| /* |
| * 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.*; |
| import java.rmi.server.*; |
| import java.net.*; |
| |
| public class Compress { |
| |
| interface CompressConstants { |
| // constants for 6-bit code values |
| static final int NOP = 0; // no operation: used to pad words on flush() |
| static final int RAW = 1; // introduces raw byte format |
| static final int BASE = 2; // base for codes found in lookup table |
| static final String codeTable = |
| "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ ,.!?\"'()"; |
| } |
| |
| public static class CompressRMIClientSocketFactory |
| implements java.rmi.server.RMIClientSocketFactory, Serializable { |
| |
| public Socket createSocket(String host, int port) |
| throws IOException { |
| |
| return ((Socket) new CompressSocket(host, port)); |
| } |
| } |
| |
| public static class CompressRMIServerSocketFactory |
| implements RMIServerSocketFactory, |
| Serializable { |
| |
| public ServerSocket createServerSocket(int port) |
| throws IOException { |
| |
| return ((ServerSocket) new CompressServerSocket(port)); |
| } |
| } |
| |
| public static class CompressSocket extends Socket { |
| private InputStream in; |
| private OutputStream out; |
| public CompressSocket() { super(); } |
| public CompressSocket(String host, int port) throws IOException { |
| super(host, port); |
| } |
| public InputStream getInputStream() throws IOException { |
| if (in == null) { |
| in = new CompressInputStream(super.getInputStream()); |
| } |
| return in; |
| } |
| public OutputStream getOutputStream() throws IOException { |
| if (out == null) { |
| out = new CompressOutputStream(super.getOutputStream()); |
| } |
| return out; |
| } |
| } |
| |
| public static class CompressServerSocket extends ServerSocket { |
| public CompressServerSocket(int port) throws IOException { |
| super(port); |
| } |
| public Socket accept() throws IOException { |
| Socket s = new CompressSocket(); |
| implAccept(s); |
| return s; |
| } |
| } |
| |
| public static 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++]; |
| } |
| } |
| |
| public static class CompressOutputStream extends FilterOutputStream |
| implements CompressConstants |
| { |
| |
| public CompressOutputStream(OutputStream out) { |
| super(out); |
| } |
| |
| // buffer of 6-bit codes to pack into next 32-bit word |
| int buf[] = new int[5]; |
| |
| // number of valid codes pending in buffer |
| int bufPos = 0; |
| |
| public void write(int b) throws IOException { |
| b &= 0xFF; // force argument to a byte |
| |
| int pos = codeTable.indexOf((char)b); |
| if (pos != -1) |
| writeCode(BASE + pos); |
| else { |
| writeCode(RAW); |
| writeCode(b >> 4); |
| writeCode(b & 0xF); |
| } |
| } |
| |
| public void write(byte b[], int off, int len) throws IOException { |
| /* |
| * This is quite an inefficient implementation, because it has to |
| * call the other write method for every byte in the array. It |
| * could be optimized for performance by doing all the processing |
| * in this method. |
| */ |
| for (int i = 0; i < len; i++) |
| write(b[off + i]); |
| } |
| |
| public void flush() throws IOException { |
| while (bufPos > 0) |
| writeCode(NOP); |
| } |
| |
| private void writeCode(int c) throws IOException { |
| buf[bufPos++] = c; |
| if (bufPos == 5) { // write next word when we have 5 codes |
| int pack = (buf[0] << 24) | (buf[1] << 18) | (buf[2] << 12) | |
| (buf[3] << 6) | buf[4]; |
| out.write((pack >>> 24) & 0xFF); |
| out.write((pack >>> 16) & 0xFF); |
| out.write((pack >>> 8) & 0xFF); |
| out.write((pack >>> 0) & 0xFF); |
| bufPos = 0; |
| } |
| } |
| } |
| } |