Mercurial > hg > blitz_stable
view src/com/go/trove/io/PushbackPositionReader.java @ 8:fa7203ea1622
Remove some dead code (Dave Brosius)
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 23 May 2009 11:27:41 +0100 |
parents | 3dc0c5604566 |
children |
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/* ==================================================================== * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group * ==================================================================== * The Tea Software License, Version 1.1 * * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by the * Walt Disney Internet Group (http://opensource.go.com/)." * Alternately, this acknowledgment may appear in the software itself, * if and wherever such third-party acknowledgments normally appear. * * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must * not be used to endorse or promote products derived from this * software without prior written permission. For written * permission, please contact opensource@dig.com. * * 5. Products derived from this software may not be called "Tea", * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet", * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior * written permission of the Walt Disney Internet Group. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * For more information about Tea, please see http://opensource.go.com/. */ package com.go.trove.io; import java.io.*; /****************************************************************************** * The PushbackPositionReader is a kind of pushback reader that tracks the * postion in the stream of the next character to be read. * The java.io.PushbackReader allows arbitrary characters * to be pushed back. Since this Reader may need to keep track of how many * characters were scanned from the underlying Reader to actually produce * a character, the unread operation cannot accept any arbitrary character. * * @author Brian S O'Neill * @version * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 12/11/00 <!-- $--> * @see java.io.PushbackReader */ public class PushbackPositionReader extends PositionReader { /** Maximum pushback allowed. */ private int mMaxPushback; /** Most recently read characters with escapes already processed. */ private int[] mCharacters; /** The scan lengths of the most recently read characters. */ private int[] mPositions; /** The cursor marks the position in the arrays of the last character. */ private int mCursor; /** Amount of characters currently pushed back. */ private int mPushback; public PushbackPositionReader(Reader reader) { this(reader, 0); } public PushbackPositionReader(Reader reader, int pushback) { super(reader); // Two more are required for correct operation pushback += 2; mMaxPushback = pushback; mCharacters = new int[pushback]; mPositions = new int[pushback]; mCursor = 0; mPushback = 0; } /** * @return the start position of the last read character. */ public int getStartPosition() { int back = mCursor - 2; if (back < 0) back += mMaxPushback; return mPositions[back]; } public int read() throws IOException { int c; if (mPushback > 0) { mPushback--; mPosition = mPositions[mCursor]; c = mCharacters[mCursor++]; if (mCursor >= mMaxPushback) mCursor = 0; return c; } c = super.read(); mPositions[mCursor] = mPosition; mCharacters[mCursor++] = c; if (mCursor >= mMaxPushback) mCursor = 0; return c; } public int peek() throws IOException { int c = read(); unread(); return c; } /** * Unread the last several characters read. * * <p>Unlike PushbackReader, unread does not allow arbitrary characters to * to be unread. Rather, it functions like an undo operation. * * @param amount Amount of characters to unread. * @see java.io.PushbackReader#unread(int) */ public void unread(int amount) throws IOException { for (int i=0; i<amount; i++) { unread(); } } /** * Unread the last character read. * * <p>Unlike PushbackReader, unread does not allow arbitrary characters to * to be unread. Rather, it functions like an undo operation. * * @see java.io.PushbackReader#unread(int) */ public void unread() throws IOException { mPushback++; if (mPushback > mMaxPushback - 2) { throw new IOException(this.getClass().getName() + ": pushback exceeded " + (mMaxPushback - 2)); } if ((--mCursor) < 0) mCursor += mMaxPushback; if (mCursor > 0) { mPosition = mPositions[mCursor - 1]; } else { mPosition = mPositions[mMaxPushback - 1]; } unreadHook(mCharacters[mCursor]); } /** * A hook call from the unread method(s). Every unread character is * passed to this method. */ protected void unreadHook(int c) { } }