rename Result->ResultNode

[sbp.git] / src / edu / berkeley / sbp / ResultNode.java

diff --git a/src/edu/berkeley/sbp/ResultNode.java b/src/edu/berkeley/sbp/ResultNode.java
new file mode 100644 (file)
index 0000000..671940a
--- /dev/null
+++ b/src/edu/berkeley/sbp/ResultNode.java
@@ -0,0 +1,124 @@
+// Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
+
+package edu.berkeley.sbp;
+import edu.berkeley.sbp.util.*;
+import edu.berkeley.sbp.Sequence.Pos;
+import edu.berkeley.sbp.Sequence.Pos;
+import java.util.*;
+
+final class ResultNode
+    implements GraphViz.ToGraphViz {
+
+    private Forest.Many f = new Forest.Many();
+    //private HashSet<StateNode> predecessors = new HashSet<StateNode>();
+    //private HashSet<StateNode> successors = new HashSet<StateNode>();
+    private FastSet<StateNode> predecessors = new FastSet<StateNode>();
+    private FastSet<StateNode> successors = new FastSet<StateNode>();
+    private boolean destroyed = false;
+    private boolean primordeal;
+    private int usedByNonDoomedNode = 0;
+    private Pos reduction;
+    private GSS.Phase predPhase;
+
+    public boolean predecessorsContains(StateNode n) {
+        return predecessors.contains(n);
+    }
+    public Pos reduction() { return reduction; }
+    public void merge(Forest newf) {
+        this.f.merge(newf);
+        /*
+        if (predecessors.contains(pred)) return;
+        addPred(pred);
+        if (fromEmptyReduction) return;
+        n.state().invokeReductions(n.phase().getToken(), n, this);        
+        */
+    }
+
+    public boolean noSuccessors() { return successors.size()==0; }
+
+    public GSS.Phase phase() { return predPhase; }
+    public Forest getForest() { return f; }
+    public Iterable<StateNode> getPreds() { return predecessors; }
+    public void addSucc(StateNode succ) {
+        if (successors.contains(succ)) return;
+        successors.add(succ);
+        usedByNonDoomedNode += succ.state().doomed ? 0 : 1;
+        if (predecessors.size() > 1) throw new Error();
+    }
+    public void removeSucc(StateNode succ) {
+        if (!successors.contains(succ)) return;
+        successors.remove(succ);
+        usedByNonDoomedNode -= succ.state().doomed ? 0 : 1;
+        check();
+    }
+
+    public boolean usedByAnyNode() { return successors.size() > 0; }
+    public boolean usedByNonDoomedNode() { return usedByNonDoomedNode > 0; }
+
+    public String toString() { return super.toString()+"->"+predPhase; }
+
+    public void check() {
+        if (successors.size()==0) destroy();
+        else if (predecessors.size()==0) destroy();
+    }
+    public void destroy() {
+        if (destroyed) return;
+        if (primordeal) return;  // never destroy the "primordeal" result
+        destroyed = true;
+        while(predecessors.size() > 0)
+            for(StateNode pred : predecessors) {
+                removePred(pred);
+                pred.removeSucc(this);
+                break;
+            }
+        predecessors = null;
+        while(successors.size() > 0)
+            for(StateNode succ : successors) {
+                removeSucc(succ);
+                succ.removeResult(this);
+                break;
+            }
+        successors = null;
+    }
+
+    public void removePred(StateNode pred) {
+        if (!predecessors.contains(pred)) return;
+        predecessors.remove(pred);
+        check();
+    }
+
+    public void addPred(StateNode pred) {
+        if (predPhase==null) predPhase = pred.phase();
+        if (predPhase != pred.phase()) throw new Error();
+        predecessors.add(pred);
+        pred.addSucc(this);
+        if (predecessors.size() > 1) throw new Error();
+    }
+        
+    public ResultNode() {
+        this(null, null, null);
+        this.primordeal = true;
+    }
+    public ResultNode(Forest f, Pos reduction, StateNode pred) {
+        this.f.merge(f);
+        this.reduction = reduction;
+        if (pred != null) addPred(pred);
+    }
+
+    // GraphViz //////////////////////////////////////////////////////////////////////////////
+
+    public GraphViz.StateNode toGraphViz(GraphViz gv) {
+        if (gv.hasNode(this)) return gv.createNode(this);
+        GraphViz.StateNode n = gv.createNode(this);
+        n.label = ""+f;
+        n.shape = "rectangle";
+        //if (pred()!=null) n.edge(pred, "");
+        n.color = "blue";
+        if (phase() != null)
+            ((GraphViz.Group)phase().toGraphViz(gv)).add(n);
+        return n;
+    }
+    public boolean isTransparent() { return false; }
+    public boolean isHidden() { return false; }
+
+}
\ No newline at end of file