sessionctx/variable: remove dependency on context package. (pingcap#2064

)

Makes using session variable easier and faster.
Prepare for use session variable to handle data truncated error.

ast/misc.go

@@ -19,7 +19,6 @@ import (
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/sessionctx/db"
 )
 
 var (
@@ -565,7 +564,7 @@ func (i Ident) Full(ctx context.Context) (full Ident) {
 	if i.Schema.O != "" {
 		full.Schema = i.Schema
 	} else {
-		full.Schema = model.NewCIStr(db.GetCurrentSchema(ctx))
+		full.Schema = model.NewCIStr(ctx.GetSessionVars().CurrentDB)
 	}
 	return
 }

bootstrap_test.go

@@ -20,10 +20,8 @@ import (
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/meta"
-	"github.com/pingcap/tidb/mysql"
 	"github.com/pingcap/tidb/parser"
 	"github.com/pingcap/tidb/sessionctx"
-	"github.com/pingcap/tidb/sessionctx/autocommit"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/util/testleak"
 )
@@ -88,18 +86,15 @@ func (s *testSessionSuite) TestBootstrap(c *C) {
 // Create a new session on store but only do ddl works.
 func (s *testSessionSuite) bootstrapWithOnlyDDLWork(store kv.Storage, c *C) {
 	ss := &session{
-		values: make(map[fmt.Stringer]interface{}),
-		store:  store,
-		parser: parser.New(),
+		values:      make(map[fmt.Stringer]interface{}),
+		store:       store,
+		parser:      parser.New(),
+		sessionVars: variable.NewSessionVars(),
 	}
 	ss.SetValue(context.Initing, true)
 	domain, err := domap.Get(store)
 	c.Assert(err, IsNil)
 	sessionctx.BindDomain(ss, domain)
-	variable.BindSessionVars(ss)
-	variable.GetSessionVars(ss).SetStatusFlag(mysql.ServerStatusAutocommit, true)
-	// session implements autocommit.Checker. Bind it to ctx
-	autocommit.BindAutocommitChecker(ss, ss)
 	sessionMu.Lock()
 	defer sessionMu.Unlock()
 	b, err := checkBootstrapped(ss)

context/context.go

@@ -17,6 +17,7 @@ import (
 	"fmt"
 
 	"github.com/pingcap/tidb/kv"
+	"github.com/pingcap/tidb/sessionctx/variable"
 )
 
 // Context is an interface for transaction and executive args environment.
@@ -41,6 +42,8 @@ type Context interface {
 
 	// ClearValue clears the value associated with this context for key.
 	ClearValue(key fmt.Stringer)
+
+	GetSessionVars() *variable.SessionVars
 }
 
 type basicCtxType int

ddl/ddl_test.go

@@ -24,7 +24,6 @@ import (
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/meta"
 	"github.com/pingcap/tidb/model"
-	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/store/localstore"
 	"github.com/pingcap/tidb/store/localstore/goleveldb"
 )
@@ -43,7 +42,6 @@ func testCreateStore(c *C, name string) kv.Storage {
 
 func testNewContext(c *C, d *ddl) context.Context {
 	ctx := d.newMockContext()
-	variable.BindSessionVars(ctx)
 	return ctx
 }
 

ddl/reorg.go

@@ -24,17 +24,20 @@ import (
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/meta"
 	"github.com/pingcap/tidb/model"
+	"github.com/pingcap/tidb/mysql"
+	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/terror"
 )
 
 var _ context.Context = &mockContext{}
 
 // mockContext implements context.Context interface for testing.
 type mockContext struct {
-	store kv.Storage
-	mux   sync.Mutex
-	m     map[fmt.Stringer]interface{}
-	txn   kv.Transaction
+	store       kv.Storage
+	mux         sync.Mutex
+	m           map[fmt.Stringer]interface{}
+	txn         kv.Transaction
+	sessionVars *variable.SessionVars
 }
 
 func (c *mockContext) GetTxn(forceNew bool) (kv.Transaction, error) {
@@ -102,12 +105,17 @@ func (c *mockContext) ClearValue(key fmt.Stringer) {
 	delete(c.m, key)
 }
 
+func (c *mockContext) GetSessionVars() *variable.SessionVars {
+	return c.sessionVars
+}
+
 func (d *ddl) newMockContext() context.Context {
 	c := &mockContext{
-		store: d.store,
-		m:     make(map[fmt.Stringer]interface{}),
+		store:       d.store,
+		m:           make(map[fmt.Stringer]interface{}),
+		sessionVars: variable.NewSessionVars(),
 	}
-
+	c.sessionVars.SetStatusFlag(mysql.ServerStatusAutocommit, false)
 	return c
 }
 

evaluator/builtin_info.go

@@ -21,23 +21,21 @@ import (
 	"github.com/juju/errors"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/sessionctx/db"
-	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/util/types"
 )
 
 // See https://dev.mysql.com/doc/refman/5.7/en/information-functions.html
 func builtinDatabase(args []types.Datum, ctx context.Context) (d types.Datum, err error) {
-	s := db.GetCurrentSchema(ctx)
-	if s == "" {
+	currentDB := ctx.GetSessionVars().CurrentDB
+	if currentDB == "" {
 		return d, nil
 	}
-	d.SetString(s)
+	d.SetString(currentDB)
 	return d, nil
 }
 
 func builtinFoundRows(arg []types.Datum, ctx context.Context) (d types.Datum, err error) {
-	data := variable.GetSessionVars(ctx)
+	data := ctx.GetSessionVars()
 	if data == nil {
 		return d, errors.Errorf("Missing session variable when evalue builtin")
 	}
@@ -49,7 +47,7 @@ func builtinFoundRows(arg []types.Datum, ctx context.Context) (d types.Datum, er
 // See https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_current-user
 // TODO: The value of CURRENT_USER() can differ from the value of USER(). We will finish this after we support grant tables.
 func builtinCurrentUser(args []types.Datum, ctx context.Context) (d types.Datum, err error) {
-	data := variable.GetSessionVars(ctx)
+	data := ctx.GetSessionVars()
 	if data == nil {
 		return d, errors.Errorf("Missing session variable when evalue builtin")
 	}
@@ -59,7 +57,7 @@ func builtinCurrentUser(args []types.Datum, ctx context.Context) (d types.Datum,
 }
 
 func builtinUser(args []types.Datum, ctx context.Context) (d types.Datum, err error) {
-	data := variable.GetSessionVars(ctx)
+	data := ctx.GetSessionVars()
 	if data == nil {
 		return d, errors.Errorf("Missing session variable when evalue builtin")
 	}
@@ -69,7 +67,7 @@ func builtinUser(args []types.Datum, ctx context.Context) (d types.Datum, err er
 }
 
 func builtinConnectionID(args []types.Datum, ctx context.Context) (d types.Datum, err error) {
-	data := variable.GetSessionVars(ctx)
+	data := ctx.GetSessionVars()
 	if data == nil {
 		return d, errors.Errorf("Missing session variable when evalue builtin")
 	}
@@ -85,10 +83,10 @@ func builtinLastInsertID(args []types.Datum, ctx context.Context) (d types.Datum
 		if err != nil {
 			return d, errors.Trace(err)
 		}
-		variable.GetSessionVars(ctx).SetLastInsertID(uint64(id))
+		ctx.GetSessionVars().SetLastInsertID(uint64(id))
 	}
 
-	d.SetUint64(variable.GetSessionVars(ctx).LastInsertID)
+	d.SetUint64(ctx.GetSessionVars().LastInsertID)
 	return
 }
 

evaluator/builtin_info_test.go

@@ -16,8 +16,6 @@ package evaluator
 import (
 	. "github.com/pingcap/check"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/sessionctx/db"
-	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/util/mock"
 	"github.com/pingcap/tidb/util/testleak"
 	"github.com/pingcap/tidb/util/types"
@@ -29,8 +27,7 @@ func (s *testEvaluatorSuite) TestDatabase(c *C) {
 	d, err := builtinDatabase(types.MakeDatums(), ctx)
 	c.Assert(err, IsNil)
 	c.Assert(d.Kind(), Equals, types.KindNull)
-
-	db.BindCurrentSchema(ctx, "test")
+	ctx.GetSessionVars().CurrentDB = "test"
 	d, err = builtinDatabase(types.MakeDatums(), ctx)
 	c.Assert(err, IsNil)
 	c.Assert(d.GetString(), Equals, "test")
@@ -40,20 +37,14 @@ func (s *testEvaluatorSuite) TestFoundRows(c *C) {
 	defer testleak.AfterTest(c)()
 	ctx := mock.NewContext()
 	d, err := builtinFoundRows(types.MakeDatums(), ctx)
-	c.Assert(err, NotNil)
-
-	variable.BindSessionVars(ctx)
-
-	d, err = builtinFoundRows(types.MakeDatums(), ctx)
 	c.Assert(err, IsNil)
 	c.Assert(d.GetUint64(), Equals, uint64(0))
 }
 
 func (s *testEvaluatorSuite) TestUser(c *C) {
 	defer testleak.AfterTest(c)()
 	ctx := mock.NewContext()
-	variable.BindSessionVars(ctx)
-	sessionVars := variable.GetSessionVars(ctx)
+	sessionVars := ctx.GetSessionVars()
 	sessionVars.User = "root@localhost"
 
 	d, err := builtinUser(types.MakeDatums(), ctx)
@@ -64,8 +55,7 @@ func (s *testEvaluatorSuite) TestUser(c *C) {
 func (s *testEvaluatorSuite) TestCurrentUser(c *C) {
 	defer testleak.AfterTest(c)()
 	ctx := mock.NewContext()
-	variable.BindSessionVars(ctx)
-	sessionVars := variable.GetSessionVars(ctx)
+	sessionVars := ctx.GetSessionVars()
 	sessionVars.User = "root@localhost"
 
 	d, err := builtinCurrentUser(types.MakeDatums(), ctx)
@@ -76,8 +66,7 @@ func (s *testEvaluatorSuite) TestCurrentUser(c *C) {
 func (s *testEvaluatorSuite) TestConnectionID(c *C) {
 	defer testleak.AfterTest(c)()
 	ctx := mock.NewContext()
-	variable.BindSessionVars(ctx)
-	sessionVars := variable.GetSessionVars(ctx)
+	sessionVars := ctx.GetSessionVars()
 	sessionVars.ConnectionID = uint64(1)
 
 	d, err := builtinConnectionID(types.MakeDatums(), ctx)

evaluator/builtin_other.go

@@ -22,7 +22,6 @@ import (
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/mysql"
 	"github.com/pingcap/tidb/parser/opcode"
-	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/util/types"
 )
 
@@ -32,7 +31,7 @@ func builtinSleep(args []types.Datum, ctx context.Context) (d types.Datum, err e
 		return d, errors.Errorf("Missing context when evalue builtin")
 	}
 
-	sessVars := variable.GetSessionVars(ctx)
+	sessVars := ctx.GetSessionVars()
 	if args[0].IsNull() {
 		if sessVars.StrictSQLMode {
 			return d, errors.New("incorrect arguments to sleep")
@@ -520,7 +519,7 @@ func CastFuncFactory(tp *types.FieldType) (BuiltinFunc, error) {
 }
 
 func builtinSetVar(args []types.Datum, ctx context.Context) (types.Datum, error) {
-	sessionVars := variable.GetSessionVars(ctx)
+	sessionVars := ctx.GetSessionVars()
 	varName, _ := args[0].ToString()
 	if !args[1].IsNull() {
 		strVal, err := args[1].ToString()
@@ -533,7 +532,7 @@ func builtinSetVar(args []types.Datum, ctx context.Context) (types.Datum, error)
 }
 
 func builtinGetVar(args []types.Datum, ctx context.Context) (types.Datum, error) {
-	sessionVars := variable.GetSessionVars(ctx)
+	sessionVars := ctx.GetSessionVars()
 	varName, _ := args[0].ToString()
 	if v, ok := sessionVars.Users[varName]; ok {
 		return types.NewDatum(v), nil

evaluator/evaluator.go

@@ -586,8 +586,8 @@ func (e *Evaluator) values(v *ast.ValuesExpr) bool {
 
 func (e *Evaluator) variable(v *ast.VariableExpr) bool {
 	name := strings.ToLower(v.Name)
-	sessionVars := variable.GetSessionVars(e.ctx)
-	globalVars := variable.GetGlobalVarAccessor(e.ctx)
+	sessionVars := e.ctx.GetSessionVars()
+	globalVars := sessionVars.GlobalVarsAccessor
 	if !v.IsSystem {
 		if v.Value != nil && !v.Value.GetDatum().IsNull() {
 			strVal, err := v.Value.GetDatum().ToString()
@@ -627,7 +627,7 @@ func (e *Evaluator) variable(v *ast.VariableExpr) bool {
 				d.SetString(sysVar.Value)
 			} else {
 				// Get global system variable and fill it in session.
-				globalVal, err := globalVars.GetGlobalSysVar(e.ctx, name)
+				globalVal, err := globalVars.GetGlobalSysVar(name)
 				if err != nil {
 					e.err = errors.Trace(err)
 					return false
@@ -643,7 +643,7 @@ func (e *Evaluator) variable(v *ast.VariableExpr) bool {
 		v.SetDatum(d)
 		return true
 	}
-	value, err := globalVars.GetGlobalSysVar(e.ctx, name)
+	value, err := globalVars.GetGlobalSysVar(name)
 	if err != nil {
 		e.err = errors.Trace(err)
 		return false

evaluator/evaluator_test.go

@@ -25,7 +25,6 @@ import (
 	"github.com/pingcap/tidb/mysql"
 	"github.com/pingcap/tidb/parser"
 	"github.com/pingcap/tidb/parser/opcode"
-	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/util/charset"
 	"github.com/pingcap/tidb/util/mock"
 	"github.com/pingcap/tidb/util/testleak"
@@ -83,8 +82,7 @@ func (s *testEvaluatorSuite) TestBetween(c *C) {
 func (s *testEvaluatorSuite) TestSleep(c *C) {
 	defer testleak.AfterTest(c)()
 	ctx := mock.NewContext()
-	variable.BindSessionVars(ctx)
-	sessVars := variable.GetSessionVars(ctx)
+	sessVars := ctx.GetSessionVars()
 
 	// non-strict model
 	sessVars.StrictSQLMode = false
@@ -697,7 +695,6 @@ func (s *testEvaluatorSuite) TestLastInsertID(c *C) {
 	}
 
 	ctx := mock.NewContext()
-	variable.BindSessionVars(ctx)
 	c.Log(ctx)
 	for _, ca := range cases {
 		expr := &ast.FuncCallExpr{
@@ -952,8 +949,7 @@ func (s *testEvaluatorSuite) TestGetTimeValue(c *C) {
 	c.Assert(timeValue.String(), Equals, "2012-12-12 00:00:00")
 
 	ctx := mock.NewContext()
-	variable.BindSessionVars(ctx)
-	sessionVars := variable.GetSessionVars(ctx)
+	sessionVars := ctx.GetSessionVars()
 	sessionVars.SetSystemVar("timestamp", types.NewStringDatum(""))
 	v, err = GetTimeValue(ctx, "2012-12-12 00:00:00", mysql.TypeTimestamp, mysql.MinFsp)
 	c.Assert(err, IsNil)

evaluator/helper.go

@@ -8,7 +8,6 @@ import (
 	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/util/types"
 )
 
@@ -117,7 +116,7 @@ func getSystemTimestamp(ctx context.Context) (time.Time, error) {
 	}
 
 	// check whether use timestamp varibale
-	sessionVars := variable.GetSessionVars(ctx)
+	sessionVars := ctx.GetSessionVars()
 	ts := sessionVars.GetSystemVar("timestamp")
 	if !ts.IsNull() && ts.GetString() != "" {
 		timestamp, err := ts.ToInt64()

executor/adapter.go

@@ -21,7 +21,6 @@ import (
 	"github.com/pingcap/tidb/infoschema"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/plan"
-	"github.com/pingcap/tidb/sessionctx/variable"
 )
 
 // recordSet wraps an executor, implements ast.RecordSet interface
@@ -110,7 +109,7 @@ func (a *statement) Exec(ctx context.Context) (ast.RecordSet, error) {
 		// In history read mode, we can not do write operations.
 		switch e.(type) {
 		case *DeleteExec, *InsertExec, *UpdateExec, *ReplaceExec, *LoadData, *DDLExec:
-			snapshotTS := variable.GetSnapshotTS(ctx)
+			snapshotTS := ctx.GetSessionVars().SnapshotTS
 			if snapshotTS != 0 {
 				return nil, errors.New("can not execute write statement when 'tidb_snapshot' is set")
 			}