fix: parse error given duplicated plan cache key (#37334)

See: #37016

---------

Signed-off-by: Ted Xu <ted.xu@zilliz.com>

internal/parser/planparserv2/plan_parser_v2.go

@@ -12,68 +12,82 @@ import (
 	"go.uber.org/zap"
 
 	"github.com/milvus-io/milvus-proto/go-api/v2/schemapb"
+	planparserv2 "github.com/milvus-io/milvus/internal/parser/planparserv2/generated"
 	"github.com/milvus-io/milvus/internal/proto/planpb"
 	"github.com/milvus-io/milvus/pkg/log"
 	"github.com/milvus-io/milvus/pkg/util/merr"
 	"github.com/milvus-io/milvus/pkg/util/typeutil"
 )
 
-// exprParseKey is used to cache the parse result. Currently only collectionName is used besides expr string, which implies
-// that the same collectionName will have the same schema thus the same parse result. In the future, if there is case that the
-// schema changes without changing the collectionName, we need to change the cache key.
-type exprParseKey struct {
-	collectionName string
-	expr           string
-}
-
-var exprCache = expirable.NewLRU[exprParseKey, any](256, nil, time.Minute*10)
-
-func handleExpr(schema *typeutil.SchemaHelper, exprStr string) interface{} {
-	parseKey := exprParseKey{collectionName: schema.GetCollectionName(), expr: exprStr}
-	val, ok := exprCache.Get(parseKey)
-	if !ok {
-		exprStr = convertHanToASCII(exprStr)
-		val = handleExprWithErrorListener(schema, exprStr, &errorListenerImpl{})
-		// Note that the errors will be cached, too.
-		exprCache.Add(parseKey, val)
+var (
+	exprCache   = expirable.NewLRU[string, any](1024, nil, time.Minute*10)
+	trueLiteral = &ExprWithType{
+		dataType: schemapb.DataType_Bool,
+		expr:     alwaysTrueExpr(),
 	}
+)
 
-	return val
-}
-
-func handleExprWithErrorListener(schema *typeutil.SchemaHelper, exprStr string, errorListener errorListener) interface{} {
-	if isEmptyExpression(exprStr) {
-		return &ExprWithType{
-			dataType: schemapb.DataType_Bool,
-			expr:     alwaysTrueExpr(),
+func handleInternal(exprStr string) (ast planparserv2.IExprContext, err error) {
+	val, ok := exprCache.Get(exprStr)
+	if ok {
+		switch v := val.(type) {
+		case planparserv2.IExprContext:
+			return v, nil
+		case error:
+			return nil, v
+		default:
+			return nil, fmt.Errorf("unknown cache error: %v", v)
 		}
 	}
 
-	inputStream := antlr.NewInputStream(exprStr)
-	lexer := getLexer(inputStream, errorListener)
-	if errorListener.Error() != nil {
-		return errorListener.Error()
+	// Note that the errors will be cached, too.
+	defer func() {
+		if err != nil {
+			exprCache.Add(exprStr, err)
+		}
+	}()
+	exprNormal := convertHanToASCII(exprStr)
+	listener := &errorListenerImpl{}
+
+	inputStream := antlr.NewInputStream(exprNormal)
+	lexer := getLexer(inputStream, listener)
+	if err = listener.Error(); err != nil {
+		return
 	}
 
-	parser := getParser(lexer, errorListener)
-	if errorListener.Error() != nil {
-		return errorListener.Error()
+	parser := getParser(lexer, listener)
+	if err = listener.Error(); err != nil {
+		return
 	}
 
-	ast := parser.Expr()
-	if errorListener.Error() != nil {
-		return errorListener.Error()
+	ast = parser.Expr()
+	if err = listener.Error(); err != nil {
+		return
 	}
 
 	if parser.GetCurrentToken().GetTokenType() != antlr.TokenEOF {
 		log.Info("invalid expression", zap.String("expr", exprStr))
-		return fmt.Errorf("invalid expression: %s", exprStr)
+		err = fmt.Errorf("invalid expression: %s", exprStr)
+		return
 	}
 
 	// lexer & parser won't be used by this thread, can be put into pool.
 	putLexer(lexer)
 	putParser(parser)
 
+	exprCache.Add(exprStr, ast)
+	return
+}
+
+func handleExpr(schema *typeutil.SchemaHelper, exprStr string) interface{} {
+	if isEmptyExpression(exprStr) {
+		return trueLiteral
+	}
+	ast, err := handleInternal(exprStr)
+	if err != nil {
+		return err
+	}
+
 	visitor := NewParserVisitor(schema)
 	return ast.Accept(visitor)
 }

internal/parser/planparserv2/plan_parser_v2_test.go

@@ -719,7 +719,7 @@ func Test_FixErrorListenerNotRemoved(t *testing.T) {
 
 	normal := "1 < Int32Field < (Int16Field)"
 	for i := 0; i < 10; i++ {
-		err := handleExprWithErrorListener(schemaHelper, normal, &errorListenerTest{})
+		err := handleExpr(schemaHelper, normal)
 		err1, ok := err.(error)
 		assert.True(t, ok)
 		assert.Error(t, err1)
@@ -1379,25 +1379,21 @@ func BenchmarkPlanCache(b *testing.B) {
 
 	b.ResetTimer()
 
-	for i := 0; i < b.N; i++ {
-		r := handleExpr(schemaHelper, "array_length(ArrayField) == 10")
-		err := getError(r)
-		assert.NoError(b, err)
-	}
-}
+	b.Run("cached", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			r := handleExpr(schemaHelper, "array_length(ArrayField) == 10")
+			err := getError(r)
+			assert.NoError(b, err)
+		}
+	})
 
-func BenchmarkNoPlanCache(b *testing.B) {
-	schema := newTestSchema()
-	schemaHelper, err := typeutil.CreateSchemaHelper(schema)
-	require.NoError(b, err)
-
-	b.ResetTimer()
-
-	for i := 0; i < b.N; i++ {
-		r := handleExpr(schemaHelper, fmt.Sprintf("array_length(ArrayField) == %d", i))
-		err := getError(r)
-		assert.NoError(b, err)
-	}
+	b.Run("uncached", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			r := handleExpr(schemaHelper, fmt.Sprintf("array_length(ArrayField) == %d", i))
+			err := getError(r)
+			assert.NoError(b, err)
+		}
+	})
 }
 
 func randomChineseString(length int) string {