| /* BufferedReader.java -- |
| Copyright (C) 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 gnu.xml.stream; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| |
| /** |
| * A mark-capable buffered reader. |
| * |
| * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a> |
| */ |
| class BufferedReader |
| extends Reader |
| { |
| |
| static final int DEFAULT_BUFFER_SIZE = 4096; |
| |
| final Reader in; |
| char[] buf; |
| int pos, count, markpos, marklimit, bufferSize; |
| |
| BufferedReader(Reader in) |
| { |
| this(in, DEFAULT_BUFFER_SIZE); |
| } |
| |
| BufferedReader(Reader in, int bufferSize) |
| { |
| if (bufferSize < 1) |
| throw new IllegalArgumentException(); |
| this.in = in; |
| this.bufferSize = bufferSize; |
| buf = new char[bufferSize]; |
| pos = count = bufferSize; |
| } |
| |
| public void close() |
| throws IOException |
| { |
| buf = null; |
| pos = count = 0; |
| markpos = -1; |
| in.close(); |
| } |
| |
| public void mark(int readlimit) |
| throws IOException |
| { |
| marklimit = readlimit; |
| markpos = pos; |
| } |
| |
| public boolean markSupported() |
| { |
| return true; |
| } |
| |
| public int read() |
| throws IOException |
| { |
| if (pos >= count && !refill()) |
| return -1; |
| return (int) buf[pos++]; |
| } |
| |
| public int read(char[] b) |
| throws IOException |
| { |
| return read(b, 0, b.length); |
| } |
| |
| public int read(char[] 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; |
| |
| int ret = Math.min(count - pos, len); |
| System.arraycopy(buf, pos, b, off, ret); |
| pos += ret; |
| off += ret; |
| len -= ret; |
| |
| while (len > 0 && refill()) |
| { |
| int remain = Math.min(count - pos, len); |
| System.arraycopy(buf, pos, b, off, remain); |
| pos += remain; |
| off += remain; |
| len -= remain; |
| ret += remain; |
| } |
| |
| return ret; |
| } |
| |
| public void reset() |
| throws IOException |
| { |
| if (markpos == -1) |
| throw new IOException(buf == null ? "Stream closed." : "Invalid mark."); |
| pos = markpos; |
| } |
| |
| public long skip(long n) |
| throws IOException |
| { |
| if (buf == null) |
| throw new IOException("Stream closed."); |
| final long origN = n; |
| while (n > 0L) |
| { |
| if (pos >= count && !refill()) |
| break; |
| int numread = (int) Math.min((long) (count - pos), n); |
| pos += numread; |
| n -= numread; |
| } |
| return origN - n; |
| } |
| |
| private boolean refill() |
| throws IOException |
| { |
| if (buf == null) |
| throw new IOException("Stream closed."); |
| |
| int markcount = count - markpos; |
| if (markpos == -1 || markcount >= marklimit) |
| { |
| markpos = -1; |
| pos = count = 0; |
| } |
| else |
| { |
| char[] newbuf = buf; |
| if (markpos < bufferSize) |
| { |
| newbuf = new char[count - markpos + bufferSize]; |
| } |
| System.arraycopy(buf, markpos, newbuf, 0, markcount); |
| buf = newbuf; |
| count = markcount; |
| pos -= markpos; |
| markpos = 0; |
| } |
| |
| int numread = in.read(buf, count, bufferSize); |
| if (numread <= 0) |
| return false; |
| |
| count += numread; |
| return true; |
| } |
| |
| } |