Class CharArrayReader

java.lang.Object
java.io.Reader
com.opensymphony.module.sitemesh.util.CharArrayReader
All Implemented Interfaces:
Closeable, AutoCloseable, Readable

public class CharArrayReader extends 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
    Description
    protected char[]
    The character buffer.
    protected int
    The index of the end of this buffer.
    protected int
    The position of mark in buffer.
    protected int
    The current buffer position.

    Fields inherited from class java.io.Reader

    lock
  • Constructor Summary

    Constructors
    Constructor
    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
    Description
    void
    Close the stream.
    void
    mark(int readAheadLimit)
    Mark the present position in the stream.
    boolean
    Tell whether this stream supports the mark() operation, which it does.
    int
    Read a single character.
    int
    read(char[] b, int off, int len)
    Read characters into a portion of an array.
    boolean
    Tell whether this stream is ready to be read.
    void
    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

    nullReader, read, read, transferTo

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • 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 Details

    • 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 Details

    • read

      public int read() throws IOException
      Read a single character.
      Overrides:
      read in class Reader
      Throws:
      IOException - If an I/O error occurs
    • read

      public int read(char[] b, int off, int len) throws IOException
      Read characters into a portion of an array.
      Specified by:
      read in class 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:
      IOException - If an I/O error occurs
    • skip

      public long skip(long n) throws IOException
      Skip characters.
      Overrides:
      skip in class Reader
      Parameters:
      n - The number of characters to skip
      Returns:
      The number of characters actually skipped
      Throws:
      IOException - If an I/O error occurs
    • ready

      public boolean ready() throws IOException
      Tell whether this stream is ready to be read. Character-array readers are always ready to be read.
      Overrides:
      ready in class Reader
      Throws:
      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 Reader
    • mark

      public void mark(int readAheadLimit) throws IOException
      Mark the present position in the stream. Subsequent calls to reset() will reposition the stream to this point.
      Overrides:
      mark in class 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:
      IOException - If an I/O error occurs
    • reset

      public void reset() throws IOException
      Reset the stream to the most recent mark, or to the beginning if it has never been marked.
      Overrides:
      reset in class Reader
      Throws:
      IOException - If an I/O error occurs
    • close

      public void close()
      Close the stream.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in class Reader