Mercurial > hg > Members > nobuyasu > tightVNCClient

comparison src/ZlibInStream.java @ 0:e04119c40b9b

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
upload all file of tighVNCClient
author e085711
date Tue, 12 Apr 2011 12:57:33 +0900
parents
children dc1d008d987b
comparison
equal deleted inserted replaced
-1:000000000000 0:e04119c40b9b
1 /* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
2 *
3 * This is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
7 *
8 * This software is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this software; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
16 * USA.
17 */
18
19 //
20 // A ZlibInStream reads from a zlib.io.InputStream
21 //
22
23 public class ZlibInStream extends InStream {
24
25 static final int defaultBufSize = 16384;
26
27 public ZlibInStream(int bufSize_) {
28 bufSize = bufSize_;
29 b = new byte[bufSize];
30 ptr = end = ptrOffset = 0;
31 inflater = new java.util.zip.Inflater();
32 }
33
34 public ZlibInStream() { this(defaultBufSize); }
35
36 public void setUnderlying(InStream is, int bytesIn_) {
37 underlying = is;
38 bytesIn = bytesIn_;
39 ptr = end = 0;
40 }
41
42 public void reset() throws Exception {
43 ptr = end = 0;
44 if (underlying == null) return;
45
46 while (bytesIn > 0) {
47 decompress();
48 end = 0; // throw away any data
49 }
50 underlying = null;
51 }
52
53 public int pos() { return ptrOffset + ptr; }
54
55 protected int overrun(int itemSize, int nItems) throws Exception {
56 if (itemSize > bufSize)
57 throw new Exception("ZlibInStream overrun: max itemSize exceeded");
58 if (underlying == null)
59 throw new Exception("ZlibInStream overrun: no underlying stream");
60
61 if (end - ptr != 0)
62 System.arraycopy(b, ptr, b, 0, end - ptr);
63
64 ptrOffset += ptr;
65 end -= ptr;
66 ptr = 0;
67
68 while (end < itemSize) {
69 decompress();
70 }
71
72 if (itemSize * nItems > end)
73 nItems = end / itemSize;
74
75 return nItems;
76 }
77
78 // decompress() calls the decompressor once. Note that this won't
79 // necessarily generate any output data - it may just consume some input
80 // data. Returns false if wait is false and we would block on the underlying
81 // stream.
82
83 private void decompress() throws Exception {
84 try {
85 underlying.check(1);
86 int avail_in = underlying.getend() - underlying.getptr();
87 if (avail_in > bytesIn)
88 avail_in = bytesIn;
89
90 if (inflater.needsInput()) {
91 inflater.setInput(underlying.getbuf(), underlying.getptr(), avail_in);
92 }
93
94 int n = inflater.inflate(b, end, bufSize - end);
95
96 end += n;
97 if (inflater.needsInput()) {
98 bytesIn -= avail_in;
99 underlying.setptr(underlying.getptr() + avail_in);
100 }
101 } catch (java.util.zip.DataFormatException e) {
102 throw new Exception("ZlibInStream: inflate failed");
103 }
104 }
105
106 private InStream underlying;
107 private int bufSize;
108 private int ptrOffset;
109 private java.util.zip.Inflater inflater;
110 private int bytesIn;
111 }