kroeders commented on a change in pull request #10427: URL: https://github.com/apache/druid/pull/10427#discussion_r493905533
########## File path: extensions-contrib/lookup-aware-server-selector/src/main/java/org/apache/druid/client/selector/filter/lookup/LookupAwareFilterStrategy.java ########## @@ -0,0 +1,181 @@ +/* + * 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.druid.client.selector.filter.lookup; + +import com.fasterxml.jackson.annotation.JacksonInject; +import com.fasterxml.jackson.annotation.JsonCreator; +import com.fasterxml.jackson.annotation.JsonTypeName; +import org.apache.druid.client.selector.QueryableDruidServer; +import org.apache.druid.client.selector.filter.ServerFilterStrategy; +import org.apache.druid.java.util.common.ISE; +import org.apache.druid.math.expr.Expr; +import org.apache.druid.query.DataSource; +import org.apache.druid.query.JoinDataSource; +import org.apache.druid.query.LookupDataSource; +import org.apache.druid.query.Query; +import org.apache.druid.query.dimension.DimensionSpec; +import org.apache.druid.query.dimension.ExtractionDimensionSpec; +import org.apache.druid.query.extraction.CascadeExtractionFn; +import org.apache.druid.query.extraction.ExtractionFn; +import org.apache.druid.query.groupby.GroupByQuery; +import org.apache.druid.query.lookup.RegisteredLookupExtractionFn; +import org.apache.druid.query.search.SearchQuery; +import org.apache.druid.query.topn.TopNQuery; +import org.apache.druid.segment.VirtualColumn; +import org.apache.druid.segment.VirtualColumns; +import org.apache.druid.segment.virtual.ExpressionVirtualColumn; + +import java.util.Collection; +import java.util.HashSet; +import java.util.Set; +import java.util.regex.Matcher; +import java.util.regex.Pattern; +import java.util.stream.Collectors; + +@JsonTypeName("lookupsLoaded") +public class LookupAwareFilterStrategy implements ServerFilterStrategy +{ + public static final String LOOKUPS_CONTEXT_KEY = "lookups"; + public static final String QUERY_LOOKUPS_CACHE_KEY = "__lookups"; + private final LookupStatusView lookupStatusView; + + @JsonCreator + public LookupAwareFilterStrategy(@JacksonInject LookupStatusView lookupStatusView) + { + this.lookupStatusView = lookupStatusView; + } + + @Override + public <T> Set<QueryableDruidServer> filter(Query<T> query, Set<QueryableDruidServer> servers) + { + if (query == null) { + return servers; + } + final Set<String> lookups; + if (query.getContext() != null + && query.getContext().containsKey(QUERY_LOOKUPS_CACHE_KEY)) { + lookups = (Set<String>) query.getContext().get(QUERY_LOOKUPS_CACHE_KEY); + } else { + lookups = new HashSet<String>(); + findLookupsInQuery(query, lookups); + if (query.getContext() != null) { + try { + query.getContext().put(QUERY_LOOKUPS_CACHE_KEY, lookups); + } + catch (UnsupportedOperationException e) { + // TODO This is for immutable contexts, what to do with it? + } + } + } + if (lookups.size() == 0) { + return servers; + } + + Set<QueryableDruidServer> filteredServers = servers.stream() + .filter(server -> lookupStatusView.hasAllLookups(server.getServer().getHostAndPort().toString(), lookups)) + .collect(Collectors.toSet()); + + if (filteredServers.size() == 0) { + throw new ISE("Unable to find servers with all lookups [%s]", lookups.stream().collect(Collectors.joining(","))); + } + + return filteredServers; + } + + private <T> Set<String> findLookupsInQuery(Query<T> query, Set<String> lookupsInQuery) + { + if (query.getContext() != null && query.getContext().containsKey(LOOKUPS_CONTEXT_KEY)) { + Object userLookups = query.getContext().get(LOOKUPS_CONTEXT_KEY); + if (userLookups instanceof Collection) { + lookupsInQuery.addAll(((Collection) userLookups)); + } + } + + findLookupsInDataSources(query.getDataSource(), lookupsInQuery); + findLookupsInDimensions(query, lookupsInQuery); + findLookupsInVirtualColumns(query, lookupsInQuery); + + return lookupsInQuery; + } + + public <T> void findLookupsInVirtualColumns(Query<T> query, Set<String> lookupsInQuery) + { + VirtualColumns virts = query.getVirtualColumns(); + for (VirtualColumn vc : virts.getVirtualColumns()) { + if (vc instanceof ExpressionVirtualColumn) { + ExpressionVirtualColumn evc = (ExpressionVirtualColumn) vc; + Expr expr = evc.getParsedExpression().get(); + Matcher m = Pattern.compile("lookup\\(.*?, \\'(.*?)\\'\\)").matcher(expr.stringify()); Review comment: I don't like using a regex here. Ideally, LookupExprMacro.LookupExpr would be promoted from a local class to something accessible - but I didn't want to include any other changes to core Druid on this PR, if the other commit gets into core then the rest of this functionality can be achieved just with this extension. ---------------------------------------------------------------- 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: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
