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/*
* Copyright (c) 1998, 2008, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
*/
import java.io.*;
class CompressInputStream extends FilterInputStream
implements CompressConstants
{
public CompressInputStream(InputStream in) {
super(in);
}
// buffer of unpacked 6-bit codes from last 32-word read
int buf[] = new int[5];
// position of next code to read in buffer (5 == end of buffer)
int bufPos = 5;
public int read() throws IOException {
try {
int code;
do {
code = readCode();
} while (code == NOP); // ignore NOP codes
if (code >= BASE)
return codeTable.charAt(code - BASE);
else if (code == RAW) {
int high = readCode();
int low = readCode();
return (high << 4) | low;
} else
throw new IOException("unknown compression code: " + code);
} catch (EOFException e) {
return -1;
}
}
public int read(byte b[], int off, int len) throws IOException {
if (len <= 0) {
return 0;
}
int c = read();
if (c == -1) {
return -1;
}
b[off] = (byte)c;
int i = 1;
/*****
try {
for (; i < len ; i++) {
c = read();
if (c == -1) {
break;
}
if (b != null) {
b[off + i] = (byte)c;
}
}
} catch (IOException ee) {
}
*****/
return i;
}
private int readCode() throws IOException {
if (bufPos == 5) {
int b1 = in.read();
int b2 = in.read();
int b3 = in.read();
int b4 = in.read();
if ((b1 | b2 | b3 | b4) < 0)
throw new EOFException();
int pack = (b1 << 24) | (b2 << 16) | (b3 << 8) | b4;
buf[0] = (pack >>> 24) & 0x3F;
buf[1] = (pack >>> 18) & 0x3F;
buf[2] = (pack >>> 12) & 0x3F;
buf[3] = (pack >>> 6) & 0x3F;
buf[4] = (pack >>> 0) & 0x3F;
bufPos = 0;
}
return buf[bufPos++];
}
}
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