org.apache.hadoop.hbase.io

Class HalfStoreFileReader

java.lang.Object

org.apache.hadoop.hbase.regionserver.StoreFileReader

org.apache.hadoop.hbase.io.HalfStoreFileReader

@InterfaceAudience.Private
public class HalfStoreFileReader
extends StoreFileReader

A facade for a HFile.Reader that serves up either the top or bottom half of a HFile where 'bottom' is the first half of the file containing the keys that sort lowest and 'top' is the second half of the file with keys that sort greater than those of the bottom half. The top includes the split files midkey, of the key that follows if it does not exist in the file.

This type works in tandem with the Reference type. This class is used reading while Reference is used writing.

This file is not splitable. Calls to midKey() return null.

Field Summary

Fields

Modifier and Type	Field and Description
private Optional<Cell>	firstKey
private boolean	firstKeySeeked
private static org.slf4j.Logger	LOG
private Cell	splitCell
protected byte[]	splitkey
(package private) boolean	top

Fields inherited from class org.apache.hadoop.hbase.regionserver.StoreFileReader

bloomFilterType, deleteFamilyBloomFilter, generalBloomFilter, sequenceID, timeRange

Constructor Summary

Constructors

Constructor and Description
HalfStoreFileReader(ReaderContext context, HFileInfo fileInfo, CacheConfig cacheConf, Reference r, AtomicInteger refCount, org.apache.hadoop.conf.Configuration conf) Creates a half file reader for a hfile referred to by an hfilelink.

Method Summary

Modifier and Type	Method and Description
long	getEntries()
long	getFilterEntries() The number of Bloom filter entries in this store file, or an estimate thereof, if the Bloom filter is not loaded.
Optional<Cell>	getFirstKey()
Optional<Cell>	getLastKey()
HFileScanner	getScanner(boolean cacheBlocks, boolean pread, boolean isCompaction)
protected boolean	isTop()
Optional<Cell>	midKey()
boolean	passesKeyRangeFilter(Scan scan) Checks whether the given scan rowkey range overlaps with the current storefile's

Methods inherited from class org.apache.hadoop.hbase.regionserver.StoreFileReader

close, getBloomFilterType, getComparator, getDeleteFamilyCnt, getHFileMinorVersion, getHFileReader, getHFileVersion, getLastRowKey, getMaxTimestamp, getPrefixLength, getReaderContext, getScanner, getSequenceID, getStoreFileScanner, getTotalBloomSize, getTotalUncompressedBytes, indexSize, isBulkLoaded, isPrimaryReplicaReader, length, loadBloomfilter, loadBloomfilter, loadFileInfo, passesDeleteFamilyBloomFilter, passesGeneralRowColBloomFilter, setBulkLoaded, setDeleteFamilyBloomFilterFaulty, setGeneralBloomFilterFaulty, setSequenceID

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

private static final org.slf4j.Logger LOG

top

final boolean top

splitkey

protected final byte[] splitkey

splitCell

private final Cell splitCell

firstKey

private Optional<Cell> firstKey

firstKeySeeked

private boolean firstKeySeeked

Constructor Detail

HalfStoreFileReader

public HalfStoreFileReader(ReaderContext context,
                           HFileInfo fileInfo,
                           CacheConfig cacheConf,
                           Reference r,
                           AtomicInteger refCount,
                           org.apache.hadoop.conf.Configuration conf)
                    throws IOException

Creates a half file reader for a hfile referred to by an hfilelink.

Parameters:

context - Reader context info

fileInfo - HFile info

cacheConf - CacheConfig

r - original reference file (contains top or bottom)

refCount - reference count

conf - Configuration

Throws:

IOException

Method Detail

isTop

protected boolean isTop()

getScanner

public HFileScanner getScanner(boolean cacheBlocks,
                               boolean pread,
                               boolean isCompaction)

Overrides:

getScanner in class StoreFileReader

Parameters:

cacheBlocks - should we cache the blocks?

pread - use pread (for concurrent small readers)

isCompaction - is scanner being used for compaction?

Returns:

the underlying HFileScanner

See Also:

HBASE-15296

passesKeyRangeFilter

public boolean passesKeyRangeFilter(Scan scan)

Description copied from class: StoreFileReader

Checks whether the given scan rowkey range overlaps with the current storefile's

Overrides:

passesKeyRangeFilter in class StoreFileReader

Parameters:

scan - the scan specification. Used to determine the rowkey range.

Returns:

true if there is overlap, false otherwise

getLastKey

public Optional<Cell> getLastKey()

Overrides:

getLastKey in class StoreFileReader

midKey

public Optional<Cell> midKey()
                      throws IOException

Overrides:

midKey in class StoreFileReader

Throws:

IOException

getFirstKey

public Optional<Cell> getFirstKey()

Overrides:

getFirstKey in class StoreFileReader

getEntries

public long getEntries()

Overrides:

getEntries in class StoreFileReader

getFilterEntries

public long getFilterEntries()

Description copied from class: StoreFileReader

The number of Bloom filter entries in this store file, or an estimate thereof, if the Bloom filter is not loaded. This always returns an upper bound of the number of Bloom filter entries.

Overrides:

getFilterEntries in class StoreFileReader

Returns:

an estimate of the number of Bloom filter entries in this file