Repair/RepairCompiler/MCC/IR/GraphNode.java

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