mnj/lua/LuaInternal.java

   1 /*  $Header: //info.ravenbrook.com/project/jili/version/1.1/code/mnj/lua/LuaInternal.java#1 $
   2  * Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies).
   3  * All rights reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sublicense, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject
  11  * to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be
  14  * included in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  19  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
  20  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
  21  * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 package mnj.lua;
  26
  27 import java.io.InputStream;
  28 import java.io.InputStreamReader;
  29 import java.io.IOException;
  30 import java.io.Reader;
  31
  32 /**
  33  * Class used to implement internal callbacks.  Currently there is only
  34  * one callback used, one that parses or loads a Lua chunk into binary
  35  * form.
  36  */
  37 final class LuaInternal extends LuaJavaCallback
  38 {
  39   private InputStream stream;
  40   private Reader reader;
  41   private String chunkname;
  42
  43   LuaInternal(InputStream in, String chunkname)
  44   {
  45     this.stream = in;
  46     this.chunkname = chunkname;
  47   }
  48
  49   LuaInternal(Reader in, String chunkname)
  50   {
  51     this.reader = in;
  52     this.chunkname = chunkname;
  53   }
  54
  55   public int luaFunction(Lua L)
  56   {
  57     try
  58     {
  59       Proto p = null;
  60
  61       // In either the stream or the reader case there is a way of
  62       // converting the input to the other type.
  63       if (stream != null)
  64       {
  65         stream.mark(1);
  66         int c = stream.read();
  67         stream.reset();
  68
  69         // Convert to Reader if looks like source code instead of
  70         // binary.
  71         if (c == Loader.HEADER[0])
  72         {
  73           Loader l = new Loader(stream, chunkname);
  74           p = l.undump();
  75         }
  76         else
  77         {
  78           reader = new InputStreamReader(stream, "UTF-8");
  79           p = Syntax.parser(L, reader, chunkname);
  80         }
  81       }
  82       else
  83       {
  84         // Convert to Stream if looks like binary (dumped via
  85         // string.dump) instead of source code.
  86         if (reader.markSupported())
  87         {
  88           reader.mark(1);
  89           int c = reader.read();
  90           reader.reset();
  91
  92           if (c == Loader.HEADER[0])
  93           {
  94             stream = new FromReader(reader);
  95             Loader l = new Loader(stream, chunkname);
  96             p = l.undump();
  97           }
  98           else
  99           {
 100             p = Syntax.parser(L, reader, chunkname);
 101           }
 102         }
 103         else
 104         {
 105           p = Syntax.parser(L, reader, chunkname);
 106         }
 107       }
 108
 109       L.push(new LuaFunction(p,
 110           new UpVal[0],
 111           L.getGlobals()));
 112       return 1;
 113     }
 114     catch (IOException e)
 115     {
 116       L.push("cannot read " + chunkname + ": " + e.toString());
 117       L.dThrow(Lua.ERRFILE);
 118       return 0;
 119     }
 120   }
 121 }