nickva commented on code in PR #4291: URL: https://github.com/apache/couchdb/pull/4291#discussion_r1170804075
########## nouveau/src/main/java/org/apache/couchdb/nouveau/core/IndexManager.java: ########## @@ -0,0 +1,323 @@ +// +// Licensed 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.couchdb.nouveau.core; + +import static com.codahale.metrics.MetricRegistry.name; + +import java.io.File; +import java.io.IOException; +import java.nio.file.FileAlreadyExistsException; +import java.nio.file.Files; +import java.nio.file.Path; +import java.time.Duration; +import java.util.List; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.TimeUnit; +import java.util.stream.Stream; + +import org.apache.couchdb.nouveau.api.IndexDefinition; +import org.eclipse.jetty.io.RuntimeIOException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import com.codahale.metrics.MetricRegistry; +import com.codahale.metrics.caffeine.MetricsStatsCounter; +import com.fasterxml.jackson.annotation.JsonProperty; +import com.fasterxml.jackson.databind.ObjectMapper; +import com.github.benmanes.caffeine.cache.Cache; +import com.github.benmanes.caffeine.cache.Caffeine; +import com.github.benmanes.caffeine.cache.RemovalCause; +import com.github.benmanes.caffeine.cache.RemovalListener; +import com.github.benmanes.caffeine.cache.Scheduler; + +import io.dropwizard.lifecycle.Managed; +import jakarta.ws.rs.WebApplicationException; +import jakarta.ws.rs.core.Response.Status; + +/** + * The central class of Nouveau, responsible for loading and unloading Lucene + * indexes and making them available for query. + */ + +public final class IndexManager implements Managed { + + @FunctionalInterface + public interface IndexFunction<V, R> { + R apply(final V value) throws IOException; + } + + private static final Logger LOGGER = LoggerFactory.getLogger(IndexManager.class); + + private int maxIndexesOpen; + + private int commitIntervalSeconds; + + private int idleSeconds; + + private Path rootDir; + + private ObjectMapper objectMapper; + + private MetricRegistry metricRegistry; + + private ScheduledExecutorService scheduler; + + private Cache<String, Index> cache; + + public <R> R with(final String name, final IndexLoader loader, final IndexFunction<Index, R> indexFun) + throws IOException, InterruptedException { + while (true) { + if (!exists(name)) { + throw new WebApplicationException("Index does not exist", Status.NOT_FOUND); + } + + final Index index; + try { + index = cache.get(name, (n) -> { + LOGGER.info("opening {}", n); + final Path path = indexPath(n); + try { + final IndexDefinition indexDefinition = loadIndexDefinition(n); + return loader.apply(path, indexDefinition); + } catch (final IOException e) { + throw new RuntimeIOException(e); + } + }); + } catch (final RuntimeIOException e) { + throw (IOException) e.getCause(); + } + + if (index.tryAcquire(1, TimeUnit.SECONDS)) { + try { + final R result = indexFun.apply(index); + if (index.needsCommit(commitIntervalSeconds, TimeUnit.SECONDS)) { + scheduler.execute(() -> { + if (index.tryAcquire()) { + try { + LOGGER.info("committing {}", name); Review Comment: Is there a `debug` level. Otherwise, would we expect to see a log entry for every index commit? -- 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]
