/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/**
* Piped character-input streams.
*
* @author Mark Reinhold
* @since JDK1.1
*/
boolean closedByWriter = false;
boolean closedByReader = false;
boolean connected = false;
/* REMIND: identification of the read and write sides needs to be
more sophisticated. Either using thread groups (but what about
pipes within a thread?) or using finalization (but it may be a
long time until the next GC). */
/**
* The size of the pipe's circular input buffer.
*/
/**
* The circular buffer into which incoming data is placed.
*/
char buffer[];
/**
* The index of the position in the circular buffer at which the
* next character of data will be stored when received from the connected
* piped writer. <code>in<0</code> implies the buffer is empty,
* <code>in==out</code> implies the buffer is full
*/
/**
* The index of the position in the circular buffer at which the next
* character of data will be read by this piped reader.
*/
/**
* Creates a <code>PipedReader</code> so
* that it is connected to the piped writer
* <code>src</code>. Data written to <code>src</code>
* will then be available as input from this stream.
*
* @param src the stream to connect to.
* @exception IOException if an I/O error occurs.
*/
this(src, DEFAULT_PIPE_SIZE);
}
/**
* Creates a <code>PipedReader</code> so that it is connected
* to the piped writer <code>src</code> and uses the specified
* pipe size for the pipe's buffer. Data written to <code>src</code>
* will then be available as input from this stream.
* @param src the stream to connect to.
* @param pipeSize the size of the pipe's buffer.
* @exception IOException if an I/O error occurs.
* @exception IllegalArgumentException if <code>pipeSize <= 0</code>.
* @since 1.6
*/
}
/**
* Creates a <code>PipedReader</code> so
* that it is not yet {@linkplain #connect(java.io.PipedWriter)
* connected}. It must be {@linkplain java.io.PipedWriter#connect(
* java.io.PipedReader) connected} to a <code>PipedWriter</code>
* before being used.
*/
public PipedReader() {
}
/**
* Creates a <code>PipedReader</code> so that it is not yet
* {@link #connect(java.io.PipedWriter) connected} and uses
* the specified pipe size for the pipe's buffer.
* It must be {@linkplain java.io.PipedWriter#connect(
* java.io.PipedReader) connected} to a <code>PipedWriter</code>
* before being used.
*
* @param pipeSize the size of the pipe's buffer.
* @exception IllegalArgumentException if <code>pipeSize <= 0</code>.
* @since 1.6
*/
}
if (pipeSize <= 0) {
throw new IllegalArgumentException("Pipe size <= 0");
}
}
/**
* Causes this piped reader to be connected
* to the piped writer <code>src</code>.
* If this object is already connected to some
* other piped writer, an <code>IOException</code>
* is thrown.
* <p>
* If <code>src</code> is an
* unconnected piped writer and <code>snk</code>
* is an unconnected piped reader, they
* may be connected by either the call:
* <p>
* <pre><code>snk.connect(src)</code> </pre>
* <p>
* or the call:
* <p>
* <pre><code>src.connect(snk)</code> </pre>
* <p>
* The two
* calls have the same effect.
*
* @param src The piped writer to connect to.
* @exception IOException if an I/O error occurs.
*/
}
/**
* Receives a char of data. This method will block if no input is
* available.
*/
if (!connected) {
throw new IOException("Pipe not connected");
} else if (closedByWriter || closedByReader) {
throw new IOException("Pipe closed");
throw new IOException("Read end dead");
}
throw new IOException("Pipe broken");
}
/* full: kick any waiting readers */
notifyAll();
try {
wait(1000);
} catch (InterruptedException ex) {
}
}
if (in < 0) {
in = 0;
out = 0;
}
in = 0;
}
}
/**
* Receives data into an array of characters. This method will
* block until some input is available.
*/
while (--len >= 0) {
}
}
/**
* Notifies all waiting threads that the last character of data has been
* received.
*/
synchronized void receivedLast() {
closedByWriter = true;
notifyAll();
}
/**
* 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 <code>-1</code> is returned.
* This method blocks until input data is available, the end of
* the stream is detected, or an exception is thrown.
*
* @return the next character of data, or <code>-1</code> if the end of the
* stream is reached.
* @exception IOException if the pipe is
* <a href=PipedInputStream.html#BROKEN> <code>broken</code></a>,
* {@link #connect(java.io.PipedWriter) unconnected}, closed,
* or an I/O error occurs.
*/
if (!connected) {
throw new IOException("Pipe not connected");
} else if (closedByReader) {
throw new IOException("Pipe closed");
throw new IOException("Write end dead");
}
int trials = 2;
while (in < 0) {
if (closedByWriter) {
/* closed by writer, return EOF */
return -1;
}
throw new IOException("Pipe broken");
}
/* might be a writer waiting */
notifyAll();
try {
wait(1000);
} catch (InterruptedException ex) {
}
}
out = 0;
}
/* now empty */
in = -1;
}
return ret;
}
/**
* Reads up to <code>len</code> characters of data from this piped
* stream into an array of characters. Less than <code>len</code> characters
* will be read if the end of the data stream is reached or if
* <code>len</code> exceeds the pipe's buffer size. This method
* blocks until at least one character of input is available.
*
* @param cbuf the buffer into which the data is read.
* @param off the start offset of the data.
* @param len the maximum number of characters read.
* @return the total number of characters read into the buffer, or
* <code>-1</code> if there is no more data because the end of
* the stream has been reached.
* @exception IOException if the pipe is
* <a href=PipedInputStream.html#BROKEN> <code>broken</code></a>,
* {@link #connect(java.io.PipedWriter) unconnected}, closed,
* or an I/O error occurs.
*/
if (!connected) {
throw new IOException("Pipe not connected");
} else if (closedByReader) {
throw new IOException("Pipe closed");
throw new IOException("Write end dead");
}
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return 0;
}
/* possibly wait on the first character */
int c = read();
if (c < 0) {
return -1;
}
int rlen = 1;
rlen++;
out = 0;
}
/* now empty */
in = -1;
}
}
return rlen;
}
/**
* Tell whether this stream is ready to be read. A piped character
* stream is ready if the circular buffer is not empty.
*
* @exception IOException if the pipe is
* <a href=PipedInputStream.html#BROKEN> <code>broken</code></a>,
* {@link #connect(java.io.PipedWriter) unconnected}, or closed.
*/
if (!connected) {
throw new IOException("Pipe not connected");
} else if (closedByReader) {
throw new IOException("Pipe closed");
throw new IOException("Write end dead");
}
if (in < 0) {
return false;
} else {
return true;
}
}
/**
* Closes this piped stream and releases any system resources
* associated with the stream.
*
* @exception IOException if an I/O error occurs.
*/
in = -1;
closedByReader = true;
}
}