domain: Optimize GetDomain api

pkg/domain/domainctx.go

@@ -18,26 +18,11 @@ import (
 	contextutil "github.com/pingcap/tidb/pkg/util/context"
 )
 
-// domainKeyType is a dummy type to avoid naming collision in context.
-type domainKeyType int
-
-// String defines a Stringer function for debugging and pretty printing.
-func (domainKeyType) String() string {
-	return "domain"
-}
-
-const domainKey domainKeyType = 0
-
-// BindDomain binds domain to context.
-func BindDomain(ctx contextutil.ValueStoreContext, domain *Domain) {
-	ctx.SetValue(domainKey, domain)
-}
-
 // GetDomain gets domain from context.
 func GetDomain(ctx contextutil.ValueStoreContext) *Domain {
-	v, ok := ctx.Value(domainKey).(*Domain)
-	if !ok {
-		return nil
+	v, ok := ctx.GetDomain().(*Domain)
+	if ok {
+		return v
 	}
-	return v
+	return nil
 }

pkg/domain/domainctx_test.go

@@ -23,13 +23,11 @@ import (
 
 func TestDomainCtx(t *testing.T) {
 	ctx := mock.NewContext()
-	require.NotEqual(t, "", domainKey.String())
-
-	BindDomain(ctx, nil)
+	ctx.BindDomain(nil)
 	v := GetDomain(ctx)
 	require.Nil(t, v)
 
-	ctx.ClearValue(domainKey)
+	ctx.BindDomain(&Domain{})
 	v = GetDomain(ctx)
-	require.Nil(t, v)
+	require.NotNil(t, v)
 }

pkg/executor/executor_pkg_test.go

@@ -332,7 +332,7 @@ func TestFilterTemporaryTableKeys(t *testing.T) {
 
 func TestErrLevelsForResetStmtContext(t *testing.T) {
 	ctx := mock.NewContext()
-	domain.BindDomain(ctx, &domain.Domain{})
+	ctx.BindDomain(&domain.Domain{})
 
 	cases := []struct {
 		name    string

pkg/executor/executor_required_rows_test.go

@@ -215,7 +215,7 @@ func defaultCtx() sessionctx.Context {
 	ctx.GetSessionVars().StmtCtx.MemTracker = memory.NewTracker(-1, ctx.GetSessionVars().MemQuotaQuery)
 	ctx.GetSessionVars().StmtCtx.DiskTracker = disk.NewTracker(-1, -1)
 	ctx.GetSessionVars().SnapshotTS = uint64(1)
-	domain.BindDomain(ctx, domain.NewMockDomain())
+	ctx.BindDomain(domain.NewMockDomain())
 	return ctx
 }
 

pkg/executor/join/joiner_test.go

@@ -38,7 +38,7 @@ func defaultCtx() sessionctx.Context {
 	ctx.GetSessionVars().StmtCtx.MemTracker = memory.NewTracker(-1, ctx.GetSessionVars().MemQuotaQuery)
 	ctx.GetSessionVars().StmtCtx.DiskTracker = disk.NewTracker(-1, -1)
 	ctx.GetSessionVars().SnapshotTS = uint64(1)
-	domain.BindDomain(ctx, domain.NewMockDomain())
+	ctx.BindDomain(domain.NewMockDomain())
 	return ctx
 }
 

pkg/executor/select_test.go

@@ -26,7 +26,7 @@ import (
 func BenchmarkResetContextOfStmt(b *testing.B) {
 	stmt := &ast.SelectStmt{}
 	ctx := mock.NewContext()
-	domain.BindDomain(ctx, &domain.Domain{})
+	ctx.BindDomain(&domain.Domain{})
 	for i := 0; i < b.N; i++ {
 		executor.ResetContextOfStmt(ctx, stmt)
 	}

pkg/planner/core/logical_plans_test.go

@@ -118,7 +118,7 @@ func createPlannerSuite() (s *plannerSuite) {
 	if err := do.CreateStatsHandle(ctx, initStatsCtx); err != nil {
 		panic(fmt.Sprintf("create mock context panic: %+v", err))
 	}
-	domain.BindDomain(ctx, do)
+	ctx.BindDomain(do)
 	ctx.SetInfoSchema(s.is)
 	s.ctx = ctx
 	s.sctx = ctx

pkg/planner/core/mock.go

@@ -429,7 +429,7 @@ func MockContext() *mock.Context {
 	if err := do.CreateStatsHandle(ctx, initStatsCtx); err != nil {
 		panic(fmt.Sprintf("create mock context panic: %+v", err))
 	}
-	domain.BindDomain(ctx, do)
+	ctx.BindDomain(do)
 	return ctx
 }
 

pkg/session/bootstrap_test.go

@@ -178,7 +178,7 @@ func TestBootstrapWithError(t *testing.T) {
 		dom, err := domap.Get(store)
 		require.NoError(t, err)
 		require.NoError(t, dom.Start(ddl.Bootstrap))
-		domain.BindDomain(se, dom)
+		se.dom = dom
 		b, err := checkBootstrapped(se)
 		require.False(t, b)
 		require.NoError(t, err)
@@ -2409,7 +2409,7 @@ func TestTiDBUpgradeToVer211(t *testing.T) {
 	require.NoError(t, err)
 	require.Less(t, int64(ver210), ver)
 
-	domain.BindDomain(seV210, dom)
+	seV210.(*session).dom = dom
 	r := MustExecToRecodeSet(t, seV210, "select count(summary) from mysql.tidb_background_subtask_history;")
 	req := r.NewChunk(nil)
 	err = r.Next(ctx, req)

pkg/session/session.go

@@ -182,6 +182,8 @@ type session struct {
 	currentCtx  context.Context // only use for runtime.trace, Please NEVER use it.
 	currentPlan base.Plan
 
+	// dom is *domain.Domain, use `any` to avoid import cycle.
+	dom   any
 	store kv.Storage
 
 	sessionPlanCache sessionctx.SessionPlanCache
@@ -3789,6 +3791,7 @@ func createSessionWithOpt(store kv.Storage, opt *Opt) (*session, error) {
 		return nil, err
 	}
 	s := &session{
+		dom:                   dom,
 		store:                 store,
 		ddlOwnerManager:       dom.DDL().OwnerManager(),
 		client:                store.GetClient(),
@@ -3808,7 +3811,6 @@ func createSessionWithOpt(store kv.Storage, opt *Opt) (*session, error) {
 	s.lockedTables = make(map[int64]model.TableLockTpInfo)
 	s.advisoryLocks = make(map[string]*advisoryLock)
 
-	domain.BindDomain(s, dom)
 	// session implements variable.GlobalVarAccessor. Bind it to ctx.
 	s.sessionVars.GlobalVarsAccessor = s
 	s.txn.init()
@@ -3852,6 +3854,7 @@ func detachStatsCollector(s *session) *session {
 // a lock context, which cause we can't call createSession directly.
 func CreateSessionWithDomain(store kv.Storage, dom *domain.Domain) (*session, error) {
 	s := &session{
+		dom:                   dom,
 		store:                 store,
 		sessionVars:           variable.NewSessionVars(nil),
 		client:                store.GetClient(),
@@ -3864,7 +3867,6 @@ func CreateSessionWithDomain(store kv.Storage, dom *domain.Domain) (*session, er
 	s.tblctx = tblsession.NewMutateContext(s)
 	s.mu.values = make(map[fmt.Stringer]any)
 	s.lockedTables = make(map[int64]model.TableLockTpInfo)
-	domain.BindDomain(s, dom)
 	// session implements variable.GlobalVarAccessor. Bind it to ctx.
 	s.sessionVars.GlobalVarsAccessor = s
 	s.txn.init()
@@ -4674,3 +4676,8 @@ func (s *session) GetCursorTracker() cursor.Tracker {
 func (s *session) GetCommitWaitGroup() *sync.WaitGroup {
 	return &s.commitWaitGroup
 }
+
+// GetDomain get domain from session.
+func (s *session) GetDomain() any {
+	return s.dom
+}

pkg/util/context/context.go

@@ -29,6 +29,9 @@ type ValueStoreContext interface {
 
 	// ClearValue clears the value associated with this context for key.
 	ClearValue(key fmt.Stringer)
+
+	// GetDomain returns the domain.
+	GetDomain() any
 }
 
 var contextIDGenerator atomic.Uint64

pkg/util/mock/context.go

@@ -66,7 +66,8 @@ var (
 type Context struct {
 	planctx.EmptyPlanContextExtended
 	*sessionexpr.ExprContext
-	txn           wrapTxn    // mock global variable
+	txn           wrapTxn // mock global variable
+	dom           any
 	Store         kv.Storage // mock global variable
 	ctx           context.Context
 	sm            util.SessionManager
@@ -639,6 +640,16 @@ func (*Context) GetCommitWaitGroup() *sync.WaitGroup {
 	return nil
 }
 
+// BindDomain bind domain into ctx.
+func (c *Context) BindDomain(dom any) {
+	c.dom = dom
+}
+
+// GetDomain get domain from ctx.
+func (c *Context) GetDomain() any {
+	return c.dom
+}
+
 // NewContextDeprecated creates a new mocked sessionctx.Context.
 // Deprecated: This method is only used for some legacy code.
 // DO NOT use mock.Context in new production code, and use the real Context instead.