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- /* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
- *
- * This 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 of the License, or
- * (at your option) any later version.
- *
- * This software 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 this software; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
- * USA.
- */
-
- //
- // A ZlibInStream reads from a zlib.io.InputStream
- //
-
- public class ZlibInStream extends InStream {
-
- static final int defaultBufSize = 16384;
-
- public ZlibInStream(int bufSize_) {
- bufSize = bufSize_;
- b = new byte[bufSize];
- ptr = end = ptrOffset = 0;
- inflater = new java.util.zip.Inflater();
- }
-
- public ZlibInStream() { this(defaultBufSize); }
-
- public void setUnderlying(InStream is, int bytesIn_) {
- underlying = is;
- bytesIn = bytesIn_;
- ptr = end = 0;
- }
-
- public void reset() throws Exception {
- ptr = end = 0;
- if (underlying == null) return;
-
- while (bytesIn > 0) {
- decompress();
- end = 0; // throw away any data
- }
- underlying = null;
- }
-
- public int pos() { return ptrOffset + ptr; }
-
- protected int overrun(int itemSize, int nItems) throws Exception {
- if (itemSize > bufSize)
- throw new Exception("ZlibInStream overrun: max itemSize exceeded");
- if (underlying == null)
- throw new Exception("ZlibInStream overrun: no underlying stream");
-
- if (end - ptr != 0)
- System.arraycopy(b, ptr, b, 0, end - ptr);
-
- ptrOffset += ptr;
- end -= ptr;
- ptr = 0;
-
- while (end < itemSize) {
- decompress();
- }
-
- if (itemSize * nItems > end)
- nItems = end / itemSize;
-
- return nItems;
- }
-
- // decompress() calls the decompressor once. Note that this won't
- // necessarily generate any output data - it may just consume some input
- // data. Returns false if wait is false and we would block on the underlying
- // stream.
-
- private void decompress() throws Exception {
- try {
- underlying.check(1);
- int avail_in = underlying.getend() - underlying.getptr();
- if (avail_in > bytesIn)
- avail_in = bytesIn;
-
- if (inflater.needsInput()) {
- inflater.setInput(underlying.getbuf(), underlying.getptr(), avail_in);
- }
-
- int n = inflater.inflate(b, end, bufSize - end);
-
- end += n;
- if (inflater.needsInput()) {
- bytesIn -= avail_in;
- underlying.setptr(underlying.getptr() + avail_in);
- }
- } catch (java.util.zip.DataFormatException e) {
- throw new Exception("ZlibInStream: inflate failed");
- }
- }
-
- private InStream underlying;
- private int bufSize;
- private int ptrOffset;
- private java.util.zip.Inflater inflater;
- private int bytesIn;
- }
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