--- /dev/null
+// 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; }
+
+}
projects / sbp.git / blobdiff