org.apache.lucene.index.BufferedDeletesStream Maven / Gradle / Ivy
package org.apache.lucene.index;
/**
* 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.
*/
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.QueryWrapperFilter;
import org.apache.lucene.util.UnicodeUtil;
import org.elasticsearch.common.Unicode;
import org.elasticsearch.common.bloom.BloomFilter;
import org.elasticsearch.index.cache.bloom.BloomCache;
import org.elasticsearch.index.mapper.internal.UidFieldMapper;
import java.io.IOException;
import java.io.PrintStream;
import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
/* Tracks the stream of {@link BuffereDeletes}.
* When DocumensWriter flushes, its buffered
* deletes are appended to this stream. We later
* apply these deletes (resolve them to the actual
* docIDs, per segment) when a merge is started
* (only to the to-be-merged segments). We
* also apply to all segments when NRT reader is pulled,
* commit/close is called, or when too many deletes are
* buffered and must be flushed (by RAM usage or by count).
*
* Each packet is assigned a generation, and each flushed or
* merged segment is also assigned a generation, so we can
* track which BufferedDeletes packets to apply to any given
* segment. */
// LUCENE MONITOR: We copied this class from Lucene, effectively overriding it with our implementation
// if it comes first in the classpath, allowing for faster apply deletes based on terms
class BufferedDeletesStream implements XIndexWriter.XBufferedDeletesStream {
// TODO: maybe linked list?
private final List deletes = new ArrayList();
// Starts at 1 so that SegmentInfos that have never had
// deletes applied (whose bufferedDelGen defaults to 0)
// will be correct:
private long nextGen = 1;
// used only by assert
private Term lastDeleteTerm;
private PrintStream infoStream;
private final AtomicLong bytesUsed = new AtomicLong();
private final AtomicInteger numTerms = new AtomicInteger();
private final int messageID;
private BloomCache bloomCache;
public BufferedDeletesStream(int messageID) {
this.messageID = messageID;
}
private synchronized void message(String message) {
if (infoStream != null) {
infoStream.println("BD " + messageID + " [" + new Date() + "; " + Thread.currentThread().getName() + "]: " + message);
}
}
public synchronized void setInfoStream(PrintStream infoStream) {
this.infoStream = infoStream;
}
public void setBloomCache(BloomCache bloomCache) {
this.bloomCache = bloomCache;
}
// Appends a new packet of buffered deletes to the stream,
// setting its generation:
public synchronized void push(FrozenBufferedDeletes packet) {
assert packet.any();
assert checkDeleteStats();
assert packet.gen < nextGen;
deletes.add(packet);
numTerms.addAndGet(packet.numTermDeletes);
bytesUsed.addAndGet(packet.bytesUsed);
if (infoStream != null) {
message("push deletes " + packet + " delGen=" + packet.gen + " packetCount=" + deletes.size());
}
assert checkDeleteStats();
}
public synchronized void clear() {
deletes.clear();
nextGen = 1;
numTerms.set(0);
bytesUsed.set(0);
}
public boolean any() {
return bytesUsed.get() != 0;
}
public int numTerms() {
return numTerms.get();
}
public long bytesUsed() {
return bytesUsed.get();
}
public static class ApplyDeletesResult {
// True if any actual deletes took place:
public final boolean anyDeletes;
// Current gen, for the merged segment:
public final long gen;
// If non-null, contains segments that are 100% deleted
public final List allDeleted;
ApplyDeletesResult(boolean anyDeletes, long gen, List allDeleted) {
this.anyDeletes = anyDeletes;
this.gen = gen;
this.allDeleted = allDeleted;
}
}
// Sorts SegmentInfos from smallest to biggest bufferedDelGen:
private static final Comparator sortByDelGen = new Comparator() {
// @Override -- not until Java 1.6
public int compare(SegmentInfo si1, SegmentInfo si2) {
final long cmp = si1.getBufferedDeletesGen() - si2.getBufferedDeletesGen();
if (cmp > 0) {
return 1;
} else if (cmp < 0) {
return -1;
} else {
return 0;
}
}
};
/**
* Resolves the buffered deleted Term/Query/docIDs, into
* actual deleted docIDs in the deletedDocs BitVector for
* each SegmentReader.
*/
public synchronized ApplyDeletesResult applyDeletes(IndexWriter.ReaderPool readerPool, List infos) throws IOException {
final long t0 = System.currentTimeMillis();
if (infos.size() == 0) {
return new ApplyDeletesResult(false, nextGen++, null);
}
assert checkDeleteStats();
if (!any()) {
message("applyDeletes: no deletes; skipping");
return new ApplyDeletesResult(false, nextGen++, null);
}
if (infoStream != null) {
message("applyDeletes: infos=" + infos + " packetCount=" + deletes.size());
}
List infos2 = new ArrayList();
infos2.addAll(infos);
Collections.sort(infos2, sortByDelGen);
CoalescedDeletes coalescedDeletes = null;
boolean anyNewDeletes = false;
int infosIDX = infos2.size() - 1;
int delIDX = deletes.size() - 1;
List allDeleted = null;
while (infosIDX >= 0) {
//System.out.println("BD: cycle delIDX=" + delIDX + " infoIDX=" + infosIDX);
final FrozenBufferedDeletes packet = delIDX >= 0 ? deletes.get(delIDX) : null;
final SegmentInfo info = infos2.get(infosIDX);
final long segGen = info.getBufferedDeletesGen();
if (packet != null && segGen < packet.gen) {
//System.out.println(" coalesce");
if (coalescedDeletes == null) {
coalescedDeletes = new CoalescedDeletes();
}
coalescedDeletes.update(packet);
delIDX--;
} else if (packet != null && segGen == packet.gen) {
//System.out.println(" eq");
// Lock order: IW -> BD -> RP
assert readerPool.infoIsLive(info);
SegmentReader reader = readerPool.get(info, false);
int delCount = 0;
final boolean segAllDeletes;
try {
if (coalescedDeletes != null) {
//System.out.println(" del coalesced");
delCount += applyTermDeletes(coalescedDeletes.termsIterable(), reader);
delCount += applyQueryDeletes(coalescedDeletes.queriesIterable(), reader);
}
//System.out.println(" del exact");
// Don't delete by Term here; DocumentsWriter
// already did that on flush:
delCount += applyQueryDeletes(packet.queriesIterable(), reader);
segAllDeletes = reader.numDocs() == 0;
} finally {
readerPool.release(reader);
}
anyNewDeletes |= delCount > 0;
if (segAllDeletes) {
if (allDeleted == null) {
allDeleted = new ArrayList();
}
allDeleted.add(info);
}
if (infoStream != null) {
message("seg=" + info + " segGen=" + segGen + " segDeletes=[" + packet + "]; coalesced deletes=[" + (coalescedDeletes == null ? "null" : coalescedDeletes) + "] delCount=" + delCount + (segAllDeletes ? " 100% deleted" : ""));
}
if (coalescedDeletes == null) {
coalescedDeletes = new CoalescedDeletes();
}
coalescedDeletes.update(packet);
delIDX--;
infosIDX--;
info.setBufferedDeletesGen(nextGen);
} else {
//System.out.println(" gt");
if (coalescedDeletes != null) {
// Lock order: IW -> BD -> RP
assert readerPool.infoIsLive(info);
SegmentReader reader = readerPool.get(info, false);
int delCount = 0;
final boolean segAllDeletes;
try {
delCount += applyTermDeletes(coalescedDeletes.termsIterable(), reader);
delCount += applyQueryDeletes(coalescedDeletes.queriesIterable(), reader);
segAllDeletes = reader.numDocs() == 0;
} finally {
readerPool.release(reader);
}
anyNewDeletes |= delCount > 0;
if (segAllDeletes) {
if (allDeleted == null) {
allDeleted = new ArrayList();
}
allDeleted.add(info);
}
if (infoStream != null) {
message("seg=" + info + " segGen=" + segGen + " coalesced deletes=[" + (coalescedDeletes == null ? "null" : coalescedDeletes) + "] delCount=" + delCount + (segAllDeletes ? " 100% deleted" : ""));
}
}
info.setBufferedDeletesGen(nextGen);
infosIDX--;
}
}
assert checkDeleteStats();
if (infoStream != null) {
message("applyDeletes took " + (System.currentTimeMillis() - t0) + " msec");
}
// assert infos != segmentInfos || !any() : "infos=" + infos + " segmentInfos=" + segmentInfos + " any=" + any;
return new ApplyDeletesResult(anyNewDeletes, nextGen++, allDeleted);
}
public synchronized long getNextGen() {
return nextGen++;
}
// Lock order IW -> BD
/* Removes any BufferedDeletes that we no longer need to
* store because all segments in the index have had the
* deletes applied. */
public synchronized void prune(SegmentInfos segmentInfos) {
assert checkDeleteStats();
long minGen = Long.MAX_VALUE;
for (SegmentInfo info : segmentInfos) {
minGen = Math.min(info.getBufferedDeletesGen(), minGen);
}
if (infoStream != null) {
message("prune sis=" + segmentInfos + " minGen=" + minGen + " packetCount=" + deletes.size());
}
final int limit = deletes.size();
for (int delIDX = 0; delIDX < limit; delIDX++) {
if (deletes.get(delIDX).gen >= minGen) {
prune(delIDX);
assert checkDeleteStats();
return;
}
}
// All deletes pruned
prune(limit);
assert !any();
assert checkDeleteStats();
}
private synchronized void prune(int count) {
if (count > 0) {
if (infoStream != null) {
message("pruneDeletes: prune " + count + " packets; " + (deletes.size() - count) + " packets remain");
}
for (int delIDX = 0; delIDX < count; delIDX++) {
final FrozenBufferedDeletes packet = deletes.get(delIDX);
numTerms.addAndGet(-packet.numTermDeletes);
assert numTerms.get() >= 0;
bytesUsed.addAndGet(-packet.bytesUsed);
assert bytesUsed.get() >= 0;
}
deletes.subList(0, count).clear();
}
}
// ES CHANGE: Add bloom filter usage
// Delete by Term
private synchronized long applyTermDeletes(Iterable termsIter, SegmentReader reader) throws IOException {
long delCount = 0;
assert checkDeleteTerm(null);
BloomFilter filter = bloomCache == null ? BloomFilter.NONE : bloomCache.filter(reader, UidFieldMapper.NAME, true);
UnicodeUtil.UTF8Result utf8 = new UnicodeUtil.UTF8Result();
TermDocs docs = reader.termDocs();
for (Term term : termsIter) {
if (term.field() == UidFieldMapper.NAME) {
Unicode.fromStringAsUtf8(term.text(), utf8);
if (!filter.isPresent(utf8.result, 0, utf8.length)) {
continue;
}
}
if (docs == null) {
docs = reader.termDocs();
}
// Since we visit terms sorted, we gain performance
// by re-using the same TermsEnum and seeking only
// forwards
assert checkDeleteTerm(term);
docs.seek(term);
while (docs.next()) {
final int docID = docs.doc();
reader.deleteDocument(docID);
// TODO: we could/should change
// reader.deleteDocument to return boolean
// true if it did in fact delete, because here
// we could be deleting an already-deleted doc
// which makes this an upper bound:
delCount++;
}
}
return delCount;
}
public static class QueryAndLimit {
public final Query query;
public final int limit;
public QueryAndLimit(Query query, int limit) {
this.query = query;
this.limit = limit;
}
}
// Delete by query
private synchronized long applyQueryDeletes(Iterable queriesIter, SegmentReader reader) throws IOException {
long delCount = 0;
for (QueryAndLimit ent : queriesIter) {
Query query = ent.query;
int limit = ent.limit;
final DocIdSet docs = new QueryWrapperFilter(query).getDocIdSet(reader);
if (docs != null) {
final DocIdSetIterator it = docs.iterator();
if (it != null) {
while (true) {
int doc = it.nextDoc();
if (doc >= limit)
break;
reader.deleteDocument(doc);
// TODO: we could/should change
// reader.deleteDocument to return boolean
// true if it did in fact delete, because here
// we could be deleting an already-deleted doc
// which makes this an upper bound:
delCount++;
}
}
}
}
return delCount;
}
// used only by assert
private boolean checkDeleteTerm(Term term) {
if (term != null) {
assert lastDeleteTerm == null || term.compareTo(lastDeleteTerm) > 0 : "lastTerm=" + lastDeleteTerm + " vs term=" + term;
}
// TODO: we re-use term now in our merged iterable, but we shouldn't clone, instead copy for this assert
lastDeleteTerm = term == null ? null : new Term(term.field(), term.text());
return true;
}
// only for assert
private boolean checkDeleteStats() {
int numTerms2 = 0;
long bytesUsed2 = 0;
for (FrozenBufferedDeletes packet : deletes) {
numTerms2 += packet.numTermDeletes;
bytesUsed2 += packet.bytesUsed;
}
assert numTerms2 == numTerms.get() : "numTerms2=" + numTerms2 + " vs " + numTerms.get();
assert bytesUsed2 == bytesUsed.get() : "bytesUsed2=" + bytesUsed2 + " vs " + bytesUsed;
return true;
}
}
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