Package com.mku.salmon.streams

Class SalmonFileInputStream

java.lang.Object

java.io.InputStream

com.mku.salmon.streams.SalmonFileInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class SalmonFileInputStream
extends InputStream

Implementation of a Java InputStream for seeking and reading a SalmonFile. This class provides a seekable source with parallel substreams and cached buffers for performance.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SalmonFileInputStream.CacheBuffer	Class will be used to cache decrypted data that can later be read via the ReadAt() method without requesting frequent decryption reads.

Constructor Summary

Constructors

Constructor	Description
SalmonFileInputStream(SalmonFile salmonFile, int buffersCount, int bufferSize, int threads, int backOffset)	Instantiate a seekable stream from an encrypted file source

Method Summary

Modifier and Type	Method	Description
void	close()	Close the stream and associated backed streams and clear buffers.
long	getPositionStart()
long	getSize()	Get the size of the stream.
int	read()	Read a byte from the stream.
int	read(byte[] buffer, int offset, int count)	Reads and decrypts the contents of an encrypted file
void	reset()
void	setPositionEnd(long pos)
void	setPositionStart(long pos)
long	skip(long bytes)	Skip a number of bytes.

Methods inherited from class java.io.InputStream

available, mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Constructor Details

SalmonFileInputStream

public SalmonFileInputStream(SalmonFile salmonFile,
 int buffersCount,
 int bufferSize,
 int threads,
 int backOffset)
                      throws IOException

Instantiate a seekable stream from an encrypted file source

Parameters:

salmonFile - The source file.

buffersCount - Number of buffers to use.

bufferSize - The length of each buffer.

threads - The number of threads/streams to source the file in parallel.

backOffset - The back offset.

Throws:

IOException - Thrown if there is an IO error.

Method Details

skip

public long skip(long bytes)

Skip a number of bytes.

Overrides:

skip in class InputStream

Parameters:

bytes - the number of bytes to be skipped.

Returns:

The byte skipped

reset

public void reset()

Overrides:

reset in class InputStream

read

public int read()
         throws IOException

Read a byte from the stream.

Specified by:

read in class InputStream

Returns:

The bytes read

Throws:

IOException - Thrown if there is an IO error.

read

public int read(byte[] buffer,
 int offset,
 int count)
         throws IOException

Reads and decrypts the contents of an encrypted file

Overrides:

read in class InputStream

Parameters:

buffer - The buffer that will store the decrypted contents

offset - The position on the buffer that the decrypted data will start

count - The length of the data requested

Throws:

IOException

getSize

public long getSize()

Get the size of the stream.

Returns:

The size

getPositionStart

public long getPositionStart()

setPositionStart

public void setPositionStart(long pos)

setPositionEnd

public void setPositionEnd(long pos)

close

public void close()
           throws IOException

Close the stream and associated backed streams and clear buffers.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException - Thrown if there is an IO error.