/*
* 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;
import java.io.*;
import java.nio.ByteBuffer;
import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.cache.InstrumentingCache;
import org.apache.cassandra.cache.KeyCacheKey;
import org.apache.cassandra.concurrent.DebuggableThreadPoolExecutor;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.config.ColumnDefinition;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.config.Schema;
import org.apache.cassandra.db.*;
import org.apache.cassandra.db.commitlog.ReplayPosition;
import org.apache.cassandra.db.index.SecondaryIndex;
import org.apache.cassandra.db.filter.QueryFilter;
import org.apache.cassandra.dht.AbstractBounds;
import org.apache.cassandra.dht.IPartitioner;
import org.apache.cassandra.dht.LocalPartitioner;
import org.apache.cassandra.dht.Range;
import org.apache.cassandra.dht.Token;
import org.apache.cassandra.io.compress.CompressedRandomAccessReader;
import org.apache.cassandra.io.compress.CompressionMetadata;
import org.apache.cassandra.io.util.*;
import org.apache.cassandra.service.CacheService;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.utils.*;
import static org.apache.cassandra.db.Directories.SECONDARY_INDEX_NAME_SEPARATOR;
/**
* SSTableReaders are open()ed by Table.onStart; after that they are created by SSTableWriter.renameAndOpen.
* Do not re-call open() on existing SSTable files; use the references kept by ColumnFamilyStore post-start instead.
*/
public class SSTableReader extends SSTable
{
private static final Logger logger = LoggerFactory.getLogger(SSTableReader.class);
// guesstimated size of INDEX_INTERVAL index entries
private static final int INDEX_FILE_BUFFER_BYTES = 16 * DatabaseDescriptor.getIndexInterval();
/**
* maxDataAge is a timestamp in local server time (e.g. System.currentTimeMilli) which represents an uppper 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 tables.
*
* The age is in milliseconds since epoc and is local to this host.
*/
public final long maxDataAge;
// indexfile and datafile: might be null before a call to load()
private SegmentedFile ifile;
private SegmentedFile dfile;
private IndexSummary indexSummary;
private IFilter bf;
private InstrumentingCache<KeyCacheKey, RowIndexEntry> keyCache;
private final BloomFilterTracker bloomFilterTracker = new BloomFilterTracker();
private final AtomicInteger references = new AtomicInteger(1);
// 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
private final AtomicBoolean isCompacted = new AtomicBoolean(false);
private final AtomicBoolean isSuspect = new AtomicBoolean(false);
private final SSTableDeletingTask deletingTask;
private final SSTableMetadata sstableMetadata;
public static long getApproximateKeyCount(Iterable<SSTableReader> sstables)
{
long count = 0;
for (SSTableReader sstable : sstables)
{
int indexKeyCount = sstable.getKeySamples().size();
count = count + (indexKeyCount + 1) * DatabaseDescriptor.getIndexInterval();
if (logger.isDebugEnabled())
logger.debug("index size for bloom filter calc for file : " + sstable.getFilename() + " : " + count);
}
return count;
}
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 openNoValidation(Descriptor descriptor, Set<Component> components, CFMetaData metadata) throws IOException
{
return open(descriptor, components, metadata, StorageService.getPartitioner(), false);
}
public static SSTableReader open(Descriptor descriptor, Set<Component> components, CFMetaData metadata, IPartitioner partitioner) throws IOException
{
return open(descriptor, components, metadata, partitioner, true);
}
private static SSTableReader open(Descriptor descriptor,
Set<Component> components,
CFMetaData metadata,
IPartitioner partitioner,
boolean validate) throws IOException
{
assert partitioner != null;
// Minimum components without which we can't do anything
assert components.contains(Component.DATA);
assert components.contains(Component.PRIMARY_INDEX);
long start = System.currentTimeMillis();
logger.info("Opening {} ({} bytes)", descriptor, new File(descriptor.filenameFor(COMPONENT_DATA)).length());
SSTableMetadata sstableMetadata = components.contains(Component.STATS)
? SSTableMetadata.serializer.deserialize(descriptor)
: SSTableMetadata.createDefaultInstance();
// 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 (sstableMetadata.partitioner != null && !partitionerName.equals(sstableMetadata.partitioner))
{
logger.error(String.format("Cannot open %s because partitioner does not match %s != %s. Please verify your partitioner in cassandra.yaml",
descriptor, sstableMetadata.partitioner, partitionerName));
System.exit(1);
}
SSTableReader sstable = new SSTableReader(descriptor,
components,
metadata,
partitioner,
null,
null,
null,
null,
System.currentTimeMillis(),
sstableMetadata);
// versions before 'c' encoded keys as utf-16 before hashing to the filter
if (descriptor.version.hasStringsInBloomFilter)
{
sstable.load(true);
}
else
{
sstable.load(false);
sstable.loadBloomFilter();
}
if (validate)
sstable.validate();
if (logger.isDebugEnabled())
logger.debug("INDEX LOAD TIME for " + descriptor + ": " + (System.currentTimeMillis() - start) + " ms.");
if (logger.isDebugEnabled() && sstable.getKeyCache() != null)
logger.debug(String.format("key cache contains %s/%s keys", sstable.getKeyCache().size(), sstable.getKeyCache().getCapacity()));
return sstable;
}
public static void logOpenException(Descriptor descriptor, IOException e)
{
if (e instanceof FileNotFoundException)
logger.error("Missing sstable component in " + descriptor + "; skipped because of " + e.getMessage());
else
logger.error("Corrupt sstable " + descriptor + "; skipped", e);
}
public static Collection<SSTableReader> batchOpen(Set<Map.Entry<Descriptor, Set<Component>>> entries,
final CFMetaData metadata,
final IPartitioner partitioner)
{
final Collection<SSTableReader> sstables = new LinkedBlockingQueue<SSTableReader>();
ExecutorService executor = DebuggableThreadPoolExecutor.createWithFixedPoolSize("SSTableBatchOpen", Runtime.getRuntime().availableProcessors());
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 (IOException ex)
{
logger.error("Corrupt sstable " + entry + "; skipped", 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).
*/
static SSTableReader internalOpen(Descriptor desc,
Set<Component> components,
CFMetaData metadata,
IPartitioner partitioner,
SegmentedFile ifile,
SegmentedFile dfile,
IndexSummary isummary,
IFilter bf,
long maxDataAge,
SSTableMetadata sstableMetadata)
{
assert desc != null && partitioner != null && ifile != null && dfile != null && isummary != null && bf != null && sstableMetadata != null;
return new SSTableReader(desc,
components,
metadata,
partitioner,
ifile, dfile,
isummary,
bf,
maxDataAge,
sstableMetadata);
}
private SSTableReader(Descriptor desc,
Set<Component> components,
CFMetaData metadata,
IPartitioner partitioner,
SegmentedFile ifile,
SegmentedFile dfile,
IndexSummary indexSummary,
IFilter bloomFilter,
long maxDataAge,
SSTableMetadata sstableMetadata)
{
super(desc, components, metadata, partitioner);
this.sstableMetadata = sstableMetadata;
this.maxDataAge = maxDataAge;
this.ifile = ifile;
this.dfile = dfile;
this.indexSummary = indexSummary;
this.bf = bloomFilter;
this.deletingTask = new SSTableDeletingTask(this);
}
public void setTrackedBy(DataTracker tracker)
{
deletingTask.setTracker(tracker);
// 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;
}
void loadBloomFilter() throws IOException
{
if (!components.contains(Component.FILTER))
{
bf = new AlwaysPresentFilter();
return;
}
DataInputStream stream = null;
try
{
stream = new DataInputStream(new BufferedInputStream(new FileInputStream(descriptor.filenameFor(Component.FILTER))));
bf = FilterFactory.deserialize(stream, descriptor.version.filterType, true);
}
finally
{
FileUtils.closeQuietly(stream);
}
}
/**
* Loads ifile, dfile and indexSummary, and optionally recreates the bloom filter.
*/
private void load(boolean recreatebloom) throws IOException
{
SegmentedFile.Builder ibuilder = SegmentedFile.getBuilder(DatabaseDescriptor.getIndexAccessMode());
SegmentedFile.Builder dbuilder = compression
? SegmentedFile.getCompressedBuilder()
: SegmentedFile.getBuilder(DatabaseDescriptor.getDiskAccessMode());
// 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)), true);
// try to load summaries from the disk and check if we need
// to read primary index because we should re-create a BloomFilter or pre-load KeyCache
final boolean summaryLoaded = loadSummary(this, ibuilder, dbuilder);
final boolean readIndex = recreatebloom || !summaryLoaded;
try
{
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 (recreatebloom)
bf = LegacyBloomFilter.getFilter(estimatedKeys, 15);
if (!summaryLoaded)
indexSummary = new IndexSummary(estimatedKeys);
long indexPosition;
while (readIndex && (indexPosition = primaryIndex.getFilePointer()) != indexSize)
{
ByteBuffer key = ByteBufferUtil.readWithShortLength(primaryIndex);
RowIndexEntry indexEntry = RowIndexEntry.serializer.deserialize(primaryIndex, descriptor.version);
DecoratedKey decoratedKey = decodeKey(partitioner, descriptor, key);
if (first == null)
first = decoratedKey;
last = decoratedKey;
if (recreatebloom)
bf.add(decoratedKey.key);
// if summary was already read from disk we don't want to re-populate it using primary index
if (!summaryLoaded)
{
indexSummary.maybeAddEntry(decoratedKey, indexPosition);
ibuilder.addPotentialBoundary(indexPosition);
dbuilder.addPotentialBoundary(indexEntry.position);
}
}
}
finally
{
FileUtils.closeQuietly(primaryIndex);
}
first = getMinimalKey(first);
last = getMinimalKey(last);
// finalize the load.
indexSummary.complete();
// finalize the state of the reader
ifile = ibuilder.complete(descriptor.filenameFor(Component.PRIMARY_INDEX));
dfile = dbuilder.complete(descriptor.filenameFor(Component.DATA));
if (readIndex) // save summary information to disk
saveSummary(this, ibuilder, dbuilder);
}
public static boolean loadSummary(SSTableReader reader, SegmentedFile.Builder ibuilder, SegmentedFile.Builder dbuilder)
{
File summariesFile = new File(reader.descriptor.filenameFor(Component.SUMMARY));
if (!summariesFile.exists())
return false;
DataInputStream iStream = null;
try
{
iStream = new DataInputStream(new FileInputStream(summariesFile));
reader.indexSummary = IndexSummary.serializer.deserialize(iStream, reader.partitioner);
reader.first = decodeKey(reader.partitioner, reader.descriptor, ByteBufferUtil.readWithLength(iStream));
reader.last = decodeKey(reader.partitioner, reader.descriptor, ByteBufferUtil.readWithLength(iStream));
ibuilder.deserializeBounds(iStream);
dbuilder.deserializeBounds(iStream);
}
catch (IOException e)
{
logger.debug("Cannot deserialize SSTable Summary: ", e);
// corrupted hence delete it and let it load it now.
if (summariesFile.exists())
summariesFile.delete();
return false;
}
finally
{
FileUtils.closeQuietly(iStream);
}
return true;
}
public static void saveSummary(SSTableReader reader, SegmentedFile.Builder ibuilder, SegmentedFile.Builder dbuilder)
{
File summariesFile = new File(reader.descriptor.filenameFor(Component.SUMMARY));
if (summariesFile.exists())
summariesFile.delete();
DataOutputStream oStream = null;
try
{
oStream = new DataOutputStream(new FileOutputStream(summariesFile));
IndexSummary.serializer.serialize(reader.indexSummary, oStream);
ByteBufferUtil.writeWithLength(reader.first.key, oStream);
ByteBufferUtil.writeWithLength(reader.last.key, 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())
summariesFile.delete();
}
finally
{
FileUtils.closeQuietly(oStream);
}
}
private void validate()
{
if (this.first.compareTo(this.last) > 0)
throw new IllegalStateException(String.format("SSTable first key %s > last key %s", this.first, this.last));
}
/** get the position in the index file to start scanning to find the given key (at most indexInterval keys away) */
public long getIndexScanPosition(RowPosition key)
{
assert indexSummary.getKeys() != null && indexSummary.getKeys().size() > 0;
int index = Collections.binarySearch(indexSummary.getKeys(), key);
if (index < 0)
{
// binary search gives us the first index _greater_ than the key searched for,
// i.e., its insertion position
int greaterThan = (index + 1) * -1;
if (greaterThan == 0)
return -1;
return indexSummary.getPosition(greaterThan - 1);
}
else
{
return indexSummary.getPosition(index);
}
}
/**
* 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");
return ((CompressedSegmentedFile)dfile).metadata;
}
/**
* For testing purposes only.
*/
public void forceFilterFailures()
{
bf = LegacyBloomFilter.alwaysMatchingBloomFilter();
}
public IFilter getBloomFilter()
{
return bf;
}
public long getBloomFilterSerializedSize()
{
return FilterFactory.serializedSize(bf, descriptor.version.filterType);
}
/**
* @return An estimate of the number of keys in this SSTable.
*/
public long estimatedKeys()
{
return indexSummary.getKeys().size() * DatabaseDescriptor.getIndexInterval();
}
/**
* @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.getKeys(), ranges);
for (Pair<Integer, Integer> sampleIndexRange : sampleIndexes)
sampleKeyCount += (sampleIndexRange.right - sampleIndexRange.left + 1);
return Math.max(1, sampleKeyCount * DatabaseDescriptor.getIndexInterval());
}
/**
* @return Approximately 1/INDEX_INTERVALth of the keys in this SSTable.
*/
public Collection<DecoratedKey> getKeySamples()
{
return indexSummary.getKeys();
}
private static List<Pair<Integer,Integer>> getSampleIndexesForRanges(List<DecoratedKey> samples, Collection<Range<Token>> ranges)
{
// use the index to determine a minimal section for each range
List<Pair<Integer,Integer>> positions = new ArrayList<Pair<Integer,Integer>>();
if (samples.isEmpty())
return positions;
for (Range<Token> range : Range.normalize(ranges))
{
RowPosition leftPosition = range.left.maxKeyBound();
RowPosition rightPosition = range.right.maxKeyBound();
int left = Collections.binarySearch(samples, leftPosition);
if (left < 0)
left = (left + 1) * -1;
else
// left range are start exclusive
left = left + 1;
if (left == samples.size())
// left is past the end of the sampling
continue;
int right = Range.isWrapAround(range.left, range.right)
? samples.size() - 1
: Collections.binarySearch(samples, 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(Integer.valueOf(left), Integer.valueOf(right)));
}
return positions;
}
public Iterable<DecoratedKey> getKeySamples(final Range<Token> range)
{
final List<DecoratedKey> samples = indexSummary.getKeys();
final List<Pair<Integer, Integer>> indexRanges = getSampleIndexesForRanges(samples, 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()
{
RowPosition k = samples.get(idx++);
// the index should only contain valid row key, we only allow RowPosition in KeyPosition for search purposes
assert k instanceof DecoratedKey;
return (DecoratedKey)k;
}
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<Pair<Long,Long>>();
for (Range<Token> range : Range.normalize(ranges))
{
AbstractBounds<RowPosition> keyRange = range.toRowBounds();
RowIndexEntry idxLeft = getPosition(keyRange.left, Operator.GT);
long left = idxLeft == null ? -1 : idxLeft.position;
if (left == -1)
// left is past the end of the file
continue;
RowIndexEntry idxRight = getPosition(keyRange.right, Operator.GT);
long right = idxRight == null ? -1 : idxRight.position;
if (right == -1 || Range.isWrapAround(range.left, range.right))
// right is past the end of the file, or it wraps
right = uncompressedLength();
if (left == right)
// empty range
continue;
positions.add(Pair.create(Long.valueOf(left), Long.valueOf(right)));
}
return positions;
}
public void cacheKey(DecoratedKey key, RowIndexEntry info)
{
CFMetaData.Caching caching = metadata.getCaching();
if (caching == CFMetaData.Caching.NONE
|| caching == CFMetaData.Caching.ROWS_ONLY
|| keyCache == null
|| keyCache.getCapacity() == 0)
{
return;
}
KeyCacheKey cacheKey = new KeyCacheKey(descriptor, key.key);
logger.trace("Adding cache entry for {} -> {}", cacheKey, info);
keyCache.put(cacheKey, info);
}
public RowIndexEntry getCachedPosition(DecoratedKey key, boolean updateStats)
{
return getCachedPosition(new KeyCacheKey(descriptor, key.key), updateStats);
}
private RowIndexEntry getCachedPosition(KeyCacheKey unifiedKey, boolean updateStats)
{
if (keyCache != null && keyCache.getCapacity() > 0)
return updateStats ? keyCache.get(unifiedKey) : keyCache.getInternal(unifiedKey);
return null;
}
/**
* Get position updating key cache and stats.
* @see #getPosition(org.apache.cassandra.db.RowPosition, org.apache.cassandra.io.sstable.SSTableReader.Operator, boolean)
*/
public RowIndexEntry getPosition(RowPosition key, Operator op)
{
return getPosition(key, op, true);
}
/**
* @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
*/
public RowIndexEntry getPosition(RowPosition key, Operator op, boolean updateCacheAndStats)
{
// first, check bloom filter
if (op == Operator.EQ)
{
assert key instanceof DecoratedKey; // EQ only make sense if the key is a valid row key
if (!bf.isPresent(((DecoratedKey)key).key))
{
logger.debug("Bloom filter allows skipping sstable {}", descriptor.generation);
return null;
}
}
// next, the key cache (only make sense for valid row key)
if ((op == Operator.EQ || op == Operator.GE) && (key instanceof DecoratedKey))
{
DecoratedKey decoratedKey = (DecoratedKey)key;
KeyCacheKey cacheKey = new KeyCacheKey(descriptor, decoratedKey.key);
RowIndexEntry cachedPosition = getCachedPosition(cacheKey, updateCacheAndStats);
if (cachedPosition != null)
{
logger.trace("Cache hit for {} -> {}", cacheKey, cachedPosition);
logger.debug("Key cache hit for sstable {}", descriptor.generation);
return cachedPosition;
}
}
// next, see if the sampled index says it's impossible for the key to be present
long sampledPosition = getIndexScanPosition(key);
if (sampledPosition == -1)
{
if (op == Operator.EQ && updateCacheAndStats)
bloomFilterTracker.addFalsePositive();
// we matched the -1th position: if the operator might match forward, we'll start at the first
// position. We however need to return the correct index entry for that first position.
if (op.apply(1) >= 0)
{
sampledPosition = 0;
}
else
{
logger.debug("Index sample allows skipping sstable {}", descriptor.generation);
return null;
}
}
// scan the on-disk index, starting at the nearest sampled position.
// The check against IndexInterval is to be exit the loop in the EQ case when the key looked for is not present
// (bloom filter false positive). But note that for non-EQ cases, we might need to check the first key of the
// next index position because the searched key can be greater the last key of the index interval checked if it
// is lesser than the first key of next interval (and in that case we must return the position of the first key
// of the next interval).
int i = 0;
Iterator<FileDataInput> segments = ifile.iterator(sampledPosition, INDEX_FILE_BUFFER_BYTES);
while (segments.hasNext() && i <= DatabaseDescriptor.getIndexInterval())
{
FileDataInput in = segments.next();
try
{
while (!in.isEOF() && i <= DatabaseDescriptor.getIndexInterval())
{
i++;
ByteBuffer indexKey = ByteBufferUtil.readWithShortLength(in);
boolean opSatisfied; // did we find an appropriate position for the op requested
boolean exactMatch; // is the current position an exact match for the key, suitable for caching
// Compare raw keys if possible for performance, otherwise compare decorated keys.
if (op == Operator.EQ)
{
opSatisfied = exactMatch = indexKey.equals(((DecoratedKey) key).key);
}
else
{
DecoratedKey indexDecoratedKey = decodeKey(partitioner, descriptor, indexKey);
int comparison = indexDecoratedKey.compareTo(key);
int v = op.apply(comparison);
opSatisfied = (v == 0);
exactMatch = (comparison == 0);
if (v < 0)
{
logger.debug("Partition index lookup allows skipping sstable {}", descriptor.generation);
return null;
}
}
if (opSatisfied)
{
// read data position from index entry
RowIndexEntry indexEntry = RowIndexEntry.serializer.deserialize(in, descriptor.version);
if (exactMatch && updateCacheAndStats)
{
assert key instanceof DecoratedKey; // key can be == to the index key only if it's a true row key
DecoratedKey decoratedKey = (DecoratedKey)key;
if (logger.isTraceEnabled())
{
// expensive sanity check! see CASSANDRA-4687
FileDataInput fdi = dfile.getSegment(indexEntry.position);
DecoratedKey keyInDisk = SSTableReader.decodeKey(partitioner, descriptor, ByteBufferUtil.readWithShortLength(fdi));
if (!keyInDisk.equals(key))
throw new AssertionError(String.format("%s != %s in %s", keyInDisk, key, fdi.getPath()));
fdi.close();
}
// store exact match for the key
cacheKey(decoratedKey, indexEntry);
}
if (op == Operator.EQ && updateCacheAndStats)
bloomFilterTracker.addTruePositive();
logger.debug("Partition index lookup complete for sstable {}", descriptor.generation);
return indexEntry;
}
RowIndexEntry.serializer.skip(in, descriptor.version);
}
}
catch (IOException e)
{
markSuspect();
throw new CorruptSSTableException(e, in.getPath());
}
finally
{
FileUtils.closeQuietly(in);
}
}
if (op == Operator.EQ && updateCacheAndStats)
bloomFilterTracker.addFalsePositive();
logger.debug("Partition index lookup complete (bloom filter false positive) {}", descriptor.generation);
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;
}
public boolean acquireReference()
{
while (true)
{
int n = references.get();
if (n <= 0)
return false;
if (references.compareAndSet(n, n + 1))
return true;
}
}
public void releaseReference()
{
if (references.decrementAndGet() == 0 && isCompacted.get())
{
// Force finalizing mmapping if necessary
ifile.cleanup();
dfile.cleanup();
deletingTask.schedule();
// close the BF so it can be opened later.
FileUtils.closeQuietly(bf);
}
assert references.get() >= 0 : "Reference counter " + references.get() + " for " + dfile.path;
}
/**
* Mark the sstable as compacted.
* 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 compacted. With rare exceptions
* (see DataTracker.unmarkCompacted) calling this multiple times would be buggy.
*/
public boolean markCompacted()
{
if (logger.isDebugEnabled())
logger.debug("Marking " + getFilename() + " compacted");
return !isCompacted.getAndSet(true);
}
public void markSuspect()
{
if (logger.isDebugEnabled())
logger.debug("Marking " + getFilename() + " as a suspect for blacklisting.");
isSuspect.getAndSet(true);
}
public boolean isMarkedSuspect()
{
return isSuspect.get();
}
/**
*
* @param filter filter to use when reading the columns
* @return A Scanner for seeking over the rows of the SSTable.
*/
public SSTableScanner getScanner(QueryFilter filter)
{
return new SSTableScanner(this, filter);
}
/**
* Direct I/O SSTableScanner
* @return A Scanner for seeking over the rows of the SSTable.
*/
public SSTableScanner getDirectScanner()
{
return new SSTableScanner(this, true);
}
/**
* 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 SSTableScanner getDirectScanner(Range<Token> range)
{
if (range == null)
return getDirectScanner();
return new SSTableBoundedScanner(this, true, range);
}
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 static long readRowSize(DataInput in, Descriptor d) throws IOException
{
if (d.version.hasIntRowSize)
return in.readInt();
return in.readLong();
}
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);
}
}
/**
* Conditionally use the deprecated 'IPartitioner.convertFromDiskFormat' method.
*/
public static DecoratedKey decodeKey(IPartitioner p, Descriptor d, ByteBuffer bytes)
{
if (d.version.hasEncodedKeys)
return p.convertFromDiskFormat(bytes);
return p.decorateKey(bytes);
}
public DecoratedKey decodeKey(ByteBuffer bytes)
{
return decodeKey(partitioner, descriptor, bytes);
}
/**
* 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 : -comparison; }
}
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 getCompressionRatio()
{
return sstableMetadata.compressionRatio;
}
public ReplayPosition getReplayPosition()
{
return sstableMetadata.replayPosition;
}
public long getMaxTimestamp()
{
return sstableMetadata.maxTimestamp;
}
public Set<Integer> getAncestors()
{
return sstableMetadata.ancestors;
}
public RandomAccessReader openDataReader(boolean skipIOCache)
{
return compression
? CompressedRandomAccessReader.open(getFilename(), getCompressionMetadata(), skipIOCache)
: RandomAccessReader.open(new File(getFilename()), skipIOCache);
}
public RandomAccessReader openIndexReader(boolean skipIOCache)
{
return RandomAccessReader.open(new File(getIndexFilename()), skipIOCache);
}
/**
* @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();
}
/**
* @param sstables
* @return true if all desired references were acquired. Otherwise, it will unreference any partial acquisition, and return false.
*/
public static boolean acquireReferences(Iterable<SSTableReader> sstables)
{
SSTableReader failed = null;
for (SSTableReader sstable : sstables)
{
if (!sstable.acquireReference())
{
failed = sstable;
break;
}
}
if (failed == null)
return true;
for (SSTableReader sstable : sstables)
{
if (sstable == failed)
break;
sstable.releaseReference();
}
return false;
}
public static void releaseReferences(Iterable<SSTableReader> sstables)
{
for (SSTableReader sstable : sstables)
{
sstable.releaseReference();
}
}
}