FixedBitSet -> BitSet

src/main/java/org/elasticsearch/common/lucene/docset/DocIdSets.java

@@ -24,10 +24,11 @@ import org.apache.lucene.search.BitsFilteredDocIdSet;
 import org.apache.lucene.search.DocIdSet;
 import org.apache.lucene.search.DocIdSetIterator;
 import org.apache.lucene.util.BitDocIdSet;
+import org.apache.lucene.util.BitSet;
 import org.apache.lucene.util.Bits;
-import org.apache.lucene.util.FixedBitSet;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.apache.lucene.util.RoaringDocIdSet;
+import org.apache.lucene.util.SparseFixedBitSet;
 import org.elasticsearch.common.Nullable;
 
 import java.io.IOException;
@@ -107,16 +108,21 @@ public class DocIdSets {
         if (iterator == null) {
             return new Bits.MatchNoBits(reader.maxDoc());
         }
-        return toFixedBitSet(iterator, reader.maxDoc());
+        return toBitSet(iterator, reader.maxDoc());
     }
 
     /**
-     * Creates a {@link FixedBitSet} from an iterator.
+     * Creates a {@link BitSet} from an iterator.
      */
-    public static FixedBitSet toFixedBitSet(DocIdSetIterator iterator, int numBits) throws IOException {
+    public static BitSet toBitSet(DocIdSetIterator iterator, int numBits) throws IOException {
-        FixedBitSet set = new FixedBitSet(numBits);
+        BitDocIdSet.Builder builder = new BitDocIdSet.Builder(numBits);
-        set.or(iterator);
+        builder.or(iterator);
-        return set;
+        BitDocIdSet result = builder.build();
+        if (result != null) {
+            return result.bits();
+        } else {
+            return new SparseFixedBitSet(numBits);
+        }
     }
 
 }

src/main/java/org/elasticsearch/index/cache/IndexCache.java

@@ -46,11 +46,11 @@ public class IndexCache extends AbstractIndexComponent implements CloseableCompo
     private ClusterService clusterService;
 
     @Inject
-    public IndexCache(Index index, @IndexSettings Settings indexSettings, FilterCache filterCache, QueryParserCache queryParserCache, BitsetFilterCache fixedBitSetFilterCache) {
+    public IndexCache(Index index, @IndexSettings Settings indexSettings, FilterCache filterCache, QueryParserCache queryParserCache, BitsetFilterCache bitsetFilterCache) {
         super(index, indexSettings);
         this.filterCache = filterCache;
         this.queryParserCache = queryParserCache;
-        this.bitsetFilterCache = fixedBitSetFilterCache;
+        this.bitsetFilterCache = bitsetFilterCache;
     }
 
     @Inject(optional = true)

src/main/java/org/elasticsearch/index/cache/bitset/BitsetFilterCache.java

@@ -29,7 +29,7 @@ import org.apache.lucene.search.DocIdSet;
 import org.apache.lucene.search.Filter;
 import org.apache.lucene.search.join.BitDocIdSetFilter;
 import org.apache.lucene.util.BitDocIdSet;
-import org.apache.lucene.util.FixedBitSet;
+import org.apache.lucene.util.SparseFixedBitSet;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
@@ -141,15 +141,19 @@ public class BitsetFilterCache extends AbstractIndexComponent implements LeafRea
             public Value call() throws Exception {
                 DocIdSet docIdSet = filter.getDocIdSet(context, null);
                 final BitDocIdSet bitSet;
-                // TODO: change to simple instanceof if BitDocIdSet gets prevSetBit
+                if (docIdSet instanceof BitDocIdSet) {
-                if (docIdSet instanceof BitDocIdSet && ((BitDocIdSet)docIdSet).bits() instanceof FixedBitSet) {
                     bitSet = (BitDocIdSet) docIdSet;
                 } else {
-                    FixedBitSet fbs = new FixedBitSet(context.reader().maxDoc());
+                    BitDocIdSet.Builder builder = new BitDocIdSet.Builder(context.reader().maxDoc());
                     if (docIdSet != null && docIdSet != DocIdSet.EMPTY) {
-                        fbs.or(docIdSet.iterator());
+                        builder.or(docIdSet.iterator());
                     }
-                    bitSet = new BitDocIdSet(fbs);
+                    BitDocIdSet bits = builder.build();
+                    // code expects this to be non-null
+                    if (bits == null) {
+                        bits = new BitDocIdSet(new SparseFixedBitSet(context.reader().maxDoc()), 0);
+                    }
+                    bitSet = bits;
                 }
 
                 Value value = new Value(bitSet, shardId);
@@ -182,8 +186,8 @@ public class BitsetFilterCache extends AbstractIndexComponent implements LeafRea
             }
             IndexShard shard = indexService.shard(entry.getValue().shardId.id());
             if (shard != null) {
-                ShardBitsetFilterCache shardFixedBitSetFilterCache = shard.shardBitsetFilterCache();
+                ShardBitsetFilterCache shardBitsetFilterCache = shard.shardBitsetFilterCache();
-                shardFixedBitSetFilterCache.onRemoval(entry.getValue().bitset.ramBytesUsed());
+                shardBitsetFilterCache.onRemoval(entry.getValue().bitset.ramBytesUsed());
             }
             // if null then this means the shard has already been removed and the stats are 0 anyway for the shard this key belongs to
         }

src/main/java/org/elasticsearch/index/engine/SegmentsStats.java

@@ -40,7 +40,7 @@ public class SegmentsStats implements Streamable, ToXContent {
     private long indexWriterMemoryInBytes;
     private long indexWriterMaxMemoryInBytes;
     private long versionMapMemoryInBytes;
-    private long fixedBitSetMemoryInBytes;
+    private long bitsetMemoryInBytes;
 
     public SegmentsStats() {
 
@@ -63,8 +63,8 @@ public class SegmentsStats implements Streamable, ToXContent {
         this.versionMapMemoryInBytes += versionMapMemoryInBytes;
     }
 
-    public void addFixedBitSetMemoryInBytes(long fixedBitSetMemoryInBytes) {
+    public void addBitsetMemoryInBytes(long bitsetMemoryInBytes) {
-        this.fixedBitSetMemoryInBytes += fixedBitSetMemoryInBytes;
+        this.bitsetMemoryInBytes += bitsetMemoryInBytes;
     }
 
     public void add(SegmentsStats mergeStats) {
@@ -75,7 +75,7 @@ public class SegmentsStats implements Streamable, ToXContent {
         addIndexWriterMemoryInBytes(mergeStats.indexWriterMemoryInBytes);
         addIndexWriterMaxMemoryInBytes(mergeStats.indexWriterMaxMemoryInBytes);
         addVersionMapMemoryInBytes(mergeStats.versionMapMemoryInBytes);
-        addFixedBitSetMemoryInBytes(mergeStats.fixedBitSetMemoryInBytes);
+        addBitsetMemoryInBytes(mergeStats.bitsetMemoryInBytes);
     }
 
     /**
@@ -130,14 +130,14 @@ public class SegmentsStats implements Streamable, ToXContent {
     }
 
     /**
-     * Estimation of how much the cached fixed bit sets are taking. (which nested and p/c rely on)
+     * Estimation of how much the cached bit sets are taking. (which nested and p/c rely on)
      */
-    public long getFixedBitSetMemoryInBytes() {
+    public long getBitsetMemoryInBytes() {
-        return fixedBitSetMemoryInBytes;
+        return bitsetMemoryInBytes;
     }
 
-    public ByteSizeValue getFixedBitSetMemory() {
+    public ByteSizeValue getBitsetMemory() {
-        return new ByteSizeValue(fixedBitSetMemoryInBytes);
+        return new ByteSizeValue(bitsetMemoryInBytes);
     }
 
     public static SegmentsStats readSegmentsStats(StreamInput in) throws IOException {
@@ -154,7 +154,7 @@ public class SegmentsStats implements Streamable, ToXContent {
         builder.byteSizeField(Fields.INDEX_WRITER_MEMORY_IN_BYTES, Fields.INDEX_WRITER_MEMORY, indexWriterMemoryInBytes);
         builder.byteSizeField(Fields.INDEX_WRITER_MAX_MEMORY_IN_BYTES, Fields.INDEX_WRITER_MAX_MEMORY, indexWriterMaxMemoryInBytes);
         builder.byteSizeField(Fields.VERSION_MAP_MEMORY_IN_BYTES, Fields.VERSION_MAP_MEMORY, versionMapMemoryInBytes);
-        builder.byteSizeField(Fields.FIXED_BIT_SET_MEMORY_IN_BYTES, Fields.FIXED_BIT_SET, fixedBitSetMemoryInBytes);
+        builder.byteSizeField(Fields.FIXED_BIT_SET_MEMORY_IN_BYTES, Fields.FIXED_BIT_SET, bitsetMemoryInBytes);
         builder.endObject();
         return builder;
     }
@@ -186,7 +186,7 @@ public class SegmentsStats implements Streamable, ToXContent {
             indexWriterMaxMemoryInBytes = in.readLong();
         }
         if (in.getVersion().onOrAfter(Version.V_1_4_0_Beta1)) {
-            fixedBitSetMemoryInBytes = in.readLong();
+            bitsetMemoryInBytes = in.readLong();
         }
     }
 
@@ -202,7 +202,7 @@ public class SegmentsStats implements Streamable, ToXContent {
             out.writeLong(indexWriterMaxMemoryInBytes);
         }
         if (out.getVersion().onOrAfter(Version.V_1_4_0_Beta1)) {
-            out.writeLong(fixedBitSetMemoryInBytes);
+            out.writeLong(bitsetMemoryInBytes);
         }
     }
 }

src/main/java/org/elasticsearch/index/fielddata/ordinals/OrdinalsBuilder.java

@@ -31,7 +31,6 @@ import org.elasticsearch.common.settings.Settings;
 import java.io.Closeable;
 import java.io.IOException;
 import java.util.Arrays;
-import java.util.Comparator;
 
 /**
  * Simple class to build document ID <-> ordinal mapping. Note: Ordinals are
@@ -379,10 +378,10 @@ public final class OrdinalsBuilder implements Closeable {
     }
 
     /**
-     * Builds a {@link FixedBitSet} where each documents bit is that that has one or more ordinals associated with it.
+     * Builds a {@link BitSet} where each documents bit is that that has one or more ordinals associated with it.
      * if every document has an ordinal associated with it this method returns <code>null</code>
      */
-    public FixedBitSet buildDocsWithValuesSet() {
+    public BitSet buildDocsWithValuesSet() {
         if (numDocsWithValue == maxDoc) {
             return null;
         }

src/main/java/org/elasticsearch/index/fielddata/plain/DoubleArrayIndexFieldData.java

@@ -117,10 +117,10 @@ public class DoubleArrayIndexFieldData extends AbstractIndexFieldData<AtomicNume
 
                 };
             } else {
-                final FixedBitSet set = builder.buildDocsWithValuesSet();
+                final BitSet set = builder.buildDocsWithValuesSet();
 
                 // there's sweet spot where due to low unique value count, using ordinals will consume less memory
-                long singleValuesArraySize = reader.maxDoc() * RamUsageEstimator.NUM_BYTES_DOUBLE + (set == null ? 0 : RamUsageEstimator.sizeOf(set.getBits()) + RamUsageEstimator.NUM_BYTES_INT);
+                long singleValuesArraySize = reader.maxDoc() * RamUsageEstimator.NUM_BYTES_DOUBLE + (set == null ? 0 : set.ramBytesUsed());
                 long uniqueValuesArraySize = values.ramBytesUsed();
                 long ordinalsSize = build.ramBytesUsed();
                 if (uniqueValuesArraySize + ordinalsSize < singleValuesArraySize) {
@@ -225,7 +225,7 @@ public class DoubleArrayIndexFieldData extends AbstractIndexFieldData<AtomicNume
         }
     }
 
-    private static SortedNumericDoubleValues singles(final DoubleArray values, FixedBitSet set) {
+    private static SortedNumericDoubleValues singles(final DoubleArray values, Bits set) {
         final NumericDoubleValues numValues = new NumericDoubleValues() {
             @Override
             public double get(int docID) {

src/main/java/org/elasticsearch/index/fielddata/plain/FloatArrayIndexFieldData.java

@@ -115,10 +115,10 @@ public class FloatArrayIndexFieldData extends AbstractIndexFieldData<AtomicNumer
 
                 };
             } else {
-                final FixedBitSet set = builder.buildDocsWithValuesSet();
+                final BitSet set = builder.buildDocsWithValuesSet();
 
                 // there's sweet spot where due to low unique value count, using ordinals will consume less memory
-                long singleValuesArraySize = reader.maxDoc() * RamUsageEstimator.NUM_BYTES_FLOAT + (set == null ? 0 : RamUsageEstimator.sizeOf(set.getBits()) + RamUsageEstimator.NUM_BYTES_INT);
+                long singleValuesArraySize = reader.maxDoc() * RamUsageEstimator.NUM_BYTES_FLOAT + (set == null ? 0 : set.ramBytesUsed());
                 long uniqueValuesArraySize = values.ramBytesUsed();
                 long ordinalsSize = build.ramBytesUsed();
                 if (uniqueValuesArraySize + ordinalsSize < singleValuesArraySize) {
@@ -223,7 +223,7 @@ public class FloatArrayIndexFieldData extends AbstractIndexFieldData<AtomicNumer
         }
     }
 
-    private static SortedNumericDoubleValues singles(final FloatArray values, FixedBitSet set) {
+    private static SortedNumericDoubleValues singles(final FloatArray values, Bits set) {
         final NumericDoubleValues numValues = new NumericDoubleValues() {
             @Override
             public double get(int docID) {

src/main/java/org/elasticsearch/index/fielddata/plain/GeoPointCompressedAtomicFieldData.java

@@ -27,7 +27,7 @@ import org.apache.lucene.index.RandomAccessOrds;
 import org.apache.lucene.index.SortedDocValues;
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.Accountables;
-import org.apache.lucene.util.FixedBitSet;
+import org.apache.lucene.util.BitSet;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.apache.lucene.util.packed.PagedMutable;
 import org.elasticsearch.common.geo.GeoPoint;
@@ -126,9 +126,9 @@ public abstract class GeoPointCompressedAtomicFieldData extends AbstractAtomicGe
 
         private final GeoPointFieldMapper.Encoding encoding;
         private final PagedMutable lon, lat;
-        private final FixedBitSet set;
+        private final BitSet set;
 
-        public Single(GeoPointFieldMapper.Encoding encoding, PagedMutable lon, PagedMutable lat, FixedBitSet set) {
+        public Single(GeoPointFieldMapper.Encoding encoding, PagedMutable lon, PagedMutable lat, BitSet set) {
             super();
             this.encoding = encoding;
             this.lon = lon;

src/main/java/org/elasticsearch/index/fielddata/plain/GeoPointCompressedIndexFieldData.java

@@ -22,7 +22,7 @@ import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.RandomAccessOrds;
 import org.apache.lucene.index.Terms;
-import org.apache.lucene.util.FixedBitSet;
+import org.apache.lucene.util.BitSet;
 import org.apache.lucene.util.packed.PackedInts;
 import org.apache.lucene.util.packed.PagedMutable;
 import org.elasticsearch.common.breaker.CircuitBreaker;
@@ -138,7 +138,7 @@ public class GeoPointCompressedIndexFieldData extends AbstractIndexGeoPointField
                         sLon.set(i, missing);
                     }
                 }
-                FixedBitSet set = builder.buildDocsWithValuesSet();
+                BitSet set = builder.buildDocsWithValuesSet();
                 data = new GeoPointCompressedAtomicFieldData.Single(encoding, sLon, sLat, set);
             }
             success = true;

src/main/java/org/elasticsearch/index/fielddata/plain/GeoPointDoubleArrayAtomicFieldData.java

@@ -27,7 +27,7 @@ import org.apache.lucene.index.RandomAccessOrds;
 import org.apache.lucene.index.SortedDocValues;
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.Accountables;
-import org.apache.lucene.util.FixedBitSet;
+import org.apache.lucene.util.BitSet;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.elasticsearch.common.geo.GeoPoint;
 import org.elasticsearch.common.util.DoubleArray;
@@ -119,9 +119,9 @@ public abstract class GeoPointDoubleArrayAtomicFieldData extends AbstractAtomicG
     public static class Single extends GeoPointDoubleArrayAtomicFieldData {
 
         private final DoubleArray lon, lat;
-        private final FixedBitSet set;
+        private final BitSet set;
 
-        public Single(DoubleArray lon, DoubleArray lat, FixedBitSet set) {
+        public Single(DoubleArray lon, DoubleArray lat, BitSet set) {
             this.lon = lon;
             this.lat = lat;
             this.set = set;

src/main/java/org/elasticsearch/index/fielddata/plain/GeoPointDoubleArrayIndexFieldData.java

@@ -22,7 +22,7 @@ import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.RandomAccessOrds;
 import org.apache.lucene.index.Terms;
-import org.apache.lucene.util.FixedBitSet;
+import org.apache.lucene.util.BitSet;
 import org.elasticsearch.common.breaker.CircuitBreaker;
 import org.elasticsearch.common.geo.GeoPoint;
 import org.elasticsearch.common.settings.Settings;
@@ -103,7 +103,7 @@ public class GeoPointDoubleArrayIndexFieldData extends AbstractIndexGeoPointFiel
                         sLon.set(i, lon.get(nativeOrdinal));
                     }
                 }
-                FixedBitSet set = builder.buildDocsWithValuesSet();
+                BitSet set = builder.buildDocsWithValuesSet();
                 data = new GeoPointDoubleArrayAtomicFieldData.Single(sLon, sLat, set);
             } else {
                 data = new GeoPointDoubleArrayAtomicFieldData.WithOrdinals(lon, lat, build, reader.maxDoc());

src/main/java/org/elasticsearch/index/fielddata/plain/PackedArrayIndexFieldData.java

@@ -138,7 +138,7 @@ public class PackedArrayIndexFieldData extends AbstractIndexFieldData<AtomicNume
                     }
                 };
             } else {
-                final FixedBitSet docsWithValues = builder.buildDocsWithValuesSet();
+                final BitSet docsWithValues = builder.buildDocsWithValuesSet();
 
                 long minV, maxV;
                 minV = maxV = 0;
@@ -524,7 +524,7 @@ public class PackedArrayIndexFieldData extends AbstractIndexFieldData<AtomicNume
         return DocValues.singleton(values, docsWithFields);
     }
 
-    private static SortedNumericDocValues pagedSingles(final PackedLongValues values, final FixedBitSet docsWithValue) {
+    private static SortedNumericDocValues pagedSingles(final PackedLongValues values, final Bits docsWithValue) {
         return DocValues.singleton(new NumericDocValues() {
             // we need to wrap since NumericDocValues must return 0 when a doc has no value
             @Override

src/main/java/org/elasticsearch/index/search/nested/IncludeNestedDocsQuery.java

@@ -24,9 +24,9 @@ import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.search.*;
 import org.apache.lucene.search.join.BitDocIdSetFilter;
+import org.apache.lucene.util.BitSet;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BitDocIdSet;
-import org.apache.lucene.util.FixedBitSet;
 
 import java.io.IOException;
 import java.util.Collection;
@@ -141,7 +141,7 @@ public class IncludeNestedDocsQuery extends Query {
     static class IncludeNestedDocsScorer extends Scorer {
 
         final Scorer parentScorer;
-        final FixedBitSet parentBits;
+        final BitSet parentBits;
 
         int currentChildPointer = -1;
         int currentParentPointer = -1;
@@ -150,8 +150,7 @@ public class IncludeNestedDocsQuery extends Query {
         IncludeNestedDocsScorer(Weight weight, Scorer parentScorer, BitDocIdSet parentBits, int currentParentPointer) {
             super(weight);
             this.parentScorer = parentScorer;
-            // TODO: remove this cast
+            this.parentBits = parentBits.bits();
-            this.parentBits = (FixedBitSet) parentBits.bits();
             this.currentParentPointer = currentParentPointer;
             if (currentParentPointer == 0) {
                 currentChildPointer = 0;

src/main/java/org/elasticsearch/index/service/IndexService.java

@@ -52,7 +52,7 @@ public interface IndexService extends IndexComponent, Iterable<IndexShard> {
 
     IndexFieldDataService fieldData();
 
-    BitsetFilterCache fixedBitSetFilterCache();
+    BitsetFilterCache bitsetFilterCache();
 
     IndexSettingsService settingsService();
 

src/main/java/org/elasticsearch/index/service/InternalIndexService.java

@@ -117,7 +117,7 @@ public class InternalIndexService extends AbstractIndexComponent implements Inde
 
     private final IndexFieldDataService indexFieldData;
 
-    private final BitsetFilterCache fixedBitSetFilterCache;
+    private final BitsetFilterCache bitsetFilterCache;
 
     private final IndexEngine indexEngine;
 
@@ -138,7 +138,7 @@ public class InternalIndexService extends AbstractIndexComponent implements Inde
                                 AnalysisService analysisService, MapperService mapperService, IndexQueryParserService queryParserService,
                                 SimilarityService similarityService, IndexAliasesService aliasesService, IndexCache indexCache, IndexEngine indexEngine,
                                 IndexGateway indexGateway, IndexStore indexStore, IndexSettingsService settingsService, IndexFieldDataService indexFieldData,
-                                BitsetFilterCache fixedBitSetFilterCache) {
+                                BitsetFilterCache bitSetFilterCache) {
         super(index, indexSettings);
         this.injector = injector;
         this.threadPool = threadPool;
@@ -154,7 +154,7 @@ public class InternalIndexService extends AbstractIndexComponent implements Inde
         this.indexGateway = indexGateway;
         this.indexStore = indexStore;
         this.settingsService = settingsService;
-        this.fixedBitSetFilterCache = fixedBitSetFilterCache;
+        this.bitsetFilterCache = bitSetFilterCache;
 
         this.pluginsService = injector.getInstance(PluginsService.class);
         this.indicesLifecycle = (InternalIndicesLifecycle) injector.getInstance(IndicesLifecycle.class);
@@ -162,7 +162,7 @@ public class InternalIndexService extends AbstractIndexComponent implements Inde
         // inject workarounds for cyclic dep
         indexCache.filter().setIndexService(this);
         indexFieldData.setIndexService(this);
-        fixedBitSetFilterCache.setIndexService(this);
+        bitSetFilterCache.setIndexService(this);
     }
 
     @Override
@@ -230,8 +230,8 @@ public class InternalIndexService extends AbstractIndexComponent implements Inde
     }
 
     @Override
-    public BitsetFilterCache fixedBitSetFilterCache() {
+    public BitsetFilterCache bitsetFilterCache() {
-        return fixedBitSetFilterCache;
+        return bitsetFilterCache;
     }
 
     @Override

src/main/java/org/elasticsearch/index/shard/service/InternalIndexShard.java

@@ -153,7 +153,7 @@ public class InternalIndexShard extends AbstractIndexShardComponent implements I
     private final IndexFieldDataService indexFieldDataService;
     private final IndexService indexService;
     private final ShardSuggestService shardSuggestService;
-    private final ShardBitsetFilterCache shardFixedBitSetFilterCache;
+    private final ShardBitsetFilterCache shardBitsetFilterCache;
 
     private final Object mutex = new Object();
     private final String checkIndexOnStartup;
@@ -179,7 +179,7 @@ public class InternalIndexShard extends AbstractIndexShardComponent implements I
     public InternalIndexShard(ShardId shardId, @IndexSettings Settings indexSettings, IndexSettingsService indexSettingsService, IndicesLifecycle indicesLifecycle, Store store, Engine engine, MergeSchedulerProvider mergeScheduler, Translog translog,
                               ThreadPool threadPool, MapperService mapperService, IndexQueryParserService queryParserService, IndexCache indexCache, IndexAliasesService indexAliasesService, ShardIndexingService indexingService, ShardGetService getService, ShardSearchService searchService, ShardIndexWarmerService shardWarmerService,
                               ShardFilterCache shardFilterCache, ShardFieldData shardFieldData, PercolatorQueriesRegistry percolatorQueriesRegistry, ShardPercolateService shardPercolateService, CodecService codecService,
-                              ShardTermVectorService termVectorService, IndexFieldDataService indexFieldDataService, IndexService indexService, ShardSuggestService shardSuggestService, ShardQueryCache shardQueryCache, ShardBitsetFilterCache shardFixedBitSetFilterCache) {
+                              ShardTermVectorService termVectorService, IndexFieldDataService indexFieldDataService, IndexService indexService, ShardSuggestService shardSuggestService, ShardQueryCache shardQueryCache, ShardBitsetFilterCache shardBitsetFilterCache) {
         super(shardId, indexSettings);
         this.indicesLifecycle = (InternalIndicesLifecycle) indicesLifecycle;
         this.indexSettingsService = indexSettingsService;
@@ -206,7 +206,7 @@ public class InternalIndexShard extends AbstractIndexShardComponent implements I
         this.indexService = indexService;
         this.codecService = codecService;
         this.shardSuggestService = shardSuggestService;
-        this.shardFixedBitSetFilterCache = shardFixedBitSetFilterCache;
+        this.shardBitsetFilterCache = shardBitsetFilterCache;
         state = IndexShardState.CREATED;
 
         this.refreshInterval = indexSettings.getAsTime(INDEX_REFRESH_INTERVAL, engine.defaultRefreshInterval());
@@ -256,7 +256,7 @@ public class InternalIndexShard extends AbstractIndexShardComponent implements I
 
     @Override
     public ShardBitsetFilterCache shardBitsetFilterCache() {
-        return shardFixedBitSetFilterCache;
+        return shardBitsetFilterCache;
     }
 
     @Override
@@ -575,7 +575,7 @@ public class InternalIndexShard extends AbstractIndexShardComponent implements I
     @Override
     public SegmentsStats segmentStats() {
         SegmentsStats segmentsStats = engine.segmentsStats();
-        segmentsStats.addFixedBitSetMemoryInBytes(shardFixedBitSetFilterCache.getMemorySizeInBytes());
+        segmentsStats.addBitsetMemoryInBytes(shardBitsetFilterCache.getMemorySizeInBytes());
         return segmentsStats;
     }
 

src/main/java/org/elasticsearch/percolator/PercolateContext.java

@@ -440,7 +440,7 @@ public class PercolateContext extends SearchContext {
 
     @Override
     public BitsetFilterCache bitsetFilterCache() {
-        return indexService.fixedBitSetFilterCache();
+        return indexService.bitsetFilterCache();
     }
 
     @Override

src/main/java/org/elasticsearch/rest/action/cat/RestIndicesAction.java

@@ -464,8 +464,8 @@ public class RestIndicesAction extends AbstractCatAction {
             table.addCell(indexStats == null ? null : indexStats.getTotal().getSegments().getVersionMapMemory());
             table.addCell(indexStats == null ? null : indexStats.getPrimaries().getSegments().getVersionMapMemory());
 
-            table.addCell(indexStats == null ? null : indexStats.getTotal().getSegments().getFixedBitSetMemory());
+            table.addCell(indexStats == null ? null : indexStats.getTotal().getSegments().getBitsetMemory());
-            table.addCell(indexStats == null ? null : indexStats.getPrimaries().getSegments().getFixedBitSetMemory());
+            table.addCell(indexStats == null ? null : indexStats.getPrimaries().getSegments().getBitsetMemory());
 
             table.addCell(indexStats == null ? null : indexStats.getTotal().getWarmer().current());
             table.addCell(indexStats == null ? null : indexStats.getPrimaries().getWarmer().current());

src/main/java/org/elasticsearch/rest/action/cat/RestNodesAction.java

@@ -296,7 +296,7 @@ public class RestNodesAction extends AbstractCatAction {
             table.addCell(stats == null ? null : stats.getIndices().getSegments().getIndexWriterMemory());
             table.addCell(stats == null ? null : stats.getIndices().getSegments().getIndexWriterMaxMemory());
             table.addCell(stats == null ? null : stats.getIndices().getSegments().getVersionMapMemory());
-            table.addCell(stats == null ? null : stats.getIndices().getSegments().getFixedBitSetMemory());
+            table.addCell(stats == null ? null : stats.getIndices().getSegments().getBitsetMemory());
 
             table.addCell(stats == null ? null : stats.getIndices().getSuggest().getCurrent());
             table.addCell(stats == null ? null : stats.getIndices().getSuggest().getTime());

src/main/java/org/elasticsearch/rest/action/cat/RestShardsAction.java

@@ -246,7 +246,7 @@ public class RestShardsAction extends AbstractCatAction {
             table.addCell(shardStats == null ? null : shardStats.getSegments().getIndexWriterMemory());
             table.addCell(shardStats == null ? null : shardStats.getSegments().getIndexWriterMaxMemory());
             table.addCell(shardStats == null ? null : shardStats.getSegments().getVersionMapMemory());
-            table.addCell(shardStats == null ? null : shardStats.getSegments().getFixedBitSetMemory());
+            table.addCell(shardStats == null ? null : shardStats.getSegments().getBitsetMemory());
 
             table.addCell(shardStats == null ? null : shardStats.getWarmer().current());
             table.addCell(shardStats == null ? null : shardStats.getWarmer().total());

src/main/java/org/elasticsearch/search/aggregations/bucket/nested/NestedAggregator.java

@@ -19,11 +19,11 @@
 package org.elasticsearch.search.aggregations.bucket.nested;
 
 import org.apache.lucene.index.LeafReaderContext;
-import org.apache.lucene.search.DocIdSet;
 import org.apache.lucene.search.Filter;
 import org.apache.lucene.search.join.BitDocIdSetFilter;
+import org.apache.lucene.util.BitDocIdSet;
+import org.apache.lucene.util.BitSet;
 import org.apache.lucene.util.Bits;
-import org.apache.lucene.util.FixedBitSet;
 import org.elasticsearch.common.lucene.ReaderContextAware;
 import org.elasticsearch.common.lucene.docset.DocIdSets;
 import org.elasticsearch.index.mapper.MapperService;
@@ -48,7 +48,7 @@ public class NestedAggregator extends SingleBucketAggregator implements ReaderCo
     private final BitDocIdSetFilter childFilter;
 
     private Bits childDocs;
-    private FixedBitSet parentDocs;
+    private BitSet parentDocs;
 
     public NestedAggregator(String name, AggregatorFactories factories, String nestedPath, AggregationContext aggregationContext, Aggregator parentAggregator, Map<String, Object> metaData) {
         super(name, factories, aggregationContext, parentAggregator, metaData);
@@ -84,14 +84,19 @@ public class NestedAggregator extends SingleBucketAggregator implements ReaderCo
         }
 
         try {
-            DocIdSet docIdSet = parentFilter.getDocIdSet(reader, null);
+            BitDocIdSet parentSet = parentFilter.getDocIdSet(reader);
-            // In ES if parent is deleted, then also the children are deleted. Therefore acceptedDocs can also null here.
+            if (DocIdSets.isEmpty(parentSet)) {
-            childDocs = DocIdSets.toSafeBits(reader.reader(), childFilter.getDocIdSet(reader, null));
-            if (DocIdSets.isEmpty(docIdSet)) {
                 parentDocs = null;
+                childDocs = null;
             } else {
-                // TODO: Remove cast when BitSet gets prevSetBit
+                parentDocs = parentSet.bits();
-                parentDocs = (FixedBitSet) docIdSet.bits();
+                // In ES if parent is deleted, then also the children are deleted. Therefore acceptedDocs can also null here.
+                BitDocIdSet childSet = childFilter.getDocIdSet(reader);
+                if (DocIdSets.isEmpty(childSet)) {
+                    childDocs = new Bits.MatchAllBits(reader.reader().maxDoc());
+                } else {
+                    childDocs = childSet.bits();
+                }
             }
         } catch (IOException ioe) {
             throw new AggregationExecutionException("Failed to aggregate [" + name + "]", ioe);

src/main/java/org/elasticsearch/search/internal/DefaultSearchContext.java

@@ -441,7 +441,7 @@ public class DefaultSearchContext extends SearchContext {
 
     @Override
     public BitsetFilterCache bitsetFilterCache() {
-        return indexService.fixedBitSetFilterCache();
+        return indexService.bitsetFilterCache();
     }
 
     public IndexFieldDataService fieldData() {

src/test/java/org/elasticsearch/common/lucene/search/TermsFilterTests.java

@@ -63,12 +63,12 @@ public class TermsFilterTests extends ElasticsearchTestCase {
 
         tf = new TermFilter(new Term(fieldName, "20"));
         DocIdSet result = tf.getDocIdSet(reader.getContext(), reader.getLiveDocs());
-        BitSet bits = DocIdSets.toFixedBitSet(result.iterator(), reader.maxDoc());
+        BitSet bits = DocIdSets.toBitSet(result.iterator(), reader.maxDoc());
         assertThat(bits.cardinality(), equalTo(1));
 
         tf = new TermFilter(new Term("all", "xxx"));
         result = tf.getDocIdSet(reader.getContext(), reader.getLiveDocs());
-        bits = DocIdSets.toFixedBitSet(result.iterator(), reader.maxDoc());
+        bits = DocIdSets.toBitSet(result.iterator(), reader.maxDoc());
         assertThat(bits.cardinality(), equalTo(100));
 
         reader.close();
@@ -98,17 +98,17 @@ public class TermsFilterTests extends ElasticsearchTestCase {
 
         tf = new TermsFilter(new Term[]{new Term(fieldName, "19"), new Term(fieldName, "20")});
         DocIdSet result = tf.getDocIdSet(reader.getContext(), reader.getLiveDocs());
-        BitSet bits = DocIdSets.toFixedBitSet(result.iterator(), reader.maxDoc());
+        BitSet bits = DocIdSets.toBitSet(result.iterator(), reader.maxDoc());
         assertThat(bits.cardinality(), equalTo(1));
 
         tf = new TermsFilter(new Term[]{new Term(fieldName, "19"), new Term(fieldName, "20"), new Term(fieldName, "10")});
         result = tf.getDocIdSet(reader.getContext(), reader.getLiveDocs());
-        bits = DocIdSets.toFixedBitSet(result.iterator(), reader.maxDoc());
+        bits = DocIdSets.toBitSet(result.iterator(), reader.maxDoc());
         assertThat(bits.cardinality(), equalTo(2));
 
         tf = new TermsFilter(new Term[]{new Term(fieldName, "19"), new Term(fieldName, "20"), new Term(fieldName, "10"), new Term(fieldName, "00")});
         result = tf.getDocIdSet(reader.getContext(), reader.getLiveDocs());
-        bits = DocIdSets.toFixedBitSet(result.iterator(), reader.maxDoc());
+        bits = DocIdSets.toBitSet(result.iterator(), reader.maxDoc());
         assertThat(bits.cardinality(), equalTo(2));
 
         reader.close();

src/test/java/org/elasticsearch/index/fielddata/AbstractFieldDataTests.java

@@ -124,7 +124,7 @@ public abstract class AbstractFieldDataTests extends ElasticsearchSingleNodeTest
     }
 
     protected Nested createNested(Filter parentFilter, Filter childFilter) {
-        BitsetFilterCache s = indexService.fixedBitSetFilterCache();
+        BitsetFilterCache s = indexService.bitsetFilterCache();
         return new Nested(s.getBitDocIdSetFilter(parentFilter), s.getBitDocIdSetFilter(childFilter));
     }
 

src/test/java/org/elasticsearch/nested/SimpleNestedTests.java

@@ -1186,7 +1186,7 @@ public class SimpleNestedTests extends ElasticsearchIntegrationTest {
 
         // No nested mapping yet, there shouldn't be anything in the fixed bit set cache
         ClusterStatsResponse clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
-        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getFixedBitSetMemoryInBytes(), equalTo(0l));
+        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getBitsetMemoryInBytes(), equalTo(0l));
 
         // Now add nested mapping
         assertAcked(
@@ -1207,7 +1207,7 @@ public class SimpleNestedTests extends ElasticsearchIntegrationTest {
 
         if (loadFixedBitSeLazily) {
             clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
-            assertThat(clusterStatsResponse.getIndicesStats().getSegments().getFixedBitSetMemoryInBytes(), equalTo(0l));
+            assertThat(clusterStatsResponse.getIndicesStats().getSegments().getBitsetMemoryInBytes(), equalTo(0l));
 
             // only when querying with nested the fixed bitsets are loaded
             SearchResponse searchResponse = client().prepareSearch("test")
@@ -1217,11 +1217,11 @@ public class SimpleNestedTests extends ElasticsearchIntegrationTest {
             assertThat(searchResponse.getHits().totalHits(), equalTo(5l));
         }
         clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
-        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getFixedBitSetMemoryInBytes(), greaterThan(0l));
+        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getBitsetMemoryInBytes(), greaterThan(0l));
 
         assertAcked(client().admin().indices().prepareDelete("test"));
         clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
-        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getFixedBitSetMemoryInBytes(), equalTo(0l));
+        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getBitsetMemoryInBytes(), equalTo(0l));
     }
 
     /**

src/test/java/org/elasticsearch/search/child/SimpleChildQuerySearchTests.java

@@ -371,7 +371,7 @@ public class SimpleChildQuerySearchTests extends ElasticsearchIntegrationTest {
 
         // No _parent field yet, there shouldn't be anything in the parent id cache
         ClusterStatsResponse clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
-        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getFixedBitSetMemoryInBytes(), equalTo(0l));
+        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getBitsetMemoryInBytes(), equalTo(0l));
 
         // Now add mapping + children
         assertAcked(
@@ -389,7 +389,7 @@ public class SimpleChildQuerySearchTests extends ElasticsearchIntegrationTest {
 
         if (loadFixedBitSetLazily) {
             clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
-            assertThat(clusterStatsResponse.getIndicesStats().getSegments().getFixedBitSetMemoryInBytes(), equalTo(0l));
+            assertThat(clusterStatsResponse.getIndicesStats().getSegments().getBitsetMemoryInBytes(), equalTo(0l));
 
             // only when querying with has_child the fixed bitsets are loaded
             SearchResponse searchResponse = client().prepareSearch("test")
@@ -400,11 +400,11 @@ public class SimpleChildQuerySearchTests extends ElasticsearchIntegrationTest {
             assertThat(searchResponse.getHits().totalHits(), equalTo(1l));
         }
         clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
-        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getFixedBitSetMemoryInBytes(), greaterThan(0l));
+        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getBitsetMemoryInBytes(), greaterThan(0l));
 
         assertAcked(client().admin().indices().prepareDelete("test"));
         clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
-        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getFixedBitSetMemoryInBytes(), equalTo(0l));
+        assertThat(clusterStatsResponse.getIndicesStats().getSegments().getBitsetMemoryInBytes(), equalTo(0l));
     }
 
     @Test

src/test/java/org/elasticsearch/test/ExternalTestCluster.java

@@ -154,7 +154,7 @@ public final class ExternalTestCluster extends TestCluster {
 
                 assertThat("Fielddata size must be 0 on node: " + stats.getNode(), stats.getIndices().getFieldData().getMemorySizeInBytes(), equalTo(0l));
                 assertThat("Filter cache size must be 0 on node: " + stats.getNode(), stats.getIndices().getFilterCache().getMemorySizeInBytes(), equalTo(0l));
-                assertThat("FixedBitSet cache size must be 0 on node: " + stats.getNode(), stats.getIndices().getSegments().getFixedBitSetMemoryInBytes(), equalTo(0l));
+                assertThat("FixedBitSet cache size must be 0 on node: " + stats.getNode(), stats.getIndices().getSegments().getBitsetMemoryInBytes(), equalTo(0l));
             }
         }
     }

src/test/java/org/elasticsearch/test/InternalTestCluster.java

@@ -1687,7 +1687,7 @@ public final class InternalTestCluster extends TestCluster {
                 NodeStats stats = nodeService.stats(CommonStatsFlags.ALL, false, false, false, false, false, false, false, false, false);
                 assertThat("Fielddata size must be 0 on node: " + stats.getNode(), stats.getIndices().getFieldData().getMemorySizeInBytes(), equalTo(0l));
                 assertThat("Filter cache size must be 0 on node: " + stats.getNode(), stats.getIndices().getFilterCache().getMemorySizeInBytes(), equalTo(0l));
-                assertThat("FixedBitSet cache size must be 0 on node: " + stats.getNode(), stats.getIndices().getSegments().getFixedBitSetMemoryInBytes(), equalTo(0l));
+                assertThat("FixedBitSet cache size must be 0 on node: " + stats.getNode(), stats.getIndices().getSegments().getBitsetMemoryInBytes(), equalTo(0l));
             }
         }
     }

src/test/java/org/elasticsearch/test/TestSearchContext.java

@@ -83,7 +83,7 @@ public class TestSearchContext extends SearchContext {
         this.indexService = indexService;
         this.filterCache = indexService.cache().filter();
         this.indexFieldDataService = indexService.fieldData();
-        this.fixedBitSetFilterCache = indexService.fixedBitSetFilterCache();
+        this.fixedBitSetFilterCache = indexService.bitsetFilterCache();
         this.threadPool = threadPool;
     }