1 /*
   2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.xml.internal.ws.api.pipe;
  27 
  28 import java.util.Map;
  29 
  30 /**
  31  * Clones the whole pipeline.
  32  *
  33  * <p>
  34  * Since {@link Tube}s may form an arbitrary directed graph, someone needs
  35  * to keep track of isomorphism for a clone to happen correctly. This class
  36  * serves that role.
  37  *
  38  * @author Kohsuke Kawaguchi
  39  */
  40 public abstract class TubeCloner {
  41     // Pipe to pipe, or tube to tube
  42     public final Map<Object,Object> master2copy;
  43 
  44     /**
  45      * Invoked by a client of a tube to clone the whole pipeline.
  46      *
  47      * <p>
  48      * {@link Tube}s implementing the {@link Tube#copy(com.sun.xml.internal.ws.api.pipe.TubeCloner)} method
  49      * shall use {@link #copy(Tube)} method.
  50      *
  51      * @param p
  52      *      The entry point of a pipeline to be copied. must not be null.
  53      * @return
  54      *      The cloned pipeline. Always non-null.
  55      */
  56     @SuppressWarnings("deprecation")
  57         public static Tube clone(Tube p) {
  58         // we often want to downcast TubeCloner to PipeCloner,
  59         // so let's create PipeCloner to make that possible
  60         return new PipeClonerImpl().copy(p);
  61     }
  62 
  63     // no need to be constructed publicly. always use the static clone method.
  64     /*package*/ TubeCloner(Map<Object,Object> master2copy) {
  65         this.master2copy = master2copy;
  66     }
  67 
  68     /**
  69      * Invoked by a {@link Tube#copy(com.sun.xml.internal.ws.api.pipe.TubeCloner)} implementation
  70      * to copy a reference to another pipe.
  71      *
  72      * <p>
  73      * This method is for {@link Tube} implementations, not for users.
  74      *
  75      * <p>
  76      * If the given tube is already copied for this cloning episode,
  77      * this method simply returns that reference. Otherwise it copies
  78      * a tube, make a note, and returns a copied tube. This additional
  79      * step ensures that a graph is cloned isomorphically correctly.
  80      *
  81      * <p>
  82      * (Think about what happens when a graph is A->B, A->C, B->D, and C->D
  83      * if you don't have this step.)
  84      *
  85      * @param t
  86      *      The tube to be copied.
  87      * @return
  88      *      The cloned tube. Always non-null.
  89      */
  90         public abstract <T extends Tube> T copy(T t);
  91 
  92     /**
  93      * This method must be called from within the copy constructor
  94      * to notify that the copy was created.
  95      *
  96      * <p>
  97      * When your pipe has references to other pipes,
  98      * it's particularly important to call this method
  99      * before you start copying the pipes you refer to,
 100      * or else there's a chance of inifinite loop.
 101      */
 102     public abstract void add(Tube original, Tube copy);
 103 }