org.spearce.jgit/src/org/spearce/jgit/transport/PacketLineOut.java

   1 /*
   2  *  Copyright (C) 2008  Shawn Pearce <spearce@spearce.org>
   3  *
   4  *  This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU General Public
   6  *  License, version 2, as published by the Free Software Foundation.
   7  *
   8  *  This library is distributed in the hope that it will be useful,
   9  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  *  General Public License for more details.
  12  *
  13  *  You should have received a copy of the GNU General Public
  14  *  License along with this library; if not, write to the Free Software
  15  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
  16  */
  17 package org.spearce.jgit.transport;
  18
  19 import java.io.IOException;
  20 import java.io.OutputStream;
  21
  22 import org.spearce.jgit.lib.Constants;
  23
  24 class PacketLineOut {
  25         private final OutputStream out;
  26
  27         private final byte[] lenbuffer;
  28
  29         PacketLineOut(final OutputStream i) {
  30                 out = i;
  31                 lenbuffer = new byte[4];
  32         }
  33
  34         void writeString(final String s) throws IOException {
  35                 writePacket(Constants.encodeASCII(s));
  36         }
  37
  38         void writePacket(final byte[] packet) throws IOException {
  39                 writeLength(packet.length + 4);
  40                 out.write(packet);
  41         }
  42
  43         void end() throws IOException {
  44                 writeLength(0);
  45                 flush();
  46         }
  47
  48         void flush() throws IOException {
  49                 out.flush();
  50         }
  51
  52         private static final byte[] hexchar = { '0', '1', '2', '3', '4', '5', '6',
  53                         '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
  54
  55         private void writeLength(int w) throws IOException {
  56                 int o = 3;
  57                 while (o >= 0 && w != 0) {
  58                         lenbuffer[o--] = hexchar[w & 0xf];
  59                         w >>>= 4;
  60                 }
  61                 while (o >= 0)
  62                         lenbuffer[o--] = '0';
  63                 out.write(lenbuffer, 0, 4);
  64         }
  65 }