NewDatum(kv.val)
+		ctx.GetSessionVars().SetUserVarVal(kv.key, types.NewDatum(kv.val))
 		var tp *types.FieldType
 		if _, ok := kv.val.(types.Time); ok {
 			tp = types.NewFieldType(mysql.TypeDatetime)
 		} else {
 			tp = types.NewFieldType(mysql.TypeVarString)
 		}
 		types.DefaultParamTypeForValue(kv.val, tp)
-		ctx.GetSessionVars().UserVarTypes[kv.key] = tp
+		ctx.GetSessionVars().SetUserVarType(kv.key, tp)
 	}
 
 	testCases := []struct {
@@ -160,7 +160,7 @@ func TestGetVar(t *testing.T) {
 		{[]interface{}{"h"}, timeDec.String()},
 	}
 	for _, tc := range testCases {
-		tp, ok := ctx.GetSessionVars().UserVarTypes[tc.args[0].(string)]
+		tp, ok := ctx.GetSessionVars().GetUserVarType(tc.args[0].(string))
 		if !ok {
 			tp = types.NewFieldType(mysql.TypeVarString)
 		}
@@ -244,9 +244,7 @@ func TestSetVarFromColumn(t *testing.T) {
 
 	// Check whether the user variable changed.
 	sessionVars := ctx.GetSessionVars()
-	sessionVars.UsersLock.RLock()
-	defer sessionVars.UsersLock.RUnlock()
-	sessionVar, ok := sessionVars.Users["a"]
+	sessionVar, ok := sessionVars.GetUserVarVal("a")
 	require.Equal(t, true, ok)
 	require.Equal(t, "a", sessionVar.GetString())
 }

expression/builtin_other_vec.go

@@ -179,8 +179,6 @@ func (b *builtinSetStringVarSig) vecEvalString(input *chunk.Chunk, result *chunk
 	}
 	result.ReserveString(n)
 	sessionVars := b.ctx.GetSessionVars()
-	sessionVars.UsersLock.Lock()
-	defer sessionVars.UsersLock.Unlock()
 	_, collation := sessionVars.GetCharsetInfo()
 	for i := 0; i < n; i++ {
 		if buf0.IsNull(i) || buf1.IsNull(i) {
@@ -189,7 +187,7 @@ func (b *builtinSetStringVarSig) vecEvalString(input *chunk.Chunk, result *chunk
 		}
 		varName := strings.ToLower(buf0.GetString(i))
 		res := buf1.GetString(i)
-		sessionVars.Users[varName] = types.NewCollationStringDatum(stringutil.Copy(res), collation)
+		sessionVars.SetUserVarVal(varName, types.NewCollationStringDatum(stringutil.Copy(res), collation))
 		result.AppendString(res)
 	}
 	return nil
@@ -220,16 +218,14 @@ func (b *builtinSetIntVarSig) vecEvalInt(input *chunk.Chunk, result *chunk.Colum
 	result.ResizeInt64(n, false)
 	i64s := result.Int64s()
 	sessionVars := b.ctx.GetSessionVars()
-	sessionVars.UsersLock.Lock()
-	defer sessionVars.UsersLock.Unlock()
 	for i := 0; i < n; i++ {
 		if buf0.IsNull(i) || buf1.IsNull(i) {
 			result.SetNull(i, true)
 			continue
 		}
 		varName := strings.ToLower(buf0.GetString(i))
 		res := buf1.GetInt64(i)
-		sessionVars.Users[varName] = types.NewIntDatum(res)
+		sessionVars.SetUserVarVal(varName, types.NewIntDatum(res))
 		i64s[i] = res
 	}
 	return nil
@@ -260,16 +256,14 @@ func (b *builtinSetRealVarSig) vecEvalReal(input *chunk.Chunk, result *chunk.Col
 	result.ResizeFloat64(n, false)
 	f64s := result.Float64s()
 	sessionVars := b.ctx.GetSessionVars()
-	sessionVars.UsersLock.Lock()
-	defer sessionVars.UsersLock.Unlock()
 	for i := 0; i < n; i++ {
 		if buf0.IsNull(i) || buf1.IsNull(i) {
 			result.SetNull(i, true)
 			continue
 		}
 		varName := strings.ToLower(buf0.GetString(i))
 		res := buf1.GetFloat64(i)
-		sessionVars.Users[varName] = types.NewFloat64Datum(res)
+		sessionVars.SetUserVarVal(varName, types.NewFloat64Datum(res))
 		f64s[i] = res
 	}
 	return nil
@@ -300,16 +294,14 @@ func (b *builtinSetDecimalVarSig) vecEvalDecimal(input *chunk.Chunk, result *chu
 	result.ResizeDecimal(n, false)
 	decs := result.Decimals()
 	sessionVars := b.ctx.GetSessionVars()
-	sessionVars.UsersLock.Lock()
-	defer sessionVars.UsersLock.Unlock()
 	for i := 0; i < n; i++ {
 		if buf0.IsNull(i) || buf1.IsNull(i) {
 			result.SetNull(i, true)
 			continue
 		}
 		varName := strings.ToLower(buf0.GetString(i))
 		res := buf1.GetDecimal(i)
-		sessionVars.Users[varName] = types.NewDecimalDatum(res)
+		sessionVars.SetUserVarVal(varName, types.NewDecimalDatum(res))
 		decs[i] = *res
 	}
 	return nil
@@ -339,15 +331,13 @@ func (b *builtinGetStringVarSig) vecEvalString(input *chunk.Chunk, result *chunk
 	}
 	result.ReserveString(n)
 	sessionVars := b.ctx.GetSessionVars()
-	sessionVars.UsersLock.Lock()
-	defer sessionVars.UsersLock.Unlock()
 	for i := 0; i < n; i++ {
 		if buf0.IsNull(i) {
 			result.AppendNull()
 			continue
 		}
 		varName := strings.ToLower(buf0.GetString(i))
-		if v, ok := sessionVars.Users[varName]; ok {
+		if v, ok := sessionVars.GetUserVarVal(varName); ok {
 			res, err := v.ToString()
 			if err != nil {
 				return err
@@ -378,14 +368,12 @@ func (b *builtinGetIntVarSig) vecEvalInt(input *chunk.Chunk, result *chunk.Colum
 	result.MergeNulls(buf0)
 	i64s := result.Int64s()
 	sessionVars := b.ctx.GetSessionVars()
-	sessionVars.UsersLock.Lock()
-	defer sessionVars.UsersLock.Unlock()
 	for i := 0; i < n; i++ {
 		if result.IsNull(i) {
 			continue
 		}
 		varName := strings.ToLower(buf0.GetString(i))
-		if v, ok := sessionVars.Users[varName]; ok {
+		if v, ok := sessionVars.GetUserVarVal(varName); ok {
 			i64s[i] = v.GetInt64()
 			continue
 		}
@@ -412,14 +400,12 @@ func (b *builtinGetRealVarSig) vecEvalReal(input *chunk.Chunk, result *chunk.Col
 	result.MergeNulls(buf0)
 	f64s := result.Float64s()
 	sessionVars := b.ctx.GetSessionVars()
-	sessionVars.UsersLock.Lock()
-	defer sessionVars.UsersLock.Unlock()
 	for i := 0; i < n; i++ {
 		if result.IsNull(i) {
 			continue
 		}
 		varName := strings.ToLower(buf0.GetString(i))
-		if v, ok := sessionVars.Users[varName]; ok {
+		if v, ok := sessionVars.GetUserVarVal(varName); ok {
 			f64s[i] = v.GetFloat64()
 			continue
 		}
@@ -446,14 +432,12 @@ func (b *builtinGetDecimalVarSig) vecEvalDecimal(input *chunk.Chunk, result *chu
 	result.MergeNulls(buf0)
 	decs := result.Decimals()
 	sessionVars := b.ctx.GetSessionVars()
-	sessionVars.UsersLock.Lock()
-	defer sessionVars.UsersLock.Unlock()
 	for i := 0; i < n; i++ {
 		if result.IsNull(i) {
 			continue
 		}
 		varName := strings.ToLower(buf0.GetString(i))
-		if v, ok := sessionVars.Users[varName]; ok {
+		if v, ok := sessionVars.GetUserVarVal(varName); ok {
 			decs[i] = *v.GetMysqlDecimal()
 			continue
 		}

planner/core/common_plans.go

@@ -204,7 +204,7 @@ func isGetVarBinaryLiteral(sctx sessionctx.Context, expr expression.Expression)
 		name, isNull, err := scalarFunc.GetArgs()[0].EvalString(sctx, chunk.Row{})
 		if err != nil || isNull {
 			res = false
-		} else if dt, ok2 := sctx.GetSessionVars().Users[name]; ok2 {
+		} else if dt, ok2 := sctx.GetSessionVars().GetUserVarVal(name); ok2 {
 			res = dt.Kind() == types.KindBinaryLiteral
 		}
 	}

planner/core/expression_rewriter.go

@@ -1280,14 +1280,10 @@ func (er *expressionRewriter) rewriteVariable(v *ast.VariableExpr) {
 			// Store the field type of the variable into SessionVars.UserVarTypes.
 			// Normally we can infer the type from SessionVars.User, but we need SessionVars.UserVarTypes when
 			// GetVar has not been executed to fill the SessionVars.Users.
-			sessionVars.UsersLock.Lock()
-			sessionVars.UserVarTypes[name] = tp
-			sessionVars.UsersLock.Unlock()
+			sessionVars.SetUserVarType(name, tp)
 			return
 		}
-		sessionVars.UsersLock.RLock()
-		tp, ok := sessionVars.UserVarTypes[name]
-		sessionVars.UsersLock.RUnlock()
+		tp, ok := sessionVars.GetUserVarType(name)
 		if !ok {
 			tp = types.NewFieldType(mysql.TypeVarString)
 			tp.SetFlen(mysql.MaxFieldVarCharLength)

planner/core/plan_cache.go

@@ -103,8 +103,8 @@ func parseParamTypes(sctx sessionctx.Context, params []expression.Expression) (p
 
 		// from text protocol, there must be a GetVar function
 		name := param.(*expression.ScalarFunction).GetArgs()[0].String()
-		tp := sctx.GetSessionVars().UserVarTypes[name]
-		if tp == nil {
+		tp, ok := sctx.GetSessionVars().GetUserVarType(name)
+		if !ok {
 			tp = types.NewFieldType(mysql.TypeNull)
 		}
 		paramTypes = append(paramTypes, tp)

planner/core/planbuilder.go

@@ -1362,7 +1362,7 @@ func (b *PlanBuilder) buildPrepare(x *ast.PrepareStmt) Plan {
 		Name: x.Name,
 	}
 	if x.SQLVar != nil {
-		if v, ok := b.ctx.GetSessionVars().Users[strings.ToLower(x.SQLVar.Name)]; ok {
+		if v, ok := b.ctx.GetSessionVars().GetUserVarVal(strings.ToLower(x.SQLVar.Name)); ok {
 			var err error
 			p.SQLText, err = v.ToString()
 			if err != nil {