com.opensymphony.module.sitemesh.util

Class CharArrayReader

java.lang.Object

java.io.Reader

com.opensymphony.module.sitemesh.util.CharArrayReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Readable

public class CharArrayReader
extends java.io.Reader

This class implements a character buffer that can be used as a character-input stream. Modified from the JDK source in that it gets rid of the ensureOpen() method, so we get unexpected behaviour if the reader is closed.

The second modification is that since this class is used internally by FastPageParser in a single thread, we don't need any locking or synchronization. Using this class instead of the standard CharArrayReader improves FastPageParser performance by 15-20%.

Author:

Hani Suleiman

Field Summary

Fields

Modifier and Type	Field and Description
protected char[]	buf The character buffer.
protected int	count The index of the end of this buffer.
protected int	markedPos The position of mark in buffer.
protected int	pos The current buffer position.

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor and Description
CharArrayReader(char[] buf) Create an CharArrayReader from the specified array of chars.
CharArrayReader(char[] buf, int offset, int length) Create an CharArrayReader from the specified array of chars.

Method Summary

Modifier and Type	Method and Description
void	close() Close the stream.
void	mark(int readAheadLimit) Mark the present position in the stream.
boolean	markSupported() Tell whether this stream supports the mark() operation, which it does.
int	read() Read a single character.
int	read(char[] b, int off, int len) Read characters into a portion of an array.
boolean	ready() Tell whether this stream is ready to be read.
void	reset() Reset the stream to the most recent mark, or to the beginning if it has never been marked.
long	skip(long n) Skip characters.

Methods inherited from class java.io.Reader

read, read

Methods inherited from class java.lang.Object

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

Field Detail

buf

protected char[] buf

The character buffer.

pos

protected int pos

The current buffer position.

markedPos

protected int markedPos

The position of mark in buffer.

count

protected int count

The index of the end of this buffer. There is not valid data at or beyond this index.

Constructor Detail

CharArrayReader

public CharArrayReader(char[] buf)

Create an CharArrayReader from the specified array of chars.

Parameters:

buf - Input buffer (not copied)

CharArrayReader

public CharArrayReader(char[] buf,
                       int offset,
                       int length)

Create an CharArrayReader from the specified array of chars.

Parameters:

buf - Input buffer (not copied)

offset - Offset of the first char to read

length - Number of chars to read

Method Detail

read

public int read()
         throws java.io.IOException

Read a single character.

Overrides:

read in class java.io.Reader

Throws:

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

read

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

Read characters into a portion of an array.

Specified by:

read in class java.io.Reader

Parameters:

b - Destination buffer

off - Offset at which to start storing characters

len - Maximum number of characters to read

Returns:

The actual number of characters read, or -1 if the end of the stream has been reached

Throws:

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

skip

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

Skip characters.

Overrides:

skip in class java.io.Reader

Parameters:

n - The number of characters to skip

Returns:

The number of characters actually skipped

Throws:

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

ready

public boolean ready()
              throws java.io.IOException

Tell whether this stream is ready to be read. Character-array readers are always ready to be read.

Overrides:

ready in class java.io.Reader

Throws:

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

markSupported

public boolean markSupported()

Tell whether this stream supports the mark() operation, which it does.

Overrides:

markSupported in class java.io.Reader

mark

public void mark(int readAheadLimit)
          throws java.io.IOException

Mark the present position in the stream. Subsequent calls to reset() will reposition the stream to this point.

Overrides:

mark in class java.io.Reader

Parameters:

readAheadLimit - Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from a character array, there is no actual limit; hence this argument is ignored.

Throws:

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

reset

public void reset()
           throws java.io.IOException

Reset the stream to the most recent mark, or to the beginning if it has never been marked.

Overrides:

reset in class java.io.Reader

Throws:

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

close

public void close()

Close the stream.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in class java.io.Reader