org.apache.hadoop.hbase.io.hfile

Class HFileReaderImpl.EncodedScanner

java.lang.Object

org.apache.hadoop.hbase.io.hfile.HFileReaderImpl.HFileScannerImpl

org.apache.hadoop.hbase.io.hfile.HFileReaderImpl.EncodedScanner

All Implemented Interfaces:

Closeable, AutoCloseable, HFileScanner, Shipper

Enclosing class:

HFileReaderImpl

protected static class HFileReaderImpl.EncodedScanner
extends HFileReaderImpl.HFileScannerImpl

Scanner that operates on encoded data blocks.

Field Summary

Fields

Modifier and Type	Field and Description
private DataBlockEncoder	dataBlockEncoder
private HFileBlockDecodingContext	decodingCtx
private DataBlockEncoder.EncodedSeeker	seeker

Fields inherited from class org.apache.hadoop.hbase.io.hfile.HFileReaderImpl.HFileScannerImpl

cacheBlocks, curBlock, isCompaction, nextIndexedKey, pair, pread, prevBlocks, reader

Constructor Summary

Constructors

Constructor and Description
EncodedScanner(HFile.Reader reader, boolean cacheBlocks, boolean pread, boolean isCompaction, HFileContext meta, org.apache.hadoop.conf.Configuration conf)

Method Summary

Modifier and Type	Method and Description
private void	assertValidSeek()
int	compareKey(CellComparator comparator, Cell key)
Cell	getCell() Returns Instance of Cell.
private ByteBuff	getEncodedBuffer(HFileBlock newBlock)
protected Cell	getFirstKeyCellInBlock(HFileBlock curBlock)
Cell	getKey() Gets the current key in the form of a cell.
String	getKeyString() Convenience method to get a copy of the key as a string - interpreting the bytes as UTF8.
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, Cell nextIndexedKey, boolean rewind, Cell key, boolean seekBefore)
boolean	next() Go to the next key/value in the block section.
protected boolean	processFirstDataBlock()
void	setNonSeekedState()
protected void	updateCurrentBlock(HFileBlock newBlock) Updates the current block to be the given HFileBlock.

Methods inherited from class org.apache.hadoop.hbase.io.hfile.HFileReaderImpl.HFileScannerImpl

assertSeeked, blockSeek, checkKeyLen, checkKeyValueLen, checkLen, close, getEffectiveDataBlockEncoding, getNextIndexedKey, getReader, readAndUpdateNewBlock, readKeyValueLen, readMvccVersion, readNextDataBlock, releaseIfNotCurBlock, reseekTo, reset, seekBefore, seekTo, seekTo, seekTo, shipped, toString, updateCurrBlockRef

Methods inherited from class java.lang.Object

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

Field Detail

decodingCtx

private final HFileBlockDecodingContext decodingCtx

seeker

private final DataBlockEncoder.EncodedSeeker seeker

dataBlockEncoder

private final DataBlockEncoder dataBlockEncoder

Constructor Detail

EncodedScanner

public EncodedScanner(HFile.Reader reader,
                      boolean cacheBlocks,
                      boolean pread,
                      boolean isCompaction,
                      HFileContext meta,
                      org.apache.hadoop.conf.Configuration conf)

Method Detail

isSeeked

public boolean isSeeked()

Specified by:

isSeeked in interface HFileScanner

Overrides:

isSeeked in class HFileReaderImpl.HFileScannerImpl

Returns:

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

setNonSeekedState

public void setNonSeekedState()

Overrides:

setNonSeekedState in class HFileReaderImpl.HFileScannerImpl

updateCurrentBlock

protected void updateCurrentBlock(HFileBlock newBlock)
                           throws CorruptHFileException

Updates the current block to be the given HFileBlock. Seeks to the the first key/value pair.

Overrides:

updateCurrentBlock in class HFileReaderImpl.HFileScannerImpl

Parameters:

newBlock - the block to make current, and read by HFileReaderImpl.readBlock(long, long, boolean, boolean, boolean, boolean, org.apache.hadoop.hbase.io.hfile.BlockType, org.apache.hadoop.hbase.io.encoding.DataBlockEncoding), it's a totally new block with new allocated ByteBuff, so if no further reference to this block, we should release it carefully.

Throws:

CorruptHFileException

getEncodedBuffer

private ByteBuff getEncodedBuffer(HFileBlock newBlock)

processFirstDataBlock

protected boolean processFirstDataBlock()
                                 throws IOException

Overrides:

processFirstDataBlock in class HFileReaderImpl.HFileScannerImpl

Throws:

IOException

next

public boolean next()
             throws IOException

Description copied from class: HFileReaderImpl.HFileScannerImpl

Go to the next key/value in the block section. Loads the next block if necessary. If successful, HFileReaderImpl.HFileScannerImpl.getKey() and HFileReaderImpl.HFileScannerImpl.getValue() can be called.

Specified by:

next in interface HFileScanner

Overrides:

next in class HFileReaderImpl.HFileScannerImpl

Returns:

true if successfully navigated to the next key/value

Throws:

IOException

getKey

public Cell getKey()

Description copied from interface: HFileScanner

Gets the current key in the form of a cell. You must call HFileScanner.seekTo(Cell) before this method.

Specified by:

getKey in interface HFileScanner

Overrides:

getKey in class HFileReaderImpl.HFileScannerImpl

Returns:

gets the current key as a Cell.

getValue

public ByteBuffer getValue()

Description copied from interface: HFileScanner

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

Specified by:

getValue in interface HFileScanner

Overrides:

getValue in class HFileReaderImpl.HFileScannerImpl

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.

getCell

public Cell getCell()

Description copied from interface: HFileScanner

Returns Instance of Cell.

Specified by:

getCell in interface HFileScanner

Overrides:

getCell in class HFileReaderImpl.HFileScannerImpl

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(Cell) before this method.

Specified by:

getKeyString in interface HFileScanner

Overrides:

getKeyString in class HFileReaderImpl.HFileScannerImpl

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(Cell) before this method.

Specified by:

getValueString in interface HFileScanner

Overrides:

getValueString in class HFileReaderImpl.HFileScannerImpl

Returns:

value as a string

assertValidSeek

private void assertValidSeek()

getFirstKeyCellInBlock

protected Cell getFirstKeyCellInBlock(HFileBlock curBlock)

Overrides:

getFirstKeyCellInBlock in class HFileReaderImpl.HFileScannerImpl

loadBlockAndSeekToKey

protected int loadBlockAndSeekToKey(HFileBlock seekToBlock,
                                    Cell nextIndexedKey,
                                    boolean rewind,
                                    Cell key,
                                    boolean seekBefore)
                             throws IOException

Overrides:

loadBlockAndSeekToKey in class HFileReaderImpl.HFileScannerImpl

Throws:

IOException

compareKey

public int compareKey(CellComparator comparator,
                      Cell key)

Overrides:

compareKey in class HFileReaderImpl.HFileScannerImpl