lkuchars commented on code in PR #10105: URL: https://github.com/apache/nifi/pull/10105#discussion_r2254064089
########## nifi-extension-bundles/nifi-confluent-platform-bundle/nifi-confluent-protobuf-antlr-parser/src/main/java/org/apache/nifi/confluent/schema/AntlrProtobufMessageSchemaParser.java: ########## @@ -0,0 +1,115 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 org.apache.nifi.confluent.schema; + +import org.antlr.v4.runtime.BaseErrorListener; +import org.antlr.v4.runtime.CharStream; +import org.antlr.v4.runtime.CharStreams; +import org.antlr.v4.runtime.CommonTokenStream; +import org.antlr.v4.runtime.RecognitionException; +import org.antlr.v4.runtime.Recognizer; +import org.apache.nifi.confluent.schema.antlr.Protobuf3BaseVisitor; +import org.apache.nifi.confluent.schema.antlr.Protobuf3Lexer; +import org.apache.nifi.confluent.schema.antlr.Protobuf3Parser; +import org.apache.nifi.confluent.schema.antlr.Protobuf3Parser.MessageDefContext; +import org.apache.nifi.confluent.schema.antlr.Protobuf3Parser.PackageStatementContext; +import org.apache.nifi.confluent.schema.antlr.Protobuf3Parser.ProtoContext; + +import java.util.ArrayList; +import java.util.List; +import java.util.Optional; +import java.util.Stack; + +/** + * Implementation of ProtobufMessageSchemaParser that uses ANTLR to parse protobuf schemas + * and extract message definitions including nested messages. + */ +public class AntlrProtobufMessageSchemaParser implements ProtobufMessageSchemaParser { + + @Override + public List<ProtobufMessageSchema> parse(final String schemaText) { + + final CharStream input = CharStreams.fromString(schemaText); + final Protobuf3Lexer lexer = new Protobuf3Lexer(input); + final Protobuf3Parser parser = getProtobuf3Parser(lexer); + + final ProtoContext tree = parser.proto(); + + // Create visitor and analyze + final SchemaVisitor visitor = new SchemaVisitor(); + visitor.visit(tree); + + return visitor.getProtoMessages(); + + } + + private Protobuf3Parser getProtobuf3Parser(final Protobuf3Lexer lexer) { + final CommonTokenStream tokens = new CommonTokenStream(lexer); + final Protobuf3Parser parser = new Protobuf3Parser(tokens); + + // Add error listener to capture parsing errors + parser.removeErrorListeners(); + parser.addErrorListener(new BaseErrorListener() { + @Override + public void syntaxError(final Recognizer<?, ?> recognizer, final Object offendingSymbol, final int line, final int charPositionInLine, final String msg, final RecognitionException e) { + throw new RuntimeException(String.format("Syntax error at line %d, position %d: %s", line, charPositionInLine, msg), e); + } + }); + return parser; + } + + private static class SchemaVisitor extends Protobuf3BaseVisitor<Void> { + + private final List<ProtobufMessageSchema> rootMessages = new ArrayList<>(); + private final Stack<ProtobufMessageSchema> messageStack = new Stack<>(); + private String currentPackage; + + @Override + public Void visitPackageStatement(final PackageStatementContext ctx) { + if (ctx.fullIdent() != null) { + currentPackage = ctx.fullIdent().getText(); + } + return null; + } + + @Override + public Void visitMessageDef(final MessageDefContext ctx) { + final String messageName = ctx.messageName().getText(); + + final ProtobufMessageSchema protobufMessageSchema = new ProtobufMessageSchema(messageName, Optional.ofNullable(currentPackage)); + + // Add to parent's nested messages or root messages + if (messageStack.isEmpty()) { + rootMessages.add(protobufMessageSchema); + } else { + final ProtobufMessageSchema parent = messageStack.peek(); + parent.addChildMessage(protobufMessageSchema); + } + + messageStack.push(protobufMessageSchema); + // Visit nested messages + super.visitMessageDef(ctx); + messageStack.pop(); + + return null; + } + + public List<ProtobufMessageSchema> getProtoMessages() { + return rootMessages.stream().toList(); Review Comment: Why, when we return unmodifiable list already? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
