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/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.index.engine;
import org.apache.lucene.document.LongPoint;
import org.apache.lucene.index.LeafReader;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.NumericDocValues;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.DocValuesFieldExistsQuery;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.util.ArrayUtil;
import org.elasticsearch.common.bytes.BytesReference;
import org.elasticsearch.common.lucene.Lucene;
import org.elasticsearch.core.internal.io.IOUtils;
import org.elasticsearch.index.fieldvisitor.FieldsVisitor;
import org.elasticsearch.index.mapper.IdFieldMapper;
import org.elasticsearch.index.mapper.MapperService;
import org.elasticsearch.index.mapper.SeqNoFieldMapper;
import org.elasticsearch.index.mapper.SourceFieldMapper;
import org.elasticsearch.index.mapper.Uid;
import org.elasticsearch.index.translog.Translog;
import java.io.Closeable;
import java.io.IOException;
import java.util.Comparator;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* A {@link Translog.Snapshot} from changes in a Lucene index
*/
final class LuceneChangesSnapshot implements Translog.Snapshot {
static final int DEFAULT_BATCH_SIZE = 1024;
private final int searchBatchSize;
private final long fromSeqNo, toSeqNo;
private long lastSeenSeqNo;
private int skippedOperations;
private final boolean requiredFullRange;
private final IndexSearcher indexSearcher;
private final MapperService mapperService;
private int docIndex = 0;
private final int totalHits;
private ScoreDoc[] scoreDocs;
private final ParallelArray parallelArray;
private final Closeable onClose;
/**
* Creates a new "translog" snapshot from Lucene for reading operations whose seq# in the specified range.
*
* @param engineSearcher the internal engine searcher which will be taken over if the snapshot is opened successfully
* @param mapperService the mapper service which will be mainly used to resolve the document's type and uid
* @param searchBatchSize the number of documents should be returned by each search
* @param fromSeqNo the min requesting seq# - inclusive
* @param toSeqNo the maximum requesting seq# - inclusive
* @param requiredFullRange if true, the snapshot will strictly check for the existence of operations between fromSeqNo and toSeqNo
*/
LuceneChangesSnapshot(Engine.Searcher engineSearcher, MapperService mapperService, int searchBatchSize,
long fromSeqNo, long toSeqNo, boolean requiredFullRange) throws IOException {
if (fromSeqNo < 0 || toSeqNo < 0 || fromSeqNo > toSeqNo) {
throw new IllegalArgumentException("Invalid range; from_seqno [" + fromSeqNo + "], to_seqno [" + toSeqNo + "]");
}
if (searchBatchSize <= 0) {
throw new IllegalArgumentException("Search_batch_size must be positive [" + searchBatchSize + "]");
}
final AtomicBoolean closed = new AtomicBoolean();
this.onClose = () -> {
if (closed.compareAndSet(false, true)) {
IOUtils.close(engineSearcher);
}
};
this.mapperService = mapperService;
final long requestingSize = (toSeqNo - fromSeqNo) == Long.MAX_VALUE ? Long.MAX_VALUE : (toSeqNo - fromSeqNo + 1L);
this.searchBatchSize = requestingSize < searchBatchSize ? Math.toIntExact(requestingSize) : searchBatchSize;
this.fromSeqNo = fromSeqNo;
this.toSeqNo = toSeqNo;
this.lastSeenSeqNo = fromSeqNo - 1;
this.requiredFullRange = requiredFullRange;
this.indexSearcher = new IndexSearcher(Lucene.wrapAllDocsLive(engineSearcher.getDirectoryReader()));
this.indexSearcher.setQueryCache(null);
this.parallelArray = new ParallelArray(this.searchBatchSize);
final TopDocs topDocs = searchOperations(null);
this.totalHits = Math.toIntExact(topDocs.totalHits.value);
this.scoreDocs = topDocs.scoreDocs;
fillParallelArray(scoreDocs, parallelArray);
}
@Override
public void close() throws IOException {
onClose.close();
}
@Override
public int totalOperations() {
return totalHits;
}
@Override
public int skippedOperations() {
return skippedOperations;
}
@Override
public Translog.Operation next() throws IOException {
Translog.Operation op = null;
for (int idx = nextDocIndex(); idx != -1; idx = nextDocIndex()) {
op = readDocAsOp(idx);
if (op != null) {
break;
}
}
if (requiredFullRange) {
rangeCheck(op);
}
if (op != null) {
lastSeenSeqNo = op.seqNo();
}
return op;
}
private void rangeCheck(Translog.Operation op) {
if (op == null) {
if (lastSeenSeqNo < toSeqNo) {
throw new MissingHistoryOperationsException("Not all operations between from_seqno [" + fromSeqNo + "] " +
"and to_seqno [" + toSeqNo + "] found; prematurely terminated last_seen_seqno [" + lastSeenSeqNo + "]");
}
} else {
final long expectedSeqNo = lastSeenSeqNo + 1;
if (op.seqNo() != expectedSeqNo) {
throw new MissingHistoryOperationsException("Not all operations between from_seqno [" + fromSeqNo + "] " +
"and to_seqno [" + toSeqNo + "] found; expected seqno [" + expectedSeqNo + "]; found [" + op + "]");
}
}
}
private int nextDocIndex() throws IOException {
// we have processed all docs in the current search - fetch the next batch
if (docIndex == scoreDocs.length && docIndex > 0) {
final ScoreDoc prev = scoreDocs[scoreDocs.length - 1];
scoreDocs = searchOperations(prev).scoreDocs;
fillParallelArray(scoreDocs, parallelArray);
docIndex = 0;
}
if (docIndex < scoreDocs.length) {
int idx = docIndex;
docIndex++;
return idx;
}
return -1;
}
private void fillParallelArray(ScoreDoc[] scoreDocs, ParallelArray parallelArray) throws IOException {
if (scoreDocs.length > 0) {
for (int i = 0; i < scoreDocs.length; i++) {
scoreDocs[i].shardIndex = i;
}
// for better loading performance we sort the array by docID and
// then visit all leaves in order.
ArrayUtil.introSort(scoreDocs, Comparator.comparingInt(i -> i.doc));
int docBase = -1;
int maxDoc = 0;
List leaves = indexSearcher.getIndexReader().leaves();
int readerIndex = 0;
CombinedDocValues combinedDocValues = null;
LeafReaderContext leaf = null;
for (ScoreDoc scoreDoc : scoreDocs) {
if (scoreDoc.doc >= docBase + maxDoc) {
do {
leaf = leaves.get(readerIndex++);
docBase = leaf.docBase;
maxDoc = leaf.reader().maxDoc();
} while (scoreDoc.doc >= docBase + maxDoc);
combinedDocValues = new CombinedDocValues(leaf.reader());
}
final int segmentDocID = scoreDoc.doc - docBase;
final int index = scoreDoc.shardIndex;
parallelArray.leafReaderContexts[index] = leaf;
parallelArray.seqNo[index] = combinedDocValues.docSeqNo(segmentDocID);
parallelArray.primaryTerm[index] = combinedDocValues.docPrimaryTerm(segmentDocID);
parallelArray.version[index] = combinedDocValues.docVersion(segmentDocID);
parallelArray.isTombStone[index] = combinedDocValues.isTombstone(segmentDocID);
parallelArray.hasRecoverySource[index] = combinedDocValues.hasRecoverySource(segmentDocID);
}
// now sort back based on the shardIndex. we use this to store the previous index
ArrayUtil.introSort(scoreDocs, Comparator.comparingInt(i -> i.shardIndex));
}
}
private TopDocs searchOperations(ScoreDoc after) throws IOException {
final Query rangeQuery = new BooleanQuery.Builder()
.add(LongPoint.newRangeQuery(SeqNoFieldMapper.NAME, Math.max(fromSeqNo, lastSeenSeqNo), toSeqNo), BooleanClause.Occur.MUST)
// exclude non-root nested documents
.add(new DocValuesFieldExistsQuery(SeqNoFieldMapper.PRIMARY_TERM_NAME), BooleanClause.Occur.MUST)
.build();
final Sort sortedBySeqNo = new Sort(new SortField(SeqNoFieldMapper.NAME, SortField.Type.LONG));
return indexSearcher.searchAfter(after, rangeQuery, searchBatchSize, sortedBySeqNo);
}
private Translog.Operation readDocAsOp(int docIndex) throws IOException {
final LeafReaderContext leaf = parallelArray.leafReaderContexts[docIndex];
final int segmentDocID = scoreDocs[docIndex].doc - leaf.docBase;
final long primaryTerm = parallelArray.primaryTerm[docIndex];
assert primaryTerm > 0 : "nested child document must be excluded";
final long seqNo = parallelArray.seqNo[docIndex];
// Only pick the first seen seq#
if (seqNo == lastSeenSeqNo) {
skippedOperations++;
return null;
}
final long version = parallelArray.version[docIndex];
final String sourceField = parallelArray.hasRecoverySource[docIndex] ? SourceFieldMapper.RECOVERY_SOURCE_NAME :
SourceFieldMapper.NAME;
final FieldsVisitor fields = new FieldsVisitor(true, sourceField);
leaf.reader().document(segmentDocID, fields);
fields.postProcess(mapperService);
final Translog.Operation op;
final boolean isTombstone = parallelArray.isTombStone[docIndex];
if (isTombstone && fields.uid() == null) {
op = new Translog.NoOp(seqNo, primaryTerm, fields.source().utf8ToString());
assert version == 1L : "Noop tombstone should have version 1L; actual version [" + version + "]";
assert assertDocSoftDeleted(leaf.reader(), segmentDocID) : "Noop but soft_deletes field is not set [" + op + "]";
} else {
final String id = fields.uid().id();
final String type = fields.uid().type();
final Term uid = new Term(IdFieldMapper.NAME, Uid.encodeId(id));
if (isTombstone) {
op = new Translog.Delete(type, id, uid, seqNo, primaryTerm, version);
assert assertDocSoftDeleted(leaf.reader(), segmentDocID) : "Delete op but soft_deletes field is not set [" + op + "]";
} else {
final BytesReference source = fields.source();
if (source == null) {
// TODO: Callers should ask for the range that source should be retained. Thus we should always
// check for the existence source once we make peer-recovery to send ops after the local checkpoint.
if (requiredFullRange) {
throw new MissingHistoryOperationsException("source not found for seqno=" + seqNo +
" from_seqno=" + fromSeqNo + " to_seqno=" + toSeqNo);
} else {
skippedOperations++;
return null;
}
}
// TODO: pass the latest timestamp from engine.
final long autoGeneratedIdTimestamp = -1;
op = new Translog.Index(type, id, seqNo, primaryTerm, version,
source.toBytesRef().bytes, fields.routing(), autoGeneratedIdTimestamp);
}
}
assert fromSeqNo <= op.seqNo() && op.seqNo() <= toSeqNo && lastSeenSeqNo < op.seqNo() : "Unexpected operation; " +
"last_seen_seqno [" + lastSeenSeqNo + "], from_seqno [" + fromSeqNo + "], to_seqno [" + toSeqNo + "], op [" + op + "]";
return op;
}
private boolean assertDocSoftDeleted(LeafReader leafReader, int segmentDocId) throws IOException {
final NumericDocValues ndv = leafReader.getNumericDocValues(Lucene.SOFT_DELETES_FIELD);
if (ndv == null || ndv.advanceExact(segmentDocId) == false) {
throw new IllegalStateException("DocValues for field [" + Lucene.SOFT_DELETES_FIELD + "] is not found");
}
return ndv.longValue() == 1;
}
private static final class ParallelArray {
final LeafReaderContext[] leafReaderContexts;
final long[] version;
final long[] seqNo;
final long[] primaryTerm;
final boolean[] isTombStone;
final boolean[] hasRecoverySource;
ParallelArray(int size) {
version = new long[size];
seqNo = new long[size];
primaryTerm = new long[size];
isTombStone = new boolean[size];
hasRecoverySource = new boolean[size];
leafReaderContexts = new LeafReaderContext[size];
}
}
}