org.apache.hadoop.hbase.io.hfile

Class HFileReaderV2.EncodedScannerV2

java.lang.Object

org.apache.hadoop.hbase.io.hfile.AbstractHFileReader.Scanner

org.apache.hadoop.hbase.io.hfile.HFileReaderV2.AbstractScannerV2

org.apache.hadoop.hbase.io.hfile.HFileReaderV2.EncodedScannerV2

All Implemented Interfaces:

HFileScanner

Direct Known Subclasses:

HFileReaderV3.EncodedScannerV3

Enclosing class:

HFileReaderV2

protected static class HFileReaderV2.EncodedScannerV2
extends HFileReaderV2.AbstractScannerV2

ScannerV2 that operates on encoded data blocks.

Field Summary

Fields

Modifier and Type	Field and Description
protected HFileContext	meta

Fields inherited from class org.apache.hadoop.hbase.io.hfile.HFileReaderV2.AbstractScannerV2

block, nextIndexedKey

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

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

Constructor Summary

Constructors

Constructor and Description
HFileReaderV2.EncodedScannerV2(HFileReaderV2 reader, boolean cacheBlocks, boolean pread, boolean isCompaction, HFileContext meta)

Method Summary

Methods

Modifier and Type	Method and Description
int	compareKey(KeyValue.KVComparator comparator, byte[] key, int offset, int length) Compare the given key against the current key
protected ByteBuffer	getFirstKeyInBlock(HFileBlock curBlock)
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.
boolean	isSeeked()
protected int	loadBlockAndSeekToKey(HFileBlock seekToBlock, byte[] nextIndexedKey, boolean rewind, byte[] key, int offset, int length, boolean seekBefore)
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.HFileReaderV2.AbstractScannerV2

readNextDataBlock, reseekTo, seekBefore, seekTo, seekTo

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

assertSeeked, getReader, reseekTo, seekBefore, seekTo, toString

Methods inherited from class java.lang.Object

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

Field Detail

meta

protected final HFileContext meta

Constructor Detail

HFileReaderV2.EncodedScannerV2

public HFileReaderV2.EncodedScannerV2(HFileReaderV2 reader,
                              boolean cacheBlocks,
                              boolean pread,
                              boolean isCompaction,
                              HFileContext meta)

Method Detail

isSeeked

public boolean isSeeked()

Specified by:

isSeeked in interface HFileScanner

Overrides:

isSeeked in class AbstractHFileReader.Scanner

Returns:

True is scanner has had one of the seek calls invoked; i.e. HFileScanner.seekBefore(byte[]) or HFileScanner.seekTo() or HFileScanner.seekTo(byte[]). Otherwise returns false.

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

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

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.

compareKey

public int compareKey(KeyValue.KVComparator comparator,
             byte[] key,
             int offset,
             int length)

Description copied from class: HFileReaderV2.AbstractScannerV2

Compare the given key against the current key

Specified by:

compareKey in class HFileReaderV2.AbstractScannerV2

Returns:

-1 is the passed key is smaller than the current key, 0 if equal and 1 if greater

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.

getKeyValue

public KeyValue getKeyValue()

Returns:

Instance of KeyValue.

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

getFirstKeyInBlock

protected ByteBuffer getFirstKeyInBlock(HFileBlock curBlock)

Specified by:

getFirstKeyInBlock in class HFileReaderV2.AbstractScannerV2

loadBlockAndSeekToKey

protected int loadBlockAndSeekToKey(HFileBlock seekToBlock,
                        byte[] nextIndexedKey,
                        boolean rewind,
                        byte[] key,
                        int offset,
                        int length,
                        boolean seekBefore)
                             throws IOException

Specified by:

loadBlockAndSeekToKey in class HFileReaderV2.AbstractScannerV2

Throws:

IOException