lightning: remove legacy code of session (pingcap#56174)

ref pingcap#53388

Author: lcwangchao

pkg/lightning/backend/kv/BUILD.bazel

@@ -18,8 +18,6 @@ go_library(
         "//pkg/expression",
         "//pkg/expression/exprctx",
         "//pkg/expression/exprstatic",
-        "//pkg/expression/sessionexpr",
-        "//pkg/infoschema/context",
         "//pkg/kv",
         "//pkg/lightning/backend/encode",
         "//pkg/lightning/common",
@@ -30,14 +28,11 @@ go_library(
         "//pkg/meta/autoid",
         "//pkg/meta/model",
         "//pkg/parser/mysql",
-        "//pkg/planner/planctx",
-        "//pkg/sessionctx",
         "//pkg/sessionctx/stmtctx",
         "//pkg/sessionctx/variable",
         "//pkg/table",
         "//pkg/table/tables",
         "//pkg/table/tblctx",
-        "//pkg/table/tblsession",
         "//pkg/tablecodec",
         "//pkg/types",
         "//pkg/util/chunk",
@@ -47,7 +42,6 @@ go_library(
         "//pkg/util/mathutil",
         "//pkg/util/redact",
         "//pkg/util/timeutil",
-        "//pkg/util/topsql/stmtstats",
         "@com_github_docker_go_units//:go-units",
         "@com_github_pingcap_errors//:errors",
         "@org_uber_go_zap//:zap",
@@ -74,7 +68,6 @@ go_test(
         "//pkg/ddl",
         "//pkg/errctx",
         "//pkg/expression/exprctx",
-        "//pkg/expression/exprstatic",
         "//pkg/kv",
         "//pkg/lightning/backend/encode",
         "//pkg/lightning/common",
@@ -95,7 +88,6 @@ go_test(
         "//pkg/tablecodec",
         "//pkg/types",
         "//pkg/util/context",
-        "//pkg/util/deeptest",
         "//pkg/util/mock",
         "//pkg/util/rowcodec",
         "//pkg/util/timeutil",

pkg/lightning/backend/kv/context_test.go

@@ -23,17 +23,13 @@ import (
 	"github.com/pingcap/errors"
 	"github.com/pingcap/tidb/pkg/errctx"
 	"github.com/pingcap/tidb/pkg/expression/exprctx"
-	"github.com/pingcap/tidb/pkg/expression/exprstatic"
-	"github.com/pingcap/tidb/pkg/lightning/backend/encode"
-	"github.com/pingcap/tidb/pkg/lightning/log"
 	"github.com/pingcap/tidb/pkg/meta/model"
 	"github.com/pingcap/tidb/pkg/parser/mysql"
 	"github.com/pingcap/tidb/pkg/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/pkg/sessionctx/variable"
 	"github.com/pingcap/tidb/pkg/table/tblctx"
 	"github.com/pingcap/tidb/pkg/types"
 	contextutil "github.com/pingcap/tidb/pkg/util/context"
-	"github.com/pingcap/tidb/pkg/util/deeptest"
 	"github.com/pingcap/tidb/pkg/util/rowcodec"
 	"github.com/pingcap/tidb/pkg/util/timeutil"
 	"github.com/stretchr/testify/require"
@@ -126,63 +122,10 @@ func TestLitExprContext(t *testing.T) {
 		},
 	}
 
-	// We need to compare the new introduced `*litExprContext` the same behavior with the old `session`.
-	// After refactoring finished, we can remove the old session and this test.
-	compareWithLegacySession := func(t *testing.T, ctx *litExprContext, opts *encode.SessionOptions) {
-		if opts.SysVars == nil {
-			opts.SysVars = make(map[string]string)
-		}
-		if _, ok := opts.SysVars["div_precision_increment"]; !ok {
-			// It seems that `DefDivPrecisionIncrement` is not set as a default value in `newSession` and its
-			// default value is 0.
-			// We should set it manually to make test pass.
-			// The legacy code has no bug for this default value because the `DefaultImportantVariables`
-			// will be loaded every time to override this variable:
-			// https://github.com/pingcap/tidb/blob/2e457b394f09165e23fa5121fcfd89c6e8a6e835/pkg/lightning/common/common.go#L33-L42
-			opts.SysVars["div_precision_increment"] = strconv.Itoa(variable.DefDivPrecisionIncrement)
-		}
-		if _, ok := opts.SysVars["block_encryption_mode"]; !ok {
-			// same reason with `DivPrecisionIncrement`, we need to set `block_encryption_mode` manually to pass test.
-			opts.SysVars["block_encryption_mode"] = variable.DefBlockEncryptionMode
-		}
-		se := newSession(opts, log.L())
-		seCtx := exprstatic.MakeExprContextStatic(se.exprCtx.ExprContext)
-		deeptest.AssertDeepClonedEqual(t, seCtx, ctx.ExprContext, deeptest.WithIgnorePath([]string{
-			"$.exprCtxState.evalCtx.id",
-			"$.exprCtxState.evalCtx.evalCtxState.typeCtx.loc",
-			"$.exprCtxState.evalCtx.evalCtxState.warnHandler",
-			"$.exprCtxState.evalCtx.evalCtxState.typeCtx.warnHandler",
-			"$.exprCtxState.evalCtx.evalCtxState.errCtx.warnHandler",
-			"$.exprCtxState.evalCtx.evalCtxState.currentTime",
-			"$.exprCtxState.evalCtx.evalCtxState.requestVerificationFn",
-			"$.exprCtxState.evalCtx.evalCtxState.requestDynamicVerificationFn",
-			"$.exprCtxState.rng",
-			"$.exprCtxState.planCacheTracker",
-		}))
-		currentTime, err := seCtx.GetEvalCtx().CurrentTime()
-		require.NoError(t, err)
-		seTime, err := seCtx.GetEvalCtx().CurrentTime()
-		require.NoError(t, err)
-		if opts.Timestamp == 0 {
-			require.InDelta(t, seTime.Unix(), currentTime.Unix(), 2)
-		} else {
-			require.Equal(t, opts.Timestamp*1000000000, currentTime.UnixNano())
-			require.Equal(t, seTime.UnixNano(), currentTime.UnixNano())
-		}
-		require.Equal(t, seCtx.GetEvalCtx().Location().String(), ctx.GetEvalCtx().Location().String())
-	}
-
 	for i, c := range cases {
 		t.Run("case-"+strconv.Itoa(i), func(t *testing.T) {
 			ctx, err := newLitExprContext(c.sqlMode, c.sysVars, c.timestamp)
 			require.NoError(t, err)
-
-			compareWithLegacySession(t, ctx, &encode.SessionOptions{
-				SQLMode:   c.sqlMode,
-				SysVars:   c.sysVars,
-				Timestamp: c.timestamp,
-			})
-
 			evalCtx := ctx.GetEvalCtx()
 			require.Equal(t, c.sqlMode, evalCtx.SQLMode())
 			tc, ec := evalCtx.TypeCtx(), evalCtx.ErrCtx()
@@ -314,31 +257,6 @@ func TestLitTableMutateContext(t *testing.T) {
 		require.Empty(t, tblCtx.GetColumnSize(456))
 	}
 
-	// We need to compare the new introduced `*litTableMutateContext` the same behavior with the old `session`.
-	// After refactoring finished, we can remove the old session and this test.
-	compareWithLegacySession := func(ctx *litTableMutateContext, vars map[string]string) {
-		se := newSession(&encode.SessionOptions{
-			SQLMode: mysql.ModeNone,
-			SysVars: vars,
-		}, log.L())
-		// make sure GetRowIDShardGenerator() internal assertion pass
-		se.GetSessionVars().TxnCtx = &variable.TransactionContext{}
-		se.GetSessionVars().TxnCtx.StartTS = 123
-		seCtx := se.GetTableCtx()
-		require.Equal(t, seCtx.ConnectionID(), ctx.ConnectionID())
-		require.Equal(t, seCtx.InRestrictedSQL(), ctx.InRestrictedSQL())
-		require.Equal(t, seCtx.TxnAssertionLevel(), ctx.TxnAssertionLevel())
-		require.Equal(t, seCtx.GetMutateBuffers(), ctx.GetMutateBuffers())
-		require.Equal(t, seCtx.EnableMutationChecker(), ctx.EnableMutationChecker())
-		require.Equal(t, seCtx.GetRowEncodingConfig(), ctx.GetRowEncodingConfig())
-		require.Equal(t, seCtx.GetRowIDShardGenerator().GetShardStep(), ctx.GetRowIDShardGenerator().GetShardStep())
-		seAlloc, ok := seCtx.GetReservedRowIDAlloc()
-		require.True(t, ok)
-		alloc, ok := ctx.GetReservedRowIDAlloc()
-		require.True(t, ok)
-		require.Equal(t, seAlloc, alloc)
-	}
-
 	// test for default
 	tblCtx, err := newLitTableMutateContext(exprCtx, nil)
 	require.NoError(t, err)
@@ -353,7 +271,6 @@ func TestLitTableMutateContext(t *testing.T) {
 	g := tblCtx.GetRowIDShardGenerator()
 	require.NotNil(t, g)
 	require.Equal(t, variable.DefTiDBShardAllocateStep, g.GetShardStep())
-	compareWithLegacySession(tblCtx, nil)
 
 	// test for load vars
 	sysVars := map[string]string{
@@ -375,7 +292,6 @@ func TestLitTableMutateContext(t *testing.T) {
 	require.NotNil(t, g)
 	require.NotEqual(t, variable.DefTiDBShardAllocateStep, g.GetShardStep())
 	require.Equal(t, 1234567, g.GetShardStep())
-	compareWithLegacySession(tblCtx, sysVars)
 
 	// test for `RowEncodingConfig.IsRowLevelChecksumEnabled` which should be loaded from global variable.
 	require.False(t, variable.EnableRowLevelChecksum.Load())
@@ -390,5 +306,4 @@ func TestLitTableMutateContext(t *testing.T) {
 		IsRowLevelChecksumEnabled: true,
 		RowEncoder:                &rowcodec.Encoder{Enable: true},
 	}, tblCtx.GetRowEncodingConfig())
-	compareWithLegacySession(tblCtx, sysVars)
 }

pkg/lightning/backend/kv/session.go

@@ -19,29 +19,20 @@ package kv
 import (
 	"context"
 	"errors"
-	"fmt"
-	"strconv"
 	"sync"
 
 	"github.com/docker/go-units"
-	"github.com/pingcap/tidb/pkg/errctx"
 	"github.com/pingcap/tidb/pkg/expression/exprctx"
-	"github.com/pingcap/tidb/pkg/expression/sessionexpr"
-	infoschema "github.com/pingcap/tidb/pkg/infoschema/context"
 	"github.com/pingcap/tidb/pkg/kv"
 	"github.com/pingcap/tidb/pkg/lightning/backend/encode"
 	"github.com/pingcap/tidb/pkg/lightning/common"
 	"github.com/pingcap/tidb/pkg/lightning/log"
 	"github.com/pingcap/tidb/pkg/lightning/manual"
 	"github.com/pingcap/tidb/pkg/meta/model"
-	planctx "github.com/pingcap/tidb/pkg/planner/planctx"
-	"github.com/pingcap/tidb/pkg/sessionctx"
 	"github.com/pingcap/tidb/pkg/sessionctx/variable"
 	"github.com/pingcap/tidb/pkg/table/tblctx"
-	"github.com/pingcap/tidb/pkg/table/tblsession"
 	"github.com/pingcap/tidb/pkg/types"
 	"github.com/pingcap/tidb/pkg/util/mathutil"
-	"github.com/pingcap/tidb/pkg/util/topsql/stmtstats"
 	"go.uber.org/zap"
 )
 
@@ -282,160 +273,6 @@ func (*transaction) MayFlush() error {
 	return nil
 }
 
-// sessExprContext implements the ExprContext interface
-// It embedded an `ExprContext` and a `sessEvalContext` to provide no optional properties.
-type sessExprContext struct {
-	*sessionexpr.ExprContext
-	evalCtx *sessEvalContext
-}
-
-// GetEvalCtx implements the ExprContext.GetEvalCtx interface
-func (ctx *sessExprContext) GetEvalCtx() exprctx.EvalContext {
-	return ctx.evalCtx
-}
-
-// sessEvalContext implements the EvalContext interface
-// It embedded an `EvalContext` and provide no optional properties.
-type sessEvalContext struct {
-	exprctx.EvalContext
-}
-
-// GetOptionalPropSet returns the optional properties provided by this context.
-func (*sessEvalContext) GetOptionalPropSet() exprctx.OptionalEvalPropKeySet {
-	return 0
-}
-
-// GetOptionalPropProvider gets the optional property provider by key
-func (*sessEvalContext) GetOptionalPropProvider(exprctx.OptionalEvalPropKey) (exprctx.OptionalEvalPropProvider, bool) {
-	return nil, false
-}
-
-// Deprecated: `session` will be removed soon.
-// session is a trimmed down Session type which only wraps our own trimmed-down
-// transaction type and provides the session variables to the TiDB library
-// optimized for Lightning.
-// The `session` object is private to make sure it is only used by public `Session` struct to provide limited access.
-// TODO: remove `session` and build related context without a mocked `sessionctx.Context` instead.
-type session struct {
-	sessionctx.Context
-	planctx.EmptyPlanContextExtended
-	txn     transaction
-	Vars    *variable.SessionVars
-	exprCtx *sessExprContext
-	tblctx  *tblsession.MutateContext
-	// currently, we only set `CommonAddRecordCtx`
-	values map[fmt.Stringer]any
-}
-
-// Deprecated: this function will be removed soon.
-// newSession creates a new trimmed down Session matching the options.
-func newSession(options *encode.SessionOptions, logger log.Logger) *session {
-	s := &session{
-		values: make(map[fmt.Stringer]any, 1),
-	}
-	sqlMode := options.SQLMode
-	vars := variable.NewSessionVars(s)
-	vars.SkipUTF8Check = true
-	vars.StmtCtx.InInsertStmt = true
-	vars.SQLMode = sqlMode
-
-	typeFlags := vars.StmtCtx.TypeFlags().
-		WithTruncateAsWarning(!sqlMode.HasStrictMode()).
-		WithIgnoreInvalidDateErr(sqlMode.HasAllowInvalidDatesMode()).
-		WithIgnoreZeroInDate(!sqlMode.HasStrictMode() || sqlMode.HasAllowInvalidDatesMode() ||
-			!sqlMode.HasNoZeroInDateMode() || !sqlMode.HasNoZeroDateMode())
-	vars.StmtCtx.SetTypeFlags(typeFlags)
-
-	errLevels := vars.StmtCtx.ErrLevels()
-	errLevels[errctx.ErrGroupBadNull] = errctx.ResolveErrLevel(false, !sqlMode.HasStrictMode())
-	errLevels[errctx.ErrGroupDividedByZero] =
-		errctx.ResolveErrLevel(!sqlMode.HasErrorForDivisionByZeroMode(), !sqlMode.HasStrictMode())
-	vars.StmtCtx.SetErrLevels(errLevels)
-
-	if options.SysVars != nil {
-		for k, v := range options.SysVars {
-			// since 6.3(current master) tidb checks whether we can set a system variable
-			// lc_time_names is a read-only variable for now, but might be implemented later,
-			// so we not remove it from defaultImportantVariables and check it in below way.
-			if sv := variable.GetSysVar(k); sv == nil {
-				logger.DPanic("unknown system var", zap.String("key", k))
-				continue
-			} else if sv.ReadOnly {
-				logger.Debug("skip read-only variable", zap.String("key", k))
-				continue
-			}
-			if err := vars.SetSystemVar(k, v); err != nil {
-				logger.DPanic("new session: failed to set system var",
-					log.ShortError(err),
-					zap.String("key", k))
-			}
-		}
-	}
-	vars.StmtCtx.SetTimeZone(vars.Location())
-	if err := vars.SetSystemVar("timestamp", strconv.FormatInt(options.Timestamp, 10)); err != nil {
-		logger.Warn("new session: failed to set timestamp",
-			log.ShortError(err))
-	}
-	vars.TxnCtx = nil
-	s.Vars = vars
-	exprCtx := sessionexpr.NewExprContext(s)
-	// The exprCtx should be an expression context providing no optional properties in `EvalContext`.
-	// That is to make sure it only allows expressions that require basic context.
-	s.exprCtx = &sessExprContext{
-		ExprContext: exprCtx,
-		evalCtx: &sessEvalContext{
-			EvalContext: exprCtx.GetEvalCtx(),
-		},
-	}
-	s.tblctx = tblsession.NewMutateContext(s)
-	s.txn.kvPairs = &Pairs{}
-
-	return s
-}
-
-// Txn implements the sessionctx.Context interface
-func (se *session) Txn(_ bool) (kv.Transaction, error) {
-	return &se.txn, nil
-}
-
-// GetSessionVars implements the sessionctx.Context interface
-func (se *session) GetSessionVars() *variable.SessionVars {
-	return se.Vars
-}
-
-// GetExprCtx returns the expression context of the session.
-func (se *session) GetExprCtx() exprctx.ExprContext {
-	return se.exprCtx
-}
-
-// GetTableCtx returns the table.MutateContext
-func (se *session) GetTableCtx() tblctx.MutateContext {
-	return se.tblctx
-}
-
-// SetValue saves a value associated with this context for key.
-func (se *session) SetValue(key fmt.Stringer, value any) {
-	se.values[key] = value
-}
-
-// Value returns the value associated with this context for key.
-func (se *session) Value(key fmt.Stringer) any {
-	return se.values[key]
-}
-
-// StmtAddDirtyTableOP implements the sessionctx.Context interface
-func (*session) StmtAddDirtyTableOP(_ int, _ int64, _ kv.Handle) {}
-
-// GetInfoSchema implements the sessionctx.Context interface.
-func (*session) GetInfoSchema() infoschema.MetaOnlyInfoSchema {
-	return nil
-}
-
-// GetStmtStats implements the sessionctx.Context interface.
-func (*session) GetStmtStats() *stmtstats.StatementStats {
-	return nil
-}
-
 // Session is used to provide context for lightning.
 type Session struct {
 	txn     transaction