com.opensymphony.module.sitemesh.util: public class: CharArrayReader

com.opensymphony.module.sitemesh.util
public class: CharArrayReader [javadoc | source]

java.lang.Object
   java.io.Reader
      com.opensymphony.module.sitemesh.util.CharArrayReader

All Implemented Interfaces:
Closeable, Readable

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
protected char[]	buf	The character buffer.
protected int	pos	The current buffer position.
protected int	markedPos	The position of mark in buffer.
protected int	count	The index of the end of this buffer. There is not valid data at or beyond this index.

Constructor:

Constructor:
public CharArrayReader(char[] buf) { this.buf = buf; this.pos = 0; this.count = buf.length; } Create an CharArrayReader from the specified array of chars. Parameters: `buf` - Input buffer (not copied)
public CharArrayReader(char[] buf, int offset, int length) { if((offset < 0) \|\| (offset > buf.length) \|\| (length < 0) \|\| ((offset + length) < 0)) { throw new IllegalArgumentException(); } this.buf = buf; this.pos = offset; this.count = Math.min(offset + length, buf.length); this.markedPos = offset; } 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

 public CharArrayReader(char[] buf) {
                    
    this.buf = buf;
    this.pos = 0;
    this.count = buf.length;
}

Create an CharArrayReader from the specified array of chars.

Parameters:

buf - Input buffer (not copied)

 public CharArrayReader(char[] buf,
    int offset,
    int length) {
    if((offset <  0) || (offset  > buf.length) || (length <  0) || ((offset + length) <  0))
    {
      throw new IllegalArgumentException();
    }
    this.buf = buf;
    this.pos = offset;
    this.count = Math.min(offset + length, buf.length);
    this.markedPos = offset;
}

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 from com.opensymphony.module.sitemesh.util.CharArrayReader Summary:
close, mark, markSupported, read, read, ready, reset, skip

Methods from java.io.Reader:
close, mark, markSupported, read, read, read, read, ready, reset, skip

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from com.opensymphony.module.sitemesh.util.CharArrayReader Detail:
public void close() { buf = null; } Close the stream.
public void mark(int readAheadLimit) throws IOException { markedPos = pos; } Mark the present position in the stream. Subsequent calls to reset() will reposition the stream to this point.
public boolean markSupported() { return true; } Tell whether this stream supports the mark() operation, which it does.
public int read() throws IOException { if(pos >= count) return -1; else return buf[pos++]; } Read a single character.
public int read(char[] b, int off, int len) throws IOException { if((off < 0) \|\| (off > b.length) \|\| (len < 0) \|\| ((off + len) > b.length) \|\| ((off + len) < 0)) { throw new IndexOutOfBoundsException(); } else if(len == 0) { return 0; } if(pos >= count) { return -1; } if(pos + len > count) { len = count - pos; } if(len < = 0) { return 0; } System.arraycopy(buf, pos, b, off, len); pos += len; return len; } Read characters into a portion of an array.
public boolean ready() throws IOException { return (count - pos) > 0; } Tell whether this stream is ready to be read. Character-array readers are always ready to be read.
public void reset() throws IOException { pos = markedPos; } Reset the stream to the most recent mark, or to the beginning if it has never been marked.
public long skip(long n) throws IOException { if(pos + n > count) { n = count - pos; } if(n < 0) { return 0; } pos += n; return n; } Skip characters.

Method from com.opensymphony.module.sitemesh.util.CharArrayReader Detail:

 public  void close() {
    buf = null;
}

Close the stream.

 public  void mark(int readAheadLimit) throws IOException {
    markedPos = pos;
}

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

 public boolean markSupported() {
    return true;
}

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

 public int read() throws IOException {
    if(pos  >= count)
      return -1;
    else
      return buf[pos++];
}

Read a single character.

 public int read(char[] b,
    int off,
    int len) throws IOException {
    if((off <  0) || (off  > b.length) || (len <  0) || ((off + len)  > b.length) || ((off + len) <  0))
    {
      throw new IndexOutOfBoundsException();
    }
    else if(len == 0)
    {
      return 0;
    }
    if(pos  >= count)
    {
      return -1;
    }
    if(pos + len  > count)
    {
      len = count - pos;
    }
    if(len < = 0)
    {
      return 0;
    }
    System.arraycopy(buf, pos, b, off, len);
    pos += len;
    return len;
}

Read characters into a portion of an array.

 public boolean ready() throws IOException {
    return (count - pos)  > 0;
}

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

 public  void reset() throws IOException {
    pos = markedPos;
}

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

 public long skip(long n) throws IOException {
    if(pos + n  > count)
    {
      n = count - pos;
    }
    if(n <  0)
    {
      return 0;
    }
    pos += n;
    return n;
}

Skip characters.