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1
9 package org.jboss.remoting.loading;
10
11 import java.io.Externalizable  ;
12 import java.io.StreamCorruptedException ;
13
14
15
22 public class CompressedClassBytes extends ClassBytes implements Externalizable
23 {
24 static final long serialVersionUID = 5984363018051268886L;
25
26 private static final int MIN_COMPRESS = Integer.parseInt(System.getProperty("jboss.remoting.compression.min", "1000"));
27 private static final boolean DEBUG = Boolean.getBoolean("jboss.remoting.compression.debug");
28 private int compressionLevel;
29 private int compressedSize;
30 private int originalSize;
31
32 static final int VERSION_5_0 = 500;
33 static final int CURRENT_VERSION = VERSION_5_0;
34
35 public CompressedClassBytes()
36 {
37 super(null, null);
38 }
39
40 public CompressedClassBytes(String className, byte data[], int compressionLevel)
41 {
42 super(className, data);
43 this.compressionLevel = compressionLevel;
44 }
45
46 public static void main(String args[])
47 {
48 try
49 {
50 String string = new String ("Hello,world - this is a test of compression, not sure what will happen. alskjfdalksjflkajsdfljaslkfjaslkdjflksajflkajsfdlkjsalkfjaslkfdjlksajflkasjfdlkajslkfjsalkfjasldfjlksadjflkasjfdlkajdsf");
51 byte buf [] = org.jboss.remoting.loading.ClassUtil.serialize(string);
52 CompressedClassBytes cb = new CompressedClassBytes("java.lang.String", buf, 9);
53 byte b1[] = org.jboss.remoting.loading.ClassUtil.serialize(cb);
54 Object obj = ClassUtil.deserialize(b1, ClassLoader.getSystemClassLoader());
55 }
56 catch(Throwable ex)
57 {
58 ex.printStackTrace();
59 }
60 }
61
62 public void readExternal(java.io.ObjectInput in) throws java.io.IOException , ClassNotFoundException
63 {
64 int version = in.readInt();
65
66 switch(version)
67 {
68
69 case VERSION_5_0:
70 {
71
72 compressionLevel = in.readInt();
73 originalSize = in.readInt();
74 compressedSize = in.readInt();
75 byte buf[] = new byte[compressedSize];
76 int count = in.read(buf, 0, compressedSize);
77 if(compressedSize != originalSize)
78 {
79 this.classBytes = uncompress(buf);
80 }
81 else
82 {
83 this.classBytes = buf;
84 }
85 if(DEBUG)
86 {
87 System.err.println("<< reading compressed: " + compressedSize + ", original: " + originalSize + ", compressionLevel:" + compressionLevel);
88 }
89 this.className = (String ) in.readObject();
90 }
91 default:
92 throw new StreamCorruptedException ("Unknown version seen: " + version);
93 }
94 }
95
96 public void writeExternal(java.io.ObjectOutput out) throws java.io.IOException
97 {
98 out.writeInt(CURRENT_VERSION);
99 out.writeInt(compressionLevel);
100 out.writeInt(classBytes.length);
101 byte compressed [] = compress(classBytes);
102 out.writeInt(compressed.length);
103 out.write(compressed);
104 out.writeObject(className);
105 out.flush();
106 }
107
108
109
114 public byte[] compress(byte[] input)
115 {
116 if(input.length < MIN_COMPRESS)
118 {
119 return input;
120 }
121
122 java.util.zip.Deflater deflater = new java.util.zip.Deflater (compressionLevel);
123 deflater.setInput(input, 0, input.length);
124 deflater.finish();
125 byte[] buff = new byte[input.length + 50];
126 deflater.deflate(buff);
127
128 int compressedSize = deflater.getTotalOut();
129
130 if(deflater.getTotalIn() != input.length)
132 {
133 if(DEBUG)
134 {
135 System.err.println(">> Attempting compression and the data didn't compress well, returning original");
136 }
137 return input;
138 }
139 if(compressedSize >= input.length - 4)
140 {
141 if(DEBUG)
142 {
143 System.err.println(">> Compressed size is larger than original .. ?");
144 }
145 return input;
146 }
147
148 byte[] output = new byte[compressedSize + 4];
149 System.arraycopy(buff, 0, output, 4, compressedSize);
150 output[0] = (byte) (input.length >> 24);
151 output[1] = (byte) (input.length >> 16);
152 output[2] = (byte) (input.length >> 8);
153 output[3] = (byte) (input.length);
154 if(DEBUG)
155 {
156 System.err.println(">> writing compressed: " + output.length + ", original: " + classBytes.length + ", compressionLevel:" + compressionLevel);
157 }
158 return output;
159 }
160
161
166 public byte[] uncompress(byte[] input) throws java.io.IOException
167 {
168 try
169 {
170 int uncompressedSize =
171 (((input[0] & 0xff) << 24) +
172 ((input[1] & 0xff) << 16) +
173 ((input[2] & 0xff) << 8) +
174 ((input[3] & 0xff)));
175
176 java.util.zip.Inflater inflater = new java.util.zip.Inflater ();
177 inflater.setInput(input, 4, input.length - 4);
178 inflater.finished();
179
180 byte[] out = new byte[uncompressedSize];
181 inflater.inflate(out);
182
183 inflater.reset();
184 return out;
185
186 }
187 catch(java.util.zip.DataFormatException e)
188 {
189 throw new java.io.IOException ("Input Stream is corrupt: " + e);
190 }
191 }
192 }
193 |
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