SequenceFileLogReader (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.regionserver.wal.ReaderBase
- - org.apache.hadoop.hbase.regionserver.wal.SequenceFileLogReader

All Implemented Interfaces:: Closeable, AutoCloseable, DefaultWALProvider.Reader, WAL.Reader

@InterfaceAudience.LimitedPrivate(value={"Coprocesssor","Phoenix","Configuration"})
public class SequenceFileLogReader
extends ReaderBase

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

private static class SequenceFileLogReader.WALReader
Hack just to set the correct file length up in SequenceFile.Reader.

Nested Classes
Modifier and Type	Class and Description
`private static class`	`SequenceFileLogReader.WALReader` Hack just to set the correct file length up in SequenceFile.Reader.

Field Summary

Fields
Modifier and Type	Field and Description
`private static int`	`COMPRESSION_VERSION`
`private static org.apache.hadoop.io.Text`	`DICTIONARY_COMPRESSION_TYPE`
`(package private) long`	`entryStart`
`private static org.apache.commons.logging.Log`	`LOG`
`protected org.apache.hadoop.io.SequenceFile.Reader`	`reader`
`private static org.apache.hadoop.io.Text`	`WAL_COMPRESSION_TYPE_KEY`
`private static org.apache.hadoop.io.Text`	`WAL_VERSION_KEY`

Fields inherited from class org.apache.hadoop.hbase.regionserver.wal.ReaderBase
compressionContext, conf, edit, emptyCompressionContext, fileLength, fs, path

Constructor Summary

Constructors
Constructor and Description

SequenceFileLogReader()

Constructors
Constructor and Description
`SequenceFileLogReader()`

Method Summary

Methods
Modifier and Type	Method and Description
`protected IOException`	`addFileInfoToException(IOException ioe)`
`void`	`close()`
`long`	`getPosition()`
`protected boolean`	`hasCompression()`
`protected boolean`	`hasTagCompression()`
`protected void`	`initAfterCompression()` Initializes the compression after the shared stuff has been initialized.
`protected void`	`initAfterCompression(String cellCodecClsName)` Initializes the compression after the shared stuff has been initialized.
`protected String`	`initReader(org.apache.hadoop.fs.FSDataInputStream stream)` Initializes the log reader with a particular stream (may be null).
`(package private) static boolean`	`isWALCompressionEnabled(org.apache.hadoop.io.SequenceFile.Metadata metadata)` Call this method after init() has been executed
`protected boolean`	`readNext(WAL.Entry e)` fill in the passed entry with teh next key/value.
`void`	`reset()`
`protected void`	`seekOnFs(long pos)` Performs a filesystem-level seek to a certain position in an underlying file.

Methods inherited from class org.apache.hadoop.hbase.regionserver.wal.ReaderBase
init, next, next, seek

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - LOG
```
private static final org.apache.commons.logging.Log LOG
```
  - WAL_VERSION_KEY
```
private static final org.apache.hadoop.io.Text WAL_VERSION_KEY
```
  - COMPRESSION_VERSION
```
private static final int COMPRESSION_VERSION
```
    See Also:
    Constant Field Values
  - WAL_COMPRESSION_TYPE_KEY
```
private static final org.apache.hadoop.io.Text WAL_COMPRESSION_TYPE_KEY
```
  - DICTIONARY_COMPRESSION_TYPE
```
private static final org.apache.hadoop.io.Text DICTIONARY_COMPRESSION_TYPE
```
  - reader
```
protected org.apache.hadoop.io.SequenceFile.Reader reader
```
  - entryStart
```
long entryStart
```
- Constructor Detail
  - SequenceFileLogReader
```
public SequenceFileLogReader()
```
- Method Detail
  - close
```
public void close()
           throws IOException
```
    Throws:
    
    IOException
  - getPosition
```
public long getPosition()
                 throws IOException
```
    Throws:
    
    IOException
  - reset
```
public void reset()
           throws IOException
```
    Throws:
    
    IOException
  - initReader
```
protected String initReader(org.apache.hadoop.fs.FSDataInputStream stream)
                     throws IOException
```
    Description copied from class: ReaderBase
    
    Initializes the log reader with a particular stream (may be null). Reader assumes ownership of the stream if not null and may use it. Called once.
    
    Specified by:
    
    initReader in class ReaderBase
    
    Returns:
    the class name of cell Codec, null if such information is not available
    
    Throws:
    
    IOException
  - initAfterCompression
```
protected void initAfterCompression(String cellCodecClsName)
                             throws IOException
```
    Description copied from class: ReaderBase
    
    Initializes the compression after the shared stuff has been initialized. Called once.
    
    Specified by:
    
    initAfterCompression in class ReaderBase
    
    Parameters:
    cellCodecClsName - class name of cell Codec
    
    Throws:
    
    IOException
  - initAfterCompression
```
protected void initAfterCompression()
                             throws IOException
```
    Description copied from class: ReaderBase
    
    Initializes the compression after the shared stuff has been initialized. Called once.
    
    Specified by:
    
    initAfterCompression in class ReaderBase
    
    Throws:
    
    IOException
  - hasCompression
```
protected boolean hasCompression()
```
    Specified by:
    
    hasCompression in class ReaderBase
    
    Returns:
    Whether compression is enabled for this log.
  - hasTagCompression
```
protected boolean hasTagCompression()
```
    Specified by:
    
    hasTagCompression in class ReaderBase
    
    Returns:
    Whether tag compression is enabled for this log.
  - isWALCompressionEnabled
```
static boolean isWALCompressionEnabled(org.apache.hadoop.io.SequenceFile.Metadata metadata)
```
    Call this method after init() has been executed
    
    Returns:
    whether WAL compression is enabled
  - readNext
```
protected boolean readNext(WAL.Entry e)
                    throws IOException
```
    fill in the passed entry with teh next key/value. Note that because this format deals with our legacy storage, the provided Entery MUST use an HLogKey for the key.
    
    Specified by:
    
    readNext in class ReaderBase
    
    Parameters:
    e - The entry to read into.
    
    Returns:
    boolean indicating if the contents of Entry have been filled in.
    
    Throws:
    
    IOException
  - seekOnFs
```
protected void seekOnFs(long pos)
                 throws IOException
```
    Description copied from class: ReaderBase
    
    Performs a filesystem-level seek to a certain position in an underlying file.
    
    Specified by:
    
    seekOnFs in class ReaderBase
    
    Throws:
    
    IOException
  - addFileInfoToException
```
protected IOException addFileInfoToException(IOException ioe)
                                      throws IOException
```
    Throws:
    
    IOException

Class SequenceFileLogReader

Nested Class Summary

Field Summary

Fields inherited from class org.apache.hadoop.hbase.regionserver.wal.ReaderBase

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.hbase.regionserver.wal.ReaderBase

Methods inherited from class java.lang.Object

Field Detail

LOG

WAL_VERSION_KEY

COMPRESSION_VERSION

WAL_COMPRESSION_TYPE_KEY

DICTIONARY_COMPRESSION_TYPE

reader

entryStart

Constructor Detail

SequenceFileLogReader

Method Detail

close

getPosition

reset

initReader

initAfterCompression

initAfterCompression

hasCompression

hasTagCompression

isWALCompressionEnabled

readNext

seekOnFs

addFileInfoToException