org.jredis.ri.alphazero.support

Class FastBufferedInputStream

java.lang.Object

java.io.InputStream

org.jredis.ri.alphazero.support.FastBufferedInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public final class FastBufferedInputStream
extends java.io.InputStream

Extension of InputStream that uses the enclosing instance's InputStream its data source. This is not supposed to be a general purpose implementation.

Since:

alpha.0

Version:

alpha.0, Sep 5, 2009

Field Summary

Fields

Modifier and Type	Field and Description
private byte[]	buffer data buffer (cache)
private java.io.InputStream	in underying input stream
private byte[]	iobuffer underlying input stream read buffer -- the size of this buffer determines the maximum bytes read
(package private) int	maxRead Note: Breaks the contract of the InputStream.read(byte[], int, int) to the extent that call will block on the underlying InputStream until it gets all the len bytes specified.
private int	offset current (read) offset of buffer

Constructor Summary

Constructors

Constructor and Description
FastBufferedInputStream(java.io.InputStream in, int bufferSize)

Method Summary

Modifier and Type	Method and Description
int	available()
private int	getMoreBytes(int len) Get more bytes from the underling InputStream.
boolean	markSupported() InputStream.mark(int) is not supported.
int	read()
int	read(byte[] b)
int	read(byte[] b, int off, int len)

Methods inherited from class java.io.InputStream

close, mark, reset, skip

Methods inherited from class java.lang.Object

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

Field Detail

buffer

private byte[] buffer

data buffer (cache)

offset

private int offset

current (read) offset of buffer

iobuffer

private final byte[] iobuffer

underlying input stream read buffer -- the size of this buffer determines the maximum bytes read

in

private final java.io.InputStream in

underying input stream

maxRead

int maxRead

Note:
Breaks the contract of the InputStream.read(byte[], int, int) to the extent that call will block on the underlying InputStream until it gets all the len bytes specified.

Also, this call will return -1 if and only if it (a) needs to get more data by calling getMoreBytes(int), and (b) that call returns -1. Note that it is possible, in a general context, that -1 is returned but there is previously accumulated data in buffer and thus available() returns a non zero positive integer which is less than specified len. But that is not expected in the specific context of Redis protocol.

See Also:

InputStream.read(byte[], int, int)

Constructor Detail

FastBufferedInputStream

public FastBufferedInputStream(java.io.InputStream in,
                               int bufferSize)

Parameters:

in - the input source

bufferSize - size of the iobuffer

Method Detail

getMoreBytes

private final int getMoreBytes(int len)
                        throws java.io.IOException

Get more bytes from the underling InputStream. Only reads from input source if len exceeds available data in buffer.

This call will block until (minimally) len bytes have been read.

Parameters:

len -

Throws:

java.io.IOException - if a read on the underlying stream returns 0 length bytes. This (obviously) shouldn't happen but if it does, it would be treated as an exception.

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

available

public int available()
              throws java.io.IOException

Overrides:

available in class java.io.InputStream

Returns:

the length of data available without making call to the underlying stream.

Throws:

java.io.IOException

See Also:

InputStream.available()

markSupported

public boolean markSupported()

InputStream.mark(int) is not supported.

Overrides:

markSupported in class java.io.InputStream

See Also:

InputStream.markSupported()

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()
         throws java.io.IOException

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException