Robust/src/Util/GraphNode.java

   1 package Util;
   2
   3 import java.util.*;
   4 import java.io.*;
   5
   6 public class GraphNode {
   7     /* NodeStatus enumeration pattern ***********/
   8
   9     public static final NodeStatus UNVISITED = new NodeStatus("UNVISITED");
  10     public static final NodeStatus PROCESSING = new NodeStatus("PROCESSING");
  11     public static final NodeStatus FINISHED = new NodeStatus("FINISHED");
  12
  13     public static class NodeStatus {
  14         private static String name;
  15         private NodeStatus(String name) { this.name = name; }
  16         public String toString() { return name; }
  17     }
  18
  19     int discoverytime = -1;
  20     int finishingtime = -1; /* used for searches */
  21
  22     protected Vector edges = new Vector();
  23     protected Vector inedges = new Vector();
  24
  25     NodeStatus status = UNVISITED;
  26     String dotnodeparams = new String();
  27     public boolean merge=false;
  28
  29     public void setMerge() {
  30         merge=true;
  31     }
  32
  33     public static void computeclosure(Collection nodes, Collection removed) {
  34         Stack tovisit=new Stack();
  35         tovisit.addAll(nodes);
  36         while(!tovisit.isEmpty()) {
  37             GraphNode gn=(GraphNode)tovisit.pop();
  38             for(Iterator it=gn.edges();it.hasNext();) {
  39                 Edge edge=(Edge)it.next();
  40                 GraphNode target=edge.getTarget();
  41                 if (!nodes.contains(target)) {
  42                     if ((removed==null)||
  43                         (!removed.contains(target))) {
  44                         nodes.add(target);
  45                         tovisit.push(target);
  46                     }
  47                 }
  48             }
  49         }
  50     }
  51
  52     public static void boundedcomputeclosure(Collection nodes, Collection removed,int depth) {
  53         Stack tovisit=new Stack();
  54         Stack newvisit=new Stack();
  55         tovisit.addAll(nodes);
  56         for(int i=0;i<depth&&!tovisit.isEmpty();i++) {
  57             while(!tovisit.isEmpty()) {
  58                 GraphNode gn=(GraphNode)tovisit.pop();
  59                 for(Iterator it=gn.edges();it.hasNext();) {
  60                     Edge edge=(Edge)it.next();
  61                     GraphNode target=edge.getTarget();
  62                     if (!nodes.contains(target)) {
  63                         if ((removed==null)||
  64                             (!removed.contains(target))) {
  65                             nodes.add(target);
  66                             newvisit.push(target);
  67                         }
  68                     }
  69                 }
  70             }
  71             tovisit=newvisit;
  72             newvisit=new Stack();
  73         }
  74     }
  75
  76     public void setDotNodeParameters(String param) {
  77         if (param == null) {
  78             throw new NullPointerException();
  79         }
  80         if (param.length() > 0) {
  81             dotnodeparams = "," + param;
  82         } else {
  83             dotnodeparams = new String();
  84         }
  85     }
  86
  87     public void setStatus(NodeStatus status) {
  88         if (status == null) {
  89             throw new NullPointerException();
  90         }
  91         this.status = status;
  92     }
  93
  94     public String getLabel() {
  95         return "";
  96     }
  97
  98     public String getTextLabel() {
  99         return "";
 100     }
 101
 102     public NodeStatus getStatus() {
 103         return this.status;
 104     }
 105
 106     public int numedges() {
 107         return edges.size();
 108     }
 109
 110     public int numinedges() {
 111         return inedges.size();
 112     }
 113
 114     public Edge getedge(int i) {
 115         return (Edge) edges.get(i);
 116     }
 117
 118     public Edge getinedge(int i) {
 119         return (Edge) inedges.get(i);
 120     }
 121
 122     public Iterator edges() {
 123         return edges.iterator();
 124     }
 125
 126     public Iterator inedges() {
 127         return inedges.iterator();
 128     }
 129
 130     public void addEdge(Edge newedge) {
 131         newedge.setSource(this);
 132         edges.addElement(newedge);
 133         GraphNode tonode=newedge.getTarget();
 134         tonode.inedges.addElement(newedge);
 135     }
 136
 137     void reset() {
 138             discoverytime = -1;
 139             finishingtime = -1;
 140             status = UNVISITED;
 141     }
 142
 143     void resetscc() {
 144         status = UNVISITED;
 145     }
 146
 147     void discover(int time) {
 148         discoverytime = time;
 149         status = PROCESSING;
 150     }
 151
 152     void finish(int time) {
 153         assert status == PROCESSING;
 154         finishingtime = time;
 155         status = FINISHED;
 156     }
 157
 158     /** Returns finishing time for dfs */
 159
 160     public int getFinishingTime() {
 161         return finishingtime;
 162     }
 163
 164
 165     public static class DOTVisitor {
 166
 167         java.io.PrintWriter output;
 168         int tokennumber;
 169         int color;
 170         Vector namers;
 171
 172         private DOTVisitor(java.io.OutputStream output, Vector namers) {
 173             tokennumber = 0;
 174             color = 0;
 175             this.output = new java.io.PrintWriter(output, true);
 176             this.namers=namers;
 177         }
 178
 179         private String getNewID(String name) {
 180             tokennumber = tokennumber + 1;
 181             return new String (name+tokennumber);
 182         }
 183
 184         Collection nodes;
 185
 186
 187         public static void visit(java.io.OutputStream output, Collection nodes, Vector namers) {
 188             DOTVisitor visitor = new DOTVisitor(output, namers);
 189             visitor.nodes = nodes;
 190             visitor.make();
 191         }
 192
 193         public static void visit(java.io.OutputStream output, Collection nodes) {
 194             Vector v=new Vector();
 195             v.add(new Namer());
 196             DOTVisitor visitor = new DOTVisitor(output, v);
 197             visitor.nodes = nodes;
 198             visitor.make();
 199         }
 200
 201         private void make() {
 202             output.println("digraph dotvisitor {");
 203             /*            output.println("\tpage=\"8.5,11\";");
 204                           output.println("\tnslimit=1000.0;");
 205                           output.println("\tnslimit1=1000.0;");
 206                           output.println("\tmclimit=1000.0;");
 207                           output.println("\tremincross=true;");*/
 208             output.println("\tnode [fontsize=10,height=\"0.1\", width=\"0.1\"];");
 209             output.println("\tedge [fontsize=6];");
 210             traverse();
 211             output.println("}\n");
 212         }
 213
 214         private void traverse() {
 215             Set cycleset=GraphNode.findcycles(nodes);
 216
 217             Iterator it = nodes.iterator();
 218             while (it.hasNext()) {
 219                 GraphNode gn = (GraphNode) it.next();
 220                 Iterator edges = gn.edges();
 221                 String label = "";
 222                 String dotnodeparams="";
 223
 224                 for(int i=0;i<namers.size();i++) {
 225                     Namer name=(Namer) namers.get(i);
 226                     String newlabel=name.nodeLabel(gn);
 227                     String newparams=name.nodeOption(gn);
 228
 229                     if (!newlabel.equals("") && !label.equals("")) {
 230                         label+=", ";
 231                     }
 232                     if (!newparams.equals("")) {
 233                         dotnodeparams+=", " + name.nodeOption(gn);
 234                     }
 235                     label+=name.nodeLabel(gn);
 236                 }
 237
 238                 if (!gn.merge)
 239                     output.println("\t" + gn.getLabel() + " [label=\"" + label + "\"" + dotnodeparams + "];");
 240
 241                 if (!gn.merge)
 242                 while (edges.hasNext()) {
 243                     Edge edge = (Edge) edges.next();
 244                     GraphNode node = edge.getTarget();
 245                     if (nodes.contains(node)) {
 246                         for(Iterator nodeit=nonmerge(node).iterator();nodeit.hasNext();) {
 247                             GraphNode node2=(GraphNode)nodeit.next();
 248                             String edgelabel = "";
 249                             String edgedotnodeparams="";
 250
 251                             for(int i=0;i<namers.size();i++) {
 252                                 Namer name=(Namer) namers.get(i);
 253                                 String newlabel=name.edgeLabel(edge);
 254                                 String newoption=name.edgeOption(edge);
 255                                 if (!newlabel.equals("")&& ! edgelabel.equals(""))
 256                                     edgelabel+=", ";
 257                                 edgelabel+=newlabel;
 258                                 if (!newoption.equals(""))
 259                                     edgedotnodeparams+=", "+newoption;
 260                             }
 261
 262                             output.println("\t" + gn.getLabel() + " -> " + node2.getLabel() + " [" + "label=\"" + edgelabel + "\"" + edgedotnodeparams + "];");
 263                         }
 264                     }
 265                 }
 266             }
 267         }
 268
 269         Set nonmerge(GraphNode gn) {
 270             HashSet newset=new HashSet();
 271             HashSet toprocess=new HashSet();
 272             toprocess.add(gn);
 273             while(!toprocess.isEmpty()) {
 274                 GraphNode gn2=(GraphNode)toprocess.iterator().next();
 275                 toprocess.remove(gn2);
 276                 if (!gn2.merge)
 277                     newset.add(gn2);
 278                 else {
 279                     Iterator edges = gn2.edges();
 280                     while (edges.hasNext()) {
 281                         Edge edge = (Edge) edges.next();
 282                         GraphNode node = edge.getTarget();
 283                         if (!newset.contains(node)&&nodes.contains(node))
 284                             toprocess.add(node);
 285                     }
 286                 }
 287             }
 288             return newset;
 289         }
 290
 291     }
 292
 293     /** This function returns the set of nodes involved in cycles.
 294      *  It only considers cycles containing nodes in the set 'nodes'.
 295     */
 296     public static Set findcycles(Collection nodes) {
 297         HashSet cycleset=new HashSet();
 298         SCC scc=DFS.computeSCC(nodes);
 299         if (!scc.hasCycles())
 300             return cycleset;
 301         for(int i=0;i<scc.numSCC();i++) {
 302             if (scc.hasCycle(i))
 303                 cycleset.addAll(scc.getSCC(i));
 304         }
 305         return cycleset;
 306     }
 307
 308     public static class SCC {
 309         boolean acyclic;
 310         HashMap map,revmap;
 311         int numscc;
 312         public SCC(boolean acyclic, HashMap map,HashMap revmap,int numscc) {
 313             this.acyclic=acyclic;
 314             this.map=map;
 315             this.revmap=revmap;
 316             this.numscc=numscc;
 317         }
 318
 319         /** Returns whether the graph has any cycles */
 320         public boolean hasCycles() {
 321             return !acyclic;
 322         }
 323
 324         /** Returns the number of Strongly Connected Components */
 325         public int numSCC() {
 326             return numscc;
 327         }
 328
 329         /** Returns the strongly connected component number for the GraphNode gn*/
 330         public int getComponent(GraphNode gn) {
 331             return ((Integer)revmap.get(gn)).intValue();
 332         }
 333
 334         /** Returns the set of nodes in the strongly connected component i*/
 335         public Set getSCC(int i) {
 336             Integer scc=new Integer(i);
 337             return (Set)map.get(scc);
 338         }
 339
 340         /** Returns whether the strongly connected component i contains a cycle */
 341         boolean hasCycle(int i) {
 342             Integer scc=new Integer(i);
 343             Set s=(Set)map.get(scc);
 344             if (s.size()>1)
 345                 return true;
 346             Object [] array=s.toArray();
 347             GraphNode gn=(GraphNode)array[0];
 348             for(Iterator it=gn.edges();it.hasNext();) {
 349                 Edge e=(Edge)it.next();
 350                 if (e.getTarget()==gn)
 351                     return true; /* Self Cycle */
 352             }
 353             return false;
 354         }
 355     }
 356
 357     /**
 358      * DFS encapsulates the depth first search algorithm
 359      */
 360     public static class DFS {
 361
 362         int time = 0;
 363         int sccindex = 0;
 364         Collection nodes;
 365         Vector finishingorder=null;
 366         HashMap sccmap;
 367         HashMap sccmaprev;
 368
 369         private DFS(Collection nodes) {
 370             this.nodes = nodes;
 371         }
 372         /** Calculates the strong connected components for the graph composed
 373          *  of the set of nodes 'nodes'*/
 374         public static SCC computeSCC(Collection nodes) {
 375             if (nodes==null) {
 376                 throw new NullPointerException();
 377             }
 378             DFS dfs=new DFS(nodes);
 379             dfs.sccmap=new HashMap();
 380             dfs.sccmaprev=new HashMap();
 381             dfs.finishingorder=new Vector();
 382             boolean acyclic=dfs.go();
 383             for (Iterator it = nodes.iterator();it.hasNext();) {
 384                 GraphNode gn = (GraphNode) it.next();
 385                 gn.resetscc();
 386             }
 387             for(int i=dfs.finishingorder.size()-1;i>=0;i--) {
 388                 GraphNode gn=(GraphNode)dfs.finishingorder.get(i);
 389                 if (gn.getStatus() == UNVISITED) {
 390                     dfs.dfsprev(gn);
 391                     dfs.sccindex++; /* Increment scc index */
 392                 }
 393             }
 394             return new SCC(acyclic,dfs.sccmap,dfs.sccmaprev,dfs.sccindex);
 395         }
 396
 397         void dfsprev(GraphNode gn) {
 398             if (gn.getStatus()==FINISHED||!nodes.contains(gn))
 399                 return;
 400             gn.setStatus(FINISHED);
 401             Integer i=new Integer(sccindex);
 402             if (!sccmap.containsKey(i))
 403                 sccmap.put(i,new HashSet());
 404             ((Set)sccmap.get(i)).add(gn);
 405             sccmaprev.put(gn,i);
 406             for(Iterator edgeit=gn.inedges();edgeit.hasNext();) {
 407                 Edge e=(Edge)edgeit.next();
 408                 GraphNode gn2=e.getSource();
 409                 dfsprev(gn2);
 410             }
 411         }
 412
 413         public static boolean depthFirstSearch(Collection nodes) {
 414             if (nodes == null) {
 415                 throw new NullPointerException();
 416             }
 417
 418             DFS dfs = new DFS(nodes);
 419             return dfs.go();
 420         }
 421
 422         private boolean go() {
 423             Iterator i;
 424             time = 0;
 425             boolean acyclic=true;
 426             i = nodes.iterator();
 427             while (i.hasNext()) {
 428                 GraphNode gn = (GraphNode) i.next();
 429                 gn.reset();
 430             }
 431
 432             i = nodes.iterator();
 433             while (i.hasNext()) {
 434                 GraphNode gn = (GraphNode) i.next();
 435                 assert gn.getStatus() != PROCESSING;
 436                 if (gn.getStatus() == UNVISITED) {
 437                     if (!dfs(gn))
 438                         acyclic=false;
 439                 }
 440             }
 441             return acyclic;
 442         }
 443
 444         private boolean dfs(GraphNode gn) {
 445             boolean acyclic=true;
 446             gn.discover(time++);
 447             Iterator edges = gn.edges();
 448
 449             while (edges.hasNext()) {
 450                 Edge edge = (Edge) edges.next();
 451                 GraphNode node = edge.getTarget();
 452                 if (!nodes.contains(node)) /* Skip nodes which aren't in the set */
 453                     continue;
 454                 if (node.getStatus() == UNVISITED) {
 455                     if (!dfs(node))
 456                         acyclic=false;
 457                 } else if (node.getStatus()==PROCESSING) {
 458                     acyclic=false;
 459                 }
 460             }
 461             if (finishingorder!=null)
 462                 finishingorder.add(gn);
 463             gn.finish(time++);
 464             return acyclic;
 465         }
 466
 467     } /* end DFS */
 468
 469 }