org.apache.hadoop.hbase.io

Class HalfStoreFileReader

java.lang.Object

org.apache.hadoop.hbase.regionserver.StoreFile.Reader

org.apache.hadoop.hbase.io.HalfStoreFileReader

@InterfaceAudience.Private
public class HalfStoreFileReader
extends StoreFile.Reader

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
protected Cell	splitCell
protected byte[]	splitkey

Fields inherited from class org.apache.hadoop.hbase.regionserver.StoreFile.Reader

bloomFilterType, deleteFamilyBloomFilter, generalBloomFilter, sequenceID, timeRangeTracker

Constructor Summary

Constructors

Constructor and Description
HalfStoreFileReader(org.apache.hadoop.fs.FileSystem fs, org.apache.hadoop.fs.Path p, CacheConfig cacheConf, Reference r, org.apache.hadoop.conf.Configuration conf) Creates a half file reader for a normal hfile.
HalfStoreFileReader(org.apache.hadoop.fs.FileSystem fs, org.apache.hadoop.fs.Path p, FSDataInputStreamWrapper in, long size, CacheConfig cacheConf, Reference r, org.apache.hadoop.conf.Configuration conf) Creates a half file reader for a hfile referred to by an hfilelink.

Method Summary

Methods

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.
byte[]	getFirstKey()
byte[]	getLastKey()
HFileScanner	getScanner(boolean cacheBlocks, boolean pread, boolean isCompaction) Warning: Do not write further code which depends on this call.
protected boolean	isTop()
byte[]	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.StoreFile.Reader

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

Methods inherited from class java.lang.Object

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

Field Detail

splitkey

protected final byte[] splitkey

splitCell

protected final Cell splitCell

Constructor Detail

HalfStoreFileReader

public HalfStoreFileReader(org.apache.hadoop.fs.FileSystem fs,
                   org.apache.hadoop.fs.Path p,
                   CacheConfig cacheConf,
                   Reference r,
                   org.apache.hadoop.conf.Configuration conf)
                    throws IOException

Creates a half file reader for a normal hfile.

Parameters:

fs - fileystem to read from

p - path to hfile

cacheConf -

r - original reference file (contains top or bottom)

conf - Configuration

Throws:

IOException

HalfStoreFileReader

public HalfStoreFileReader(org.apache.hadoop.fs.FileSystem fs,
                   org.apache.hadoop.fs.Path p,
                   FSDataInputStreamWrapper in,
                   long size,
                   CacheConfig cacheConf,
                   Reference r,
                   org.apache.hadoop.conf.Configuration conf)
                    throws IOException

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

Parameters:

fs - fileystem to read from

p - path to hfile

in - FSDataInputStreamWrapper

size - Full size of the hfile file

cacheConf -

r - original reference file (contains top or bottom)

conf - Configuration

Throws:

IOException

Method Detail

isTop

protected boolean isTop()

getScanner

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

Description copied from class: StoreFile.Reader

Warning: Do not write further code which depends on this call. Instead use getStoreFileScanner() which uses the StoreFileScanner class/interface which is the preferred way to scan a store with higher level concepts.

Overrides:

getScanner in class StoreFile.Reader

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

passesKeyRangeFilter

public boolean passesKeyRangeFilter(Scan scan)

Description copied from class: StoreFile.Reader

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

Overrides:

passesKeyRangeFilter in class StoreFile.Reader

Parameters:

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

Returns:

true if there is overlap, false otherwise

getLastKey

public byte[] getLastKey()

Overrides:

getLastKey in class StoreFile.Reader

midkey

public byte[] midkey()
              throws IOException

Overrides:

midkey in class StoreFile.Reader

Throws:

IOException

getFirstKey

public byte[] getFirstKey()

Overrides:

getFirstKey in class StoreFile.Reader

getEntries

public long getEntries()

Overrides:

getEntries in class StoreFile.Reader

getFilterEntries

public long getFilterEntries()

Description copied from class: StoreFile.Reader

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 StoreFile.Reader

Returns:

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