OrderingSupport


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4    * compliance with the License.
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11   * If applicable, add the following below the CDDL Header, with the fields
12   * enclosed by brackets [] replaced by your own identifying information:
13   * "Portions Copyrighted [year] [name of copyright owner]"
14   *
15   * The Original Software is NetBeans. The Initial Developer of the Original
16   * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
17   * Microsystems, Inc. All Rights Reserved.
18   */
19  
20  package org.netbeans.modules.registry;
21  
22  import org.netbeans.api.registry.Context;
23  import org.netbeans.api.registry.ContextException;
24  import org.netbeans.spi.registry.BasicContext;
25  import org.openide.ErrorManager;
26  import org.openide.util.TopologicalSortException;
27  import org.openide.util.Utilities;
28  
29  import java.util.*;
30  
31  /**
32   * This class orders context items according to positional attributes
33   * and for backward compatibility it also accepts relative ordering
34   * attributes. After the relative ordering attrs are removed the
35   * ordering functionality in this class can be simplified.
36   * 
37   * There are also several checks for "ordered" attribute
38   * which are commented out till this mechanism gets common.
39   *
40   * @author copy & pasted from old Datasystems
41   */
42  public class OrderingSupport {
43  
44      private static final char SEP = '/';
45  
46      public static final OrderingSupport DEFAULT = new OrderingSupport();
47      
48      private OrderingSupport() {
49      }
50  
51      /**
52       * @return ordered list of binding names and subcontext names.
53       *
54       */
55      public List getOrderedNames(Context ctx) {
56          
57          // check that context is ordered
58          String   ordered = ctx.getAttribute(null, "ordered", null);
59          if (ordered == null || (!ordered.equals("true"))) {
60              // TODO: add this diagnostic later
61              // ErrorManager.getDefault().log(ErrorManager.WARNING, "Context "+ctx+" is not marked as ordered.");
62          }
63          
64          List l = getItems(ctx);
65          Map constraints = getOrderingConstraints(ctx);
66          if (constraints.keySet().size() != 0) {
67              try {
68                  l = Utilities.topologicalSort(l, constraints);
69              } catch (TopologicalSortException ex) {
70                  List corrected = ex.partialSort();
71                  ErrorManager.getDefault().log(ErrorManager.WARNING, "Note: context [" + ctx + "] cannot be consistently sorted due to ordering conflicts."); // NOI18N
72                  ErrorManager.getDefault().notify(ErrorManager.INFORMATIONAL, ex);
73                  ErrorManager.getDefault().log(ErrorManager.WARNING, "Using partial sort: " + corrected); // NOI18N
74                  l = corrected;
75              }
76          }
77          
78          // check for fullorder attribute
79          String   fullorder = ctx.getAttribute(null, "fullorder", null);
80          if (fullorder != null) {
81              List list = new ArrayList();
82              // ensure that items are returned in specified full order
83              // and additional items are left as they are at the end
84              StringTokenizer tok = new StringTokenizer(fullorder, ",");
85              while (tok.hasMoreTokens()) {
86                  String   token = tok.nextToken();
87                  if (l.remove(token)) {
88                      list.add(token);
89                  }
90              }
91              list.addAll(l);
92              l = list;
93          }
94          return l;
95      }
96  
97      // list all items of the context
98      private List getItems(Context ctx) {
99          List l = new ArrayList();
100         Iterator i = ctx.getBindingNames().iterator();
101         while (i.hasNext()) {
102             l.add((String  )i.next());
103         }
104         i = ctx.getSubcontextNames().iterator();
105         while (i.hasNext()) {
106             l.add(((String  )i.next())+"/");
107         }
108         return l;
109     }
110     
111     private Map getOrderingConstraints(Context ctx) {
112         Map map = new HashMap();
113         try {
114             addPositions(map, ctx);
115         } catch (ContextException ex) {
116             ErrorManager.getDefault().log(ErrorManager.EXCEPTION, ex.toString());
117         }
118         addPartials(map, ctx);
119         return map;
120     }
121 
122     
123     /** 
124      * Read old partial ordering attributes. Method updates the passed map.
125      *
126      * @param m map<String, List<String>> where key is 
127      * binding name or subcontext name and value is list of
128      * binding names or subcontext names which must go after the key.
129      */
130     private void addPartials(Map m, Context ctx) {
131         Iterator i = ctx.getAttributeNames(null).iterator();
132         while (i.hasNext()) {
133             String   attrName = (String  )i.next();
134             if (attrName.indexOf (SEP) != -1) {
135                 // TODO: convert bool attr to String in ContextImpl
136                 String   value = ctx.getAttribute(null, attrName, "");
137                 if (value.equals("true")) {
138                     int idx = attrName.indexOf(SEP);
139                     String   a = attrName.substring(0, idx);
140                     String   b = attrName.substring(idx + 1);
141                     
142                     // this might not work in some cases, but this is just backward solution
143                     // so I guess it is OK: I expect that file with extension is a binding and
144                     // file without extension is subcontext.
145                     idx = a.lastIndexOf('.');
146                     if (idx != -1) {
147                         // probably binding. cut off extension
148                         a = a.substring(0, idx);
149                     } else {
150                         // probably subcontext. append "/"
151                         a = a + "/";
152                     }
153                     idx = b.lastIndexOf('.');
154                     if (idx != -1) {
155                         // probably binding. cut off extension
156                         b = b.substring(0, idx);
157                     } else {
158                         // probably subcontext. append "/"
159                         b = b + "/";
160                     }
161                     
162                     List l = (List)m.get(a);
163                     if (l == null) {
164                         m.put(a, l = new LinkedList());
165                     }
166                     l.add(b);
167                     
168                 }
169             }
170         }
171     }
172 
173     /** 
174      * Read positional ordering attributes. Method updates the passed map.
175      *
176      * @param m map<String, List<String>> where key is 
177      * binding name or subcontext name and value is list of
178      * binding names or subcontext names which must go after the key.
179      */
180     private void addPositions(Map m, Context ctx) throws ContextException {
181         Map map = new HashMap();
182         BasicContext basicCtx = ApiContextFactory.DEFAULT.getBasicContext(ctx);
183         Iterator i = ctx.getBindingNames().iterator();
184         while (i.hasNext()) {
185             String   bindingName = (String  )i.next();
186             String   position = ctx.getAttribute(bindingName, "position", null);
187             if (position != null) {
188                 try {
189                     Float   f = new Float  (position);
190                     String   bnd = (String  )map.put(f, bindingName);
191                     if (bnd != null) {
192                         ErrorManager.getDefault().log(ErrorManager.WARNING, "Ordering Error: Two items in context ["+ctx+
193                             "] has the same position ["+position+"]: "+bnd+" "+bindingName);
194                     }
195                 } catch (NumberFormatException   ex) {
196                     // ok to ignore.
197                 }
198             } else {
199                 // TODO: add this diagnostic later
200                 // ErrorManager.getDefault().log(ErrorManager.WARNING, "Binding "+bindingName+" in context "+ctx+" does not have position attribute.");
201             }
202         }
203         i = ctx.getSubcontextNames().iterator();
204         while (i.hasNext()) {
205             String   subcontextName = (String  )i.next();
206             Context subCtx = ctx.getSubcontext(subcontextName);
207             if (subCtx == null) {
208                 continue;
209             }
210             String   position = subCtx.getAttribute(null, "position", null);
211             if (position != null) {
212                 try {
213                     Float   f = new Float  (position);
214                     String   sub = (String  )map.put(f, subcontextName+"/");
215                     if (sub != null) {
216                         ErrorManager.getDefault().log(ErrorManager.WARNING, "Ordering Error: Two items in context ["+ctx+
217                             "] has the same position ["+position+"]: "+sub+" "+subcontextName);
218                     }
219                 } catch (NumberFormatException   ex) {
220                     // ok to ignore.
221                 }
222             } else {
223                 // TODO: add this diagnostic later
224                 // ErrorManager.getDefault().log(ErrorManager.WARNING, "Subcontext "+subcontextName+" in context "+ctx+" does not have position attribute.");
225             }
226         }
227         List l = new ArrayList(map.keySet());
228         Collections.sort(l);
229         for (int k=0; k<l.size(); k++) {
230             String   itemA = (String  )map.get(l.get(k));
231             List list = (List)m.get(itemA);
232             if (list == null) {
233                 m.put(itemA, list = new LinkedList());
234             }
235             for (int j=k+1; j<l.size(); j++) {
236                 String   itemB = (String  )map.get(l.get(j));
237                 list.add(itemB);
238             }
239         }
240     }
241     
242     
243 }
244
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