| /* |
| * 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.drill.exec.store.mongo; |
| |
| import com.mongodb.client.model.Accumulators; |
| import com.mongodb.client.model.Aggregates; |
| import com.mongodb.client.model.BsonField; |
| import org.apache.calcite.rel.core.Aggregate; |
| import org.apache.calcite.rel.core.AggregateCall; |
| import org.apache.calcite.rel.type.RelDataType; |
| import org.apache.calcite.sql.fun.SqlStdOperatorTable; |
| import org.apache.calcite.sql.validate.SqlValidatorUtil; |
| import org.apache.drill.exec.store.mongo.common.MongoOp; |
| import org.bson.BsonArray; |
| import org.bson.BsonDocument; |
| import org.bson.BsonElement; |
| import org.bson.BsonInt32; |
| import org.bson.BsonNull; |
| import org.bson.BsonString; |
| import org.bson.Document; |
| import org.bson.conversions.Bson; |
| |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.function.BiFunction; |
| import java.util.stream.Collectors; |
| import java.util.stream.StreamSupport; |
| |
| public class MongoAggregateUtils { |
| |
| public static List<String> mongoFieldNames(RelDataType rowType) { |
| List<String> renamed = rowType.getFieldNames().stream() |
| .map(name -> name.startsWith("$") ? "_" + name.substring(2) : name) |
| .collect(Collectors.toList()); |
| return SqlValidatorUtil.uniquify(renamed, true); |
| } |
| |
| public static String maybeQuote(String s) { |
| if (!needsQuote(s)) { |
| return s; |
| } |
| return quote(s); |
| } |
| |
| public static String quote(String s) { |
| return "'" + s + "'"; |
| } |
| |
| private static boolean needsQuote(String s) { |
| for (int i = 0, n = s.length(); i < n; i++) { |
| char c = s.charAt(i); |
| if (!Character.isJavaIdentifierPart(c) |
| || c == '$') { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| public static List<Bson> getAggregateOperations(Aggregate aggregate, RelDataType rowType) { |
| List<String> inNames = mongoFieldNames(rowType); |
| List<String> outNames = mongoFieldNames(aggregate.getRowType()); |
| Object id; |
| if (aggregate.getGroupSet().cardinality() == 1) { |
| String inName = inNames.get(aggregate.getGroupSet().nth(0)); |
| id = "$" + inName; |
| } else { |
| List<BsonElement> elements = |
| StreamSupport.stream(aggregate.getGroupSet().spliterator(), false) |
| .map(inNames::get) |
| .map(inName -> new BsonElement(inName, new BsonString("$" + inName))) |
| .collect(Collectors.toList()); |
| id = new BsonDocument(elements); |
| } |
| int outNameIndex = aggregate.getGroupSet().cardinality(); |
| List<BsonField> accumList = new ArrayList<>(); |
| for (AggregateCall aggCall : aggregate.getAggCallList()) { |
| accumList.add(bsonAggregate(inNames, outNames.get(outNameIndex++), aggCall)); |
| } |
| List<Bson> operationsList = new ArrayList<>(); |
| operationsList.add(Aggregates.group(id, accumList).toBsonDocument()); |
| List<BsonElement> projectFields = new ArrayList<>(); |
| if (aggregate.getGroupSet().cardinality() == 1) { |
| for (int index = 0; index < outNames.size(); index++) { |
| String outName = outNames.get(index); |
| projectFields.add(new BsonElement(maybeQuote(outName), |
| new BsonString("$" + (index == 0 ? "_id" : outName)))); |
| } |
| } else { |
| projectFields.add(new BsonElement("_id", new BsonInt32(0))); |
| for (int group : aggregate.getGroupSet()) { |
| projectFields.add( |
| new BsonElement(maybeQuote(outNames.get(group)), |
| new BsonString("$_id." + outNames.get(group)))); |
| } |
| outNameIndex = aggregate.getGroupSet().cardinality(); |
| for (AggregateCall ignored : aggregate.getAggCallList()) { |
| String outName = outNames.get(outNameIndex++); |
| projectFields.add(new BsonElement(maybeQuote(outName), new BsonString("$" + outName))); |
| } |
| } |
| if (!aggregate.getGroupSet().isEmpty()) { |
| operationsList.add(Aggregates.project(new BsonDocument(projectFields)).toBsonDocument()); |
| } |
| |
| return operationsList; |
| } |
| |
| private static BsonField bsonAggregate(List<String> inNames, String outName, AggregateCall aggCall) { |
| String aggregationName = aggCall.getAggregation().getName(); |
| List<Integer> args = aggCall.getArgList(); |
| if (aggregationName.equals(SqlStdOperatorTable.COUNT.getName())) { |
| Object expr; |
| if (args.size() == 0) { |
| // count(*) case |
| expr = 1; |
| } else { |
| assert args.size() == 1; |
| String inName = inNames.get(args.get(0)); |
| expr = new BsonDocument(MongoOp.COND.getCompareOp(), |
| new BsonArray(Arrays.asList( |
| new Document(MongoOp.EQUAL.getCompareOp(), |
| new BsonArray(Arrays.asList( |
| new BsonString(quote(inName)), |
| BsonNull.VALUE))).toBsonDocument(), |
| new BsonInt32(0), |
| new BsonInt32(1) |
| )) |
| ); |
| } |
| return Accumulators.sum(maybeQuote(outName), expr); |
| } else { |
| BiFunction<String, Object, BsonField> mongoAccumulator = mongoAccumulator(aggregationName); |
| if (mongoAccumulator != null) { |
| return mongoAccumulator.apply(maybeQuote(outName), "$" + inNames.get(args.get(0))); |
| } |
| } |
| return null; |
| } |
| |
| private static <T> BiFunction<String, T, BsonField> mongoAccumulator(String aggregationName) { |
| if (aggregationName.equals(SqlStdOperatorTable.SUM.getName()) |
| || aggregationName.equals(SqlStdOperatorTable.SUM0.getName())) { |
| return Accumulators::sum; |
| } else if (aggregationName.equals(SqlStdOperatorTable.MIN.getName())) { |
| return Accumulators::min; |
| } else if (aggregationName.equals(SqlStdOperatorTable.MAX.getName())) { |
| return Accumulators::max; |
| } else if (aggregationName.equals(SqlStdOperatorTable.AVG.getName())) { |
| return Accumulators::avg; |
| } else if (aggregationName.equals(SqlStdOperatorTable.FIRST.getName())) { |
| return Accumulators::first; |
| } else if (aggregationName.equals(SqlStdOperatorTable.LAST.getName())) { |
| return Accumulators::last; |
| } else if (aggregationName.equals(SqlStdOperatorTable.STDDEV.getName()) |
| || aggregationName.equals(SqlStdOperatorTable.STDDEV_SAMP.getName())) { |
| return Accumulators::stdDevSamp; |
| } else if (aggregationName.equals(SqlStdOperatorTable.STDDEV_POP.getName())) { |
| return Accumulators::stdDevPop; |
| } |
| return null; |
| } |
| |
| public static boolean supportsAggregation(AggregateCall aggregateCall) { |
| String name = aggregateCall.getAggregation().getName(); |
| return name.equals(SqlStdOperatorTable.COUNT.getName()) |
| || name.equals(SqlStdOperatorTable.SUM.getName()) |
| || name.equals(SqlStdOperatorTable.SUM0.getName()) |
| || name.equals(SqlStdOperatorTable.MIN.getName()) |
| || name.equals(SqlStdOperatorTable.MAX.getName()) |
| || name.equals(SqlStdOperatorTable.AVG.getName()) |
| || name.equals(SqlStdOperatorTable.FIRST.getName()) |
| || name.equals(SqlStdOperatorTable.LAST.getName()) |
| || name.equals(SqlStdOperatorTable.STDDEV.getName()) |
| || name.equals(SqlStdOperatorTable.STDDEV_SAMP.getName()) |
| || name.equals(SqlStdOperatorTable.STDDEV_POP.getName()); |
| } |
| } |