+++ /dev/null
-/* Reader.java -- base class of classes that read input as a stream of chars
- Copyright (C) 1998, 1999, 2000 Free Software Foundation
-
-This file is part of GNU Classpath.
-
-GNU Classpath is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
-
-GNU Classpath 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 for more details.
-
-You should have received a copy of the GNU General Public License
-along with GNU Classpath; see the file COPYING. If not, write to the
-Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-02111-1307 USA.
-
-Linking this library statically or dynamically with other modules is
-making a combined work based on this library. Thus, the terms and
-conditions of the GNU General Public License cover the whole
-combination.
-
-As a special exception, the copyright holders of this library give you
-permission to link this library with independent modules to produce an
-executable, regardless of the license terms of these independent
-modules, and to copy and distribute the resulting executable under
-terms of your choice, provided that you also meet, for each linked
-independent module, the terms and conditions of the license of that
-module. An independent module is a module which is not derived from
-or based on this library. If you modify this library, you may extend
-this exception to your version of the library, but you are not
-obligated to do so. If you do not wish to do so, delete this
-exception statement from your version. */
-
-package java.io;
-
-/* Written using "Java Class Libraries", 2nd edition, plus online
- * API docs for JDK 1.2 beta from http://www.javasoft.com.
- * Status: Believed complete and correct.
- */
-
-/**
- * This abstract class forms the base of the hierarchy of classes that read
- * input as a stream of characters. It provides a common set of methods for
- * reading characters from streams. Subclasses implement and extend these
- * methods to read characters from a particular input source such as a file
- * or network connection.
- *
- * @author Per Bothner <bothner@cygnus.com>
- * @date April 21, 1998.
- * @author Aaron M. Renn (arenn@urbanophile.com)
- */
-public abstract class Reader
-{
- /**
- * This is the <code>Object</code> used for synchronizing critical code
- * sections. Subclasses should use this variable instead of a
- * synchronized method or an explicit synchronization on <code>this</code>
- */
- protected Object lock;
-
- /**
- * Unitializes a <code>Reader</code> that will use the object
- * itself for synchronization of critical code sections.
- */
- protected Reader()
- {
- this.lock = this;
- }
-
- /**
- * Initializes a <code>Reader</code> that will use the specified
- * <code>Object</code> for synchronization of critical code sections.
- *
- * @param lock The <code>Object</code> to use for synchronization
- */
- protected Reader(Object lock)
- {
- this.lock = lock;
- }
-
- /**
- * Read chars from a stream and stores them into a caller
- * supplied buffer. It starts storing the data at index <code>offset</code>
- * into the buffer and attempts to read <code>len</code> chars. This method
- * can return before reading the number of chars requested. The actual
- * number of chars read is returned as an int. A -1 is returned to indicate
- * the end of the stream.
- * <p>
- * This method will block until some data can be read.
- * <p>
- * This method operates by calling the single char <code>read()</code> method
- * in a loop until the desired number of chars are read. The read loop
- * stops short if the end of the stream is encountered or if an IOException
- * is encountered on any read operation except the first. If the first
- * attempt to read a chars fails, the IOException is allowed to propagate
- * upward. And subsequent IOException is caught and treated identically
- * to an end of stream condition. Subclasses can (and should if possible)
- * override this method to provide a more efficient implementation.
- *
- * @param buf The array into which the chars read should be stored
- * @param offset The offset into the array to start storing chars
- * @param len The requested number of chars to read
- *
- * @return The actual number of chars read, or -1 if end of stream.
- *
- * @exception IOException If an error occurs.
- */
- public abstract int read(char buf[], int offset, int count)
- throws IOException;
-
- /**
- * Reads chars from a stream and stores them into a caller
- * supplied buffer. This method attempts to completely fill the buffer,
- * but can return before doing so. The actual number of chars read is
- * returned as an int. A -1 is returned to indicate the end of the stream.
- * <p>
- * This method will block until some data can be read.
- * <p>
- * This method operates by calling an overloaded read method like so:
- * <code>read(buf, 0, buf.length)</code>
- *
- * @param buf The buffer into which the chars read will be stored.
- *
- * @return The number of chars read or -1 if end of stream.
- *
- * @exception IOException If an error occurs.
- */
- public int read(char buf[]) throws IOException
- {
- return read(buf, 0, buf.length);
- }
-
- /**
- * Reads an char from the input stream and returns it
- * as an int in the range of 0-65535. This method also will return -1 if
- * the end of the stream has been reached.
- * <p>
- * This method will block until the char can be read.
- *
- * @return The char read or -1 if end of stream
- *
- * @exception IOException If an error occurs
- */
- public int read() throws IOException
- {
- char[] buf = new char[1];
- int count = read(buf, 0, 1);
- return count > 0 ? buf[0] : -1;
- }
-
- /**
- * Closes the stream. Any futher attempts to read from the
- * stream may generate an <code>IOException</code>.
- *
- * @exception IOException If an error occurs
- */
- public abstract void close() throws IOException;
-
- /**
- * Returns a boolean that indicates whether the mark/reset
- * methods are supported in this class. Those methods can be used to
- * remember a specific point in the stream and reset the stream to that
- * point.
- * <p>
- * This method always returns <code>false</code> in this class, but
- * subclasses can override this method to return <code>true</code> if they
- * support mark/reset functionality.
- *
- * @return <code>true</code> if mark/reset functionality is supported,
- * <code>false</code> otherwise
- *
- */
- public boolean markSupported()
- {
- return false;
- }
-
- /**
- * Marks a position in the input to which the stream can be
- * "reset" by calling the <code>reset()</code> method. The parameter
- * <code>readlimit</code> is the number of chars that can be read from the
- * stream after setting the mark before the mark becomes invalid. For
- * example, if <code>mark()</code> is called with a read limit of 10, then
- * when 11 chars of data are read from the stream before the
- * <code>reset()</code> method is called, then the mark is invalid and the
- * stream object instance is not required to remember the mark.
- *
- * @param readlimit The number of chars that can be read before the mark
- * becomes invalid
- *
- * @exception IOException If an error occurs such as mark not being
- * supported for this class
- */
- public void mark(int readLimit) throws IOException
- {
- throw new IOException("mark not supported");
- }
-
- /**
- * Resets a stream to the point where the <code>mark()</code>
- * method was called. Any chars that were read after the mark point was
- * set will be re-read during subsequent reads.
- * <p>
- * This method always throws an IOException in this class, but subclasses
- * can override this method if they provide mark/reset functionality.
- *
- * @exception IOException Always thrown for this class
- */
- public void reset() throws IOException
- {
- throw new IOException("reset not supported");
- }
-
- /**
- * Determines whether or not this stream is ready to be
- * read. If it returns <code>false</code> the stream may block if a
- * read is attempted, but it is not guaranteed to do so.
- * <p>
- * This method always returns <code>false</code> in this class
- *
- * @return <code>true</code> if the stream is ready to be read, <code>false</code> otherwise.
- *
- * @exception IOException If an error occurs
- */
- public boolean ready() throws IOException
- {
- return false;
- }
-
- /**
- * Skips the specified number of chars in the stream. It
- * returns the actual number of chars skipped, which may be less than the
- * requested amount.
- * <p>
- * This method reads and discards chars into a 256 char array until the
- * specified number of chars were skipped or until either the end of stream
- * is reached or a read attempt returns a short count. Subclasses can
- * override this method to provide a more efficient implementation where
- * one exists.
- *
- * @param num_chars The requested number of chars to skip
- *
- * @return The actual number of chars skipped.
- *
- * @exception IOException If an error occurs
- */
- public long skip(long count) throws IOException
- {
- if (count <= 0)
- return 0;
- int bsize = count > 1024 ? 1024 : (int) count;
- char[] buffer = new char[bsize];
- long todo = count;
- synchronized (lock)
- {
- while (todo > 0)
- {
- int skipped = read(buffer, 0, bsize > todo ? (int) todo : bsize);
- if (skipped <= 0)
- break;
- todo -= skipped;
- }
- }
- return count - todo;
- }
-}
projects / msp430-gcc.git / blobdiff