org.apache.hadoop.hbase.io
Class HalfStoreFileReader

java.lang.Object
  extended by org.apache.hadoop.hbase.regionserver.StoreFile.Reader
      extended by org.apache.hadoop.hbase.io.HalfStoreFileReader

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
protected  byte[] splitkey
           
 
Fields inherited from class org.apache.hadoop.hbase.regionserver.StoreFile.Reader
bloomFilter, bloomFilterType, sequenceID, timeRangeTracker
 
Constructor Summary
HalfStoreFileReader(org.apache.hadoop.fs.FileSystem fs, org.apache.hadoop.fs.Path p, BlockCache c, Reference r)
           
 
Method Summary
 byte[] getLastKey()
           
 HFileScanner getScanner(boolean cacheBlocks, boolean pread)
          Warning: Do not write further code which depends on this call.
protected  boolean isTop()
           
 byte[] midkey()
           
 
Methods inherited from class org.apache.hadoop.hbase.regionserver.StoreFile.Reader
close, getBloomFilterType, getComparator, getEntries, getFilterEntries, getFirstKey, getMetaBlock, getSequenceID, getStoreFileScanner, indexSize, length, loadBloomfilter, loadFileInfo, setBloomFilterFaulty, setSequenceID, shouldSeek
 
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
Constructor Detail

HalfStoreFileReader

public HalfStoreFileReader(org.apache.hadoop.fs.FileSystem fs,
                           org.apache.hadoop.fs.Path p,
                           BlockCache c,
                           Reference r)
                    throws IOException
Parameters:
fs -
p -
c -
r -
Throws:
IOException
Method Detail

isTop

protected boolean isTop()

getScanner

public HFileScanner getScanner(boolean cacheBlocks,
                               boolean pread)
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)
Returns:
the underlying HFileScanner

getLastKey

public byte[] getLastKey()
Overrides:
getLastKey in class StoreFile.Reader

midkey

public byte[] midkey()
              throws IOException
Overrides:
midkey in class StoreFile.Reader
Throws:
IOException


Copyright © 2011 The Apache Software Foundation. All Rights Reserved.