planner: move rule_constant_propagation to rule pkg. (pingcap#55231)

pkg/planner/core/BUILD.bazel

@@ -69,7 +69,6 @@ go_library(
         "rule_aggregation_skew_rewrite.go",
         "rule_collect_plan_stats.go",
         "rule_column_pruning.go",
-        "rule_constant_propagation.go",
         "rule_decorrelate.go",
         "rule_derive_topn_from_window.go",
         "rule_eliminate_projection.go",

pkg/planner/core/logical_selection.go

@@ -190,7 +190,7 @@ func (p *LogicalSelection) PullUpConstantPredicates() []expression.Expression {
 	var result []expression.Expression
 	for _, candidatePredicate := range p.Conditions {
 		// the candidate predicate should be a constant and compare predicate
-		match := validCompareConstantPredicate(p.SCtx().GetExprCtx().GetEvalCtx(), candidatePredicate)
+		match := ruleutil.ValidCompareConstantPredicate(p.SCtx().GetExprCtx().GetEvalCtx(), candidatePredicate)
 		if match {
 			result = append(result, candidatePredicate)
 		}

pkg/planner/core/optimizer.go

@@ -109,7 +109,7 @@ var optRuleList = []base.LogicalOptRule{
 	&SkewDistinctAggRewriter{},
 	&ProjectionEliminator{},
 	&MaxMinEliminator{},
-	&ConstantPropagationSolver{},
+	&rule.ConstantPropagationSolver{},
 	&ConvertOuterToInnerJoin{},
 	&PPDSolver{},
 	&OuterJoinEliminator{},

pkg/planner/core/rule/BUILD.bazel

@@ -4,6 +4,7 @@ go_library(
     name = "rule",
     srcs = [
         "rule_build_key_info.go",
+        "rule_constant_propagation.go",
         "rule_init.go",
     ],
     importpath = "github.com/pingcap/tidb/pkg/planner/core/rule",

pkg/planner/core/rule_constant_propagation.go → pkg/planner/core/rule/rule_constant_propagation.go

@@ -12,13 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package core
+package rule
 
 import (
 	"context"
 
-	"github.com/pingcap/tidb/pkg/expression"
-	"github.com/pingcap/tidb/pkg/parser/ast"
 	"github.com/pingcap/tidb/pkg/planner/core/base"
 	"github.com/pingcap/tidb/pkg/planner/util/optimizetrace"
 )
@@ -87,26 +85,3 @@ func (cp *ConstantPropagationSolver) execOptimize(currentPlan base.LogicalPlan,
 func (*ConstantPropagationSolver) Name() string {
 	return "constant_propagation"
 }
-
-// validComparePredicate checks if the predicate is an expression like [column '>'|'>='|'<'|'<='|'=' constant].
-// return param1: return true, if the predicate is a compare constant predicate.
-// return param2: return the column side of predicate.
-func validCompareConstantPredicate(ctx expression.EvalContext, candidatePredicate expression.Expression) bool {
-	scalarFunction, ok := candidatePredicate.(*expression.ScalarFunction)
-	if !ok {
-		return false
-	}
-	if scalarFunction.FuncName.L != ast.GT && scalarFunction.FuncName.L != ast.GE &&
-		scalarFunction.FuncName.L != ast.LT && scalarFunction.FuncName.L != ast.LE &&
-		scalarFunction.FuncName.L != ast.EQ {
-		return false
-	}
-	column, _ := expression.ValidCompareConstantPredicateHelper(ctx, scalarFunction, true)
-	if column == nil {
-		column, _ = expression.ValidCompareConstantPredicateHelper(ctx, scalarFunction, false)
-	}
-	if column == nil {
-		return false
-	}
-	return true
-}

pkg/planner/core/rule/util/BUILD.bazel

@@ -5,11 +5,13 @@ go_library(
     srcs = [
         "build_key_info_misc.go",
         "misc.go",
+        "rule_constant_propagation.go",
     ],
     importpath = "github.com/pingcap/tidb/pkg/planner/core/rule/util",
     visibility = ["//visibility:public"],
     deps = [
         "//pkg/expression",
+        "//pkg/parser/ast",
         "//pkg/parser/model",
         "//pkg/parser/mysql",
         "//pkg/planner/core/base",

pkg/planner/core/rule/util/rule_constant_propagation.go

@@ -0,0 +1,43 @@
+// Copyright 2023 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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package util
+
+import (
+	"github.com/pingcap/tidb/pkg/expression"
+	"github.com/pingcap/tidb/pkg/parser/ast"
+)
+
+// ValidCompareConstantPredicate checks if the predicate is an expression like [column '>'|'>='|'<'|'<='|'=' constant].
+// return param1: return true, if the predicate is a compare constant predicate.
+// return param2: return the column side of predicate.
+func ValidCompareConstantPredicate(ctx expression.EvalContext, candidatePredicate expression.Expression) bool {
+	scalarFunction, ok := candidatePredicate.(*expression.ScalarFunction)
+	if !ok {
+		return false
+	}
+	if scalarFunction.FuncName.L != ast.GT && scalarFunction.FuncName.L != ast.GE &&
+		scalarFunction.FuncName.L != ast.LT && scalarFunction.FuncName.L != ast.LE &&
+		scalarFunction.FuncName.L != ast.EQ {
+		return false
+	}
+	column, _ := expression.ValidCompareConstantPredicateHelper(ctx, scalarFunction, true)
+	if column == nil {
+		column, _ = expression.ValidCompareConstantPredicateHelper(ctx, scalarFunction, false)
+	}
+	if column == nil {
+		return false
+	}
+	return true
+}