Mark-Zeng commented on a change in pull request #12232: URL: https://github.com/apache/beam/pull/12232#discussion_r464338700
########## File path: sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/impl/cep/CEPUtil.java ########## @@ -0,0 +1,155 @@ +/* + * 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.beam.sdk.extensions.sql.impl.cep; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import java.util.Map; +import org.apache.beam.sdk.schemas.Schema; +import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.RelCollation; +import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.RelFieldCollation; +import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rex.RexCall; +import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rex.RexLiteral; +import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rex.RexNode; +import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlKind; +import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlOperator; + +/** + * Some utility methods for transforming Calcite's constructs into our own Beam constructs (for + * serialization purpose). + */ +public class CEPUtil { + + private static Quantifier getQuantifier(int start, int end, boolean isReluctant) { + Quantifier quantToAdd; + if (!isReluctant) { + if (start == end) { + quantToAdd = new Quantifier("{ " + start + " }"); + } else { + if (end == -1) { + if (start == 0) { + quantToAdd = Quantifier.ASTERISK; + } else if (start == 1) { + quantToAdd = Quantifier.PLUS; + } else { + quantToAdd = new Quantifier("{ " + start + " }"); + } + } else { + if (start == 0 && end == 1) { + quantToAdd = Quantifier.QMARK; + } else if (start == -1) { + quantToAdd = new Quantifier("{ , " + end + " }"); + } else { + quantToAdd = new Quantifier("{ " + start + " , }"); + } + } + } + } else { + if (start == end) { + quantToAdd = new Quantifier("{ " + start + " }?"); + } else { + if (end == -1) { + if (start == 0) { + quantToAdd = Quantifier.ASTERISK_RELUCTANT; + } else if (start == 1) { + quantToAdd = Quantifier.PLUS_RELUCTANT; + } else { + quantToAdd = new Quantifier("{ " + start + " }?"); + } + } else { + if (start == 0 && end == 1) { + quantToAdd = Quantifier.QMARK_RELUCTANT; + } else if (start == -1) { + quantToAdd = new Quantifier("{ , " + end + " }?"); + } else { + quantToAdd = new Quantifier("{ " + start + " , }?"); + } + } + } + } + + return quantToAdd; + } + + /** Construct a list of {@code CEPPattern}s from a {@code RexNode}. */ + public static ArrayList<CEPPattern> getCEPPatternFromPattern( + Schema upStreamSchema, RexNode call, Map<String, RexNode> patternDefs) { + ArrayList<CEPPattern> patternList = new ArrayList<>(); + if (call.getClass() == RexLiteral.class) { + String p = ((RexLiteral) call).getValueAs(String.class); + RexNode pd = patternDefs.get(p); + patternList.add(CEPPattern.of(upStreamSchema, p, (RexCall) pd, Quantifier.NONE)); + } else { + RexCall patCall = (RexCall) call; + SqlOperator operator = patCall.getOperator(); + List<RexNode> operands = patCall.getOperands(); + + // check if if the node has quantifier + if (operator.getKind() == SqlKind.PATTERN_QUANTIFIER) { + String p = ((RexLiteral) operands.get(0)).getValueAs(String.class); + RexNode pd = patternDefs.get(p); + int start = ((RexLiteral) operands.get(1)).getValueAs(Integer.class); + int end = ((RexLiteral) operands.get(2)).getValueAs(Integer.class); + boolean isReluctant = ((RexLiteral) operands.get(3)).getValueAs(Boolean.class); + + patternList.add( + CEPPattern.of(upStreamSchema, p, (RexCall) pd, getQuantifier(start, end, isReluctant))); + } else { + for (RexNode i : operands) { + patternList.addAll(getCEPPatternFromPattern(upStreamSchema, i, patternDefs)); + } + } + } + return patternList; + } + + /** Recursively construct a regular expression from a {@code RexNode}. */ + public static String getRegexFromPattern(RexNode call) { + if (call.getClass() == RexLiteral.class) { + return ((RexLiteral) call).getValueAs(String.class); + } else { + RexCall opr = (RexCall) call; + SqlOperator operator = opr.getOperator(); + List<RexNode> operands = opr.getOperands(); + if (operator.getKind() == SqlKind.PATTERN_QUANTIFIER) { + String p = ((RexLiteral) operands.get(0)).getValueAs(String.class); + int start = ((RexLiteral) operands.get(1)).getValueAs(Integer.class); + int end = ((RexLiteral) operands.get(2)).getValueAs(Integer.class); + boolean isReluctant = ((RexLiteral) operands.get(3)).getValueAs(Boolean.class); + Quantifier quantifier = getQuantifier(start, end, isReluctant); + return p + quantifier.toString(); + } + return getRegexFromPattern(opr.getOperands().get(0)) + + getRegexFromPattern(opr.getOperands().get(1)); + } + } + + /** Transform a list of keys in Calcite to {@code ORDER BY} to {@code OrderKey}s. */ + public static ArrayList<OrderKey> makeOrderKeysFromCollation(RelCollation orderKeys) { + List<RelFieldCollation> revOrderKeys = orderKeys.getFieldCollations(); + Collections.reverse(revOrderKeys); Review comment: I have changed this part as well. I think reversing the order could be confusing. I moved it into the SortKey transform. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
