Package org.ka2ddo.yaac.io

Class PipedReader

java.lang.Object
java.io.Reader
org.ka2ddo.yaac.io.PipedReader
All Implemented Interfaces:
Closeable, AutoCloseable, Readable
public class PipedReader extends Reader
This is a performance-optimized clone of the java.io.PipedReader class.
Author:
Andrew Pavlin, KA2DDO

  • Field Summary

    Fields inherited from class java.io.Reader

    lock

  • Constructor Summary

    Constructors
    Constructor
    Description
    PipedReader(PipedWriter src, int pipeSize)
    Creates a PipedReader so that it is connected to the piped writer src and uses the specified pipe size for the pipe's buffer.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clearStatistics()
    Reset the statistics counters.
    void
    close()
    Closes this piped stream and releases any system resources associated with the stream.
    void
    connect(PipedWriter src)
    Causes this piped reader to be connected to the piped writer src.
    int
    getNumEmpty()
    Report the number of times the pipe was found empty.
    int
    getNumFull()
    Report the number of times the pipe was found full.
    long
    getWaitOnEmpty()
    Report the number of milliseconds spent waiting on an empty pipe.
    long
    getWaitOnFull()
    Report the number of milliseconds spent waiting on a full pipe.
    int
    read()
    Reads the next character of data from this piped stream.
    int
    read(char[] cbuf, int off, int len)
    Reads up to len characters of data from this piped stream into an array of characters.
    boolean
    ready()
    Tell whether this stream is ready to be read.
    void
    receive(char[] c, int off, int len)
    Receives data into an array of characters.
    void
    setReaderThread()
    Mark the thread that is reading from the pipe.

    Methods inherited from class java.io.Reader

    mark, markSupported, nullReader, read, read, reset, skip, transferTo

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • PipedReader

      public PipedReader(PipedWriter src, int pipeSize) throws IOException
      Creates a PipedReader so that it is connected to the piped writer src and uses the specified pipe size for the pipe's buffer. Data written to src will then be available as input from this stream.
      Parameters:
      src - the stream to connect to.
      pipeSize - the size of the pipe's buffer.
      Throws:
      IOException - if an I/O error occurs.
      IllegalArgumentException - if pipeSize <= 0.

  • Method Details

    • connect

      public void connect(PipedWriter src) throws IOException
      Causes this piped reader to be connected to the piped writer src. If this object is already connected to some other piped writer, an IOException is thrown.

      If src is an unconnected piped writer and snk is an unconnected piped reader, they may be connected by either the call: 

      snk.connect(src)

      or the call: 

      src.connect(snk)

      The two calls have the same effect.

      Parameters:
      src - The piped writer to connect to.
      Throws:
      IOException - if an I/O error occurs.

    • receive

      public void receive(char[] c, int off, int len) throws IOException
      Receives data into an array of characters. This method will block until there is room to write some input. This method requires that the single writer thread register itself with setWriterThread() prior to first calling this method.
      Parameters:
      c - the data.
      off - the start offset in the data.
      len - the number of characters to write.
      Throws:
      IOException - if the pipe is broken, unconnected, closed or an I/O error occurs.

    • setReaderThread

      public void setReaderThread()
      Mark the thread that is reading from the pipe.

    • read

      public int read() throws IOException
      Reads the next character of data from this piped stream. If no character is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.
      Overrides:
      read in class Reader
      Returns:
      the next character of data, or -1 if the end of the stream is reached.
      Throws:
      IOException - if the pipe is broken, unconnected, closed, or an I/O error occurs.

    • read

      public int read(char[] cbuf, int off, int len) throws IOException
      Reads up to len characters of data from this piped stream into an array of characters. Less than len characters will be read if the end of the data stream is reached or if len exceeds the pipe's buffer size. This method blocks until at least one character of input is available.
      Specified by:
      read in class Reader
      Parameters:
      cbuf - the buffer into which the data is read.
      off - the start offset of the data.
      len - the maximum number of characters read.
      Returns:
      the total number of characters read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
      Throws:
      IOException - if the pipe is broken, unconnected, closed, or an I/O error occurs.

    • ready

      public boolean ready() throws IOException
      Tell whether this stream is ready to be read. A piped character stream is ready if the circular buffer is not empty.
      Overrides:
      ready in class Reader
      Throws:
      IOException - if the pipe is broken, unconnected, or closed.

    • close

      public void close() throws IOException
      Closes this piped stream and releases any system resources associated with the stream.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in class Reader
      Throws:
      IOException - if an I/O error occurs.

    • getNumEmpty

      public int getNumEmpty()
      Report the number of times the pipe was found empty.
      Returns:
      empty count

    • getWaitOnEmpty

      public long getWaitOnEmpty()
      Report the number of milliseconds spent waiting on an empty pipe.
      Returns:
      wait time in milliseconds

    • getNumFull

      public int getNumFull()
      Report the number of times the pipe was found full.
      Returns:
      full count

    • getWaitOnFull

      public long getWaitOnFull()
      Report the number of milliseconds spent waiting on a full pipe.
      Returns:
      wait time in milliseconds

    • clearStatistics

      public void clearStatistics()
      Reset the statistics counters.