+++ /dev/null
-/* ByteArrayInputStream.java -- Read an array as a stream
- Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc.
-
-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;
-
-/**
- * This class permits an array of bytes to be read as an input stream.
- *
- * @author Warren Levy <warrenl@cygnus.com>
- * @author Aaron M. Renn (arenn@urbanophile.com)
- */
-public class ByteArrayInputStream extends InputStream
-{
- /**
- * The array that contains the data supplied during read operations
- */
- protected byte[] buf;
-
- /**
- * The array index of the next byte to be read from the buffer
- * <code>buf</code>
- */
- protected int pos;
-
- /**
- * The currently marked position in the stream. This defaults to 0, so a
- * reset operation on the stream resets it to read from array index 0 in
- * the buffer - even if the stream was initially created with an offset
- * greater than 0
- */
- protected int mark;
-
- /**
- * This indicates the maximum number of bytes that can be read from this
- * stream. It is the array index of the position after the last valid
- * byte in the buffer <code>buf</code>
- */
- protected int count;
-
- /**
- * Create a new ByteArrayInputStream that will read bytes from the passed
- * in byte array. This stream will read from the beginning to the end
- * of the array. It is identical to calling an overloaded constructor
- * as <code>ByteArrayInputStream(buf, 0, buf.length)</code>.
- * <p>
- * Note that this array is not copied. If its contents are changed
- * while this stream is being read, those changes will be reflected in the
- * bytes supplied to the reader. Please use caution in changing the
- * contents of the buffer while this stream is open.
- *
- * @param buf The byte array buffer this stream will read from.
- */
- public ByteArrayInputStream(byte[] buffer)
- {
- this(buffer, 0, buffer.length);
- }
-
- /**
- * Create a new ByteArrayInputStream that will read bytes from the
- * passed in byte array. This stream will read from position
- * <code>offset</code> in the array for a length of
- * <code>length</code> bytes past <code>offset</code>. If the
- * stream is reset to a position before <code>offset</code> then
- * more than <code>length</code> bytes can be read from the stream.
- * The <code>length</code> value should be viewed as the array index
- * one greater than the last position in the buffer to read.
- * <p>
- * Note that this array is not copied. If its contents are changed
- * while this stream is being read, those changes will be reflected in the
- * bytes supplied to the reader. Please use caution in changing the
- * contents of the buffer while this stream is open.
- *
- * @param buf The byte array buffer this stream will read from.
- * @param offset The index into the buffer to start reading bytes from
- * @param length The number of bytes to read from the buffer
- */
- public ByteArrayInputStream(byte[] buffer, int offset, int length)
- {
- if (offset < 0 || length < 0 || offset > buffer.length)
- throw new IllegalArgumentException();
-
- buf = buffer;
-
- count = offset + length;
- if (count > buf.length)
- count = buf.length;
-
- pos = offset;
- mark = pos;
- }
-
- /**
- * This method returns the number of bytes available to be read from this
- * stream. The value returned will be equal to <code>count - pos</code>.
- *
- * @return The number of bytes that can be read from this stream
- * before blocking, which is all of them
- */
- public synchronized int available()
- {
- return count - pos;
- }
-
- /**
- * This method sets the mark position in this stream to the current
- * position. Note that the <code>readlimit</code> parameter in this
- * method does nothing as this stream is always capable of
- * remembering all the bytes int it.
- * <p>
- * Note that in this class the mark position is set by default to
- * position 0 in the stream. This is in constrast to some other
- * stream types where there is no default mark position.
- *
- * @param readlimit The number of bytes this stream must remember.
- * This parameter is ignored.
- */
- public synchronized void mark(int readAheadLimit)
- {
- // readAheadLimit is ignored per Java Class Lib. book, p.220.
- mark = pos;
- }
-
- /**
- * This method overrides the <code>markSupported</code> method in
- * <code>InputStream</code> in order to return <code>true</code> -
- * indicating that this stream class supports mark/reset
- * functionality.
- *
- * @return <code>true</code> to indicate that this class supports
- * mark/reset.
- */
- public boolean markSupported()
- {
- return true;
- }
-
- /**
- * This method reads one byte from the stream. The <code>pos</code>
- * counter is advanced to the next byte to be read. The byte read is
- * returned as an int in the range of 0-255. If the stream position
- * is already at the end of the buffer, no byte is read and a -1 is
- * returned in order to indicate the end of the stream.
- *
- * @return The byte read, or -1 if end of stream
- */
- public synchronized int read()
- {
- if (pos < count)
- return ((int) buf[pos++]) & 0xFF;
- return -1;
- }
-
- /**
- * This method reads bytes from the 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> bytes. This method can return before reading
- * the number of bytes requested if the end of the stream is
- * encountered first. The actual number of bytes read is returned.
- * If no bytes can be read because the stream is already at the end
- * of stream position, a -1 is returned.
- * <p>
- * This method does not block.
- *
- * @param buf The array into which the bytes read should be stored.
- * @param offset The offset into the array to start storing bytes
- * @param len The requested number of bytes to read
- *
- * @return The actual number of bytes read, or -1 if end of stream.
- */
- public synchronized int read(byte[] b, int off, int len)
- {
- if (pos >= count)
- return -1;
-
- int numBytes = Math.min(count - pos, len);
- System.arraycopy(buf, pos, b, off, numBytes);
- pos += numBytes;
- return numBytes;
- }
-
- /**
- * This method sets the read position in the stream to the mark
- * point by setting the <code>pos</code> variable equal to the
- * <code>mark</code> variable. Since a mark can be set anywhere in
- * the array, the mark/reset methods int this class can be used to
- * provide random search capabilities for this type of stream.
- */
- public synchronized void reset()
- {
- pos = mark;
- }
-
- /**
- * This method attempts to skip the requested number of bytes in the
- * input stream. It does this by advancing the <code>pos</code>
- * value by the specified number of bytes. It this would exceed the
- * length of the buffer, then only enough bytes are skipped to
- * position the stream at the end of the buffer. The actual number
- * of bytes skipped is returned.
- *
- * @param num_bytes The requested number of bytes to skip
- *
- * @return The actual number of bytes skipped.
- */
- public synchronized long skip(long n)
- {
- // Even though the var numBytes is a long, in reality it can never
- // be larger than an int since the result of subtracting 2 positive
- // ints will always fit in an int. Since we have to return a long
- // anyway, numBytes might as well just be a long.
- long numBytes = Math.min((long) (count - pos), n < 0 ? 0L : n);
- pos += numBytes;
- return numBytes;
- }
-}
projects / msp430-gcc.git / blobdiff