org.apache.hadoop.hbase.io.hfile
Class HFileReaderV1.ScannerV1

java.lang.Object
  org.apache.hadoop.hbase.io.hfile.AbstractHFileReader.Scanner
      org.apache.hadoop.hbase.io.hfile.HFileReaderV1.AbstractScannerV1
          org.apache.hadoop.hbase.io.hfile.HFileReaderV1.ScannerV1

All Implemented Interfaces:

HFileScanner

Enclosing class:

HFileReaderV1

protected static class HFileReaderV1.ScannerV1
extends HFileReaderV1.AbstractScannerV1

Implementation of HFileScanner interface.

Field Summary

Fields inherited from class org.apache.hadoop.hbase.io.hfile.HFileReaderV1.AbstractScannerV1

currBlock

Fields inherited from class org.apache.hadoop.hbase.io.hfile.AbstractHFileReader.Scanner

blockBuffer, blockFetches, cacheBlocks, currKeyLen, currMemstoreTS, currMemstoreTSLen, currValueLen, isCompaction, pread

Constructor Summary

HFileReaderV1.ScannerV1(HFileReaderV1 reader, boolean cacheBlocks, boolean pread, boolean isCompaction)

Method Summary

protected int	blockSeek(byte[] key, int offset, int length, boolean seekBefore) Within a loaded block, seek looking for the first key that is smaller than (or equal to?) the key we are interested in.
ByteBuffer	getKey() Gets a buffer view to the current key.
String	getKeyString() Convenience method to get a copy of the key as a string - interpreting the bytes as UTF8.
KeyValue	getKeyValue()
ByteBuffer	getValue() Gets a buffer view to the current value.
String	getValueString() Convenience method to get a copy of the value as a string - interpreting the bytes as UTF8.
protected void	loadBlock(int bloc, boolean rewind)
boolean	next() Scans to the next entry in the file.
boolean	seekTo() Positions this scanner at the start of the file.

Methods inherited from class org.apache.hadoop.hbase.io.hfile.HFileReaderV1.AbstractScannerV1

reseekTo, seekBefore, seekTo

Methods inherited from class org.apache.hadoop.hbase.io.hfile.AbstractHFileReader.Scanner

assertSeeked, getReader, isSeeked, reseekTo, seekBefore, seekTo, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

HFileReaderV1.ScannerV1

public HFileReaderV1.ScannerV1(HFileReaderV1 reader,
                               boolean cacheBlocks,
                               boolean pread,
                               boolean isCompaction)

Method Detail

getKeyValue

public KeyValue getKeyValue()

Returns:

Instance of KeyValue.

getKey

public ByteBuffer getKey()

Description copied from interface: HFileScanner

Gets a buffer view to the current key. You must call HFileScanner.seekTo(byte[]) before this method.

Returns:

byte buffer for the key. The limit is set to the key size, and the position is 0, the start of the buffer view.

getValue

public ByteBuffer getValue()

Description copied from interface: HFileScanner

Gets a buffer view to the current value. You must call HFileScanner.seekTo(byte[]) before this method.

Returns:

byte buffer for the value. The limit is set to the value size, and the position is 0, the start of the buffer view.

next

public boolean next()
             throws IOException

Description copied from interface: HFileScanner

Scans to the next entry in the file.

Returns:

Returns false if you are at the end otherwise true if more in file.

Throws:

IOException

blockSeek

protected int blockSeek(byte[] key,
                        int offset,
                        int length,
                        boolean seekBefore)

Description copied from class: HFileReaderV1.AbstractScannerV1

Within a loaded block, seek looking for the first key that is smaller than (or equal to?) the key we are interested in. A note on the seekBefore - if you have seekBefore = true, AND the first key in the block = key, then you'll get thrown exceptions.

Specified by:

blockSeek in class HFileReaderV1.AbstractScannerV1

Parameters:

key - to find

seekBefore - find the key before the exact match.

getKeyString

public String getKeyString()

Description copied from interface: HFileScanner

Convenience method to get a copy of the key as a string - interpreting the bytes as UTF8. You must call HFileScanner.seekTo(byte[]) before this method.

Returns:

key as a string

getValueString

public String getValueString()

Description copied from interface: HFileScanner

Convenience method to get a copy of the value as a string - interpreting the bytes as UTF8. You must call HFileScanner.seekTo(byte[]) before this method.

Returns:

value as a string

seekTo

public boolean seekTo()
               throws IOException

Description copied from interface: HFileScanner

Positions this scanner at the start of the file.

Returns:

False if empty file; i.e. a call to next would return false and the current key and value are undefined.

Throws:

IOException

loadBlock

protected void loadBlock(int bloc,
                         boolean rewind)
                  throws IOException

Specified by:

loadBlock in class HFileReaderV1.AbstractScannerV1

Throws:

IOException