com.day.durbo.io

Class RegionFileInputStream

java.lang.Object

java.io.InputStream

com.day.durbo.io.RegionFileInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class RegionFileInputStream
extends java.io.InputStream

RegionFileInputStream implements an input stream that streams the contents of a region of a file. The reading is buffered. The file is opened upon the first access. this helps minimizing the total number of open files.

Constructor Summary

Constructors

Constructor and Description
RegionFileInputStream(java.io.File file) Same as RegionFileInputStream(File, boolean) with inflate set to false.
RegionFileInputStream(java.io.File file, boolean inflate) Same as RegionFileInputStream(File, long, long, boolean) where offset is 0 and len the length of the file.
RegionFileInputStream(java.io.File file, long off, long len) Creates a new input stream that reads for the region [off, off+len] of the given file.
RegionFileInputStream(java.io.File file, long off, long len, boolean inflate) Creates a new input stream that reads for the region [off, off+len] of the given file.

Method Summary

Modifier and Type	Method and Description
int	available()
void	close()
RegionFileInputStream	duplicate() Duplicates this stream.
long	getAbsolutePosition() Returns the read pointer position relative to this file.
java.io.File	getFile() Returns the underlying file.
long	getPosition() Returns the read pointer position relative to this region.
long	getRemaining() Returns the remaining bytes available in this region
void	mark(int readlimit)
boolean	markSupported()
int	read()
int	read(byte[] b)
int	read(byte[] b, int off, int len)
void	reset()
long	skip(long n)
RegionFileInputStream	substream(long off, long len) Creates a new RegionFileInputStream that is based on this one.

Methods inherited from class java.lang.Object

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

Constructor Detail

RegionFileInputStream

public RegionFileInputStream(java.io.File file)
                      throws java.io.IOException,
                             java.io.FileNotFoundException

Same as RegionFileInputStream(File, boolean) with inflate set to false.

Parameters:

file - the file to read from.

Throws:

java.io.FileNotFoundException - if the file was not found

java.io.IOException - if an I/O error occurs

RegionFileInputStream

public RegionFileInputStream(java.io.File file,
                             boolean inflate)
                      throws java.io.IOException,
                             java.io.FileNotFoundException

Same as RegionFileInputStream(File, long, long, boolean) where offset is 0 and len the length of the file.

Parameters:

file - the file to read from.

inflate - indicates if the file is compressed

Throws:

java.io.FileNotFoundException - if the file was not found

java.io.IOException - if an I/O error occurs

RegionFileInputStream

public RegionFileInputStream(java.io.File file,
                             long off,
                             long len)
                      throws java.io.IOException,
                             java.io.FileNotFoundException

Creates a new input stream that reads for the region [off, off+len] of the given file. If the region is greater than the length of the file an IOException os thrown.

Parameters:

file - the file to read from.

off - the absolute offset in the file to read from

len - the total length of the region

Throws:

java.io.FileNotFoundException - if the file was not found

java.io.IOException - if an I/O error occurs

RegionFileInputStream

public RegionFileInputStream(java.io.File file,
                             long off,
                             long len,
                             boolean inflate)
                      throws java.io.FileNotFoundException,
                             java.io.IOException

Creates a new input stream that reads for the region [off, off+len] of the given file. If the region is greater than the length of the file an IOException os thrown.

Parameters:

file - the file to read from.

off - the absolute offset in the file to read from

len - the total length of the region

inflate - indicates if the file is compressed

Throws:

java.io.FileNotFoundException - if the file was not found

java.io.IOException - if an I/O error occurs

Method Detail

available

public int available()
              throws java.io.IOException

Overrides:

available in class java.io.InputStream

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException

reset

public void reset()
           throws java.io.IOException

Overrides:

reset in class java.io.InputStream

Throws:

java.io.IOException

markSupported

public boolean markSupported()

Overrides:

markSupported in class java.io.InputStream

mark

public void mark(int readlimit)

Overrides:

mark in class java.io.InputStream

skip

public long skip(long n)
          throws java.io.IOException

Overrides:

skip in class java.io.InputStream

Throws:

java.io.IOException

read

public int read()
         throws java.io.IOException

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

read

public int read(byte[] b)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException

read

public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException

getFile

public java.io.File getFile()

Returns the underlying file.

Returns:

the underlying file.

getAbsolutePosition

public long getAbsolutePosition()
                         throws java.io.IOException

Returns the read pointer position relative to this file.

Returns:

the read pointer position relative to this file.

Throws:

java.io.IOException - if an I/O error occurs.

getPosition

public long getPosition()
                 throws java.io.IOException

Returns the read pointer position relative to this region.

Returns:

the read pointer position relative to this region.

Throws:

java.io.IOException - if an I/O error occurs.

getRemaining

public long getRemaining()
                  throws java.io.IOException

Returns the remaining bytes available in this region

Returns:

the remaining bytes available in this region

Throws:

java.io.IOException - if an I/O error occurs.

substream

public RegionFileInputStream substream(long off,
                                       long len)
                                throws java.io.IOException

Creates a new RegionFileInputStream that is based on this one.

Parameters:

off - relative offset to the current read pointer of this region

len - total length of this new stream.

Returns:

the new region stream

Throws:

java.io.IOException - if an I/O error occurs.

duplicate

public RegionFileInputStream duplicate()
                                throws java.io.IOException

Duplicates this stream. If the stream is already consumed or compressed, null is returned.

Returns:

a duplicate of this stream or null

Throws:

java.io.IOException - if an I/O error occurs.