org.apache.derbyTesting.functionTests.util.streams
Class LoopingAlphabetReader

java.lang.Object
  java.io.Reader
      org.apache.derbyTesting.functionTests.util.streams.LoopingAlphabetReader

All Implemented Interfaces:

java.io.Closeable, java.lang.Readable

public class LoopingAlphabetReader
extends java.io.Reader

A stream returning characters by looping over an alphabet.

Field Summary

private CharAlphabet	alphabet The alphabet to draw letters from.
private char[]	buffer Internal buffer of characters.
private boolean	closed Tell if the reader is closed or not.
private long	length Number of characters in the reader.
private static int	MAX_BUF_SIZE Maximum size of buffer.
private long	remainingBlanks Remaining blanks.
private long	remainingNonBlanks Remaining non-blank characters.
private static int	SPACE The character used for blanks (SPACE).
private int	trailingBlanks Number of blanks at the end of stream.

Fields inherited from class java.io.Reader

lock

Constructor Summary

LoopingAlphabetReader(long length)
Create a looping modern latin alphabet reader of the specified length.

LoopingAlphabetReader(long length, CharAlphabet alphabet)
Create a looping alphabet of the specified type and length.

LoopingAlphabetReader(long length, CharAlphabet alphabet, int trailingBlanks)
Create a looping alphabet of the specified type and length, with the specified number of trailing blanks.

LoopingAlphabetReader(long length, int trailingBlanks)
Create a looping modern latin alphabet of the specified length, with the specified number of trailing blanks.

Method Summary

int	available() Return remaining characters in the stream.
void	close() Close the reader.
private void	ensureOpen() Ensure reader is open.
private int	fillBlanks(char[] buf, int off, int length) Fill array with blanks (SPACE).
private void	fillBuffer(int bufSize) Fill internal buffer of character sequence.
int	read()
int	read(char[] buf, int off, int length)
void	reset() Reset the stream.

Methods inherited from class java.io.Reader

mark, markSupported, read, read, ready, skip

Methods inherited from class java.lang.Object

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

Field Detail

MAX_BUF_SIZE

private static final int MAX_BUF_SIZE

Maximum size of buffer. Balance between size and memory usage.

See Also:

Constant Field Values

SPACE

private static final int SPACE

The character used for blanks (SPACE).

See Also:

Constant Field Values

length

private final long length

Number of characters in the reader.

trailingBlanks

private final int trailingBlanks

Number of blanks at the end of stream.

remainingNonBlanks

private long remainingNonBlanks

Remaining non-blank characters.

remainingBlanks

private long remainingBlanks

Remaining blanks.

buffer

private char[] buffer

Internal buffer of characters. Used by the read-methods with a char[] argument.

alphabet

private final CharAlphabet alphabet

The alphabet to draw letters from.

closed

private boolean closed

Tell if the reader is closed or not.

Constructor Detail

LoopingAlphabetReader

public LoopingAlphabetReader(long length)

Create a looping modern latin alphabet reader of the specified length.

Parameters:

length - the number of characters

LoopingAlphabetReader

public LoopingAlphabetReader(long length,
                             int trailingBlanks)

Create a looping modern latin alphabet of the specified length, with the specified number of trailing blanks. The number of non-blank characters is length - trailingBlanks.

Parameters:

length - total number of characters

trailingBlanks - number of blank characters at the end

LoopingAlphabetReader

public LoopingAlphabetReader(long length,
                             CharAlphabet alphabet)

Create a looping alphabet of the specified type and length.

Parameters:

length - the number of chars in the reader

alphabet - the alphabet to loop over

LoopingAlphabetReader

public LoopingAlphabetReader(long length,
                             CharAlphabet alphabet,
                             int trailingBlanks)

Create a looping alphabet of the specified type and length, with the specified number of trailing blanks. The number of non-blank characters is length - trailingBlanks.

Parameters:

length - total number of characters

alphabet - the alphabet to draw characters from

trailingBlanks - number of blank characters at the end

Method Detail

read

public int read()
         throws java.io.IOException

Overrides:

read in class java.io.Reader

Throws:

java.io.IOException

read

public int read(char[] buf,
                int off,
                int length)
         throws java.io.IOException

Specified by:

read in class java.io.Reader

Throws:

java.io.IOException

reset

public void reset()
           throws java.io.IOException

Reset the stream.

Overrides:

reset in class java.io.Reader

Throws:

java.io.IOException

available

public int available()

Return remaining characters in the stream.

close

public void close()

Close the reader.

Specified by:

close in interface java.io.Closeable

Specified by:

close in class java.io.Reader

fillBuffer

private void fillBuffer(int bufSize)

Fill internal buffer of character sequence.

Parameters:

bufSize - the wanted size, might be ignored if too big

fillBlanks

private int fillBlanks(char[] buf,
                       int off,
                       int length)

Fill array with blanks (SPACE).

Parameters:

buf - array to fill

off - starting offset

length - maximum number of blanks to fill in

ensureOpen

private final void ensureOpen()
                       throws java.io.IOException

Ensure reader is open.

Throws:

java.io.IOException - if reader is closed