Mercurial > hg > Members > nobuyasu > tightVNCProxy

comparison src/myVncProxy/ZlibInStream.java @ 24:87b29d6039a6

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add package myVncProxy
author e085711
date Sun, 24 Apr 2011 23:03:00 +0900
parents src/ZlibInStream.java@ccad9909e0e2
children 0571d955da35
comparison
equal deleted inserted replaced
23:b51bb7bc0766 24:87b29d6039a6
1 package myVncProxy;
2 /* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
3 *
4 * This is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This software is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this software; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
17 * USA.
18 */
19
20 //
21 // A ZlibInStream reads from a zlib.io.InputStream
22 //
23
24 public class ZlibInStream extends InStream {
25
26 static final int defaultBufSize = 16384;
27
28 public ZlibInStream(int bufSize_) {
29 bufSize = bufSize_;
30 b = new byte[bufSize];
31 ptr = end = ptrOffset = 0;
32 inflater = new java.util.zip.Inflater();
33 }
34
35 public ZlibInStream() { this(defaultBufSize); }
36
37 public void setUnderlying(InStream is, int bytesIn_) {
38 underlying = is;
39 bytesIn = bytesIn_;
40 ptr = end = 0;
41 }
42
43 public void reset() throws Exception {
44 ptr = end = 0;
45 if (underlying == null) return;
46
47 while (bytesIn > 0) {
48 decompress();
49 end = 0; // throw away any data
50 }
51 underlying = null;
52 }
53
54 public int pos() { return ptrOffset + ptr; }
55
56
57 protected int overrun(int itemSize, int nItems) throws Exception {
58 if (itemSize > bufSize)
59 throw new Exception("ZlibInStream overrun: max itemSize exceeded");
60 if (underlying == null)
61 throw new Exception("ZlibInStream overrun: no underlying stream");
62
63 if (end - ptr != 0)
64 System.arraycopy(b, ptr, b, 0, end - ptr);
65
66 ptrOffset += ptr;
67 end -= ptr;
68 ptr = 0;
69
70 while (end < itemSize) {
71 decompress();
72 }
73
74 if (itemSize * nItems > end)
75 nItems = end / itemSize;
76
77 return nItems;
78 }
79
80 // decompress() calls the decompressor once. Note that this won't
81 // necessarily generate any output data - it may just consume some input
82 // data. Returns false if wait is false and we would block on the underlying
83 // stream.
84
85 private void decompress() throws Exception {
86 try {
87 underlying.check(1);
88 int avail_in = underlying.getend() - underlying.getptr();
89 if (avail_in > bytesIn)
90 avail_in = bytesIn;
91
92 if (inflater.needsInput()) {
93 inflater.setInput(underlying.getbuf(), underlying.getptr(), avail_in);
94 }
95
96 int n = inflater.inflate(b, end, bufSize - end);
97
98 end += n;
99 if (inflater.needsInput()) {
100 bytesIn -= avail_in;
101 underlying.setptr(underlying.getptr() + avail_in);
102 }
103 } catch (java.util.zip.DataFormatException e) {
104 throw new Exception("ZlibInStream: inflate failed");
105 }
106 }
107
108 private InStream underlying;
109 private int bufSize;
110 private int ptrOffset;
111 private java.util.zip.Inflater inflater;
112 private int bytesIn;
113 }