Java tutorial
/* * 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.calcite.adapter.geode.rel; import org.apache.calcite.adapter.geode.util.GeodeUtils; import org.apache.calcite.adapter.geode.util.JavaTypeFactoryExtImpl; import org.apache.calcite.adapter.java.AbstractQueryableTable; import org.apache.calcite.linq4j.AbstractEnumerable; import org.apache.calcite.linq4j.Enumerable; import org.apache.calcite.linq4j.Enumerator; import org.apache.calcite.linq4j.QueryProvider; import org.apache.calcite.linq4j.Queryable; import org.apache.calcite.plan.RelOptCluster; import org.apache.calcite.plan.RelOptTable; import org.apache.calcite.rel.RelNode; import org.apache.calcite.rel.type.RelDataType; import org.apache.calcite.rel.type.RelDataTypeFactory; import org.apache.calcite.rel.type.RelDataTypeImpl; import org.apache.calcite.rel.type.RelProtoDataType; import org.apache.calcite.runtime.Hook; import org.apache.calcite.schema.SchemaPlus; import org.apache.calcite.schema.TranslatableTable; import org.apache.calcite.schema.impl.AbstractTableQueryable; import org.apache.calcite.sql.type.SqlTypeName; import org.apache.calcite.util.Util; import org.apache.geode.cache.GemFireCache; import org.apache.geode.cache.Region; import org.apache.geode.cache.query.QueryService; import org.apache.geode.cache.query.SelectResults; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableList.Builder; import com.google.common.collect.ImmutableMap; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.List; import java.util.Locale; import java.util.Map; /** * Table based on a Geode Region */ public class GeodeTable extends AbstractQueryableTable implements TranslatableTable { private static final Logger LOGGER = LoggerFactory.getLogger(GeodeTable.class.getName()); private final String regionName; private final RelDataType rowType; GeodeTable(Region<?, ?> region) { super(Object[].class); this.regionName = region.getName(); this.rowType = GeodeUtils.autodetectRelTypeFromRegion(region); } public String toString() { return "GeodeTable {" + regionName + "}"; } /** * Executes an OQL query on the underlying table. * * <p>Called by the {@link GeodeQueryable} which in turn is * called via the generated code. * * @param clientCache Geode client cache * @param fields List of fields to project * @param predicates A list of predicates which should be used in the query * @return Enumerator of results */ public Enumerable<Object> query(final GemFireCache clientCache, final List<Map.Entry<String, Class>> fields, final List<Map.Entry<String, String>> selectFields, final List<Map.Entry<String, String>> aggregateFunctions, final List<String> groupByFields, List<String> predicates, List<String> orderByFields, Long limit) { final RelDataTypeFactory typeFactory = new JavaTypeFactoryExtImpl(); final RelDataTypeFactory.Builder fieldInfo = typeFactory.builder(); for (Map.Entry<String, Class> field : fields) { SqlTypeName typeName = typeFactory.createJavaType(field.getValue()).getSqlTypeName(); fieldInfo.add(field.getKey(), typeFactory.createSqlType(typeName)).nullable(true); } final RelProtoDataType resultRowType = RelDataTypeImpl.proto(fieldInfo.build()); ImmutableMap<String, String> aggFuncMap = ImmutableMap.of(); if (!aggregateFunctions.isEmpty()) { ImmutableMap.Builder<String, String> aggFuncMapBuilder = ImmutableMap.builder(); for (Map.Entry<String, String> e : aggregateFunctions) { aggFuncMapBuilder.put(e.getKey(), e.getValue()); } aggFuncMap = aggFuncMapBuilder.build(); } // Construct the list of fields to project Builder<String> selectBuilder = ImmutableList.builder(); if (!groupByFields.isEmpty()) { // manually add GROUP BY to select clause (GeodeProjection was not visited) for (String groupByField : groupByFields) { selectBuilder.add(groupByField + " AS " + groupByField); } if (!aggFuncMap.isEmpty()) { for (Map.Entry<String, String> e : aggFuncMap.entrySet()) { selectBuilder.add(e.getValue() + " AS " + e.getKey()); } } } else { if (selectFields.isEmpty()) { if (!aggFuncMap.isEmpty()) { for (Map.Entry<String, String> e : aggFuncMap.entrySet()) { selectBuilder.add(e.getValue() + " AS " + e.getKey()); } } else { selectBuilder.add("*"); } } else { if (!aggFuncMap.isEmpty()) { for (Map.Entry<String, String> e : aggFuncMap.entrySet()) { selectBuilder.add(e.getValue() + " AS " + e.getKey()); } } else { for (Map.Entry<String, String> field : selectFields) { selectBuilder.add(field.getKey() + " AS " + field.getValue()); } } } } final String oqlSelectStatement = Util.toString(selectBuilder.build(), "", ", ", ""); // Combine all predicates conjunctively String whereClause = ""; if (!predicates.isEmpty()) { whereClause = " WHERE "; whereClause += Util.toString(predicates, "", " AND ", ""); } // Build and issue the query and return an Enumerator over the results StringBuilder queryBuilder = new StringBuilder("SELECT "); queryBuilder.append(oqlSelectStatement); queryBuilder.append(" FROM /" + regionName); queryBuilder.append(whereClause); if (!groupByFields.isEmpty()) { queryBuilder.append(Util.toString(groupByFields, " GROUP BY ", ", ", "")); } if (!orderByFields.isEmpty()) { queryBuilder.append(Util.toString(orderByFields, " ORDER BY ", ", ", "")); } if (limit != null) { queryBuilder.append(" LIMIT " + limit); } final String oqlQuery = queryBuilder.toString(); Hook.QUERY_PLAN.run(oqlQuery); LOGGER.info("OQL: " + oqlQuery); return new AbstractEnumerable<Object>() { public Enumerator<Object> enumerator() { final QueryService queryService = clientCache.getQueryService(); try { SelectResults results = (SelectResults) queryService.newQuery(oqlQuery).execute(); return new GeodeEnumerator(results, resultRowType); } catch (Exception e) { String message = String.format(Locale.ROOT, "Failed to execute query [%s] on %s", oqlQuery, clientCache.getName()); throw new RuntimeException(message, e); } } }; } public <T> Queryable<T> asQueryable(QueryProvider queryProvider, SchemaPlus schema, String tableName) { return new GeodeQueryable<>(queryProvider, schema, this, tableName); } @Override public RelNode toRel(RelOptTable.ToRelContext context, RelOptTable relOptTable) { final RelOptCluster cluster = context.getCluster(); return new GeodeTableScan(cluster, cluster.traitSetOf(GeodeRel.CONVENTION), relOptTable, this, null); } @Override public RelDataType getRowType(RelDataTypeFactory typeFactory) { return rowType; } /** * Implementation of {@link Queryable} based on a {@link GeodeTable}. * * @param <T> type */ public static class GeodeQueryable<T> extends AbstractTableQueryable<T> { public GeodeQueryable(QueryProvider queryProvider, SchemaPlus schema, GeodeTable table, String tableName) { super(queryProvider, schema, table, tableName); } // tzolov: this should never be called for queryable tables??? public Enumerator<T> enumerator() { throw new UnsupportedOperationException("Enumerator on Queryable should never be called"); } private GeodeTable getTable() { return (GeodeTable) table; } private GemFireCache getClientCache() { return schema.unwrap(GeodeSchema.class).cache; } /** * Called via code-generation. */ @SuppressWarnings("UnusedDeclaration") public Enumerable<Object> query(List<Map.Entry<String, Class>> fields, List<Map.Entry<String, String>> selectFields, List<Map.Entry<String, String>> aggregateFunctions, List<String> groupByFields, List<String> predicates, List<String> order, Long limit) { return getTable().query(getClientCache(), fields, selectFields, aggregateFunctions, groupByFields, predicates, order, limit); } } } // End GeodeTable.java