org.apache.hadoop.fs

类 BufferedFSInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

java.io.BufferedInputStream

org.apache.hadoop.fs.BufferedFSInputStream

所有已实现的接口:

Closeable, AutoCloseable, HasFileDescriptor, PositionedReadable, Seekable

public class BufferedFSInputStream
extends BufferedInputStream
implements Seekable, PositionedReadable, HasFileDescriptor

A class optimizes reading from FSInputStream by bufferring

字段概要

从类继承的字段 java.io.BufferedInputStream

buf, count, marklimit, markpos, pos

从类继承的字段 java.io.FilterInputStream

in

构造器概要

构造器

构造器和说明
BufferedFSInputStream(FSInputStream in, int size) Creates a BufferedFSInputStream with the specified buffer size, and saves its argument, the input stream in, for later use.

方法概要

方法

限定符和类型	方法和说明
FileDescriptor	getFileDescriptor()
long	getPos() Return the current offset from the start of the file
int	read(long position, byte[] buffer, int offset, int length) Read upto the specified number of bytes, from a given position within a file, and return the number of bytes read.
void	readFully(long position, byte[] buffer) Read number of bytes equalt to the length of the buffer, from a given position within a file.
void	readFully(long position, byte[] buffer, int offset, int length) Read the specified number of bytes, from a given position within a file.
void	seek(long pos) Seek to the given offset from the start of the file.
boolean	seekToNewSource(long targetPos) Seeks a different copy of the data.
long	skip(long n)

从类继承的方法 java.io.BufferedInputStream

available, close, mark, markSupported, read, read, reset

从类继承的方法 java.io.FilterInputStream

read

从类继承的方法 java.lang.Object

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

构造器详细资料

BufferedFSInputStream

public BufferedFSInputStream(FSInputStream in,
                     int size)

Creates a BufferedFSInputStream with the specified buffer size, and saves its argument, the input stream in, for later use. An internal buffer array of length size is created and stored in buf.

参数:

in - the underlying input stream.

size - the buffer size.

抛出:

IllegalArgumentException - if size <= 0.

方法详细资料

getPos

public long getPos()
            throws IOException

从接口复制的说明: Seekable

Return the current offset from the start of the file

指定者:

getPos 在接口中 Seekable

抛出:

IOException

skip

public long skip(long n)
          throws IOException

覆盖:

skip 在类中 BufferedInputStream

抛出:

IOException

seek

public void seek(long pos)
          throws IOException

从接口复制的说明: Seekable

Seek to the given offset from the start of the file. The next read() will be from that location. Can't seek past the end of the file.

指定者:

seek 在接口中 Seekable

抛出:

IOException

seekToNewSource

public boolean seekToNewSource(long targetPos)
                        throws IOException

从接口复制的说明: Seekable

Seeks a different copy of the data. Returns true if found a new source, false otherwise.

指定者:

seekToNewSource 在接口中 Seekable

抛出:

IOException

read

public int read(long position,
       byte[] buffer,
       int offset,
       int length)
         throws IOException

从接口复制的说明: PositionedReadable

Read upto the specified number of bytes, from a given position within a file, and return the number of bytes read. This does not change the current offset of a file, and is thread-safe.

指定者:

read 在接口中 PositionedReadable

抛出:

IOException

readFully

public void readFully(long position,
             byte[] buffer,
             int offset,
             int length)
               throws IOException

从接口复制的说明: PositionedReadable

Read the specified number of bytes, from a given position within a file. This does not change the current offset of a file, and is thread-safe.

指定者:

readFully 在接口中 PositionedReadable

抛出:

IOException

readFully

public void readFully(long position,
             byte[] buffer)
               throws IOException

从接口复制的说明: PositionedReadable

Read number of bytes equalt to the length of the buffer, from a given position within a file. This does not change the current offset of a file, and is thread-safe.

指定者:

readFully 在接口中 PositionedReadable

抛出:

IOException

getFileDescriptor

public FileDescriptor getFileDescriptor()
                                 throws IOException

指定者:

getFileDescriptor 在接口中 HasFileDescriptor

返回:

the FileDescriptor

抛出:

IOException