| /* |
| * 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.solr.core; |
| |
| import java.io.IOException; |
| import java.lang.invoke.MethodHandles; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| import org.apache.lucene.index.IndexCommit; |
| import org.apache.lucene.index.IndexDeletionPolicy; |
| import org.apache.lucene.index.IndexWriter; |
| import org.apache.lucene.store.Directory; |
| import org.apache.solr.core.snapshots.SolrSnapshotMetaDataManager; |
| import org.apache.solr.update.SolrIndexWriter; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * A wrapper for an IndexDeletionPolicy instance. |
| * <p> |
| * Provides features for looking up IndexCommit given a version. Allows reserving index |
| * commit points for certain amounts of time to support features such as index replication |
| * or snapshooting directly out of a live index directory. |
| * <p> |
| * <b>NOTE</b>: The {@link #clone()} method returns <tt>this</tt> in order to make |
| * this {@link IndexDeletionPolicy} instance trackable across {@link IndexWriter} |
| * instantiations. This is correct because each core has its own |
| * {@link IndexDeletionPolicy} and never has more than one open {@link IndexWriter}. |
| * |
| * @see org.apache.lucene.index.IndexDeletionPolicy |
| */ |
| public final class IndexDeletionPolicyWrapper extends IndexDeletionPolicy { |
| private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass()); |
| |
| private final IndexDeletionPolicy deletionPolicy; |
| private volatile Map<Long, IndexCommit> solrVersionVsCommits = new ConcurrentHashMap<>(); |
| private final Map<Long, Long> reserves = new ConcurrentHashMap<>(); |
| private volatile IndexCommit latestCommit; |
| private final ConcurrentHashMap<Long, AtomicInteger> savedCommits = new ConcurrentHashMap<>(); |
| private final SolrSnapshotMetaDataManager snapshotMgr; |
| |
| public IndexDeletionPolicyWrapper(IndexDeletionPolicy deletionPolicy, SolrSnapshotMetaDataManager snapshotMgr) { |
| this.deletionPolicy = deletionPolicy; |
| this.snapshotMgr = snapshotMgr; |
| } |
| |
| /** |
| * Gets the most recent commit point |
| * <p> |
| * It is recommended to reserve a commit point for the duration of usage so that |
| * it is not deleted by the underlying deletion policy |
| * |
| * @return the most recent commit point |
| */ |
| public IndexCommit getLatestCommit() { |
| return latestCommit; |
| } |
| |
| public IndexDeletionPolicy getWrappedDeletionPolicy() { |
| return deletionPolicy; |
| } |
| |
| /** |
| * Set the duration for which commit point is to be reserved by the deletion policy. |
| * |
| * @param indexGen gen of the commit point to be reserved |
| * @param reserveTime time in milliseconds for which the commit point is to be reserved |
| */ |
| public void setReserveDuration(Long indexGen, long reserveTime) { |
| long timeToSet = System.nanoTime() + TimeUnit.NANOSECONDS.convert(reserveTime, TimeUnit.MILLISECONDS); |
| for(;;) { |
| Long previousTime = reserves.put(indexGen, timeToSet); |
| |
| // this is the common success case: the older time didn't exist, or |
| // came before the new time. |
| if (previousTime == null || previousTime <= timeToSet) { |
| LOG.debug("Commit point reservation for generation {} set to {} (requested reserve time of {})", |
| indexGen, timeToSet, reserveTime); |
| break; |
| } |
| |
| // At this point, we overwrote a longer reservation, so we want to restore the older one. |
| // the problem is that an even longer reservation may come in concurrently |
| // and we don't want to overwrite that one too. We simply keep retrying in a loop |
| // with the maximum time value we have seen. |
| timeToSet = previousTime; |
| } |
| } |
| |
| private void cleanReserves() { |
| long currentTime = System.nanoTime(); |
| for (Map.Entry<Long, Long> entry : reserves.entrySet()) { |
| if (entry.getValue() < currentTime) { |
| reserves.remove(entry.getKey()); |
| } |
| } |
| } |
| |
| private List<IndexCommitWrapper> wrap(List<? extends IndexCommit> list) { |
| List<IndexCommitWrapper> result = new ArrayList<>(); |
| for (IndexCommit indexCommit : list) result.add(new IndexCommitWrapper(indexCommit)); |
| return result; |
| } |
| |
| /** Permanently prevent this commit point from being deleted. |
| * A counter is used to allow a commit point to be correctly saved and released |
| * multiple times. */ |
| public synchronized void saveCommitPoint(Long indexCommitGen) { |
| AtomicInteger reserveCount = savedCommits.get(indexCommitGen); |
| if (reserveCount == null) reserveCount = new AtomicInteger(); |
| reserveCount.incrementAndGet(); |
| savedCommits.put(indexCommitGen, reserveCount); |
| } |
| |
| /** Release a previously saved commit point */ |
| public synchronized void releaseCommitPoint(Long indexCommitGen) { |
| AtomicInteger reserveCount = savedCommits.get(indexCommitGen); |
| if (reserveCount == null) return;// this should not happen |
| if (reserveCount.decrementAndGet() <= 0) { |
| savedCommits.remove(indexCommitGen); |
| } |
| } |
| |
| /** |
| * Internal use for Lucene... do not explicitly call. |
| */ |
| @Override |
| public void onInit(List<? extends IndexCommit> list) throws IOException { |
| List<IndexCommitWrapper> wrapperList = wrap(list); |
| deletionPolicy.onInit(wrapperList); |
| updateCommitPoints(wrapperList); |
| cleanReserves(); |
| } |
| |
| /** |
| * Internal use for Lucene... do not explicitly call. |
| */ |
| @Override |
| public void onCommit(List<? extends IndexCommit> list) throws IOException { |
| List<IndexCommitWrapper> wrapperList = wrap(list); |
| deletionPolicy.onCommit(wrapperList); |
| updateCommitPoints(wrapperList); |
| cleanReserves(); |
| } |
| |
| private class IndexCommitWrapper extends IndexCommit { |
| IndexCommit delegate; |
| |
| |
| IndexCommitWrapper(IndexCommit delegate) { |
| this.delegate = delegate; |
| } |
| |
| @Override |
| public String getSegmentsFileName() { |
| return delegate.getSegmentsFileName(); |
| } |
| |
| @Override |
| public Collection getFileNames() throws IOException { |
| return delegate.getFileNames(); |
| } |
| |
| @Override |
| public Directory getDirectory() { |
| return delegate.getDirectory(); |
| } |
| |
| @Override |
| public void delete() { |
| Long gen = delegate.getGeneration(); |
| Long reserve = reserves.get(gen); |
| if (reserve != null && System.nanoTime() < reserve) return; |
| if (savedCommits.containsKey(gen)) return; |
| if (snapshotMgr.isSnapshotted(gen)) return; |
| delegate.delete(); |
| } |
| |
| @Override |
| public int getSegmentCount() { |
| return delegate.getSegmentCount(); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| return delegate.equals(o); |
| } |
| |
| @Override |
| public int hashCode() { |
| return delegate.hashCode(); |
| } |
| |
| @Override |
| public long getGeneration() { |
| return delegate.getGeneration(); |
| } |
| |
| @Override |
| public boolean isDeleted() { |
| return delegate.isDeleted(); |
| } |
| |
| @Override |
| public Map getUserData() throws IOException { |
| return delegate.getUserData(); |
| } |
| } |
| |
| /** |
| * @param gen the gen of the commit point |
| * @return a commit point corresponding to the given version |
| */ |
| public IndexCommit getCommitPoint(Long gen) { |
| return solrVersionVsCommits.get(gen); |
| } |
| |
| /** |
| * Gets the commit points for the index. |
| * This map instance may change between commits and commit points may be deleted. |
| * It is recommended to reserve a commit point for the duration of usage |
| * |
| * @return a Map of version to commit points |
| */ |
| public Map<Long, IndexCommit> getCommits() { |
| return solrVersionVsCommits; |
| } |
| |
| private void updateCommitPoints(List<IndexCommitWrapper> list) { |
| Map<Long, IndexCommit> map = new ConcurrentHashMap<>(); |
| for (IndexCommitWrapper wrapper : list) { |
| if (!wrapper.isDeleted()) |
| map.put(wrapper.delegate.getGeneration(), wrapper.delegate); |
| } |
| solrVersionVsCommits = map; |
| if (!list.isEmpty()) { |
| latestCommit = ((list.get(list.size() - 1)).delegate); |
| } |
| } |
| |
| public static long getCommitTimestamp(IndexCommit commit) throws IOException { |
| final Map<String,String> commitData = commit.getUserData(); |
| String commitTime = commitData.get(SolrIndexWriter.COMMIT_TIME_MSEC_KEY); |
| if (commitTime != null) { |
| return Long.parseLong(commitTime); |
| } else { |
| return 0; |
| } |
| } |
| |
| @Override |
| public IndexDeletionPolicy clone() { |
| // see class-level javadocs |
| return this; |
| } |
| } |
| |