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Diffstat (limited to 'libjava/java/io/BufferedInputStream.java')
-rw-r--r-- | libjava/java/io/BufferedInputStream.java | 390 |
1 files changed, 0 insertions, 390 deletions
diff --git a/libjava/java/io/BufferedInputStream.java b/libjava/java/io/BufferedInputStream.java deleted file mode 100644 index 36e58f6..0000000 --- a/libjava/java/io/BufferedInputStream.java +++ /dev/null @@ -1,390 +0,0 @@ -/* BufferedInputStream.java -- An input stream that implements buffering - Copyright (C) 1998, 1999, 2001, 2004, 2005 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., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 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, ISBN 0-201-31002-3 - * "The Java Language Specification", ISBN 0-201-63451-1 - * plus online API docs for JDK 1.2 beta from http://www.javasoft.com. - * Status: Believed complete and correct. - */ - -/** - * This subclass of <code>FilterInputStream</code> buffers input from an - * underlying implementation to provide a possibly more efficient read - * mechanism. It maintains the buffer and buffer state in instance - * variables that are available to subclasses. The default buffer size - * of 2048 bytes can be overridden by the creator of the stream. - * <p> - * This class also implements mark/reset functionality. It is capable - * of remembering any number of input bytes, to the limits of - * system memory or the size of <code>Integer.MAX_VALUE</code> - * <p> - * Please note that this class does not properly handle character - * encodings. Consider using the <code>BufferedReader</code> class which - * does. - * - * @author Aaron M. Renn (arenn@urbanophile.com) - * @author Warren Levy (warrenl@cygnus.com) - * @author Jeroen Frijters (jeroen@frijters.net) - */ -public class BufferedInputStream extends FilterInputStream -{ - - /** - * This is the default buffer size - */ - private static final int DEFAULT_BUFFER_SIZE = 2048; - - /** - * The buffer used for storing data from the underlying stream. - */ - protected byte[] buf; - - /** - * The number of valid bytes currently in the buffer. It is also the index - * of the buffer position one byte past the end of the valid data. - */ - protected int count; - - /** - * The index of the next character that will by read from the buffer. - * When <code>pos == count</code>, the buffer is empty. - */ - protected int pos; - - /** - * The value of <code>pos</code> when the <code>mark()</code> method was - * called. - * This is set to -1 if there is no mark set. - */ - protected int markpos = -1; - - /** - * This is the maximum number of bytes than can be read after a - * call to <code>mark()</code> before the mark can be discarded. - * After this may bytes are read, the <code>reset()</code> method - * may not be called successfully. - */ - protected int marklimit; - - /** - * This is the initial buffer size. When the buffer is grown because - * of marking requirements, it will be grown by bufferSize increments. - * The underlying stream will be read in chunks of bufferSize. - */ - private final int bufferSize; - - /** - * This method initializes a new <code>BufferedInputStream</code> that will - * read from the specified subordinate stream with a default buffer size - * of 2048 bytes - * - * @param in The subordinate stream to read from - */ - public BufferedInputStream(InputStream in) - { - this(in, DEFAULT_BUFFER_SIZE); - } - - /** - * This method initializes a new <code>BufferedInputStream</code> that will - * read from the specified subordinate stream with a buffer size that - * is specified by the caller. - * - * @param in The subordinate stream to read from - * @param size The buffer size to use - * - * @exception IllegalArgumentException when size is smaller then 1 - */ - public BufferedInputStream(InputStream in, int size) - { - super(in); - if (size <= 0) - throw new IllegalArgumentException(); - buf = new byte[size]; - // initialize pos & count to bufferSize, to prevent refill from - // allocating a new buffer (if the caller starts out by calling mark()). - pos = count = bufferSize = size; - } - - /** - * This method returns the number of bytes that can be read from this - * stream before a read can block. A return of 0 indicates that blocking - * might (or might not) occur on the very next read attempt. - * <p> - * The number of available bytes will be the number of read ahead bytes - * stored in the internal buffer plus the number of available bytes in - * the underlying stream. - * - * @return The number of bytes that can be read before blocking could occur - * - * @exception IOException If an error occurs - */ - public synchronized int available() throws IOException - { - return count - pos + in.available(); - } - - /** - * This method closes the underlying input stream and frees any - * resources associated with it. Sets <code>buf</code> to <code>null</code>. - * - * @exception IOException If an error occurs. - */ - public void close() throws IOException - { - // Free up the array memory. - buf = null; - pos = count = 0; - markpos = -1; - in.close(); - } - - /** - * This method 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 bytes 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 bytes 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. - * <p> - * Note that the number of bytes that can be remembered by this method - * can be greater than the size of the internal read buffer. It is also - * not dependent on the subordinate stream supporting mark/reset - * functionality. - * - * @param readlimit The number of bytes that can be read before the mark - * becomes invalid - */ - public synchronized void mark(int readlimit) - { - marklimit = readlimit; - markpos = pos; - } - - /** - * This method returns <code>true</code> to indicate that this class - * supports mark/reset functionality. - * - * @return <code>true</code> to indicate that mark/reset functionality is - * supported - * - */ - public boolean markSupported() - { - return true; - } - - /** - * This method reads an unsigned byte from the input stream and returns it - * as an int in the range of 0-255. This method also will return -1 if - * the end of the stream has been reached. - * <p> - * This method will block until the byte can be read. - * - * @return The byte read or -1 if end of stream - * - * @exception IOException If an error occurs - */ - public synchronized int read() throws IOException - { - if (pos >= count && !refill()) - return -1; // EOF - - return buf[pos++] & 0xFF; - } - - /** - * This method reads bytes from a stream and stores them into a caller - * supplied buffer. It starts storing the data at index <code>off</code> - * into the buffer and attempts to read <code>len</code> bytes. This method - * can return before reading the number of bytes requested, but it will try - * to read the requested number of bytes by repeatedly calling the underlying - * stream as long as available() for this stream continues to return a - * non-zero value (or until the requested number of bytes have been read). - * The actual number of bytes 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. - * - * @param b The array into which the bytes read should be stored - * @param off 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. - * - * @exception IOException If an error occurs. - * @exception IndexOutOfBoundsException when <code>off</code> or - * <code>len</code> are negative, or when <code>off + len</code> - * is larger then the size of <code>b</code>, - */ - public synchronized int read(byte[] b, int off, int len) throws IOException - { - if (off < 0 || len < 0 || b.length - off < len) - throw new IndexOutOfBoundsException(); - - if (len == 0) - return 0; - - if (pos >= count && !refill()) - return -1; // No bytes were read before EOF. - - int totalBytesRead = Math.min(count - pos, len); - System.arraycopy(buf, pos, b, off, totalBytesRead); - pos += totalBytesRead; - off += totalBytesRead; - len -= totalBytesRead; - - while (len > 0 && in.available() > 0 && refill()) - { - int remain = Math.min(count - pos, len); - System.arraycopy(buf, pos, b, off, remain); - pos += remain; - off += remain; - len -= remain; - totalBytesRead += remain; - } - - return totalBytesRead; - } - - /** - * This method resets a stream to the point where the <code>mark()</code> - * method was called. Any bytes that were read after the mark point was - * set will be re-read during subsequent reads. - * <p> - * This method will throw an IOException if the number of bytes read from - * the stream since the call to <code>mark()</code> exceeds the mark limit - * passed when establishing the mark. - * - * @exception IOException If <code>mark()</code> was never called or more - * then <code>marklimit</code> bytes were read since the last - * call to <code>mark()</code> - */ - public synchronized void reset() throws IOException - { - if (markpos == -1) - throw new IOException(buf == null ? "Stream closed." : "Invalid mark."); - - pos = markpos; - } - - /** - * This method skips the specified number of bytes in the stream. It - * returns the actual number of bytes skipped, which may be less than the - * requested amount. - * - * @param n The requested number of bytes to skip - * - * @return The actual number of bytes skipped. - * - * @exception IOException If an error occurs - */ - public synchronized long skip(long n) throws IOException - { - if (buf == null) - throw new IOException("Stream closed."); - - final long origN = n; - - while (n > 0L) - { - if (pos >= count) - { - if (markpos == -1) - { - // Buffer is empty and no mark is set, skip on the - // underlying stream. - n -= in.skip(n); - break; - } - else if (!refill()) - break; - } - - int numread = (int) Math.min((long) (count - pos), n); - pos += numread; - n -= numread; - } - - return origN - n; - } - - // GCJ LOCAL: package-private for use by InputStreamReader - /** - * Called to refill the buffer (when count is equal to pos). - * - * @return <code>true</code> when at least one additional byte was read - * into <code>buf</code>, <code>false</code> otherwise (at EOF). - */ - boolean refill() throws IOException - { - if (buf == null) - throw new IOException("Stream closed."); - - if (markpos == -1 || count - markpos >= marklimit) - { - markpos = -1; - pos = count = 0; - } - else - { - byte[] newbuf = buf; - if (markpos < bufferSize) - { - newbuf = new byte[count - markpos + bufferSize]; - } - System.arraycopy(buf, markpos, newbuf, 0, count - markpos); - buf = newbuf; - count -= markpos; - pos -= markpos; - markpos = 0; - } - - int numread = in.read(buf, count, bufferSize); - - if (numread <= 0) // EOF - return false; - - count += numread; - return true; - } -} |