kristoffSC commented on code in PR #21393: URL: https://github.com/apache/flink/pull/21393#discussion_r1067856440
########## flink-table/flink-table-code-splitter/src/main/java/org/apache/flink/table/codesplit/BlockStatementGrouper.java: ########## @@ -0,0 +1,432 @@ +/* + * 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.flink.table.codesplit; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.codesplit.JavaParser.BlockStatementContext; +import org.apache.flink.table.codesplit.JavaParser.StatementContext; + +import org.antlr.v4.runtime.CharStreams; +import org.antlr.v4.runtime.CommonTokenStream; +import org.antlr.v4.runtime.ParserRuleContext; +import org.antlr.v4.runtime.Token; +import org.antlr.v4.runtime.TokenStreamRewriter; +import org.antlr.v4.runtime.atn.PredictionMode; +import org.apache.commons.lang3.tuple.Pair; + +import java.util.ArrayList; +import java.util.List; +import java.util.stream.Collectors; + +/** + * Groups end extract single line statements such as operations on fields/local variables and + * extract new method for each group making them smaller. + * + * <p><i>Before</i> + * + * <pre><code> + * { + * a[0] += b[1]; + * b[1] += a[1]; + * while (counter > 0) { + * myFun_whileBody0_0(a, b); + * if (a[0] > 0) { + * myFun_whileBody0_0_ifBody0(a, b); + * } else { + * myFun_whileBody0_0_ifBody1(a, b); + * } + * counter--; + * } + * + * a[2] += b[2]; + * b[3] += a[3]; + * } + * + * </code></pre> + * + * <p><i>After</i> + * + * <pre><code> + * { + * myFun_rewriteGroup1(a, b); + * myFun_rewriteGroup2(a, b); + * } + * </code></pre> + * + * <p>Where bodies of extracted "methods" are: + * + * <pre><code> + * myFun_rewriteGroup1 -> + * a[0] += b[1]; + * b[1] += a[1]; + * while (counter > 0) { + * myFun_rewriteGroup0_rewriteGroup1(a, b); + * counter--; + * } + * </code></pre> + * + * <pre><code> + * myFun_rewriteGroup2 -> + * a[2] += b[2]; + * b[3] += a[3]; + * </code></pre> + * + * <pre><code> + * myFun_rewriteGroup0_rewriteGroup1 -> + * myFun_whileBody0_0(a, b); + * if (a[0] > 0) { + * myFun_whileBody0_0_ifBody0(a, b); + * } else { + * myFun_whileBody0_0_ifBody1(a, b); + * } + * </code></pre> + */ +@Internal +public class BlockStatementGrouper { + + private final String code; + + private final long maxMethodLength; + + private final String parameters; + + /** + * Initialize new BlockStatementGrouper. + * + * @param code code block that should be rewritten for statement grouping. + * @param maxMethodLength maximal length of the extracted code block. + * @param parameters parameters definition that should be used for extracted methods. + */ + public BlockStatementGrouper(String code, long maxMethodLength, String parameters) { + this.code = code; + this.maxMethodLength = maxMethodLength; + this.parameters = parameters; + } + + /** + * Rewrite code block used for initialization of this object. The code block is grouped into new + * methods. + * + * @param context prefix used for extracted group names. + * @return {@link RewriteGroupedCode} representing rewritten code block and containing extracted + * groups with their names and content. + */ + public RewriteGroupedCode rewrite(String context) { + + BlockStatementGrouperVisitor visitor = + new BlockStatementGrouperVisitor(code, context, maxMethodLength, parameters); + JavaParser javaParser = new JavaParser(visitor.tokenStream); + javaParser.getInterpreter().setPredictionMode(PredictionMode.SLL); + visitor.visitStatement(javaParser.statement()); + + visitor.rewriteToGroups(); + List<Pair<String, List<LocalGroupElement>>> groups = visitor.getGroups(); + + List<Pair<String, List<String>>> groupStrings = new ArrayList<>(groups.size()); + for (Pair<String, List<LocalGroupElement>> group : groups) { + List<String> collectedStringGroups = + group.getValue().stream() + .map(LocalGroupElement::getBody) + .collect(Collectors.toList()); + groupStrings.add(Pair.of(group.getKey(), collectedStringGroups)); + } + + return new RewriteGroupedCode(visitor.rewriter.getText(), groupStrings); + } + + private static class BlockStatementGrouperVisitor extends JavaParserBaseVisitor<Void> { + + private final List<BlockStatementGrouperVisitor> children = new ArrayList<>(); + + private final String context; + + private final CommonTokenStream tokenStream; + + private final TokenStreamRewriter rewriter; + + private final long maxMethodLength; + + private final List<Pair<String, List<LocalGroupElement>>> groups = new ArrayList<>(); + + private final String parameters; + + private int counter = 0; + + private BlockStatementGrouperVisitor( + String code, String context, long maxMethodLength, String parameters) { + this.tokenStream = new CommonTokenStream(new JavaLexer(CharStreams.fromString(code))); + this.rewriter = new TokenStreamRewriter(tokenStream); + this.context = context; + this.maxMethodLength = maxMethodLength; + this.parameters = parameters; + } + + @Override + public Void visitStatement(StatementContext ctx) { + + if (ctx.getChildCount() == 0) { + return null; + } + + if (ctx.WHILE() != null || ctx.IF() != null || ctx.ELSE() != null) { + for (StatementContext statement : ctx.statement()) { + if (shouldExtract(statement)) { + groupBlock(statement); + } + } + } else { + if (shouldExtract(ctx)) { + groupBlock(ctx); + } + } + + return null; + } + + public List<Pair<String, List<LocalGroupElement>>> getGroups() { + List<Pair<String, List<LocalGroupElement>>> groupsTmp = new ArrayList<>(); + for (BlockStatementGrouperVisitor child : children) { + groupsTmp.addAll(child.getGroups()); + } + + groupsTmp.addAll(this.groups); + + return groupsTmp; + } + + private void addGroups(List<Pair<String, List<LocalGroupElement>>> groups) { + this.groups.addAll(groups); + } Review Comment: It was used at some point during the development, but now it, like you wrote, no one is calling it. I will remove it. -- 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]
