libjava/classpath/gnu/classpath/jdwp/util/Location.java

   1 /* Location.java -- class to read/write JDWP locations
   2    Copyright (C) 2005, 2006 Free Software Foundation
   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.classpath.jdwp.util;
  40
  41 import gnu.classpath.jdwp.VMIdManager;
  42 import gnu.classpath.jdwp.VMMethod;
  43 import gnu.classpath.jdwp.exception.JdwpException;
  44 import gnu.classpath.jdwp.id.ClassReferenceTypeId;
  45
  46 import java.io.DataOutputStream;
  47 import java.io.IOException;
  48 import java.nio.ByteBuffer;
  49
  50 /**
  51  * A class to read/write JDWP locations.
  52  *
  53  * @author Aaron Luchko <aluchko@redhat.com>
  54  */
  55 public class Location
  56 {
  57   private VMMethod method;
  58   private long index;
  59
  60   /**
  61    * Create a location with the given parameters.
  62    *
  63    * @param method the method
  64    * @param index location in the method
  65    */
  66   public Location(VMMethod method, long index)
  67   {
  68     this.method = method;
  69     this.index = index;
  70   }
  71
  72   /**
  73    * Read a location from the given bytebuffer, consists of a TAG (byte),
  74    * followed by a ReferenceTypeId, a MethodId and an index (long).
  75    *
  76    * @param bb this holds the location
  77    * @throws IOException    when an error occurs reading from the buffer
  78    * @throws JdwpException  for invalid class or method IDs
  79    */
  80   public Location(ByteBuffer bb)
  81     throws IOException, JdwpException
  82   {
  83     byte tag = bb.get();
  84     ClassReferenceTypeId classId =
  85       (ClassReferenceTypeId) VMIdManager.getDefault().readReferenceTypeId(bb);
  86     Class klass = classId.getType();
  87     method = VMMethod.readId(klass, bb);
  88     index = bb.getLong();
  89   }
  90
  91   /**
  92    * Write the given location to an output stream.
  93    *
  94    * @param os stream to write to
  95    * @throws IOException when an error occurs writing to the stream
  96    */
  97   public void write(DataOutputStream os)
  98     throws IOException
  99   {
 100     VMIdManager idm = VMIdManager.getDefault();
 101     ClassReferenceTypeId crti = (ClassReferenceTypeId)
 102       idm.getReferenceTypeId(method.getDeclaringClass());
 103
 104     crti.writeTagged(os);
 105     method.writeId(os);
 106     os.writeLong(index);
 107   }
 108
 109   /**
 110    * Gets the method of this location
 111    *
 112    * @return the method
 113    */
 114   public VMMethod getMethod()
 115   {
 116     return method;
 117   }
 118
 119   /**
 120    * Gets the code index of this location
 121    *
 122    * @return the code index
 123    */
 124   public long getIndex ()
 125   {
 126     return index;
 127   }
 128
 129   // convenient for debugging
 130   public String toString ()
 131   {
 132     return method.toString () + "." + index;
 133   }
 134 }