org.apache.hadoop.hbase.regionserver.wal

类 ProtobufLogReader

java.lang.Object

org.apache.hadoop.hbase.regionserver.wal.ReaderBase

org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader

所有已实现的接口:

Closeable, AutoCloseable, AbstractFSWALProvider.Reader, WAL.Reader

直接已知子类:

SecureProtobufLogReader

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

A Protobuf based WAL has the following structure:

<PB_WAL_MAGIC><WALHeader><WALEdits>...<WALEdits><Trailer> <TrailerSize> <PB_WAL_COMPLETE_MAGIC>

The Reader reads meta information (WAL Compression state, WALTrailer, etc) in ProtobufLogReader#initReader(FSDataInputStream). A WALTrailer is an extensible structure which is appended at the end of the WAL. This is empty for now; it can contain some meta information such as Region level stats, etc in future.

字段概要

字段

限定符和类型	字段和说明
protected WALCellCodec.ByteStringUncompressor	byteStringUncompressor
protected Codec.Decoder	cellDecoder
protected boolean	hasCompression
protected boolean	hasTagCompression
protected org.apache.hadoop.fs.FSDataInputStream	inputStream
static byte[]	PB_WAL_COMPLETE_MAGIC
static byte[]	PB_WAL_MAGIC
protected org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos.WALTrailer	trailer
protected int	trailerWarnSize

从类继承的字段 org.apache.hadoop.hbase.regionserver.wal.ReaderBase

compressionContext, conf, edit, emptyCompressionContext, fileLength, fs, path

构造器概要

构造器

构造器和说明
ProtobufLogReader()

方法概要

限定符和类型	方法和说明
void	close()
protected WALCellCodec	getCodec(org.apache.hadoop.conf.Configuration conf, String cellCodecClsName, CompressionContext compressionContext)
String	getCodecClsName()
long	getPosition()
List<String>	getWriterClsNames()
protected boolean	hasCompression()
protected boolean	hasTagCompression()
void	init(org.apache.hadoop.fs.FileSystem fs, org.apache.hadoop.fs.Path path, org.apache.hadoop.conf.Configuration conf, org.apache.hadoop.fs.FSDataInputStream stream)
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).
protected org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader.WALHdrContext	readHeader(org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos.WALHeader.Builder builder, org.apache.hadoop.fs.FSDataInputStream stream)
protected boolean	readNext(WAL.Entry entry) Read next entry.
void	reset()
protected void	seekOnFs(long pos) Performs a filesystem-level seek to a certain position in an underlying file.
long	trailerSize()

从类继承的方法 org.apache.hadoop.hbase.regionserver.wal.ReaderBase

next, next, seek

从类继承的方法 java.lang.Object

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

字段详细资料

PB_WAL_MAGIC

@InterfaceAudience.Private
public static final byte[] PB_WAL_MAGIC

PB_WAL_COMPLETE_MAGIC

@InterfaceAudience.Private
public static final byte[] PB_WAL_COMPLETE_MAGIC

inputStream

protected org.apache.hadoop.fs.FSDataInputStream inputStream

cellDecoder

protected Codec.Decoder cellDecoder

byteStringUncompressor

protected WALCellCodec.ByteStringUncompressor byteStringUncompressor

hasCompression

protected boolean hasCompression

hasTagCompression

protected boolean hasTagCompression

trailer

protected org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos.WALTrailer trailer

trailerWarnSize

protected int trailerWarnSize

构造器详细资料

ProtobufLogReader

public ProtobufLogReader()

方法详细资料

trailerSize

@InterfaceAudience.Private
public long trailerSize()

close

public void close()
           throws IOException

抛出:

IOException

getPosition

public long getPosition()
                 throws IOException

抛出:

IOException

reset

public void reset()
           throws IOException

抛出:

IOException

init

public void init(org.apache.hadoop.fs.FileSystem fs,
                 org.apache.hadoop.fs.Path path,
                 org.apache.hadoop.conf.Configuration conf,
                 org.apache.hadoop.fs.FSDataInputStream stream)
          throws IOException

指定者:

init 在接口中 AbstractFSWALProvider.Reader

覆盖:

init 在类中 ReaderBase

参数:

fs - File system.

path - Path.

conf - Configuration.

stream - Input stream that may have been pre-opened by the caller; may be null.

抛出:

IOException

initReader

protected String initReader(org.apache.hadoop.fs.FSDataInputStream stream)
                     throws IOException

从类复制的说明: 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.

指定者:

initReader 在类中 ReaderBase

返回:

the class name of cell Codec, null if such information is not available

抛出:

IOException

getWriterClsNames

public List<String> getWriterClsNames()

getCodecClsName

public String getCodecClsName()

readHeader

protected org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader.WALHdrContext readHeader(org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos.WALHeader.Builder builder,
                                                                                              org.apache.hadoop.fs.FSDataInputStream stream)
                                                                                       throws IOException

抛出:

IOException

getCodec

protected WALCellCodec getCodec(org.apache.hadoop.conf.Configuration conf,
                                String cellCodecClsName,
                                CompressionContext compressionContext)
                         throws IOException

抛出:

IOException

initAfterCompression

protected void initAfterCompression()
                             throws IOException

从类复制的说明: ReaderBase

Initializes the compression after the shared stuff has been initialized. Called once.

指定者:

initAfterCompression 在类中 ReaderBase

抛出:

IOException

initAfterCompression

protected void initAfterCompression(String cellCodecClsName)
                             throws IOException

从类复制的说明: ReaderBase

Initializes the compression after the shared stuff has been initialized. Called once.

指定者:

initAfterCompression 在类中 ReaderBase

参数:

cellCodecClsName - class name of cell Codec

抛出:

IOException

hasCompression

protected boolean hasCompression()

指定者:

hasCompression 在类中 ReaderBase

返回:

Whether compression is enabled for this log.

hasTagCompression

protected boolean hasTagCompression()

指定者:

hasTagCompression 在类中 ReaderBase

返回:

Whether tag compression is enabled for this log.

readNext

protected boolean readNext(WAL.Entry entry)
                    throws IOException

从类复制的说明: ReaderBase

Read next entry.

指定者:

readNext 在类中 ReaderBase

参数:

entry - The entry to read into.

返回:

Whether there was anything to read.

抛出:

IOException

seekOnFs

protected void seekOnFs(long pos)
                 throws IOException

从类复制的说明: ReaderBase

Performs a filesystem-level seek to a certain position in an underlying file.

指定者:

seekOnFs 在类中 ReaderBase

抛出:

IOException