old-autovect-branch/libjava/classpath/gnu/CORBA/GIOP/CodeSetServiceContext.java

   1 /* CodeSet_sctx.java --
   2    Copyright (C) 2005 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package gnu.CORBA.GIOP;
  40
  41 import gnu.CORBA.CDR.AbstractCdrInput;
  42 import gnu.CORBA.CDR.AbstractCdrOutput;
  43 import gnu.CORBA.IOR;
  44 import gnu.CORBA.IOR.CodeSets_profile;
  45
  46 import java.io.IOException;
  47
  48 /**
  49  * The code set service context. This context must be included in all
  50  * messages that use wide characters.
  51  *
  52  * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
  53  */
  54 public class CodeSetServiceContext
  55   extends ServiceContext
  56 {
  57   /**
  58    * The context code sets id.
  59    */
  60   public static final int ID = 1;
  61
  62   /**
  63    * The standard component to include in the messages.
  64    */
  65   public static final CodeSetServiceContext STANDARD = new CodeSetServiceContext();
  66
  67   /**
  68    * The encoding, used to transfer the narrow (1 byte) character data.
  69    * The default value is taken from {@link CharSets_OSF#NATIVE_CHARACTER}.
  70    */
  71   public int char_data = CharSets_OSF.NATIVE_CHARACTER;
  72
  73   /**
  74    * The encoding, used to transfer the wide character data.
  75    * The default value is taken from
  76    * {@link CharSets_OSF#NATIVE_WIDE_CHARACTER}.
  77    */
  78   public int wide_char_data = CharSets_OSF.NATIVE_WIDE_CHARACTER;
  79
  80   /**
  81    * Find and return the code set service context in the give
  82    * contexts array. Returns {@link #STANDARD} if no code set
  83    * context is present.
  84    *
  85    * @param contexts the array of contexts, can be null.
  86    */
  87   public static CodeSetServiceContext find(ServiceContext[] contexts)
  88   {
  89     if (contexts != null)
  90       for (int i = 0; i < contexts.length; i++)
  91         {
  92           if (contexts [ i ] instanceof CodeSetServiceContext)
  93             return (CodeSetServiceContext) contexts [ i ];
  94         }
  95     return STANDARD;
  96   }
  97
  98   /**
  99    * Select the suitable encoding that is defined in the provided profile.
 100    *
 101    * TODO character encoding. Now the encoding can be set, but it is ignored.
 102    * If you take this task, scan 'TODO character encoding' for
 103    * relevant places.
 104    */
 105   public static CodeSetServiceContext negotiate(IOR.CodeSets_profile profile)
 106   {
 107     if (profile.negotiated != null)
 108       return profile.negotiated;
 109
 110     CodeSetServiceContext use = new CodeSetServiceContext();
 111
 112     use.char_data =
 113       negotiate(profile.narrow, STANDARD.char_data, CharSets_OSF.ISO8859_1);
 114
 115     use.wide_char_data =
 116       negotiate(profile.wide, STANDARD.wide_char_data, CharSets_OSF.UTF16);
 117
 118     profile.negotiated = use;
 119
 120     return use;
 121   }
 122
 123   /**
 124    * Read the context from the given stream. Does not read the
 125    * code sets id.
 126    */
 127   public void readContext(AbstractCdrInput input)
 128   {
 129     AbstractCdrInput encap = input.read_encapsulation();
 130
 131     char_data = encap.read_ulong();
 132     wide_char_data = encap.read_ulong();
 133   }
 134
 135   /**
 136    * Return a string representation.
 137    */
 138   public String toString()
 139   {
 140     return " Encoding: narrow " + name(char_data) + ", wide " +
 141            name(wide_char_data) + ". ";
 142   }
 143
 144   /**
 145    * Write the context to the given stream, including the code
 146    * sets id.
 147    */
 148   public void write(AbstractCdrOutput output)
 149   {
 150     output.write_ulong(ID);
 151
 152     AbstractCdrOutput enout = output.createEncapsulation();
 153
 154     enout.write_long(char_data);
 155     enout.write_ulong(wide_char_data);
 156
 157     try
 158       {
 159         enout.close();
 160       }
 161     catch (IOException ex)
 162       {
 163         InternalError t = new InternalError();
 164         t.initCause(ex);
 165         throw t;
 166       }
 167   }
 168
 169   /**
 170    * Negotiate about the character encoding. Prefer our native encoding,
 171    * if no, prefer IORs native encoding, if no, find any encoding,
 172    * supported by both sides, if no, return the specified final decission.
 173    *
 174    * @param profile the component profile in IOR.
 175    * @param our_native our native encoding
 176    * @param final_decission the encoding that must be returned if no
 177    * compromise is found.
 178    *
 179    * @return the resulted encoding.
 180    */
 181   protected static int negotiate(IOR.CodeSets_profile.CodeSet_component profile,
 182                                  int our_native, int final_decission
 183                                 )
 184   {
 185     // If our and IORs native sets match, use the native set.
 186     if (profile.native_set == our_native)
 187       return our_native;
 188
 189     // If the native sets do not match, but the IOR says it
 190     // supports our native set, use our native set.
 191     if (profile.conversion != null)
 192       for (int i = 0; i < profile.conversion.length; i++)
 193         {
 194           if (our_native == profile.conversion [ i ])
 195             return our_native;
 196         }
 197
 198     // At this point, we suggest to use the IORs native set.
 199     int[] allSupported = CharSets_OSF.getSupportedCharSets();
 200
 201     for (int s = 0; s < allSupported.length; s++)
 202       if (allSupported [ s ] == profile.native_set)
 203         return profile.native_set;
 204
 205     // Any compromise left?
 206     if (profile.conversion != null)
 207       for (int s = 0; s < allSupported.length; s++)
 208         for (int i = 0; i < profile.conversion.length; i++)
 209           if (allSupported [ s ] == profile.conversion [ i ])
 210             return allSupported [ s ];
 211
 212     // Return the CORBA default char encoding.
 213     return final_decission;
 214   }
 215
 216   /**
 217    * Conveniency method, used in toString()
 218    */
 219   private String name(int set)
 220   {
 221     return "0x" + Integer.toHexString(set) + " (" + CharSets_OSF.getName(set) +
 222            ") ";
 223   }
 224 }