Package net.sf.basedb.util

Class InputStreamTracker

java.lang.Object

java.io.InputStream

net.sf.basedb.util.InputStreamTracker

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

ProgressInputStream

public class InputStreamTracker
extends InputStream

This class is used to keep track of the number of bytes read from the underlying input stream. This is very useful for code that needs to reporter progress but are having difficulties to know the number of processed bytes.

Version:

2.4

Author:

nicklas

Last modified

$Date: 2020-11-09 14:40:05 +0100 (Mon, 09 Nov 2020) $

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	InputStreamTracker.CurvedScaleFactor	Apply a curved scale factor that has a max upper limit.
static class	InputStreamTracker.IdentityScaleFactor	Do not scale number of bytes.
static class	InputStreamTracker.LinearScaleFactor	Apply a linear scale factor so that when we have read N actual bytes the getNumRead() method return N*scale bytes.
static interface	InputStreamTracker.ScaleFactor	A scale factor can be used to match number of read bytes to something that better resembles actual progress.

Field Summary

Fields

Modifier and Type	Field	Description
private final InputStream	in	The source input stream to read from.
private long	numRead	The number of bytes that has been read from the underlying input stream so far.
private long	numReadAtMark	The number of bytes that had been read when mark(int) was called.
private final InputStreamTracker.ScaleFactor	scaleFactor	A scale factor to apply when counting bytes.

Constructor Summary

Constructors

Constructor	Description
InputStreamTracker(InputStream in)	Create a new input stream tracker.
InputStreamTracker(InputStream in, InputStreamTracker.ScaleFactor scaleFactor)	Create a new input stream tracker.

Method Summary

Modifier and Type	Method	Description
int	available()
void	close()
long	getNumRead()	Get the number of bytes read or skipped from the input stream.
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)

Methods inherited from class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Field Details

in

private final InputStream in

The source input stream to read from.

scaleFactor

private final InputStreamTracker.ScaleFactor scaleFactor

A scale factor to apply when counting bytes.

numRead

private long numRead

The number of bytes that has been read from the underlying input stream so far.

numReadAtMark

private long numReadAtMark

The number of bytes that had been read when mark(int) was called.

Constructor Details

InputStreamTracker

public InputStreamTracker(InputStream in)

Create a new input stream tracker.

Parameters:

in - The input stream to read from

InputStreamTracker

public InputStreamTracker(InputStream in,
 InputStreamTracker.ScaleFactor scaleFactor)

Create a new input stream tracker.

Parameters:

in - The input stream to read from

scaleFactor - A scale factor to apply when counting bytes

Since:

3.17.1

Method Details

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

mark

public void mark(int readlimit)

Overrides:

mark in class InputStream

markSupported

public boolean markSupported()

Overrides:

markSupported in class InputStream

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

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

Overrides:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

reset

public void reset()
           throws IOException

Overrides:

reset in class InputStream

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class InputStream

Throws:

IOException

getNumRead

public long getNumRead()

Get the number of bytes read or skipped from the input stream. If the underlying stream supports reset() this will also reset the number of read bytes to the latest mark(int) position.

Returns:

The number of bytes that has been read so far