| /* |
| * 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.googlesheets; |
| |
| import org.apache.calcite.rex.RexNode; |
| import org.apache.calcite.util.Pair; |
| import org.apache.drill.common.expression.SchemaPath; |
| import org.apache.drill.common.map.CaseInsensitiveMap; |
| import org.apache.drill.common.types.TypeProtos.MinorType; |
| import org.apache.drill.exec.ops.OptimizerRulesContext; |
| import org.apache.drill.exec.physical.base.GroupScan; |
| import org.apache.drill.exec.store.StoragePluginOptimizerRule; |
| import org.apache.drill.exec.store.base.filter.ExprNode; |
| import org.apache.drill.exec.store.base.filter.ExprNode.AndNode; |
| import org.apache.drill.exec.store.base.filter.ExprNode.ColRelOpConstNode; |
| import org.apache.drill.exec.store.base.filter.ExprNode.OrNode; |
| import org.apache.drill.exec.store.base.filter.FilterPushDownListener; |
| import org.apache.drill.exec.store.base.filter.FilterPushDownStrategy; |
| |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * The GoogleSheets storage plugin accepts filters which are: |
| * <ul> |
| * <li>A single column = value expression </li> |
| * <li>An AND'ed set of such expressions,</li> |
| * <li>If the value is one with an unambiguous conversion to |
| * a string. (That is, not dates, binary, maps, etc.)</li> |
| * </ul> |
| * |
| * Note, at the moment, no filters are pushed down. Once we figure out the Google SDK for this, |
| * we can easily uncomment out the lines below and the filters will be pushed down. |
| */ |
| public class GoogleSheetsPushDownListener implements FilterPushDownListener { |
| |
| public static Set<StoragePluginOptimizerRule> rulesFor(OptimizerRulesContext optimizerRulesContext) { |
| return FilterPushDownStrategy.rulesFor(new GoogleSheetsPushDownListener()); |
| } |
| |
| @Override |
| public String prefix() { |
| return "GoogleSheets"; |
| } |
| |
| @Override |
| public boolean isTargetScan(GroupScan groupScan) { |
| return groupScan instanceof GoogleSheetsGroupScan; |
| } |
| |
| @Override |
| public ScanPushDownListener builderFor(GroupScan groupScan) { |
| GoogleSheetsGroupScan gsScan = (GoogleSheetsGroupScan) groupScan; |
| if (gsScan.hasFilters() || !gsScan.allowsFilters()) { |
| return null; |
| } else { |
| return new GoogleSheetsScanPushDownListener(gsScan); |
| } |
| } |
| |
| private static class GoogleSheetsScanPushDownListener implements ScanPushDownListener { |
| |
| private final GoogleSheetsGroupScan groupScan; |
| private final Map<String, String> filterParams = CaseInsensitiveMap.newHashMap(); |
| |
| GoogleSheetsScanPushDownListener(GoogleSheetsGroupScan groupScan) { |
| this.groupScan = groupScan; |
| for (SchemaPath field : groupScan.columns()) { |
| filterParams.put(field.getAsUnescapedPath(), field.getAsUnescapedPath()); |
| } |
| } |
| |
| @Override |
| public ExprNode accept(ExprNode node) { |
| if (node instanceof OrNode) { |
| return null; |
| } else if (node instanceof ColRelOpConstNode) { |
| // TODO Implement Filter Pushdowns |
| // This entire method always returns null. Google Sheets SDK may allow |
| // filter pushdowns, however the SDK was so complicated and poorly documented, I was not able |
| // to figure out how to implement filter pushdowns. If and when we figure that out, uncomment |
| // the line below, and then the filter rules will be pushed down. |
| return null; |
| //return acceptRelOp((ColRelOpConstNode) node); |
| } else { |
| return null; |
| } |
| } |
| |
| private ColRelOpConstNode acceptRelOp(ColRelOpConstNode relOp) { |
| return acceptColumn(relOp.colName) && acceptType(relOp.value.type) ? relOp : null; |
| } |
| |
| /** |
| * Only accept columns in the filter params list. |
| */ |
| private boolean acceptColumn(String colName) { |
| return filterParams.containsKey(colName); |
| } |
| |
| /** |
| * Only accept types which have an unambiguous mapping to |
| * String. |
| */ |
| private boolean acceptType(MinorType type) { |
| switch (type) { |
| case BIGINT: |
| case BIT: |
| case FLOAT4: |
| case FLOAT8: |
| case INT: |
| case SMALLINT: |
| case VARCHAR: |
| case VARDECIMAL: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| /** |
| * Convert the nodes to a map of param/string pairs using |
| * the case specified in the storage plugin config. |
| */ |
| @Override |
| public Pair<GroupScan, List<RexNode>> transform(AndNode andNode) { |
| Map<String, ExprNode.ColRelOpConstNode> filters = new HashMap<>(); |
| double selectivity = 1; |
| for (ExprNode expr : andNode.children) { |
| ColRelOpConstNode relOp = (ColRelOpConstNode) expr; |
| filters.put(filterParams.get(relOp.colName), relOp); |
| selectivity *= relOp.op.selectivity(); |
| } |
| GoogleSheetsGroupScan newScan = new GoogleSheetsGroupScan(groupScan, filters, selectivity); |
| return Pair.of(newScan, Collections.emptyList()); |
| } |
| } |
| } |