X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FStateNode.java;fp=src%2Fedu%2Fberkeley%2Fsbp%2FStateNode.java;h=8fb1fd71bd6ef638d16821df0d158a485d4204b9;hp=0000000000000000000000000000000000000000;hb=24219bdf084b45273e869cd19382d1640b396566;hpb=14b3d2ee6a2d2ef84628e541ec291961f2061a5a

diff --git a/src/edu/berkeley/sbp/StateNode.java b/src/edu/berkeley/sbp/StateNode.java
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+++ b/src/edu/berkeley/sbp/StateNode.java
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+// Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
+
+package edu.berkeley.sbp;
+import edu.berkeley.sbp.*;
+import edu.berkeley.sbp.util.*;
+import edu.berkeley.sbp.Parser.Table.*;
+import edu.berkeley.sbp.Sequence.Pos;
+import edu.berkeley.sbp.Sequence.Pos;
+import java.io.*;
+import java.util.*;
+import java.lang.reflect.*;
+
+/** a node in the GSS */
+final class StateNode
+    implements Invokable<Pos, Result, Object>,
+               IntegerMappable,
+               GraphViz.ToGraphViz,
+               Iterable<Result> {
+
+    /** which GSS.Phase this StateNode belongs to */
+    public GSS.Phase phase() { return phase; }
+    public Iterator<Result> iterator() { return results.iterator(); }
+    public Parser.Table.State state() { return state; }
+
+    public int toInt() { return idx; }
+
+    boolean destroyed = false;
+
+    public void check() {
+        if (destroyed) return;
+        boolean dead = true;
+        // - all nodes must have a predecessor
+        // - non-doomed nodes must either:
+        //      - be on the frontier or
+        //      - have a non-doomed node closer to the frontier than themself
+        if (phase.isFrontier()) dead = false;
+        else for(Result r : successors)
+                 if (state.doomed) { if (r.usedByAnyNode()) { dead = false; break; } }
+                 else              { if (r.usedByNonDoomedNode()) { dead = false; break; } }
+        dead |= results.size()==0;
+        if (!dead) return;
+        destroyed = true;
+        if (phase() != null && phase().hash != null)
+            phase().hash.remove(state, predPhase);
+        while(successors.size()>0)
+            for(Result r : successors) {
+                successors.remove(r);
+                r.removePred(this);
+                break;
+            }
+        while(results.size()>0)
+            for(Result r : results) {
+                results.remove(r);
+                r.removeSucc(this);
+                break;
+            }
+        results = null;
+        successors = null;
+    }
+
+    //////////////////////////////////////////////////////////////////////
+
+    private static int node_idx = 0;
+    private final int idx = node_idx++;
+
+    private final GSS.Phase phase;
+    private final GSS.Phase predPhase;
+    private final Parser.Table.State state;
+    private  boolean fromEmptyReduction;
+    private       FastSet<Result> results = new FastSet<Result>();
+    private       FastSet<Result> successors = new FastSet<Result>();
+    //private       HashSet<Result> results = new HashSet<Result>();
+    //private       HashSet<Result> successors = new HashSet<Result>();
+
+    public final void invoke(Pos r, Result only, Object o) {
+        boolean emptyProductions = only==null;
+        if (emptyProductions != (r.numPops()==0)) return;
+        if (r.numPops()!=0)  reduce(r, r.numPops()-1, phase(), only);
+        else {
+            Input.Region region = phase().getLocation().createRegion(phase().getLocation());
+            phase().newNodeFromReduction(r.rewrite(region), r, this);
+        }
+    }
+
+    private void reduce(Pos r, int pos, GSS.Phase target, Result only) {
+        for(Result res : results)
+            if (only == null || res == only)
+                for(StateNode pred : res.getPreds())
+                    reduce2(r, pos, target, pred, res.getForest());
+    }
+
+    void reduce2(Pos r, int pos, GSS.Phase target, StateNode pred, Forest f) {
+        Forest[] holder = r.holder;
+        Forest old = pos >= holder.length ? null : holder[pos];
+        if (pos < holder.length) holder[pos] = f;
+        if (pos>0)  pred.reduce(r, pos-1, target, null);
+        else {
+            Input.Region region = pred.phase().getLocation().createRegion(target.getLocation());
+            new Reduction(pred, r, r.rewrite(region), target);
+        }
+        if (pos < holder.length) holder[pos] = old;
+    }
+
+    StateNode(GSS.Phase phase, Forest f, Pos reduction, StateNode pred, State state, boolean fromEmptyReduction) {
+        this(phase, new Result(f, reduction, pred), state, fromEmptyReduction);
+    }
+    StateNode(GSS.Phase phase, Result pred, State state, boolean fromEmptyReduction) {
+        this.phase = phase;
+        this.state = state;
+        this.fromEmptyReduction = fromEmptyReduction;
+        if (phase.hash.get(state, pred.phase()) != null) throw new Error("severe problem!");
+        this.predPhase = pred.phase();
+        phase.hash.put(state, pred.phase(), this);
+
+        results.add(pred);
+        pred.addSucc(this);
+        if (!fromEmptyReduction)
+            state.invokeReductions(phase().getToken(), this, pred);
+
+        state.invokeEpsilonReductions(phase().token, this);
+    }
+
+    // Add/Remove Successors/Results //////////////////////////////////////////////////////////////////////////////
+
+    public void removeSucc(Result succ)   {
+        successors.remove(succ);
+        check();
+    }
+    public void removeResult(Result result) {
+        results.remove(result);
+        check();
+    }
+    public void addSucc(Result succ)      {
+        successors.add(succ);
+    }
+    public void addResult(Forest f, Pos reduction, StateNode pred) {
+        for(Result r : results)
+            if (r.predecessorsContains(pred)) {
+                r.merge(f);
+                return;
+            }
+        Result result = new Result(f, reduction, pred);
+        results.add(result);
+        result.addSucc(this);
+        if (!this.fromEmptyReduction) state.invokeReductions(phase().getToken(), this, result);
+    }
+
+    // GraphViz //////////////////////////////////////////////////////////////////////////////
+
+    public GraphViz.StateNode toGraphViz(GraphViz gv) {
+        if (results.size()==0) return null;
+        if (gv.hasNode(this)) return gv.createNode(this);
+        GraphViz.StateNode n = gv.createNode(this);
+        n.label = "state["+state.toInt()+"]";
+        n.shape = "rectangle";
+        boolean haspreds = false;
+        for(Result r : results) n.edge(r, "");
+        n.color = state.doomed ? "red" : "green";
+        ((GraphViz.Group)phase().toGraphViz(gv)).add(n);
+        return n;
+    }
+    public boolean isTransparent() { return false; }
+    public boolean isHidden() { return false; }
+
+}