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From sn...@apache.org
Subject [2/4] cassandra git commit: Merge branch 'cassandra-2.1' into cassandra-2.2
Date Mon, 31 Aug 2015 09:08:37 GMT
http://git-wip-us.apache.org/repos/asf/cassandra/blob/c870adc2/src/java/org/apache/cassandra/io/sstable/format/SSTableReader.java
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diff --cc src/java/org/apache/cassandra/io/sstable/format/SSTableReader.java
index 0c4b797,0000000..d843d4d
mode 100644,000000..100644
--- a/src/java/org/apache/cassandra/io/sstable/format/SSTableReader.java
+++ b/src/java/org/apache/cassandra/io/sstable/format/SSTableReader.java
@@@ -1,2287 -1,0 +1,2287 @@@
 +/*
 + * 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.cassandra.io.sstable.format;
 +
 +import java.io.*;
 +import java.nio.ByteBuffer;
 +import java.util.*;
 +import java.util.concurrent.*;
 +import java.util.concurrent.atomic.AtomicBoolean;
 +import java.util.concurrent.atomic.AtomicLong;
 +
 +import com.google.common.annotations.VisibleForTesting;
 +import com.google.common.base.Predicate;
 +import com.google.common.collect.Iterables;
 +import com.google.common.collect.Iterators;
 +import com.google.common.collect.Ordering;
 +import com.google.common.primitives.Longs;
 +import com.google.common.util.concurrent.RateLimiter;
 +
 +import com.clearspring.analytics.stream.cardinality.CardinalityMergeException;
 +import com.clearspring.analytics.stream.cardinality.HyperLogLogPlus;
 +import com.clearspring.analytics.stream.cardinality.ICardinality;
 +import com.codahale.metrics.Counter;
 +import org.apache.cassandra.cache.CachingOptions;
 +import org.apache.cassandra.cache.InstrumentingCache;
 +import org.apache.cassandra.cache.KeyCacheKey;
 +import org.apache.cassandra.concurrent.DebuggableThreadPoolExecutor;
 +import org.apache.cassandra.concurrent.ScheduledExecutors;
 +import org.apache.cassandra.config.*;
 +import org.apache.cassandra.db.*;
 +import org.apache.cassandra.db.columniterator.OnDiskAtomIterator;
 +import org.apache.cassandra.db.commitlog.ReplayPosition;
 +import org.apache.cassandra.db.composites.CellName;
 +import org.apache.cassandra.db.filter.ColumnSlice;
 +import org.apache.cassandra.db.index.SecondaryIndex;
 +import org.apache.cassandra.db.lifecycle.Tracker;
 +import org.apache.cassandra.dht.*;
 +import org.apache.cassandra.io.FSError;
 +import org.apache.cassandra.io.compress.CompressionMetadata;
 +import org.apache.cassandra.io.sstable.*;
 +import org.apache.cassandra.io.sstable.metadata.*;
 +import org.apache.cassandra.io.util.*;
 +import org.apache.cassandra.metrics.RestorableMeter;
 +import org.apache.cassandra.metrics.StorageMetrics;
 +import org.apache.cassandra.service.ActiveRepairService;
 +import org.apache.cassandra.service.CacheService;
 +import org.apache.cassandra.service.StorageService;
 +import org.apache.cassandra.utils.*;
 +import org.apache.cassandra.utils.concurrent.OpOrder;
 +import org.slf4j.Logger;
 +import org.slf4j.LoggerFactory;
 +import org.apache.cassandra.utils.concurrent.Ref;
 +import org.apache.cassandra.utils.concurrent.SelfRefCounted;
 +
 +import static org.apache.cassandra.db.Directories.SECONDARY_INDEX_NAME_SEPARATOR;
 +
 +/**
 + * An SSTableReader can be constructed in a number of places, but typically is either
 + * read from disk at startup, or constructed from a flushed memtable, or after compaction
 + * to replace some existing sstables. However once created, an sstablereader may also be modified.
 + *
 + * A reader's OpenReason describes its current stage in its lifecycle, as follows:
 + * 
 + * 
 + * <pre> {@code
 + * NORMAL
 + * From:       None        => Reader has been read from disk, either at startup or from a flushed memtable
 + *             EARLY       => Reader is the final result of a compaction
 + *             MOVED_START => Reader WAS being compacted, but this failed and it has been restored to NORMAL status
 + *
 + * EARLY
 + * From:       None        => Reader is a compaction replacement that is either incomplete and has been opened
 + *                            to represent its partial result status, or has been finished but the compaction
 + *                            it is a part of has not yet completed fully
 + *             EARLY       => Same as from None, only it is not the first time it has been
 + *
 + * MOVED_START
 + * From:       NORMAL      => Reader is being compacted. This compaction has not finished, but the compaction result
 + *                            is either partially or fully opened, to either partially or fully replace this reader.
 + *                            This reader's start key has been updated to represent this, so that reads only hit
 + *                            one or the other reader.
 + *
 + * METADATA_CHANGE
 + * From:       NORMAL      => Reader has seen low traffic and the amount of memory available for index summaries is
 + *                            constrained, so its index summary has been downsampled.
 + *         METADATA_CHANGE => Same
 + * } </pre>
 + *
 + * Note that in parallel to this, there are two different Descriptor types; TMPLINK and FINAL; the latter corresponds
 + * to NORMAL state readers and all readers that replace a NORMAL one. TMPLINK is used for EARLY state readers and
 + * no others.
 + *
 + * When a reader is being compacted, if the result is large its replacement may be opened as EARLY before compaction
 + * completes in order to present the result to consumers earlier. In this case the reader will itself be changed to
 + * a MOVED_START state, where its start no longer represents its on-disk minimum key. This is to permit reads to be
 + * directed to only one reader when the two represent the same data. The EARLY file can represent a compaction result
 + * that is either partially complete and still in-progress, or a complete and immutable sstable that is part of a larger
 + * macro compaction action that has not yet fully completed.
 + *
 + * Currently ALL compaction results at least briefly go through an EARLY open state prior to completion, regardless
 + * of if early opening is enabled.
 + *
 + * Since a reader can be created multiple times over the same shared underlying resources, and the exact resources
 + * it shares between each instance differ subtly, we track the lifetime of any underlying resource with its own
 + * reference count, which each instance takes a Ref to. Each instance then tracks references to itself, and once these
 + * all expire it releases its Refs to these underlying resources.
 + *
 + * There is some shared cleanup behaviour needed only once all sstablereaders in a certain stage of their lifecycle
 + * (i.e. EARLY or NORMAL opening), and some that must only occur once all readers of any kind over a single logical
 + * sstable have expired. These are managed by the TypeTidy and GlobalTidy classes at the bottom, and are effectively
 + * managed as another resource each instance tracks its own Ref instance to, to ensure all of these resources are
 + * cleaned up safely and can be debugged otherwise.
 + *
 + * TODO: fill in details about Tracker and lifecycle interactions for tools, and for compaction strategies
 + */
 +public abstract class SSTableReader extends SSTable implements SelfRefCounted<SSTableReader>
 +{
 +    private static final Logger logger = LoggerFactory.getLogger(SSTableReader.class);
 +
 +    private static final ScheduledThreadPoolExecutor syncExecutor = new ScheduledThreadPoolExecutor(1);
 +    static
 +    {
 +        // Immediately remove readMeter sync task when cancelled.
 +        syncExecutor.setRemoveOnCancelPolicy(true);
 +    }
 +    private static final RateLimiter meterSyncThrottle = RateLimiter.create(100.0);
 +
 +    public static final Comparator<SSTableReader> maxTimestampComparator = new Comparator<SSTableReader>()
 +    {
 +        public int compare(SSTableReader o1, SSTableReader o2)
 +        {
 +            long ts1 = o1.getMaxTimestamp();
 +            long ts2 = o2.getMaxTimestamp();
 +            return (ts1 > ts2 ? -1 : (ts1 == ts2 ? 0 : 1));
 +        }
 +    };
 +
 +    // it's just an object, which we use regular Object equality on; we introduce a special class just for easy recognition
 +    public static final class UniqueIdentifier {}
 +
 +    public static final Comparator<SSTableReader> sstableComparator = new Comparator<SSTableReader>()
 +    {
 +        public int compare(SSTableReader o1, SSTableReader o2)
 +        {
 +            return o1.first.compareTo(o2.first);
 +        }
 +    };
 +
 +    public static final Ordering<SSTableReader> sstableOrdering = Ordering.from(sstableComparator);
 +
 +    /**
 +     * maxDataAge is a timestamp in local server time (e.g. System.currentTimeMilli) which represents an upper bound
 +     * to the newest piece of data stored in the sstable. In other words, this sstable does not contain items created
 +     * later than maxDataAge.
 +     *
 +     * The field is not serialized to disk, so relying on it for more than what truncate does is not advised.
 +     *
 +     * When a new sstable is flushed, maxDataAge is set to the time of creation.
 +     * When a sstable is created from compaction, maxDataAge is set to max of all merged sstables.
 +     *
 +     * The age is in milliseconds since epoc and is local to this host.
 +     */
 +    public final long maxDataAge;
 +
 +    public enum OpenReason
 +    {
 +        NORMAL,
 +        EARLY,
 +        METADATA_CHANGE,
 +        MOVED_START
 +    }
 +
 +    public final OpenReason openReason;
 +    public final UniqueIdentifier instanceId = new UniqueIdentifier();
 +
 +    // indexfile and datafile: might be null before a call to load()
 +    protected SegmentedFile ifile;
 +    protected SegmentedFile dfile;
 +    protected IndexSummary indexSummary;
 +    protected IFilter bf;
 +
 +    protected final RowIndexEntry.IndexSerializer rowIndexEntrySerializer;
 +
 +    protected InstrumentingCache<KeyCacheKey, RowIndexEntry> keyCache;
 +
 +    protected final BloomFilterTracker bloomFilterTracker = new BloomFilterTracker();
 +
 +    // technically isCompacted is not necessary since it should never be unreferenced unless it is also compacted,
 +    // but it seems like a good extra layer of protection against reference counting bugs to not delete data based on that alone
 +    protected final AtomicBoolean isSuspect = new AtomicBoolean(false);
 +
 +    // not final since we need to be able to change level on a file.
 +    protected volatile StatsMetadata sstableMetadata;
 +
 +    protected final AtomicLong keyCacheHit = new AtomicLong(0);
 +    protected final AtomicLong keyCacheRequest = new AtomicLong(0);
 +
 +    private final InstanceTidier tidy = new InstanceTidier(descriptor, metadata);
 +    private final Ref<SSTableReader> selfRef = new Ref<>(this, tidy);
 +
 +    private RestorableMeter readMeter;
 +
 +    /**
 +     * Calculate approximate key count.
 +     * If cardinality estimator is available on all given sstables, then this method use them to estimate
 +     * key count.
 +     * If not, then this uses index summaries.
 +     *
 +     * @param sstables SSTables to calculate key count
 +     * @return estimated key count
 +     */
 +    public static long getApproximateKeyCount(Collection<SSTableReader> sstables)
 +    {
 +        long count = -1;
 +
 +        // check if cardinality estimator is available for all SSTables
 +        boolean cardinalityAvailable = !sstables.isEmpty() && Iterators.all(sstables.iterator(), new Predicate<SSTableReader>()
 +        {
 +            public boolean apply(SSTableReader sstable)
 +            {
 +                return sstable.descriptor.version.hasNewStatsFile();
 +            }
 +        });
 +
 +        // if it is, load them to estimate key count
 +        if (cardinalityAvailable)
 +        {
 +            boolean failed = false;
 +            ICardinality cardinality = null;
 +            for (SSTableReader sstable : sstables)
 +            {
 +                if (sstable.openReason == OpenReason.EARLY)
 +                    continue;
 +
 +                try
 +                {
 +                    CompactionMetadata metadata = (CompactionMetadata) sstable.descriptor.getMetadataSerializer().deserialize(sstable.descriptor, MetadataType.COMPACTION);
 +                    assert metadata != null : sstable.getFilename();
 +                    if (cardinality == null)
 +                        cardinality = metadata.cardinalityEstimator;
 +                    else
 +                        cardinality = cardinality.merge(metadata.cardinalityEstimator);
 +                }
 +                catch (IOException e)
 +                {
 +                    logger.warn("Reading cardinality from Statistics.db failed.", e);
 +                    failed = true;
 +                    break;
 +                }
 +                catch (CardinalityMergeException e)
 +                {
 +                    logger.warn("Cardinality merge failed.", e);
 +                    failed = true;
 +                    break;
 +                }
 +            }
 +            if (cardinality != null && !failed)
 +                count = cardinality.cardinality();
 +        }
 +
 +        // if something went wrong above or cardinality is not available, calculate using index summary
 +        if (count < 0)
 +        {
 +            for (SSTableReader sstable : sstables)
 +                count += sstable.estimatedKeys();
 +        }
 +        return count;
 +    }
 +
 +    /**
 +     * Estimates how much of the keys we would keep if the sstables were compacted together
 +     */
 +    public static double estimateCompactionGain(Set<SSTableReader> overlapping)
 +    {
 +        Set<ICardinality> cardinalities = new HashSet<>(overlapping.size());
 +        for (SSTableReader sstable : overlapping)
 +        {
 +            try
 +            {
 +                ICardinality cardinality = ((CompactionMetadata) sstable.descriptor.getMetadataSerializer().deserialize(sstable.descriptor, MetadataType.COMPACTION)).cardinalityEstimator;
 +                if (cardinality != null)
 +                    cardinalities.add(cardinality);
 +                else
 +                    logger.debug("Got a null cardinality estimator in: {}", sstable.getFilename());
 +            }
 +            catch (IOException e)
 +            {
 +                logger.warn("Could not read up compaction metadata for {}", sstable, e);
 +            }
 +        }
 +        long totalKeyCountBefore = 0;
 +        for (ICardinality cardinality : cardinalities)
 +        {
 +            totalKeyCountBefore += cardinality.cardinality();
 +        }
 +        if (totalKeyCountBefore == 0)
 +            return 1;
 +
 +        long totalKeyCountAfter = mergeCardinalities(cardinalities).cardinality();
 +        logger.debug("Estimated compaction gain: {}/{}={}", totalKeyCountAfter, totalKeyCountBefore, ((double)totalKeyCountAfter)/totalKeyCountBefore);
 +        return ((double)totalKeyCountAfter)/totalKeyCountBefore;
 +    }
 +
 +    private static ICardinality mergeCardinalities(Collection<ICardinality> cardinalities)
 +    {
 +        ICardinality base = new HyperLogLogPlus(13, 25); // see MetadataCollector.cardinality
 +        try
 +        {
 +            base = base.merge(cardinalities.toArray(new ICardinality[cardinalities.size()]));
 +        }
 +        catch (CardinalityMergeException e)
 +        {
 +            logger.warn("Could not merge cardinalities", e);
 +        }
 +        return base;
 +    }
 +
 +    public static SSTableReader open(Descriptor descriptor) throws IOException
 +    {
 +        CFMetaData metadata;
 +        if (descriptor.cfname.contains(SECONDARY_INDEX_NAME_SEPARATOR))
 +        {
 +            int i = descriptor.cfname.indexOf(SECONDARY_INDEX_NAME_SEPARATOR);
 +            String parentName = descriptor.cfname.substring(0, i);
 +            CFMetaData parent = Schema.instance.getCFMetaData(descriptor.ksname, parentName);
 +            ColumnDefinition def = parent.getColumnDefinitionForIndex(descriptor.cfname.substring(i + 1));
 +            metadata = CFMetaData.newIndexMetadata(parent, def, SecondaryIndex.getIndexComparator(parent, def));
 +        }
 +        else
 +        {
 +            metadata = Schema.instance.getCFMetaData(descriptor.ksname, descriptor.cfname);
 +        }
 +        return open(descriptor, metadata);
 +    }
 +
 +    public static SSTableReader open(Descriptor desc, CFMetaData metadata) throws IOException
 +    {
 +        IPartitioner p = desc.cfname.contains(SECONDARY_INDEX_NAME_SEPARATOR)
 +                ? new LocalPartitioner(metadata.getKeyValidator())
 +                : StorageService.getPartitioner();
 +        return open(desc, componentsFor(desc), metadata, p);
 +    }
 +
 +    public static SSTableReader open(Descriptor descriptor, Set<Component> components, CFMetaData metadata, IPartitioner partitioner) throws IOException
 +    {
 +        return open(descriptor, components, metadata, partitioner, true, true);
 +    }
 +
 +    // use only for offline or "Standalone" operations
 +    public static SSTableReader openNoValidation(Descriptor descriptor, Set<Component> components, ColumnFamilyStore cfs) throws IOException
 +    {
 +        return open(descriptor, components, cfs.metadata, cfs.partitioner, false, false); // do not track hotness
 +    }
 +
 +    /**
 +     * Open SSTable reader to be used in batch mode(such as sstableloader).
 +     *
 +     * @param descriptor
 +     * @param components
 +     * @param metadata
 +     * @param partitioner
 +     * @return opened SSTableReader
 +     * @throws IOException
 +     */
 +    public static SSTableReader openForBatch(Descriptor descriptor, Set<Component> components, CFMetaData metadata, IPartitioner partitioner) throws IOException
 +    {
 +        // Minimum components without which we can't do anything
 +        assert components.contains(Component.DATA) : "Data component is missing for sstable " + descriptor;
 +        assert components.contains(Component.PRIMARY_INDEX) : "Primary index component is missing for sstable " + descriptor;
 +
 +        Map<MetadataType, MetadataComponent> sstableMetadata = descriptor.getMetadataSerializer().deserialize(descriptor,
 +                EnumSet.of(MetadataType.VALIDATION, MetadataType.STATS));
 +        ValidationMetadata validationMetadata = (ValidationMetadata) sstableMetadata.get(MetadataType.VALIDATION);
 +        StatsMetadata statsMetadata = (StatsMetadata) sstableMetadata.get(MetadataType.STATS);
 +
 +        // Check if sstable is created using same partitioner.
 +        // Partitioner can be null, which indicates older version of sstable or no stats available.
 +        // In that case, we skip the check.
 +        String partitionerName = partitioner.getClass().getCanonicalName();
 +        if (validationMetadata != null && !partitionerName.equals(validationMetadata.partitioner))
 +        {
 +            logger.error(String.format("Cannot open %s; partitioner %s does not match system partitioner %s.  Note that the default partitioner starting with Cassandra 1.2 is Murmur3Partitioner, so you will need to edit that to match your old partitioner if upgrading.",
 +                    descriptor, validationMetadata.partitioner, partitionerName));
 +            System.exit(1);
 +        }
 +
 +        logger.info("Opening {} ({} bytes)", descriptor, new File(descriptor.filenameFor(Component.DATA)).length());
 +        SSTableReader sstable = internalOpen(descriptor, components, metadata, partitioner, System.currentTimeMillis(),
 +                statsMetadata, OpenReason.NORMAL);
 +
 +        // special implementation of load to use non-pooled SegmentedFile builders
 +        try(SegmentedFile.Builder ibuilder = new BufferedSegmentedFile.Builder();
 +            SegmentedFile.Builder dbuilder = sstable.compression
 +                ? new CompressedSegmentedFile.Builder(null)
 +                : new BufferedSegmentedFile.Builder())
 +        {
 +            if (!sstable.loadSummary(ibuilder, dbuilder))
 +                sstable.buildSummary(false, ibuilder, dbuilder, false, Downsampling.BASE_SAMPLING_LEVEL);
 +            sstable.ifile = ibuilder.complete(sstable.descriptor.filenameFor(Component.PRIMARY_INDEX));
 +            sstable.dfile = dbuilder.complete(sstable.descriptor.filenameFor(Component.DATA));
 +            sstable.bf = FilterFactory.AlwaysPresent;
 +            sstable.setup(false);
 +            return sstable;
 +        }
 +    }
 +
 +    public static SSTableReader open(Descriptor descriptor,
 +                                      Set<Component> components,
 +                                      CFMetaData metadata,
 +                                      IPartitioner partitioner,
 +                                      boolean validate,
 +                                      boolean trackHotness) throws IOException
 +    {
 +        // Minimum components without which we can't do anything
 +        assert components.contains(Component.DATA) : "Data component is missing for sstable " + descriptor;
 +        assert !validate || components.contains(Component.PRIMARY_INDEX) : "Primary index component is missing for sstable " + descriptor;
 +
 +        Map<MetadataType, MetadataComponent> sstableMetadata = descriptor.getMetadataSerializer().deserialize(descriptor,
 +                                                                                                               EnumSet.of(MetadataType.VALIDATION, MetadataType.STATS));
 +        ValidationMetadata validationMetadata = (ValidationMetadata) sstableMetadata.get(MetadataType.VALIDATION);
 +        StatsMetadata statsMetadata = (StatsMetadata) sstableMetadata.get(MetadataType.STATS);
 +
 +        // Check if sstable is created using same partitioner.
 +        // Partitioner can be null, which indicates older version of sstable or no stats available.
 +        // In that case, we skip the check.
 +        String partitionerName = partitioner.getClass().getCanonicalName();
 +        if (validationMetadata != null && !partitionerName.equals(validationMetadata.partitioner))
 +        {
 +            logger.error(String.format("Cannot open %s; partitioner %s does not match system partitioner %s.  Note that the default partitioner starting with Cassandra 1.2 is Murmur3Partitioner, so you will need to edit that to match your old partitioner if upgrading.",
 +                    descriptor, validationMetadata.partitioner, partitionerName));
 +            System.exit(1);
 +        }
 +
 +        logger.info("Opening {} ({} bytes)", descriptor, new File(descriptor.filenameFor(Component.DATA)).length());
 +        SSTableReader sstable = internalOpen(descriptor, components, metadata, partitioner, System.currentTimeMillis(),
 +                                             statsMetadata, OpenReason.NORMAL);
 +        try
 +        {
 +            // load index and filter
 +            long start = System.nanoTime();
 +            sstable.load(validationMetadata);
 +            logger.debug("INDEX LOAD TIME for {}: {} ms.", descriptor, TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start));
 +
 +            sstable.setup(trackHotness);
 +            if (validate)
 +                sstable.validate();
 +
 +            if (sstable.getKeyCache() != null)
 +                logger.debug("key cache contains {}/{} keys", sstable.getKeyCache().size(), sstable.getKeyCache().getCapacity());
 +
 +            return sstable;
 +        }
 +        catch (Throwable t)
 +        {
 +            sstable.selfRef().release();
 +            throw t;
 +        }
 +    }
 +
 +    public static void logOpenException(Descriptor descriptor, IOException e)
 +    {
 +        if (e instanceof FileNotFoundException)
 +            logger.error("Missing sstable component in {}; skipped because of {}", descriptor, e.getMessage());
 +        else
 +            logger.error("Corrupt sstable {}; skipped", descriptor, e);
 +    }
 +
 +    public static Collection<SSTableReader> openAll(Set<Map.Entry<Descriptor, Set<Component>>> entries,
 +                                                    final CFMetaData metadata,
 +                                                    final IPartitioner partitioner)
 +    {
 +        final Collection<SSTableReader> sstables = new LinkedBlockingQueue<>();
 +
 +        ExecutorService executor = DebuggableThreadPoolExecutor.createWithFixedPoolSize("SSTableBatchOpen", FBUtilities.getAvailableProcessors());
 +        for (final Map.Entry<Descriptor, Set<Component>> entry : entries)
 +        {
 +            Runnable runnable = new Runnable()
 +            {
 +                public void run()
 +                {
 +                    SSTableReader sstable;
 +                    try
 +                    {
 +                        sstable = open(entry.getKey(), entry.getValue(), metadata, partitioner);
 +                    }
 +                    catch (CorruptSSTableException ex)
 +                    {
 +                        FileUtils.handleCorruptSSTable(ex);
 +                        logger.error("Corrupt sstable {}; skipping table", entry, ex);
 +                        return;
 +                    }
 +                    catch (FSError ex)
 +                    {
 +                        FileUtils.handleFSError(ex);
 +                        logger.error("Cannot read sstable {}; file system error, skipping table", entry, ex);
 +                        return;
 +                    }
 +                    catch (IOException ex)
 +                    {
 +                        logger.error("Cannot read sstable {}; other IO error, skipping table", entry, ex);
 +                        return;
 +                    }
 +                    sstables.add(sstable);
 +                }
 +            };
 +            executor.submit(runnable);
 +        }
 +
 +        executor.shutdown();
 +        try
 +        {
 +            executor.awaitTermination(7, TimeUnit.DAYS);
 +        }
 +        catch (InterruptedException e)
 +        {
 +            throw new AssertionError(e);
 +        }
 +
 +        return sstables;
 +
 +    }
 +
 +    /**
 +     * Open a RowIndexedReader which already has its state initialized (by SSTableWriter).
 +     */
 +    public static SSTableReader internalOpen(Descriptor desc,
 +                                      Set<Component> components,
 +                                      CFMetaData metadata,
 +                                      IPartitioner partitioner,
 +                                      SegmentedFile ifile,
 +                                      SegmentedFile dfile,
 +                                      IndexSummary isummary,
 +                                      IFilter bf,
 +                                      long maxDataAge,
 +                                      StatsMetadata sstableMetadata,
 +                                      OpenReason openReason)
 +    {
 +        assert desc != null && partitioner != null && ifile != null && dfile != null && isummary != null && bf != null && sstableMetadata != null;
 +
 +        SSTableReader reader = internalOpen(desc, components, metadata, partitioner, maxDataAge, sstableMetadata, openReason);
 +
 +        reader.bf = bf;
 +        reader.ifile = ifile;
 +        reader.dfile = dfile;
 +        reader.indexSummary = isummary;
 +        reader.setup(true);
 +
 +        return reader;
 +    }
 +
 +
 +    private static SSTableReader internalOpen(final Descriptor descriptor,
 +                                            Set<Component> components,
 +                                            CFMetaData metadata,
 +                                            IPartitioner partitioner,
 +                                            Long maxDataAge,
 +                                            StatsMetadata sstableMetadata,
 +                                            OpenReason openReason)
 +    {
 +        Factory readerFactory = descriptor.getFormat().getReaderFactory();
 +
 +        return readerFactory.open(descriptor, components, metadata, partitioner, maxDataAge, sstableMetadata, openReason);
 +    }
 +
 +    protected SSTableReader(final Descriptor desc,
 +                            Set<Component> components,
 +                            CFMetaData metadata,
 +                            IPartitioner partitioner,
 +                            long maxDataAge,
 +                            StatsMetadata sstableMetadata,
 +                            OpenReason openReason)
 +    {
 +        super(desc, components, metadata, partitioner);
 +        this.sstableMetadata = sstableMetadata;
 +        this.maxDataAge = maxDataAge;
 +        this.openReason = openReason;
 +        this.rowIndexEntrySerializer = descriptor.version.getSSTableFormat().getIndexSerializer(metadata);
 +    }
 +
 +    public static long getTotalBytes(Iterable<SSTableReader> sstables)
 +    {
 +        long sum = 0;
 +        for (SSTableReader sstable : sstables)
 +            sum += sstable.onDiskLength();
 +        return sum;
 +    }
 +
 +    public static long getTotalUncompressedBytes(Iterable<SSTableReader> sstables)
 +    {
 +        long sum = 0;
 +        for (SSTableReader sstable : sstables)
 +            sum += sstable.uncompressedLength();
 +
 +        return sum;
 +    }
 +
 +    public boolean equals(Object that)
 +    {
 +        return that instanceof SSTableReader && ((SSTableReader) that).descriptor.equals(this.descriptor);
 +    }
 +
 +    public int hashCode()
 +    {
 +        return this.descriptor.hashCode();
 +    }
 +
 +    public String getFilename()
 +    {
 +        return dfile.path();
 +    }
 +
 +    public void setupKeyCache()
 +    {
 +        // under normal operation we can do this at any time, but SSTR is also used outside C* proper,
 +        // e.g. by BulkLoader, which does not initialize the cache.  As a kludge, we set up the cache
 +        // here when we know we're being wired into the rest of the server infrastructure.
 +        keyCache = CacheService.instance.keyCache;
 +    }
 +
 +    private void load(ValidationMetadata validation) throws IOException
 +    {
 +        if (metadata.getBloomFilterFpChance() == 1.0)
 +        {
 +            // bf is disabled.
 +            load(false, true);
 +            bf = FilterFactory.AlwaysPresent;
 +        }
 +        else if (!components.contains(Component.PRIMARY_INDEX))
 +        {
 +            // avoid any reading of the missing primary index component.
 +            // this should only happen during StandaloneScrubber
 +            load(false, false);
 +        }
 +        else if (!components.contains(Component.FILTER) || validation == null)
 +        {
 +            // bf is enabled, but filter component is missing.
 +            load(true, true);
 +        }
 +        else if (validation.bloomFilterFPChance != metadata.getBloomFilterFpChance())
 +        {
 +            // bf fp chance in sstable metadata and it has changed since compaction.
 +            load(true, true);
 +        }
 +        else
 +        {
 +            // bf is enabled and fp chance matches the currently configured value.
 +            load(false, true);
 +            loadBloomFilter();
 +        }
 +    }
 +
 +    /**
 +     * Load bloom filter from Filter.db file.
 +     *
 +     * @throws IOException
 +     */
 +    private void loadBloomFilter() throws IOException
 +    {
 +        try (DataInputStream stream = new DataInputStream(new BufferedInputStream(new FileInputStream(descriptor.filenameFor(Component.FILTER)))))
 +        {
 +            bf = FilterFactory.deserialize(stream, true);
 +        }
 +    }
 +
 +    /**
 +     * Loads ifile, dfile and indexSummary, and optionally recreates the bloom filter.
 +     * @param saveSummaryIfCreated for bulk loading purposes, if the summary was absent and needed to be built, you can
 +     *                             avoid persisting it to disk by setting this to false
 +     */
 +    private void load(boolean recreateBloomFilter, boolean saveSummaryIfCreated) throws IOException
 +    {
 +        try(SegmentedFile.Builder ibuilder = SegmentedFile.getBuilder(DatabaseDescriptor.getIndexAccessMode(), false);
 +            SegmentedFile.Builder dbuilder = SegmentedFile.getBuilder(DatabaseDescriptor.getDiskAccessMode(), compression))
 +        {
 +            boolean summaryLoaded = loadSummary(ibuilder, dbuilder);
 +            boolean builtSummary = false;
 +            if (recreateBloomFilter || !summaryLoaded)
 +            {
 +                buildSummary(recreateBloomFilter, ibuilder, dbuilder, summaryLoaded, Downsampling.BASE_SAMPLING_LEVEL);
 +                builtSummary = true;
 +            }
 +
 +            if (components.contains(Component.PRIMARY_INDEX))
 +                ifile = ibuilder.complete(descriptor.filenameFor(Component.PRIMARY_INDEX));
 +
 +            dfile = dbuilder.complete(descriptor.filenameFor(Component.DATA));
 +
 +            // Check for an index summary that was downsampled even though the serialization format doesn't support
 +            // that.  If it was downsampled, rebuild it.  See CASSANDRA-8993 for details.
 +        if (!descriptor.version.hasSamplingLevel() && !builtSummary && !validateSummarySamplingLevel() && ifile != null)
 +            {
 +                indexSummary.close();
 +                ifile.close();
 +                dfile.close();
 +
 +                logger.info("Detected erroneously downsampled index summary; will rebuild summary at full sampling");
 +                FileUtils.deleteWithConfirm(new File(descriptor.filenameFor(Component.SUMMARY)));
 +
 +                try(SegmentedFile.Builder ibuilderRebuild = SegmentedFile.getBuilder(DatabaseDescriptor.getIndexAccessMode(), false);
 +                    SegmentedFile.Builder dbuilderRebuild = SegmentedFile.getBuilder(DatabaseDescriptor.getDiskAccessMode(), compression))
 +                {
 +                    buildSummary(false, ibuilderRebuild, dbuilderRebuild, false, Downsampling.BASE_SAMPLING_LEVEL);
 +                    ifile = ibuilderRebuild.complete(descriptor.filenameFor(Component.PRIMARY_INDEX));
 +                    dfile = dbuilderRebuild.complete(descriptor.filenameFor(Component.DATA));
 +                    saveSummary(ibuilderRebuild, dbuilderRebuild);
 +                }
 +            }
 +            else if (saveSummaryIfCreated && builtSummary)
 +            {
 +                saveSummary(ibuilder, dbuilder);
 +            }
 +        }
 +        catch (Throwable t)
 +        { // Because the tidier has not been set-up yet in SSTableReader.open(), we must release the files in case of error
 +            if (ifile != null)
 +            {
 +                ifile.close();
 +                ifile = null;
 +            }
 +
 +            if (dfile != null)
 +            {
 +                dfile.close();
 +                dfile = null;
 +            }
 +
 +            if (indexSummary != null)
 +            {
 +                indexSummary.close();
 +                indexSummary = null;
 +            }
 +
 +            throw t;
 +        }
 +    }
 +
 +    /**
 +     * Build index summary(and optionally bloom filter) by reading through Index.db file.
 +     *
 +     * @param recreateBloomFilter true if recreate bloom filter
 +     * @param ibuilder
 +     * @param dbuilder
 +     * @param summaryLoaded true if index summary is already loaded and not need to build again
 +     * @throws IOException
 +     */
 +    private void buildSummary(boolean recreateBloomFilter, SegmentedFile.Builder ibuilder, SegmentedFile.Builder dbuilder, boolean summaryLoaded, int samplingLevel) throws IOException
 +    {
 +         if (!components.contains(Component.PRIMARY_INDEX))
 +             return;
 +
 +        // we read the positions in a BRAF so we don't have to worry about an entry spanning a mmap boundary.
 +        try (RandomAccessReader primaryIndex = RandomAccessReader.open(new File(descriptor.filenameFor(Component.PRIMARY_INDEX))))
 +        {
 +            long indexSize = primaryIndex.length();
 +            long histogramCount = sstableMetadata.estimatedRowSize.count();
 +            long estimatedKeys = histogramCount > 0 && !sstableMetadata.estimatedRowSize.isOverflowed()
 +                    ? histogramCount
 +                    : estimateRowsFromIndex(primaryIndex); // statistics is supposed to be optional
 +
 +            if (recreateBloomFilter)
 +                bf = FilterFactory.getFilter(estimatedKeys, metadata.getBloomFilterFpChance(), true);
 +
 +            try (IndexSummaryBuilder summaryBuilder = summaryLoaded ? null : new IndexSummaryBuilder(estimatedKeys, metadata.getMinIndexInterval(), samplingLevel))
 +            {
 +                long indexPosition;
 +                RowIndexEntry.IndexSerializer rowIndexSerializer = descriptor.getFormat().getIndexSerializer(metadata);
 +
 +                while ((indexPosition = primaryIndex.getFilePointer()) != indexSize)
 +                {
 +                    ByteBuffer key = ByteBufferUtil.readWithShortLength(primaryIndex);
 +                    RowIndexEntry indexEntry = rowIndexSerializer.deserialize(primaryIndex, descriptor.version);
 +                    DecoratedKey decoratedKey = partitioner.decorateKey(key);
 +                    if (first == null)
 +                        first = decoratedKey;
 +                    last = decoratedKey;
 +
 +                    if (recreateBloomFilter)
 +                        bf.add(decoratedKey);
 +
 +                    // if summary was already read from disk we don't want to re-populate it using primary index
 +                    if (!summaryLoaded)
 +                    {
 +                        summaryBuilder.maybeAddEntry(decoratedKey, indexPosition);
 +                        ibuilder.addPotentialBoundary(indexPosition);
 +                        dbuilder.addPotentialBoundary(indexEntry.position);
 +                    }
 +                }
 +
 +                if (!summaryLoaded)
 +                    indexSummary = summaryBuilder.build(partitioner);
 +            }
 +        }
 +
 +        first = getMinimalKey(first);
 +        last = getMinimalKey(last);
 +    }
 +
 +    /**
 +     * Load index summary from Summary.db file if it exists.
 +     *
 +     * if loaded index summary has different index interval from current value stored in schema,
 +     * then Summary.db file will be deleted and this returns false to rebuild summary.
 +     *
 +     * @param ibuilder
 +     * @param dbuilder
 +     * @return true if index summary is loaded successfully from Summary.db file.
 +     */
 +    @SuppressWarnings("resource")
 +    public boolean loadSummary(SegmentedFile.Builder ibuilder, SegmentedFile.Builder dbuilder)
 +    {
 +        File summariesFile = new File(descriptor.filenameFor(Component.SUMMARY));
 +        if (!summariesFile.exists())
 +            return false;
 +
 +        DataInputStream iStream = null;
 +        try
 +        {
 +            iStream = new DataInputStream(new FileInputStream(summariesFile));
 +            indexSummary = IndexSummary.serializer.deserialize(
 +                    iStream, partitioner, descriptor.version.hasSamplingLevel(),
 +                    metadata.getMinIndexInterval(), metadata.getMaxIndexInterval());
 +            first = partitioner.decorateKey(ByteBufferUtil.readWithLength(iStream));
 +            last = partitioner.decorateKey(ByteBufferUtil.readWithLength(iStream));
 +            ibuilder.deserializeBounds(iStream);
 +            dbuilder.deserializeBounds(iStream);
 +        }
 +        catch (IOException e)
 +        {
 +            if (indexSummary != null)
 +                indexSummary.close();
 +            logger.debug("Cannot deserialize SSTable Summary File {}: {}", summariesFile.getPath(), e.getMessage());
 +            // corrupted; delete it and fall back to creating a new summary
 +            FileUtils.closeQuietly(iStream);
 +            // delete it and fall back to creating a new summary
 +            FileUtils.deleteWithConfirm(summariesFile);
 +            return false;
 +        }
 +        finally
 +        {
 +            FileUtils.closeQuietly(iStream);
 +        }
 +
 +        return true;
 +    }
 +
 +    /**
 +     * Validates that an index summary has full sampling, as expected when the serialization format does not support
 +     * persisting the sampling level.
 +     * @return true if the summary has full sampling, false otherwise
 +     */
 +    private boolean validateSummarySamplingLevel()
 +    {
 +        // We need to check index summary entries against the index to verify that none of them were dropped due to
 +        // downsampling.  Downsampling can drop any of the first BASE_SAMPLING_LEVEL entries (repeating that drop pattern
 +        // for the remainder of the summary).  Unfortunately, the first entry to be dropped is the entry at
 +        // index (BASE_SAMPLING_LEVEL - 1), so we need to check a full set of BASE_SAMPLING_LEVEL entries.
 +        if (ifile == null)
 +            return false;
 +
 +        Iterator<FileDataInput> segments = ifile.iterator(0);
 +        int i = 0;
 +        int summaryEntriesChecked = 0;
 +        int expectedIndexInterval = getMinIndexInterval();
 +        while (segments.hasNext())
 +        {
 +            String path = null;
 +            try (FileDataInput in = segments.next())
 +            {
 +                path = in.getPath();
 +                while (!in.isEOF())
 +                {
 +                    ByteBuffer indexKey = ByteBufferUtil.readWithShortLength(in);
 +                    if (i % expectedIndexInterval == 0)
 +                    {
 +                        ByteBuffer summaryKey = ByteBuffer.wrap(indexSummary.getKey(i / expectedIndexInterval));
 +                        if (!summaryKey.equals(indexKey))
 +                            return false;
 +                        summaryEntriesChecked++;
 +
 +                        if (summaryEntriesChecked == Downsampling.BASE_SAMPLING_LEVEL)
 +                            return true;
 +                    }
 +                    RowIndexEntry.Serializer.skip(in);
 +                    i++;
 +                }
 +            }
 +            catch (IOException e)
 +            {
 +                markSuspect();
 +                throw new CorruptSSTableException(e, path);
 +            }
 +        }
 +
 +        return true;
 +    }
 +
 +    /**
 +     * Save index summary to Summary.db file.
 +     *
 +     * @param ibuilder
 +     * @param dbuilder
 +     */
 +
 +    public void saveSummary(SegmentedFile.Builder ibuilder, SegmentedFile.Builder dbuilder)
 +    {
 +        saveSummary(this.descriptor, this.first, this.last, ibuilder, dbuilder, indexSummary);
 +    }
 +
 +    private void saveSummary(SegmentedFile.Builder ibuilder, SegmentedFile.Builder dbuilder, IndexSummary newSummary)
 +    {
 +        saveSummary(this.descriptor, this.first, this.last, ibuilder, dbuilder, newSummary);
 +    }
 +    /**
 +     * Save index summary to Summary.db file.
 +     */
 +    public static void saveSummary(Descriptor descriptor, DecoratedKey first, DecoratedKey last,
 +                                   SegmentedFile.Builder ibuilder, SegmentedFile.Builder dbuilder, IndexSummary summary)
 +    {
 +        File summariesFile = new File(descriptor.filenameFor(Component.SUMMARY));
 +        if (summariesFile.exists())
 +            FileUtils.deleteWithConfirm(summariesFile);
 +
 +        try (DataOutputStreamPlus oStream = new BufferedDataOutputStreamPlus(new FileOutputStream(summariesFile));)
 +        {
 +            IndexSummary.serializer.serialize(summary, oStream, descriptor.version.hasSamplingLevel());
 +            ByteBufferUtil.writeWithLength(first.getKey(), oStream);
 +            ByteBufferUtil.writeWithLength(last.getKey(), oStream);
 +            ibuilder.serializeBounds(oStream);
 +            dbuilder.serializeBounds(oStream);
 +        }
 +        catch (IOException e)
 +        {
 +            logger.debug("Cannot save SSTable Summary: ", e);
 +
 +            // corrupted hence delete it and let it load it now.
 +            if (summariesFile.exists())
 +                FileUtils.deleteWithConfirm(summariesFile);
 +        }
 +    }
 +
 +    public void setReplaced()
 +    {
 +        synchronized (tidy.global)
 +        {
 +            assert !tidy.isReplaced;
 +            tidy.isReplaced = true;
 +        }
 +    }
 +
 +    public boolean isReplaced()
 +    {
 +        synchronized (tidy.global)
 +        {
 +            return tidy.isReplaced;
 +        }
 +    }
 +
 +    // runOnClose must NOT be an anonymous or non-static inner class, nor must it retain a reference chain to this reader
 +    public void runOnClose(final Runnable runOnClose)
 +    {
 +        synchronized (tidy.global)
 +        {
 +            final Runnable existing = tidy.runOnClose;
 +            tidy.runOnClose = AndThen.get(existing, runOnClose);
 +        }
 +    }
 +
 +    private static class AndThen implements Runnable
 +    {
 +        final Runnable runFirst;
 +        final Runnable runSecond;
 +
 +        private AndThen(Runnable runFirst, Runnable runSecond)
 +        {
 +            this.runFirst = runFirst;
 +            this.runSecond = runSecond;
 +        }
 +
 +        public void run()
 +        {
 +            runFirst.run();
 +            runSecond.run();
 +        }
 +
 +        static Runnable get(Runnable runFirst, Runnable runSecond)
 +        {
 +            if (runFirst == null)
 +                return runSecond;
 +            return new AndThen(runFirst, runSecond);
 +        }
 +    }
 +
 +    /**
 +     * Clone this reader with the provided start and open reason, and set the clone as replacement.
 +     *
 +     * @param newFirst the first key for the replacement (which can be different from the original due to the pre-emptive
 +     * opening of compaction results).
 +     * @param reason the {@code OpenReason} for the replacement.
 +     *
 +     * @return the cloned reader. That reader is set as a replacement by the method.
 +     */
 +    private SSTableReader cloneAndReplace(DecoratedKey newFirst, OpenReason reason)
 +    {
 +        return cloneAndReplace(newFirst, reason, indexSummary.sharedCopy());
 +    }
 +
 +    /**
 +     * Clone this reader with the new values and set the clone as replacement.
 +     *
 +     * @param newFirst the first key for the replacement (which can be different from the original due to the pre-emptive
 +     * opening of compaction results).
 +     * @param reason the {@code OpenReason} for the replacement.
 +     * @param newSummary the index summary for the replacement.
 +     *
 +     * @return the cloned reader. That reader is set as a replacement by the method.
 +     */
 +    private SSTableReader cloneAndReplace(DecoratedKey newFirst, OpenReason reason, IndexSummary newSummary)
 +    {
 +        SSTableReader replacement = internalOpen(descriptor,
 +                                                 components,
 +                                                 metadata,
 +                                                 partitioner,
 +                                                 ifile != null ? ifile.sharedCopy() : null,
 +                                                 dfile.sharedCopy(),
 +                                                 newSummary,
 +                                                 bf.sharedCopy(),
 +                                                 maxDataAge,
 +                                                 sstableMetadata,
 +                                                 reason);
 +        replacement.first = newFirst;
 +        replacement.last = last;
 +        replacement.isSuspect.set(isSuspect.get());
 +        return replacement;
 +    }
 +
 +    // runOnClose must NOT be an anonymous or non-static inner class, nor must it retain a reference chain to this reader
 +    public SSTableReader cloneWithNewStart(DecoratedKey newStart, final Runnable runOnClose)
 +    {
 +        synchronized (tidy.global)
 +        {
 +            assert openReason != OpenReason.EARLY;
 +            // TODO: merge with caller's firstKeyBeyond() work,to save time
 +            if (newStart.compareTo(first) > 0)
 +            {
 +                final long dataStart = getPosition(newStart, Operator.EQ).position;
 +                final long indexStart = getIndexScanPosition(newStart);
 +                this.tidy.runOnClose = new DropPageCache(dfile, dataStart, ifile, indexStart, runOnClose);
 +            }
 +
 +            return cloneAndReplace(newStart, OpenReason.MOVED_START);
 +        }
 +    }
 +
 +    private static class DropPageCache implements Runnable
 +    {
 +        final SegmentedFile dfile;
 +        final long dfilePosition;
 +        final SegmentedFile ifile;
 +        final long ifilePosition;
 +        final Runnable andThen;
 +
 +        private DropPageCache(SegmentedFile dfile, long dfilePosition, SegmentedFile ifile, long ifilePosition, Runnable andThen)
 +        {
 +            this.dfile = dfile;
 +            this.dfilePosition = dfilePosition;
 +            this.ifile = ifile;
 +            this.ifilePosition = ifilePosition;
 +            this.andThen = andThen;
 +        }
 +
 +        public void run()
 +        {
 +            dfile.dropPageCache(dfilePosition);
 +
 +            if (ifile != null)
 +                ifile.dropPageCache(ifilePosition);
 +            andThen.run();
 +        }
 +    }
 +
 +    /**
 +     * Returns a new SSTableReader with the same properties as this SSTableReader except that a new IndexSummary will
 +     * be built at the target samplingLevel.  This (original) SSTableReader instance will be marked as replaced, have
 +     * its DeletingTask removed, and have its periodic read-meter sync task cancelled.
 +     * @param samplingLevel the desired sampling level for the index summary on the new SSTableReader
 +     * @return a new SSTableReader
 +     * @throws IOException
 +     */
 +    @SuppressWarnings("resource")
 +    public SSTableReader cloneWithNewSummarySamplingLevel(ColumnFamilyStore parent, int samplingLevel) throws IOException
 +    {
 +        assert descriptor.version.hasSamplingLevel();
 +
 +        synchronized (tidy.global)
 +        {
 +            assert openReason != OpenReason.EARLY;
 +
 +            int minIndexInterval = metadata.getMinIndexInterval();
 +            int maxIndexInterval = metadata.getMaxIndexInterval();
 +            double effectiveInterval = indexSummary.getEffectiveIndexInterval();
 +
 +            IndexSummary newSummary;
 +            long oldSize = bytesOnDisk();
 +
 +            // We have to rebuild the summary from the on-disk primary index in three cases:
 +            // 1. The sampling level went up, so we need to read more entries off disk
 +            // 2. The min_index_interval changed (in either direction); this changes what entries would be in the summary
 +            //    at full sampling (and consequently at any other sampling level)
 +            // 3. The max_index_interval was lowered, forcing us to raise the sampling level
 +            if (samplingLevel > indexSummary.getSamplingLevel() || indexSummary.getMinIndexInterval() != minIndexInterval || effectiveInterval > maxIndexInterval)
 +            {
 +                newSummary = buildSummaryAtLevel(samplingLevel);
 +            }
 +            else if (samplingLevel < indexSummary.getSamplingLevel())
 +            {
 +                // we can use the existing index summary to make a smaller one
 +                newSummary = IndexSummaryBuilder.downsample(indexSummary, samplingLevel, minIndexInterval, partitioner);
 +
 +                try(SegmentedFile.Builder ibuilder = SegmentedFile.getBuilder(DatabaseDescriptor.getIndexAccessMode(), false);
 +                    SegmentedFile.Builder dbuilder = SegmentedFile.getBuilder(DatabaseDescriptor.getDiskAccessMode(), compression))
 +                {
 +                    saveSummary(ibuilder, dbuilder, newSummary);
 +                }
 +            }
 +            else
 +            {
 +                throw new AssertionError("Attempted to clone SSTableReader with the same index summary sampling level and " +
 +                        "no adjustments to min/max_index_interval");
 +            }
 +
 +            long newSize = bytesOnDisk();
 +            StorageMetrics.load.inc(newSize - oldSize);
 +            parent.metric.liveDiskSpaceUsed.inc(newSize - oldSize);
 +
 +            return cloneAndReplace(first, OpenReason.METADATA_CHANGE, newSummary);
 +        }
 +    }
 +
 +    private IndexSummary buildSummaryAtLevel(int newSamplingLevel) throws IOException
 +    {
 +        // we read the positions in a BRAF so we don't have to worry about an entry spanning a mmap boundary.
 +        RandomAccessReader primaryIndex = RandomAccessReader.open(new File(descriptor.filenameFor(Component.PRIMARY_INDEX)));
 +        try
 +        {
 +            long indexSize = primaryIndex.length();
 +            try (IndexSummaryBuilder summaryBuilder = new IndexSummaryBuilder(estimatedKeys(), metadata.getMinIndexInterval(), newSamplingLevel))
 +            {
 +                long indexPosition;
 +                while ((indexPosition = primaryIndex.getFilePointer()) != indexSize)
 +                {
 +                    summaryBuilder.maybeAddEntry(partitioner.decorateKey(ByteBufferUtil.readWithShortLength(primaryIndex)), indexPosition);
 +                    RowIndexEntry.Serializer.skip(primaryIndex);
 +                }
 +
 +                return summaryBuilder.build(partitioner);
 +            }
 +        }
 +        finally
 +        {
 +            FileUtils.closeQuietly(primaryIndex);
 +        }
 +    }
 +
 +    public RestorableMeter getReadMeter()
 +    {
 +        return readMeter;
 +    }
 +
 +    public int getIndexSummarySamplingLevel()
 +    {
 +        return indexSummary.getSamplingLevel();
 +    }
 +
 +    public long getIndexSummaryOffHeapSize()
 +    {
 +        return indexSummary.getOffHeapSize();
 +    }
 +
 +    public int getMinIndexInterval()
 +    {
 +        return indexSummary.getMinIndexInterval();
 +    }
 +
 +    public double getEffectiveIndexInterval()
 +    {
 +        return indexSummary.getEffectiveIndexInterval();
 +    }
 +
 +    public void releaseSummary()
 +    {
 +        tidy.releaseSummary();
 +        indexSummary = null;
 +    }
 +
 +    private void validate()
 +    {
 +        if (this.first.compareTo(this.last) > 0)
 +        {
 +            selfRef().release();
 +            throw new IllegalStateException(String.format("SSTable first key %s > last key %s", this.first, this.last));
 +        }
 +    }
 +
 +    /**
 +     * Gets the position in the index file to start scanning to find the given key (at most indexInterval keys away,
 +     * modulo downsampling of the index summary). Always returns a value >= 0
 +     */
 +    public long getIndexScanPosition(RowPosition key)
 +    {
 +        if (openReason == OpenReason.MOVED_START && key.compareTo(first) < 0)
 +            key = first;
 +
 +        return getIndexScanPositionFromBinarySearchResult(indexSummary.binarySearch(key), indexSummary);
 +    }
 +
 +    @VisibleForTesting
 +    public static long getIndexScanPositionFromBinarySearchResult(int binarySearchResult, IndexSummary referencedIndexSummary)
 +    {
 +        if (binarySearchResult == -1)
 +            return 0;
 +        else
 +            return referencedIndexSummary.getPosition(getIndexSummaryIndexFromBinarySearchResult(binarySearchResult));
 +    }
 +
 +    public static int getIndexSummaryIndexFromBinarySearchResult(int binarySearchResult)
 +    {
 +        if (binarySearchResult < 0)
 +        {
 +            // binary search gives us the first index _greater_ than the key searched for,
 +            // i.e., its insertion position
 +            int greaterThan = (binarySearchResult + 1) * -1;
 +            if (greaterThan == 0)
 +                return -1;
 +            return greaterThan - 1;
 +        }
 +        else
 +        {
 +            return binarySearchResult;
 +        }
 +    }
 +
 +    /**
 +     * Returns the compression metadata for this sstable.
 +     * @throws IllegalStateException if the sstable is not compressed
 +     */
 +    public CompressionMetadata getCompressionMetadata()
 +    {
 +        if (!compression)
 +            throw new IllegalStateException(this + " is not compressed");
 +
 +        CompressionMetadata cmd = ((ICompressedFile) dfile).getMetadata();
 +
 +        //We need the parent cf metadata
 +        String cfName = metadata.isSecondaryIndex() ? metadata.getParentColumnFamilyName() : metadata.cfName;
 +        cmd.parameters.setLiveMetadata(Schema.instance.getCFMetaData(metadata.ksName, cfName));
 +
 +        return cmd;
 +    }
 +
 +    /**
 +     * Returns the amount of memory in bytes used off heap by the compression meta-data.
 +     * @return the amount of memory in bytes used off heap by the compression meta-data
 +     */
 +    public long getCompressionMetadataOffHeapSize()
 +    {
 +        if (!compression)
 +            return 0;
 +
 +        return getCompressionMetadata().offHeapSize();
 +    }
 +
 +    /**
 +     * For testing purposes only.
 +     */
 +    public void forceFilterFailures()
 +    {
 +        bf = FilterFactory.AlwaysPresent;
 +    }
 +
 +    public IFilter getBloomFilter()
 +    {
 +        return bf;
 +    }
 +
 +    public long getBloomFilterSerializedSize()
 +    {
 +        return bf.serializedSize();
 +    }
 +
 +    /**
 +     * Returns the amount of memory in bytes used off heap by the bloom filter.
 +     * @return the amount of memory in bytes used off heap by the bloom filter
 +     */
 +    public long getBloomFilterOffHeapSize()
 +    {
 +        return bf.offHeapSize();
 +    }
 +
 +    /**
 +     * @return An estimate of the number of keys in this SSTable based on the index summary.
 +     */
 +    public long estimatedKeys()
 +    {
 +        return indexSummary.getEstimatedKeyCount();
 +    }
 +
 +    /**
 +     * @param ranges
 +     * @return An estimate of the number of keys for given ranges in this SSTable.
 +     */
 +    public long estimatedKeysForRanges(Collection<Range<Token>> ranges)
 +    {
 +        long sampleKeyCount = 0;
 +        List<Pair<Integer, Integer>> sampleIndexes = getSampleIndexesForRanges(indexSummary, ranges);
 +        for (Pair<Integer, Integer> sampleIndexRange : sampleIndexes)
 +            sampleKeyCount += (sampleIndexRange.right - sampleIndexRange.left + 1);
 +
 +        // adjust for the current sampling level: (BSL / SL) * index_interval_at_full_sampling
 +        long estimatedKeys = sampleKeyCount * ((long) Downsampling.BASE_SAMPLING_LEVEL * indexSummary.getMinIndexInterval()) / indexSummary.getSamplingLevel();
 +        return Math.max(1, estimatedKeys);
 +    }
 +
 +    /**
 +     * Returns the number of entries in the IndexSummary.  At full sampling, this is approximately 1/INDEX_INTERVALth of
 +     * the keys in this SSTable.
 +     */
 +    public int getIndexSummarySize()
 +    {
 +        return indexSummary.size();
 +    }
 +
 +    /**
 +     * Returns the approximate number of entries the IndexSummary would contain if it were at full sampling.
 +     */
 +    public int getMaxIndexSummarySize()
 +    {
 +        return indexSummary.getMaxNumberOfEntries();
 +    }
 +
 +    /**
 +     * Returns the key for the index summary entry at `index`.
 +     */
 +    public byte[] getIndexSummaryKey(int index)
 +    {
 +        return indexSummary.getKey(index);
 +    }
 +
 +    private static List<Pair<Integer,Integer>> getSampleIndexesForRanges(IndexSummary summary, Collection<Range<Token>> ranges)
 +    {
 +        // use the index to determine a minimal section for each range
 +        List<Pair<Integer,Integer>> positions = new ArrayList<>();
 +
 +        for (Range<Token> range : Range.normalize(ranges))
 +        {
 +            RowPosition leftPosition = range.left.maxKeyBound();
 +            RowPosition rightPosition = range.right.maxKeyBound();
 +
 +            int left = summary.binarySearch(leftPosition);
 +            if (left < 0)
 +                left = (left + 1) * -1;
 +            else
 +                // left range are start exclusive
 +                left = left + 1;
 +            if (left == summary.size())
 +                // left is past the end of the sampling
 +                continue;
 +
 +            int right = Range.isWrapAround(range.left, range.right)
 +                    ? summary.size() - 1
 +                    : summary.binarySearch(rightPosition);
 +            if (right < 0)
 +            {
 +                // range are end inclusive so we use the previous index from what binarySearch give us
 +                // since that will be the last index we will return
 +                right = (right + 1) * -1;
 +                if (right == 0)
 +                    // Means the first key is already stricly greater that the right bound
 +                    continue;
 +                right--;
 +            }
 +
 +            if (left > right)
 +                // empty range
 +                continue;
 +            positions.add(Pair.create(left, right));
 +        }
 +        return positions;
 +    }
 +
 +    public Iterable<DecoratedKey> getKeySamples(final Range<Token> range)
 +    {
 +        final List<Pair<Integer, Integer>> indexRanges = getSampleIndexesForRanges(indexSummary, Collections.singletonList(range));
 +
 +        if (indexRanges.isEmpty())
 +            return Collections.emptyList();
 +
 +        return new Iterable<DecoratedKey>()
 +        {
 +            public Iterator<DecoratedKey> iterator()
 +            {
 +                return new Iterator<DecoratedKey>()
 +                {
 +                    private Iterator<Pair<Integer, Integer>> rangeIter = indexRanges.iterator();
 +                    private Pair<Integer, Integer> current;
 +                    private int idx;
 +
 +                    public boolean hasNext()
 +                    {
 +                        if (current == null || idx > current.right)
 +                        {
 +                            if (rangeIter.hasNext())
 +                            {
 +                                current = rangeIter.next();
 +                                idx = current.left;
 +                                return true;
 +                            }
 +                            return false;
 +                        }
 +
 +                        return true;
 +                    }
 +
 +                    public DecoratedKey next()
 +                    {
 +                        byte[] bytes = indexSummary.getKey(idx++);
 +                        return partitioner.decorateKey(ByteBuffer.wrap(bytes));
 +                    }
 +
 +                    public void remove()
 +                    {
 +                        throw new UnsupportedOperationException();
 +                    }
 +                };
 +            }
 +        };
 +    }
 +
 +    /**
 +     * Determine the minimal set of sections that can be extracted from this SSTable to cover the given ranges.
 +     * @return A sorted list of (offset,end) pairs that cover the given ranges in the datafile for this SSTable.
 +     */
 +    public List<Pair<Long,Long>> getPositionsForRanges(Collection<Range<Token>> ranges)
 +    {
 +        // use the index to determine a minimal section for each range
 +        List<Pair<Long,Long>> positions = new ArrayList<>();
 +        for (Range<Token> range : Range.normalize(ranges))
 +        {
 +            assert !range.isWrapAround() || range.right.isMinimum();
 +            // truncate the range so it at most covers the sstable
 +            AbstractBounds<RowPosition> bounds = Range.makeRowRange(range);
 +            RowPosition leftBound = bounds.left.compareTo(first) > 0 ? bounds.left : first.getToken().minKeyBound();
 +            RowPosition rightBound = bounds.right.isMinimum() ? last.getToken().maxKeyBound() : bounds.right;
 +
 +            if (leftBound.compareTo(last) > 0 || rightBound.compareTo(first) < 0)
 +                continue;
 +
 +            long left = getPosition(leftBound, Operator.GT).position;
 +            long right = (rightBound.compareTo(last) > 0)
 +                         ? uncompressedLength()
 +                         : getPosition(rightBound, Operator.GT).position;
 +
 +            if (left == right)
 +                // empty range
 +                continue;
 +
 +            assert left < right : String.format("Range=%s openReason=%s first=%s last=%s left=%d right=%d", range, openReason, first, last, left, right);
 +            positions.add(Pair.create(left, right));
 +        }
 +        return positions;
 +    }
 +
 +    public KeyCacheKey getCacheKey(DecoratedKey key)
 +    {
 +        return new KeyCacheKey(metadata.cfId, descriptor, key.getKey());
 +    }
 +
 +    public void cacheKey(DecoratedKey key, RowIndexEntry info)
 +    {
 +        CachingOptions caching = metadata.getCaching();
 +
 +        if (!caching.keyCache.isEnabled()
 +                || keyCache == null
 +                || keyCache.getCapacity() == 0)
 +        {
 +            return;
 +        }
 +
 +        KeyCacheKey cacheKey = new KeyCacheKey(metadata.cfId, descriptor, key.getKey());
 +        logger.trace("Adding cache entry for {} -> {}", cacheKey, info);
 +        keyCache.put(cacheKey, info);
 +    }
 +
 +    public RowIndexEntry getCachedPosition(DecoratedKey key, boolean updateStats)
 +    {
 +        return getCachedPosition(new KeyCacheKey(metadata.cfId, descriptor, key.getKey()), updateStats);
 +    }
 +
 +    protected RowIndexEntry getCachedPosition(KeyCacheKey unifiedKey, boolean updateStats)
 +    {
-         if (keyCache != null && keyCache.getCapacity() > 0) {
++        if (keyCache != null && keyCache.getCapacity() > 0 && metadata.getCaching().keyCache.isEnabled()) {
 +            if (updateStats)
 +            {
 +                RowIndexEntry cachedEntry = keyCache.get(unifiedKey);
 +                keyCacheRequest.incrementAndGet();
 +                if (cachedEntry != null)
 +                {
 +                    keyCacheHit.incrementAndGet();
 +                    bloomFilterTracker.addTruePositive();
 +                }
 +                return cachedEntry;
 +            }
 +            else
 +            {
 +                return keyCache.getInternal(unifiedKey);
 +            }
 +        }
 +        return null;
 +    }
 +
 +    /**
 +     * Get position updating key cache and stats.
 +     * @see #getPosition(org.apache.cassandra.db.RowPosition, SSTableReader.Operator, boolean)
 +     */
 +    public RowIndexEntry getPosition(RowPosition key, Operator op)
 +    {
 +        return getPosition(key, op, true, false);
 +    }
 +
 +    public RowIndexEntry getPosition(RowPosition key, Operator op, boolean updateCacheAndStats)
 +    {
 +        return getPosition(key, op, updateCacheAndStats, false);
 +    }
 +    /**
 +     * @param key The key to apply as the rhs to the given Operator. A 'fake' key is allowed to
 +     * allow key selection by token bounds but only if op != * EQ
 +     * @param op The Operator defining matching keys: the nearest key to the target matching the operator wins.
 +     * @param updateCacheAndStats true if updating stats and cache
 +     * @return The index entry corresponding to the key, or null if the key is not present
 +     */
 +    protected abstract RowIndexEntry getPosition(RowPosition key, Operator op, boolean updateCacheAndStats, boolean permitMatchPastLast);
 +
 +    //Corresponds to a name column
 +    public abstract OnDiskAtomIterator iterator(DecoratedKey key, SortedSet<CellName> columns);
 +    public abstract OnDiskAtomIterator iterator(FileDataInput file, DecoratedKey key, SortedSet<CellName> columns, RowIndexEntry indexEntry);
 +
 +    //Corresponds to a slice query
 +    public abstract OnDiskAtomIterator iterator(DecoratedKey key, ColumnSlice[] slices, boolean reverse);
 +    public abstract OnDiskAtomIterator iterator(FileDataInput file, DecoratedKey key, ColumnSlice[] slices, boolean reversed, RowIndexEntry indexEntry);
 +
 +    /**
 +     * Finds and returns the first key beyond a given token in this SSTable or null if no such key exists.
 +     */
 +    public DecoratedKey firstKeyBeyond(RowPosition token)
 +    {
 +        if (token.compareTo(first) < 0)
 +            return first;
 +
 +        long sampledPosition = getIndexScanPosition(token);
 +
 +        if (ifile == null)
 +            return null;
 +
 +        Iterator<FileDataInput> segments = ifile.iterator(sampledPosition);
 +        while (segments.hasNext())
 +        {
 +            String path = null;
 +            try (FileDataInput in = segments.next();)
 +            {
 +                path = in.getPath();
 +                while (!in.isEOF())
 +                {
 +                    ByteBuffer indexKey = ByteBufferUtil.readWithShortLength(in);
 +                    DecoratedKey indexDecoratedKey = partitioner.decorateKey(indexKey);
 +                    if (indexDecoratedKey.compareTo(token) > 0)
 +                        return indexDecoratedKey;
 +
 +                    RowIndexEntry.Serializer.skip(in);
 +                }
 +            }
 +            catch (IOException e)
 +            {
 +                markSuspect();
 +                throw new CorruptSSTableException(e, path);
 +            }
 +        }
 +
 +        return null;
 +    }
 +
 +    /**
 +     * @return The length in bytes of the data for this SSTable. For
 +     * compressed files, this is not the same thing as the on disk size (see
 +     * onDiskLength())
 +     */
 +    public long uncompressedLength()
 +    {
 +        return dfile.length;
 +    }
 +
 +    /**
 +     * @return The length in bytes of the on disk size for this SSTable. For
 +     * compressed files, this is not the same thing as the data length (see
 +     * length())
 +     */
 +    public long onDiskLength()
 +    {
 +        return dfile.onDiskLength;
 +    }
 +
 +    /**
 +     * Mark the sstable as obsolete, i.e., compacted into newer sstables.
 +     *
 +     * When calling this function, the caller must ensure that the SSTableReader is not referenced anywhere
 +     * except for threads holding a reference.
 +     *
 +     * @return true if the this is the first time the file was marked obsolete.  Calling this
 +     * multiple times is usually buggy (see exceptions in Tracker.unmarkCompacting and removeOldSSTablesSize).
 +     */
 +    public boolean markObsolete(Tracker tracker)
 +    {
 +        if (logger.isDebugEnabled())
 +            logger.debug("Marking {} compacted", getFilename());
 +
 +        synchronized (tidy.global)
 +        {
 +            assert !tidy.isReplaced;
 +        }
 +        if (!tidy.global.isCompacted.getAndSet(true))
 +        {
 +            tidy.type.markObsolete(this, tracker);
 +            return true;
 +        }
 +        return false;
 +    }
 +
 +    public boolean isMarkedCompacted()
 +    {
 +        return tidy.global.isCompacted.get();
 +    }
 +
 +    public void markSuspect()
 +    {
 +        if (logger.isDebugEnabled())
 +            logger.debug("Marking {} as a suspect for blacklisting.", getFilename());
 +
 +        isSuspect.getAndSet(true);
 +    }
 +
 +    public boolean isMarkedSuspect()
 +    {
 +        return isSuspect.get();
 +    }
 +
 +
 +    /**
 +     * I/O SSTableScanner
 +     * @return A Scanner for seeking over the rows of the SSTable.
 +     */
 +    public ISSTableScanner getScanner()
 +    {
 +        return getScanner((RateLimiter) null);
 +    }
 +
 +    public ISSTableScanner getScanner(RateLimiter limiter)
 +    {
 +        return getScanner(DataRange.allData(partitioner), limiter);
 +    }
 +
 +    /**
 +     *
 +     * @param dataRange filter to use when reading the columns
 +     * @return A Scanner for seeking over the rows of the SSTable.
 +     */
 +    public ISSTableScanner getScanner(DataRange dataRange)
 +    {
 +        return getScanner(dataRange, null);
 +    }
 +
 +    /**
 +     * Direct I/O SSTableScanner over a defined range of tokens.
 +     *
 +     * @param range the range of keys to cover
 +     * @return A Scanner for seeking over the rows of the SSTable.
 +     */
 +    public ISSTableScanner getScanner(Range<Token> range, RateLimiter limiter)
 +    {
 +        if (range == null)
 +            return getScanner(limiter);
 +        return getScanner(Collections.singletonList(range), limiter);
 +    }
 +
 +    /**
 +     * Direct I/O SSTableScanner over a defined collection of ranges of tokens.
 +     *
 +     * @param ranges the range of keys to cover
 +     * @return A Scanner for seeking over the rows of the SSTable.
 +     */
 +    public abstract ISSTableScanner getScanner(Collection<Range<Token>> ranges, RateLimiter limiter);
 +
 +    /**
 +     *
 +     * @param dataRange filter to use when reading the columns
 +     * @return A Scanner for seeking over the rows of the SSTable.
 +     */
 +    public abstract ISSTableScanner getScanner(DataRange dataRange, RateLimiter limiter);
 +
 +
 +
 +    public FileDataInput getFileDataInput(long position)
 +    {
 +        return dfile.getSegment(position);
 +    }
 +
 +    /**
 +     * Tests if the sstable contains data newer than the given age param (in localhost currentMilli time).
 +     * This works in conjunction with maxDataAge which is an upper bound on the create of data in this sstable.
 +     * @param age The age to compare the maxDataAre of this sstable. Measured in millisec since epoc on this host
 +     * @return True iff this sstable contains data that's newer than the given age parameter.
 +     */
 +    public boolean newSince(long age)
 +    {
 +        return maxDataAge > age;
 +    }
 +
 +    public void createLinks(String snapshotDirectoryPath)
 +    {
 +        for (Component component : components)
 +        {
 +            File sourceFile = new File(descriptor.filenameFor(component));
 +            File targetLink = new File(snapshotDirectoryPath, sourceFile.getName());
 +            FileUtils.createHardLink(sourceFile, targetLink);
 +        }
 +    }
 +
 +    public boolean isRepaired()
 +    {
 +        return sstableMetadata.repairedAt != ActiveRepairService.UNREPAIRED_SSTABLE;
 +    }
 +
 +    /**
 +     * TODO: Move someplace reusable
 +     */
 +    public abstract static class Operator
 +    {
 +        public static final Operator EQ = new Equals();
 +        public static final Operator GE = new GreaterThanOrEqualTo();
 +        public static final Operator GT = new GreaterThan();
 +
 +        /**
 +         * @param comparison The result of a call to compare/compareTo, with the desired field on the rhs.
 +         * @return less than 0 if the operator cannot match forward, 0 if it matches, greater than 0 if it might match forward.
 +         */
 +        public abstract int apply(int comparison);
 +
 +        final static class Equals extends Operator
 +        {
 +            public int apply(int comparison) { return -comparison; }
 +        }
 +
 +        final static class GreaterThanOrEqualTo extends Operator
 +        {
 +            public int apply(int comparison) { return comparison >= 0 ? 0 : 1; }
 +        }
 +
 +        final static class GreaterThan extends Operator
 +        {
 +            public int apply(int comparison) { return comparison > 0 ? 0 : 1; }
 +        }
 +    }
 +
 +    public long getBloomFilterFalsePositiveCount()
 +    {
 +        return bloomFilterTracker.getFalsePositiveCount();
 +    }
 +
 +    public long getRecentBloomFilterFalsePositiveCount()
 +    {
 +        return bloomFilterTracker.getRecentFalsePositiveCount();
 +    }
 +
 +    public long getBloomFilterTruePositiveCount()
 +    {
 +        return bloomFilterTracker.getTruePositiveCount();
 +    }
 +
 +    public long getRecentBloomFilterTruePositiveCount()
 +    {
 +        return bloomFilterTracker.getRecentTruePositiveCount();
 +    }
 +
 +    public InstrumentingCache<KeyCacheKey, RowIndexEntry> getKeyCache()
 +    {
 +        return keyCache;
 +    }
 +
 +    public EstimatedHistogram getEstimatedRowSize()
 +    {
 +        return sstableMetadata.estimatedRowSize;
 +    }
 +
 +    public EstimatedHistogram getEstimatedColumnCount()
 +    {
 +        return sstableMetadata.estimatedColumnCount;
 +    }
 +
 +    public double getEstimatedDroppableTombstoneRatio(int gcBefore)
 +    {
 +        return sstableMetadata.getEstimatedDroppableTombstoneRatio(gcBefore);
 +    }
 +
 +    public double getDroppableTombstonesBefore(int gcBefore)
 +    {
 +        return sstableMetadata.getDroppableTombstonesBefore(gcBefore);
 +    }
 +
 +    public double getCompressionRatio()
 +    {
 +        return sstableMetadata.compressionRatio;
 +    }
 +
 +    public ReplayPosition getReplayPosition()
 +    {
 +        return sstableMetadata.replayPosition;
 +    }
 +
 +    public long getMinTimestamp()
 +    {
 +        return sstableMetadata.minTimestamp;
 +    }
 +
 +    public long getMaxTimestamp()
 +    {
 +        return sstableMetadata.maxTimestamp;
 +    }
 +
 +    public Set<Integer> getAncestors()
 +    {
 +        try
 +        {
 +            CompactionMetadata compactionMetadata = (CompactionMetadata) descriptor.getMetadataSerializer().deserialize(descriptor, MetadataType.COMPACTION);
 +            if (compactionMetadata != null)
 +                return compactionMetadata.ancestors;
 +            return Collections.emptySet();
 +        }
 +        catch (IOException e)
 +        {
 +            SSTableReader.logOpenException(descriptor, e);
 +            return Collections.emptySet();
 +        }
 +    }
 +
 +    public int getSSTableLevel()
 +    {
 +        return sstableMetadata.sstableLevel;
 +    }
 +
 +    /**
 +     * Reloads the sstable metadata from disk.
 +     *
 +     * Called after level is changed on sstable, for example if the sstable is dropped to L0
 +     *
 +     * Might be possible to remove in future versions
 +     *
 +     * @throws IOException
 +     */
 +    public void reloadSSTableMetadata() throws IOException
 +    {
 +        this.sstableMetadata = (StatsMetadata) descriptor.getMetadataSerializer().deserialize(descriptor, MetadataType.STATS);
 +    }
 +
 +    public StatsMetadata getSSTableMetadata()
 +    {
 +        return sstableMetadata;
 +    }
 +
 +    public RandomAccessReader openDataReader(RateLimiter limiter)
 +    {
 +        assert limiter != null;
 +        return dfile.createThrottledReader(limiter);
 +    }
 +
 +    public RandomAccessReader openDataReader()
 +    {
 +        return dfile.createReader();
 +    }
 +
 +    public RandomAccessReader openIndexReader()
 +    {
 +        if (ifile != null)
 +            return ifile.createReader();
 +        return null;
 +    }
 +
 +    /**
 +     * @param component component to get timestamp.
 +     * @return last modified time for given component. 0 if given component does not exist or IO error occurs.
 +     */
 +    public long getCreationTimeFor(Component component)
 +    {
 +        return new File(descriptor.filenameFor(component)).lastModified();
 +    }
 +
 +    /**
 +     * @return Number of key cache hit
 +     */
 +    public long getKeyCacheHit()
 +    {
 +        return keyCacheHit.get();
 +    }
 +
 +    /**
 +     * @return Number of key cache request
 +     */
 +    public long getKeyCacheRequest()
 +    {
 +        return keyCacheRequest.get();
 +    }
 +
 +    /**
 +     * Increment the total row read count and read rate for this SSTable.  This should not be incremented for range
 +     * slice queries, row cache hits, or non-query reads, like compaction.
 +     */
 +    public void incrementReadCount()
 +    {
 +        if (readMeter != null)
 +            readMeter.mark();
 +    }
 +
 +    public static class SizeComparator implements Comparator<SSTableReader>
 +    {
 +        public int compare(SSTableReader o1, SSTableReader o2)
 +        {
 +            return Longs.compare(o1.onDiskLength(), o2.onDiskLength());
 +        }
 +    }
 +
 +    public Ref<SSTableReader> tryRef()
 +    {
 +        return selfRef.tryRef();
 +    }
 +
 +    public Ref<SSTableReader> selfRef()
 +    {
 +        return selfRef;
 +    }
 +
 +    public Ref<SSTableReader> ref()
 +    {
 +        return selfRef.ref();
 +    }
 +
 +    void setup(boolean trackHotness)
 +    {
 +        tidy.setup(this, trackHotness);
 +        this.readMeter = tidy.global.readMeter;
 +    }
 +
 +    @VisibleForTesting
 +    public void overrideReadMeter(RestorableMeter readMeter)
 +    {
 +        this.readMeter = tidy.global.readMeter = readMeter;
 +    }
 +
 +    /**
 +     * One instance per SSTableReader we create. This references the type-shared tidy, which in turn references
 +     * the globally shared tidy, i.e.
 +     *
 +     * InstanceTidier => DescriptorTypeTitdy => GlobalTidy
 +     *
 +     * We can create many InstanceTidiers (one for every time we reopen an sstable with MOVED_START for example), but there can only be
 +     * two DescriptorTypeTidy (FINAL and TEMPLINK) and only one GlobalTidy for one single logical sstable.
 +     *
 +     * When the InstanceTidier cleansup, it releases its reference to its DescriptorTypeTidy; when all InstanceTidiers
 +     * for that type have run, the DescriptorTypeTidy cleansup. DescriptorTypeTidy behaves in the same way towards GlobalTidy.
 +     *
 +     * For ease, we stash a direct reference to both our type-shared and global tidier
 +     */
 +    private static final class InstanceTidier implements Tidy
 +    {
 +        private final Descriptor descriptor;
 +        private final CFMetaData metadata;
 +        private IFilter bf;
 +        private IndexSummary summary;
 +
 +        private SegmentedFile dfile;
 +        private SegmentedFile ifile;
 +        private Runnable runOnClose;
 +        private boolean isReplaced = false;
 +
 +        // a reference to our shared per-Descriptor.Type tidy instance, that
 +        // we will release when we are ourselves released
 +        private Ref<DescriptorTypeTidy> typeRef;
 +
 +        // a convenience stashing of the shared per-descriptor-type tidy instance itself
 +        // and the per-logical-sstable globally shared state that it is linked to
 +        private DescriptorTypeTidy type;
 +        private GlobalTidy global;
 +
 +        private boolean setup;
 +
 +        void setup(SSTableReader reader, boolean trackHotness)
 +        {
 +            this.setup = true;
 +            this.bf = reader.bf;
 +            this.summary = reader.indexSummary;
 +            this.dfile = reader.dfile;
 +            this.ifile = reader.ifile;
 +            // get a new reference to the shared descriptor-type tidy
 +            this.typeRef = DescriptorTypeTidy.get(reader);
 +            this.type = typeRef.get();
 +            this.global = type.globalRef.get();
 +            if (trackHotness)
 +                global.ensureReadMeter();
 +        }
 +
 +        InstanceTidier(Descriptor descriptor, CFMetaData metadata)
 +        {
 +            this.descriptor = descriptor;
 +            this.metadata = metadata;
 +        }
 +
 +        public void tidy()
 +        {
 +            // don't try to cleanup if the sstablereader was never fully constructed
 +            if (!setup)
 +                return;
 +
 +            final ColumnFamilyStore cfs = Schema.instance.getColumnFamilyStoreInstance(metadata.cfId);
 +            final OpOrder.Barrier barrier;
 +            if (cfs != null)
 +            {
 +                barrier = cfs.readOrdering.newBarrier();
 +                barrier.issue();
 +            }
 +            else
 +                barrier = null;
 +
 +            ScheduledExecutors.nonPeriodicTasks.execute(new Runnable()
 +            {
 +                public void run()
 +                {
 +                    if (barrier != null)
 +                        barrier.await();
 +                    if (bf != null)
 +                        bf.close();
 +                    if (summary != null)
 +                        summary.close();
 +                    if (runOnClose != null)
 +                        runOnClose.run();
 +                    if (dfile != null)
 +                        dfile.close();
 +                    if (ifile != null)
 +                        ifile.close();
 +                    typeRef.release();
 +                }
 +            });
 +        }
 +
 +        public String name()
 +        {
 +            return descriptor.toString();
 +        }
 +
 +        void releaseSummary()
 +        {
 +            summary.close();
 +            assert summary.isCleanedUp();
 +            summary = null;
 +        }
 +    }
 +
 +    /**
 +     * One shared between all instances of a given Descriptor.Type.
 +     * Performs only two things: the deletion of the sstables for the type,
 +     * if necessary; and the shared reference to the globally shared state.
 +     *
 +     * All InstanceTidiers, on setup(), ask the static get() method for their shared state,
 +     * and stash a reference to it to be released when they are. Once all such references are
 +     * released, the shared tidy will be performed.
 +     */
 +    static final class DescriptorTypeTidy implements Tidy
 +    {
 +        // keyed by REAL descriptor (TMPLINK/FINAL), mapping to the shared DescriptorTypeTidy for that descriptor
 +        static final ConcurrentMap<Descriptor, Ref<DescriptorTypeTidy>> lookup = new ConcurrentHashMap<>();
 +
 +        private final Descriptor desc;
 +        private final Ref<GlobalTidy> globalRef;
 +        private final Set<Component> components;
 +        private long sizeOnDelete;
 +        private Counter totalDiskSpaceUsed;
 +
 +        DescriptorTypeTidy(Descriptor desc, SSTableReader sstable)
 +        {
 +            this.desc = desc;
 +            // get a new reference to the shared global tidy
 +            this.globalRef = GlobalTidy.get(sstable);
 +            this.components = sstable.components;
 +        }
 +
 +        void markObsolete(SSTableReader instance, Tracker tracker)
 +        {
 +            // the tracker is used only to notify listeners of deletion of the sstable;
 +            // since deletion of a non-final file is not really deletion of the sstable,
 +            // we don't want to notify the listeners in this event
 +            if (tracker != null && tracker.cfstore != null && desc.type == Descriptor.Type.FINAL)
 +            {
 +                sizeOnDelete = instance.bytesOnDisk();
 +                totalDiskSpaceUsed = tracker.cfstore.metric.totalDiskSpaceUsed;
 +                tracker.notifyDeleting(instance);
 +            }
 +        }
 +
 +        public void tidy()
 +        {
 +            lookup.remove(desc);
 +            boolean isCompacted = globalRef.get().isCompacted.get();
 +            globalRef.release();
 +            switch (desc.type)
 +            {
 +                case FINAL:
 +                    if (isCompacted)
 +                        new SSTableDeletingTask(desc, components, totalDiskSpaceUsed, sizeOnDelete).run();
 +                    break;
 +                case TEMPLINK:
 +                    new SSTableDeletingTask(desc, components, null, 0).run();
 +                    break;
 +                default:
 +                    throw new IllegalStateException();
 +            }
 +        }
 +
 +        public String name()
 +        {
 +            return desc.toString();
 +        }
 +
 +        // get a new reference to the shared DescriptorTypeTidy for this sstable
 +        @SuppressWarnings("resource")
 +        public static Ref<DescriptorTypeTidy> get(SSTableReader sstable)
 +        {
 +            Descriptor desc = sstable.descriptor;
 +            if (sstable.openReason == OpenReason.EARLY)
 +                desc = desc.asType(Descriptor.Type.TEMPLINK);
 +            Ref<DescriptorTypeTidy> refc = lookup.get(desc);
 +            if (refc != null)
 +                return refc.ref();
 +            final DescriptorTypeTidy tidy = new DescriptorTypeTidy(desc, sstable);
 +            refc = new Ref<>(tidy, tidy);
 +            Ref<?> ex = lookup.putIfAbsent(desc, refc);
 +            if (ex != null)
 +            {
 +                refc.close();
 +                throw new AssertionError();
 +            }
 +            return refc;
 +        }
 +    }
 +
 +    /**
 +     * One insta

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