org.apache.hadoop.hbase.io

类 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.

字段概要

字段

限定符和类型	字段和说明
protected Cell	splitCell
protected byte[]	splitkey

从类继承的字段 org.apache.hadoop.hbase.regionserver.StoreFile.Reader

bloomFilterType, deleteFamilyBloomFilter, generalBloomFilter, sequenceID, timeRange

构造器概要

构造器

构造器和说明
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.

方法概要

方法

限定符和类型	方法和说明
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)
protected boolean	isTop()
byte[]	midkey()
boolean	passesKeyRangeFilter(Scan scan) Checks whether the given scan rowkey range overlaps with the current storefile's

从类继承的方法 org.apache.hadoop.hbase.regionserver.StoreFile.Reader

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

从类继承的方法 java.lang.Object

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

字段详细资料

splitkey

protected final byte[] splitkey

splitCell

protected final Cell splitCell

构造器详细资料

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.

参数:

fs - fileystem to read from

p - path to hfile

cacheConf -

r - original reference file (contains top or bottom)

conf - Configuration

抛出:

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.

参数:

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

抛出:

IOException

方法详细资料

isTop

protected boolean isTop()

getScanner

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

覆盖:

getScanner 在类中 StoreFile.Reader

参数:

cacheBlocks - should we cache the blocks?

pread - use pread (for concurrent small readers)

isCompaction - is scanner being used for compaction?

返回:

the underlying HFileScanner

passesKeyRangeFilter

public boolean passesKeyRangeFilter(Scan scan)

从类复制的说明: StoreFile.Reader

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

覆盖:

passesKeyRangeFilter 在类中 StoreFile.Reader

参数:

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

返回:

true if there is overlap, false otherwise

getLastKey

public byte[] getLastKey()

覆盖:

getLastKey 在类中 StoreFile.Reader

midkey

public byte[] midkey()
              throws IOException

覆盖:

midkey 在类中 StoreFile.Reader

抛出:

IOException

getFirstKey

public byte[] getFirstKey()

覆盖:

getFirstKey 在类中 StoreFile.Reader

getEntries

public long getEntries()

覆盖:

getEntries 在类中 StoreFile.Reader

getFilterEntries

public long getFilterEntries()

从类复制的说明: 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.

覆盖:

getFilterEntries 在类中 StoreFile.Reader

返回:

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