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- /* java.util.zip.PendingBuffer
- Copyright (C) 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., 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.util.zip;
- /**
- * This class is general purpose class for writing data to a buffer.
- *
- * It allows you to write bits as well as bytes
- *
- * Based on DeflaterPending.java
- *
- * @author Jochen Hoenicke
- * @date Jan 5, 2000
- */
- class PendingBuffer
- {
- protected byte[] buf;
- int start;
- int end;
- int bits;
- int bitCount;
- public PendingBuffer()
- {
- this( 4096 );
- }
- public PendingBuffer(int bufsize)
- {
- buf = new byte[bufsize];
- }
- public final void reset() {
- start = end = bitCount = 0;
- }
- public final void writeByte(int b)
- {
- if (DeflaterConstants.DEBUGGING && start != 0)
- throw new IllegalStateException();
- buf[end++] = (byte) b;
- }
- public final void writeShort(int s)
- {
- if (DeflaterConstants.DEBUGGING && start != 0)
- throw new IllegalStateException();
- buf[end++] = (byte) s;
- buf[end++] = (byte) (s >> 8);
- }
- public final void writeInt(int s)
- {
- if (DeflaterConstants.DEBUGGING && start != 0)
- throw new IllegalStateException();
- buf[end++] = (byte) s;
- buf[end++] = (byte) (s >> 8);
- buf[end++] = (byte) (s >> 16);
- buf[end++] = (byte) (s >> 24);
- }
- public final void writeBlock(byte[] block, int offset, int len)
- {
- if (DeflaterConstants.DEBUGGING && start != 0)
- throw new IllegalStateException();
- System.arraycopy(block, offset, buf, end, len);
- end += len;
- }
- public final int getBitCount() {
- return bitCount;
- }
- public final void alignToByte() {
- if (DeflaterConstants.DEBUGGING && start != 0)
- throw new IllegalStateException();
- if (bitCount > 0)
- {
- buf[end++] = (byte) bits;
- if (bitCount > 8)
- buf[end++] = (byte) (bits >>> 8);
- }
- bits = 0;
- bitCount = 0;
- }
- public final void writeBits(int b, int count)
- {
- if (DeflaterConstants.DEBUGGING && start != 0)
- throw new IllegalStateException();
- if (DeflaterConstants.DEBUGGING)
- System.err.println("writeBits("+Integer.toHexString(b)+","+count+")");
- bits |= b << bitCount;
- bitCount += count;
- if (bitCount >= 16) {
- buf[end++] = (byte) bits;
- buf[end++] = (byte) (bits >>> 8);
- bits >>>= 16;
- bitCount -= 16;
- }
- }
- public final void writeShortMSB(int s) {
- if (DeflaterConstants.DEBUGGING && start != 0)
- throw new IllegalStateException();
- buf[end++] = (byte) (s >> 8);
- buf[end++] = (byte) s;
- }
- public final boolean isFlushed() {
- return end == 0;
- }
- /**
- * Flushes the pending buffer into the given output array. If the
- * output array is to small, only a partial flush is done.
- *
- * @param output the output array;
- * @param offset the offset into output array;
- * @param length the maximum number of bytes to store;
- * @exception IndexOutOfBoundsException if offset or length are
- * invalid.
- */
- public final int flush(byte[] output, int offset, int length) {
- if (bitCount >= 8)
- {
- buf[end++] = (byte) bits;
- bits >>>= 8;
- bitCount -= 8;
- }
- if (length > end - start)
- {
- length = end - start;
- System.arraycopy(buf, start, output, offset, length);
- start = 0;
- end = 0;
- }
- else
- {
- System.arraycopy(buf, start, output, offset, length);
- start += length;
- }
- return length;
- }
- /**
- * Flushes the pending buffer and returns that data in a new array
- *
- * @return the output stream
- */
- public final byte[] toByteArray()
- {
- byte[] ret = new byte[ end - start ];
- System.arraycopy(buf, start, ret, 0, ret.length);
- start = 0;
- end = 0;
- return ret;
- }
- }
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