HFileReaderV2.EncodedScannerV2 (Apache HBase 1.2.12 API)

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
`private DataBlockEncoder`	`dataBlockEncoder`
`private HFileBlockDecodingContext`	`decodingCtx`
`protected HFileContext`	`meta`
`private DataBlockEncoder.EncodedSeeker`	`seeker`

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
`private void`	`assertValidSeek()`
`int`	`compareKey(KeyValue.KVComparator comparator, byte[] key, int offset, int length)` Compare the given key against the current key
`int`	`compareKey(KeyValue.KVComparator comparator, Cell key)`
`private ByteBuffer`	`getEncodedBuffer(HFileBlock newBlock)`
`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.
`Cell`	`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, Cell nextIndexedKey, boolean rewind, Cell key, boolean seekBefore)`
`boolean`	`next()` Scans to the next entry in the file.
`boolean`	`seekTo()` Positions this scanner at the start of the file.
`private void`	`updateCurrentBlock(HFileBlock newBlock)` Updates the current block to be the given `HFileBlock`.

Methods inherited from class org.apache.hadoop.hbase.io.hfile.HFileReaderV2.AbstractScannerV2
getEffectiveDataBlockEncoding, getNextIndexedKey, readNextDataBlock, reseekTo, reseekTo, seekBefore, seekBefore, seekTo, seekTo, seekTo

Methods inherited from class org.apache.hadoop.hbase.io.hfile.AbstractHFileReader.Scanner
assertSeeked, close, getReader, reseekTo, seekBefore, seekTo, toString

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
```
  - 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.
  - updateCurrentBlock
```
private void updateCurrentBlock(HFileBlock newBlock)
                         throws CorruptHFileException
```
    Updates the current block to be the given HFileBlock. Seeks to the the first key/value pair.
    
    Parameters:
    newBlock - the block to make current
    
    Throws:
    
    CorruptHFileException
  - getEncodedBuffer
```
private ByteBuffer getEncodedBuffer(HFileBlock newBlock)
```
  - 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 Cell 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
  - assertValidSeek
```
private void assertValidSeek()
```
  - getFirstKeyInBlock
```
protected ByteBuffer getFirstKeyInBlock(HFileBlock curBlock)
```
    Specified by:
    
    getFirstKeyInBlock in class HFileReaderV2.AbstractScannerV2
  - loadBlockAndSeekToKey
```
protected int loadBlockAndSeekToKey(HFileBlock seekToBlock,
                        Cell nextIndexedKey,
                        boolean rewind,
                        Cell key,
                        boolean seekBefore)
                             throws IOException
```
    Specified by:
    
    loadBlockAndSeekToKey in class HFileReaderV2.AbstractScannerV2
    
    Throws:
    
    IOException
  - compareKey
```
public int compareKey(KeyValue.KVComparator comparator,
             Cell key)
```
    Specified by:
    
    compareKey in class HFileReaderV2.AbstractScannerV2

Class HFileReaderV2.EncodedScannerV2

Field Summary

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

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

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

Field Detail

decodingCtx

seeker

dataBlockEncoder

meta

Constructor Detail

HFileReaderV2.EncodedScannerV2

Method Detail

isSeeked

updateCurrentBlock

getEncodedBuffer

seekTo

next

getKey

compareKey

getValue

getKeyValue

getKeyString

getValueString

assertValidSeek

getFirstKeyInBlock

loadBlockAndSeekToKey

compareKey