bhabegger commented on code in PR #3085: URL: https://github.com/apache/jackrabbit-oak/pull/3085#discussion_r3892042464
########## oak-search-elastic/src/main/java/org/apache/jackrabbit/oak/plugins/index/elastic/index/LazyElasticIndexWriter.java: ########## @@ -0,0 +1,95 @@ +/* + * 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.jackrabbit.oak.plugins.index.elastic.index; + +import org.apache.jackrabbit.oak.plugins.index.elastic.ElasticConnection; +import org.apache.jackrabbit.oak.plugins.index.elastic.ElasticIndexDefinition; +import org.apache.jackrabbit.oak.plugins.index.search.spi.editor.FulltextIndexWriter; +import org.apache.jackrabbit.oak.spi.state.NodeBuilder; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.util.function.Supplier; + +/** + * A {@link FulltextIndexWriter} proxy that defers creation of the real {@link ElasticIndexWriter} + * to the first {@link #updateDocument}, {@link #deleteDocumentTree} or {@link #deleteDocument} + * call (OAK-12249). + * + * <p>If {@link #close} is called before any document is written — i.e. the reindex produced zero + * documents — the supplier is never invoked, so no Elasticsearch index or alias is created. + * Instead, {@link ElasticIndexDefinition#PROP_REQUIRES_PROVISIONING} is set on the definition + * node so the next incremental-write cycle provisions the index on demand. If the index was + * already provisioned before this reindex (i.e. it previously had documents), its now-stale + * alias and backing index are removed — otherwise pre-reindex content would keep being served + * indefinitely. + * + * <p>The supplier is expected to create and provision the index as a side effect of construction + * (as {@link ElasticIndexWriter} does). Thread safety is not required: Oak calls each writer + * instance from a single thread. + */ +class LazyElasticIndexWriter implements FulltextIndexWriter<ElasticDocument> { + private static final Logger LOG = LoggerFactory.getLogger(LazyElasticIndexWriter.class); + + private final Supplier<ElasticIndexWriter> writerSupplier; + private final NodeBuilder definitionBuilder; + private final ElasticConnection elasticConnection; + private final ElasticIndexDefinition indexDefinition; + private ElasticIndexWriter delegate; + + LazyElasticIndexWriter(Supplier<ElasticIndexWriter> writerSupplier, NodeBuilder definitionBuilder, + ElasticConnection elasticConnection, ElasticIndexDefinition indexDefinition) { + this.writerSupplier = writerSupplier; + this.definitionBuilder = definitionBuilder; + this.elasticConnection = elasticConnection; + this.indexDefinition = indexDefinition; + } + + @Override + public void updateDocument(String path, ElasticDocument doc) throws IOException { + getOrCreate().updateDocument(path, doc); + } + + @Override + public void deleteDocumentTree(String path) throws IOException { + getOrCreate().deleteDocumentTree(path); + } + + @Override + public void deleteDocument(String path) throws IOException { + getOrCreate().deleteDocument(path); + } + + @Override + public boolean close(long timestamp) throws IOException { + if (delegate == null) { + LOG.info("Reindex produced no documents — skipping ES index creation (OAK-12249)"); + definitionBuilder.setProperty(ElasticIndexDefinition.PROP_REQUIRES_PROVISIONING, true); + ElasticIndexWriter.unaliasIfProvisioned(elasticConnection, indexDefinition); Review Comment: I agree about the location. As for the static, I prefer keeping it as when a method does not depend at all on class fields marking it as static makes that independence clear. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
