fastest yet, with codegen

Author: hmottestad

core/sail/lmdb/src/main/java/org/eclipse/rdf4j/sail/lmdb/LmdbLftjBindingState.java

@@ -13,6 +13,7 @@
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.function.BiConsumer;
 
@@ -28,6 +29,8 @@ public final class LmdbLftjBindingState {
 	private final BindingSet inputBindings;
 	private final LmdbQueryAccess queryAccess;
 	private final String[] variableNames;
+	private final String[] outputNames;
+	private final int[] outputSlots;
 	private final Map<String, Integer> variableSlots = new HashMap<>();
 	private final long[] fixedValues;
 	private final boolean[] fixedPresent;
@@ -52,6 +55,19 @@ public final class LmdbLftjBindingState {
 		for (int i = 0; i < variableCount; i++) {
 			variableSlots.put(variableNames[i], i);
 		}
+		List<LmdbLftjPlan.OutputBinding> outputBindings = plan.outputBindings();
+		this.outputNames = new String[outputBindings.size()];
+		this.outputSlots = new int[outputBindings.size()];
+		for (int i = 0; i < outputBindings.size(); i++) {
+			LmdbLftjPlan.OutputBinding outputBinding = outputBindings.get(i);
+			Integer slot = variableSlots.get(outputBinding.sourceVariable());
+			if (slot == null) {
+				throw new IllegalArgumentException(
+						"Unknown LMDB LFTJ output source variable: " + outputBinding.sourceVariable());
+			}
+			outputNames[i] = outputBinding.outputName();
+			outputSlots[i] = slot;
+		}
 	}
 
 	public boolean initialize() {
@@ -150,9 +166,10 @@ long fixedId(LmdbLftjPatternPlan.TermRef term) {
 	public BindingSet materialize(QueryEvaluationContext context) {
 		MutableBindingSet result = context.createBindingSet(inputBindings);
 		BiConsumer<Value, MutableBindingSet>[] setters = bindingSetters(context);
-		for (int slot = 0; slot < variableNames.length; slot++) {
-			if (assignedPresent[slot]) {
-				setters[slot].accept(queryAccess.resolveValue(assignedValues[slot]), result);
+		for (int outputIndex = 0; outputIndex < outputSlots.length; outputIndex++) {
+			int slot = outputSlots[outputIndex];
+			if (isBound(slot)) {
+				setters[outputIndex].accept(queryAccess.lazyValue(value(slot)), result);
 			}
 		}
 		return result;
@@ -182,9 +199,9 @@ private BiConsumer<Value, MutableBindingSet>[] bindingSetters(QueryEvaluationCon
 		if (bindingSetters != null && bindingSettersContext == context) {
 			return bindingSetters;
 		}
-		BiConsumer<Value, MutableBindingSet>[] setters = new BiConsumer[variableNames.length];
-		for (int slot = 0; slot < variableNames.length; slot++) {
-			setters[slot] = context.setBinding(variableNames[slot]);
+		BiConsumer<Value, MutableBindingSet>[] setters = new BiConsumer[outputNames.length];
+		for (int outputIndex = 0; outputIndex < outputNames.length; outputIndex++) {
+			setters[outputIndex] = context.setBinding(outputNames[outputIndex]);
 		}
 		bindingSetters = setters;
 		bindingSettersContext = context;

core/sail/lmdb/src/main/java/org/eclipse/rdf4j/sail/lmdb/LmdbLftjExecutionShape.java

@@ -19,7 +19,7 @@
 
 public final class LmdbLftjExecutionShape {
 
-	private static final int FULL_STACK_TEMPLATE_VERSION = 3;
+	private static final int FULL_STACK_TEMPLATE_VERSION = 4;
 
 	private final int variableCount;
 	private final int[][] cursorOrdinalsBySlot;

core/sail/lmdb/src/main/java/org/eclipse/rdf4j/sail/lmdb/LmdbLftjExecutor.java

@@ -157,6 +157,10 @@ protected void handleClose() {
 		private BindingSet computeNextElement() {
 			while (depth >= 0) {
 				if (depth == searchSlots.length) {
+					if (!passesInequalityConstraints(plan, state)) {
+						backtrackAfterLeaf();
+						continue;
+					}
 					long multiplicity = witnessMultiplicity(plan, metrics, frontierProvider);
 					backtrackAfterLeaf();
 					if (multiplicity > 0) {
@@ -258,6 +262,15 @@ private void releaseDepth(int depth) {
 		}
 	}
 
+	private static boolean passesInequalityConstraints(LmdbLftjPlan plan, LmdbLftjBindingState state) {
+		for (LmdbLftjPlan.InequalityConstraint inequality : plan.inequalityConstraints()) {
+			if (state.value(inequality.leftVariable()) == state.value(inequality.rightVariable())) {
+				return false;
+			}
+		}
+		return true;
+	}
+
 	private int[] collectSearchSlots(LmdbLftjPlan plan, LmdbLftjBindingState state) {
 		int[] searchSlots = new int[plan.variableOrder().size()];
 		int count = 0;

core/sail/lmdb/src/main/java/org/eclipse/rdf4j/sail/lmdb/LmdbLftjFullCodegenCompiler.java

@@ -318,6 +318,10 @@ private void appendComputeNextElement(StringBuilder source, int variableCount) {
 			source.append("    protected BindingSet computeNextElement() {\n");
 			source.append("      while (depth >= 0) {\n");
 			source.append("        if (depth == ").append(variableCount).append(") {\n");
+			source.append("          if (!passesInequalityConstraints()) {\n");
+			source.append("            backtrackAfterLeaf();\n");
+			source.append("            continue;\n");
+			source.append("          }\n");
 			source.append("          long multiplicity = 1L;\n");
 			for (int patternOrdinal = 0; patternOrdinal < shape.patternCount(); patternOrdinal++) {
 				source.append("          long witnesses")
@@ -1214,6 +1218,7 @@ private void appendHelpers(StringBuilder source) {
 			source.append("        throw new SailException(e);\n");
 			source.append("      }\n");
 			source.append("    }\n\n");
+			appendInequalityHelper(source);
 			for (int patternOrdinal = 0; patternOrdinal < shape.patternCount(); patternOrdinal++) {
 				LmdbLftjExecutionShape.PatternShape patternShape = shape.pattern(patternOrdinal);
 				if (patternShape.derivedBinaryRelation()) {
@@ -1227,6 +1232,28 @@ private void appendHelpers(StringBuilder source) {
 			}
 		}
 
+		private void appendInequalityHelper(StringBuilder source) {
+			source.append("    private boolean passesInequalityConstraints() {\n");
+			if (plan.inequalityConstraints().isEmpty()) {
+				source.append("      return true;\n");
+			} else {
+				source.append("      return ");
+				for (int i = 0; i < plan.inequalityConstraints().size(); i++) {
+					LmdbLftjPlan.InequalityConstraint inequality = plan.inequalityConstraints().get(i);
+					if (i > 0) {
+						source.append("\n          && ");
+					}
+					source.append("state().value(")
+							.append(variableSlot(inequality.leftVariable()))
+							.append(") != state().value(")
+							.append(variableSlot(inequality.rightVariable()))
+							.append(')');
+				}
+				source.append(";\n");
+			}
+			source.append("    }\n\n");
+		}
+
 		private void appendCursorRowHelpers(StringBuilder source, int patternOrdinal, int slot,
 				LmdbLftjExecutionShape.PatternShape patternShape) {
 			String suffix = slotSuffix(patternOrdinal, slot);
@@ -1393,6 +1420,14 @@ private String slotSuffix(int patternOrdinal, int slot) {
 			return "P" + patternOrdinal + (slot >= 0 ? "S" + slot : "W");
 		}
 
+		private int variableSlot(String variableName) {
+			int slot = plan.variableOrder().indexOf(variableName);
+			if (slot < 0) {
+				throw new IllegalArgumentException("Unknown LMDB LFTJ variable in full-stack codegen: " + variableName);
+			}
+			return slot;
+		}
+
 		private String componentAccessor(int patternOrdinal, int slot, String kind, int component) {
 			return componentFieldName(component) + slotSuffix(patternOrdinal, slot) + kind;
 		}