1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
/*
* ConnectBot: simple, powerful, open-source SSH client for Android
* Copyright 2007 Kenny Root, Jeffrey Sharkey
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.trilead.ssh2.compression;
import com.jcraft.jzlib.JZlib;
import com.jcraft.jzlib.ZStream;
/**
* @author Kenny Root
*
*/
public class Zlib implements ICompressor {
static private final int DEFAULT_BUF_SIZE = 4096;
static private final int LEVEL = 5;
private ZStream deflate;
private byte[] deflate_tmpbuf;
private ZStream inflate;
private byte[] inflate_tmpbuf;
private byte[] inflated_buf;
public Zlib() {
deflate = new ZStream();
inflate = new ZStream();
deflate.deflateInit(LEVEL);
inflate.inflateInit();
deflate_tmpbuf = new byte[DEFAULT_BUF_SIZE];
inflate_tmpbuf = new byte[DEFAULT_BUF_SIZE];
inflated_buf = new byte[DEFAULT_BUF_SIZE];
}
public boolean canCompressPreauth() {
return true;
}
public int getBufferSize() {
return DEFAULT_BUF_SIZE;
}
public int compress(byte[] buf, int start, int len, byte[] output) {
deflate.next_in = buf;
deflate.next_in_index = start;
deflate.avail_in = len - start;
if ((buf.length + 1024) > deflate_tmpbuf.length) {
deflate_tmpbuf = new byte[buf.length + 1024];
}
deflate.next_out = deflate_tmpbuf;
deflate.next_out_index = 0;
deflate.avail_out = output.length;
if (deflate.deflate(JZlib.Z_PARTIAL_FLUSH) != JZlib.Z_OK) {
System.err.println("compress: compression failure");
}
if (deflate.avail_in > 0) {
System.err.println("compress: deflated data too large");
}
int outputlen = output.length - deflate.avail_out;
System.arraycopy(deflate_tmpbuf, 0, output, 0, outputlen);
return outputlen;
}
public byte[] uncompress(byte[] buffer, int start, int[] length) {
int inflated_end = 0;
inflate.next_in = buffer;
inflate.next_in_index = start;
inflate.avail_in = length[0];
while (true) {
inflate.next_out = inflate_tmpbuf;
inflate.next_out_index = 0;
inflate.avail_out = DEFAULT_BUF_SIZE;
int status = inflate.inflate(JZlib.Z_PARTIAL_FLUSH);
switch (status) {
case JZlib.Z_OK:
if (inflated_buf.length < inflated_end + DEFAULT_BUF_SIZE
- inflate.avail_out) {
byte[] foo = new byte[inflated_end + DEFAULT_BUF_SIZE
- inflate.avail_out];
System.arraycopy(inflated_buf, 0, foo, 0, inflated_end);
inflated_buf = foo;
}
System.arraycopy(inflate_tmpbuf, 0, inflated_buf, inflated_end,
DEFAULT_BUF_SIZE - inflate.avail_out);
inflated_end += (DEFAULT_BUF_SIZE - inflate.avail_out);
length[0] = inflated_end;
break;
case JZlib.Z_BUF_ERROR:
if (inflated_end > buffer.length - start) {
byte[] foo = new byte[inflated_end + start];
System.arraycopy(buffer, 0, foo, 0, start);
System.arraycopy(inflated_buf, 0, foo, start, inflated_end);
buffer = foo;
} else {
System.arraycopy(inflated_buf, 0, buffer, start,
inflated_end);
}
length[0] = inflated_end;
return buffer;
default:
System.err.println("uncompress: inflate returnd " + status);
return null;
}
}
}
}
|
