Compute hash without serializing to string

17 files changed, 105 insertions, 40 deletions

diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/Value.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/Value.java
index 6490c69894f..207603c5038 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/Value.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/Value.java
@@ -97,6 +97,7 @@ public abstract class Value {
     @Override
     public abstract boolean equals(Object other);
 
+    /** Returns a hash which only depends on the content of this value. */
     @Override
     public abstract int hashCode();
 
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/gbdtoptimization/GBDTForestNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/gbdtoptimization/GBDTForestNode.java
index 13db51c1363..c8b20e774b5 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/gbdtoptimization/GBDTForestNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/gbdtoptimization/GBDTForestNode.java
@@ -11,7 +11,9 @@ import com.yahoo.searchlib.rankingexpression.rule.SerializationContext;
 import com.yahoo.tensor.TensorType;
 import com.yahoo.tensor.evaluation.TypeContext;
 
+import java.util.Arrays;
 import java.util.Deque;
+import java.util.Objects;
 
 /**
  * An optimized version of a sum of consecutive decision trees.
@@ -42,8 +44,12 @@ public class GBDTForestNode extends ExpressionNode {
     }
 
     /** Returns (optimized sum of condition trees) */
+    @Override
     public StringBuilder toString(StringBuilder string, SerializationContext context, Deque<String> path, CompositeNode parent) {
         return string.append("(optimized sum of condition trees of size ").append(values.length*8).append(" bytes)");
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("gbdtForest", Arrays.hashCode(values)); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/gbdtoptimization/GBDTNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/gbdtoptimization/GBDTNode.java
index 6c6166c2869..949e1f026f7 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/gbdtoptimization/GBDTNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/gbdtoptimization/GBDTNode.java
@@ -11,7 +11,9 @@ import com.yahoo.searchlib.rankingexpression.rule.SerializationContext;
 import com.yahoo.tensor.TensorType;
 import com.yahoo.tensor.evaluation.TypeContext;
 
+import java.util.Arrays;
 import java.util.Deque;
+import java.util.Objects;
 
 /**
  * An optimized version of a decision tree.
@@ -105,4 +107,8 @@ public final class GBDTNode extends ExpressionNode {
     public StringBuilder toString(StringBuilder string, SerializationContext context, Deque<String> path, CompositeNode parent) {
         return string.append("(optimized condition tree)");
     }
+
+    @Override
+    public int hashCode() { return Objects.hash("gbdtNode", Arrays.hashCode(values)); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ArithmeticNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ArithmeticNode.java
index 55fe66be69e..580f42e67cb 100755
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ArithmeticNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ArithmeticNode.java
@@ -13,6 +13,7 @@ import java.util.ArrayList;
 import java.util.Deque;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A binary mathematical operation
@@ -115,6 +116,16 @@ public final class ArithmeticNode extends CompositeNode {
         lhs.value = rhs.op.evaluate(lhs.value, rhs.value);
     }
 
+    @Override
+    public CompositeNode setChildren(List<ExpressionNode> newChildren) {
+        if (children.size() != newChildren.size())
+            throw new IllegalArgumentException("Expected " + children.size() + " children but got " + newChildren.size());
+        return new ArithmeticNode(newChildren, operators);
+    }
+
+    @Override
+    public int hashCode() { return Objects.hash(children, operators); }
+
     public static ArithmeticNode resolve(ExpressionNode left, ArithmeticOperator op, ExpressionNode right) {
         if ( ! (left instanceof ArithmeticNode)) return new ArithmeticNode(left, op, right);
 
@@ -140,12 +151,5 @@ public final class ArithmeticNode extends CompositeNode {
         }
     }
 
-    @Override
-    public CompositeNode setChildren(List<ExpressionNode> newChildren) {
-        if (children.size() != newChildren.size())
-            throw new IllegalArgumentException("Expected " + children.size() + " children but got " + newChildren.size());
-        return new ArithmeticNode(newChildren, operators);
-    }
-
 }
 
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ComparisonNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ComparisonNode.java
index 600d3b8d408..e726a351f74 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ComparisonNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ComparisonNode.java
@@ -9,6 +9,7 @@ import com.yahoo.tensor.evaluation.TypeContext;
 
 import java.util.Deque;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A node which returns the outcome of a comparison.
@@ -62,4 +63,7 @@ public class ComparisonNode extends BooleanNode {
         return new ComparisonNode(children.get(0), operator, children.get(1));
     }
 
+    @Override
+    public int hashCode() { return Objects.hash(operator, conditions); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ConstantNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ConstantNode.java
index ffbeec37c78..46e833197f9 100755
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ConstantNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ConstantNode.java
@@ -8,6 +8,7 @@ import com.yahoo.tensor.TensorType;
 import com.yahoo.tensor.evaluation.TypeContext;
 
 import java.util.Deque;
+import java.util.Objects;
 
 /**
  * A node which holds a constant (frozen) value.
@@ -55,4 +56,7 @@ public final class ConstantNode extends ExpressionNode {
         return value;
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("constantNode", value); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/EmbracedNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/EmbracedNode.java
index 9d389a4f6e9..64a1f42a7ba 100755
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/EmbracedNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/EmbracedNode.java
@@ -10,6 +10,7 @@ import com.yahoo.tensor.evaluation.TypeContext;
 import java.util.Collections;
 import java.util.Deque;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * This class represents another expression enclosed in braces.
@@ -60,4 +61,7 @@ public final class EmbracedNode extends CompositeNode {
         return new EmbracedNode(newChildren.get(0));
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("embraced", value); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ExpressionNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ExpressionNode.java
index 8e00be3f056..51067930dd0 100755
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ExpressionNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ExpressionNode.java
@@ -18,31 +18,13 @@ import java.util.Deque;
  */
 public abstract class ExpressionNode implements Serializable {
 
-    @Override
-    public int hashCode() {
-        return toString().hashCode();
-    }
-
-    @Override
-    public final boolean equals(Object obj) {
-        return obj instanceof ExpressionNode && toString().equals(obj.toString());
-    }
-
-    @Override
-    public final String toString() {
-        return toString(new SerializationContext()).toString();
-    }
-    public final StringBuilder toString(SerializationContext context) {
-        return toString(new StringBuilder(), context, null, null);
-    }
-
     /**
-     * Returns a script instance of this based on the supplied script functions.
+     * Returns this in serialized form.
      *
      * @param builder the StringBuilder that will be appended to
      * @param context the serialization context
      * @param path the call path to this, used for cycle detection, or null if this is a root
-     * @param parent the parent node of this, or null if it a root
+     * @param parent the parent node of this, or null if it is a root
      * @return the main script, referring to script instances.
      */
     public abstract StringBuilder toString(StringBuilder builder, SerializationContext context, Deque<String> path, CompositeNode parent);
@@ -63,4 +45,22 @@ public abstract class ExpressionNode implements Serializable {
      */
     public abstract Value evaluate(Context context);
 
+    public final StringBuilder toString(SerializationContext context) {
+        return toString(new StringBuilder(), context, null, null);
+    }
+
+    @Override
+    public final boolean equals(Object obj) {
+        return obj instanceof ExpressionNode && toString().equals(obj.toString());
+    }
+
+    /** Returns a hashcode computed from the data in this */
+    @Override
+    public abstract int hashCode();
+
+    @Override
+    public final String toString() {
+        return toString(new SerializationContext()).toString();
+    }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/FunctionNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/FunctionNode.java
index d32cfb51f95..5e8bfc245a7 100755
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/FunctionNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/FunctionNode.java
@@ -14,6 +14,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Deque;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * Invocation of a native function.
@@ -108,4 +109,7 @@ public final class FunctionNode extends CompositeNode {
             return new FunctionNode(function, children.get(0), children.get(1));
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("functionNode", function, arguments); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/GeneratorLambdaFunctionNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/GeneratorLambdaFunctionNode.java
index 7ff3a71d036..8d858341976 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/GeneratorLambdaFunctionNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/GeneratorLambdaFunctionNode.java
@@ -11,6 +11,7 @@ import com.yahoo.tensor.evaluation.TypeContext;
 import java.util.Collections;
 import java.util.Deque;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A tensor generating function, whose arguments are determined by a tensor type
@@ -31,6 +32,11 @@ public class GeneratorLambdaFunctionNode extends CompositeNode {
         this.generator = generator;
     }
 
+    /** Returns this as an operator which converts a list of integers into a double. */
+    public LongListToDoubleLambda asLongListToDoubleOperator() {
+        return new LongListToDoubleLambda();
+    }
+
     @Override
     public List<ExpressionNode> children() {
         return Collections.singletonList(generator);
@@ -57,12 +63,8 @@ public class GeneratorLambdaFunctionNode extends CompositeNode {
         return generator.evaluate(context);
     }
 
-    /**
-     * Returns this as an operator which converts a list of integers into a double
-     */
-    public LongListToDoubleLambda asLongListToDoubleOperator() {
-        return new LongListToDoubleLambda();
-    }
+    @Override
+    public int hashCode() { return Objects.hash("generator", type, generator); }
 
     private class LongListToDoubleLambda implements java.util.function.Function<List<Long>, Double> {
 
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/IfNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/IfNode.java
index 02d437e83bf..6f46222c1d8 100755
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/IfNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/IfNode.java
@@ -9,6 +9,7 @@ import com.yahoo.tensor.evaluation.TypeContext;
 
 import java.util.Deque;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A conditional branch of a ranking expression.
@@ -17,8 +18,9 @@ import java.util.List;
  * @author bratseth
  */
 public final class IfNode extends CompositeNode {
-    /** [condition, trueExpression, falseExpression]*/
-    private final List<ExpressionNode> asList;
+
+    /** [condition, trueExpression, falseExpression] */
+    private final List<ExpressionNode> arguments;
     private final Double trueProbability;
 
     public IfNode(ExpressionNode condition, ExpressionNode trueExpression, ExpressionNode falseExpression) {
@@ -39,19 +41,19 @@ public final class IfNode extends CompositeNode {
         if (trueProbability != null && ( trueProbability < 0.0 || trueProbability > 1.0) )
             throw new IllegalArgumentException("trueProbability must be a between 0.0 and 1.0, not " + trueProbability);
         this.trueProbability = trueProbability;
-        this.asList = List.of(condition, trueExpression, falseExpression);
+        this.arguments = List.of(condition, trueExpression, falseExpression);
     }
 
     @Override
     public List<ExpressionNode> children() {
-        return asList;
+        return arguments;
     }
 
-    public ExpressionNode getCondition() { return asList.get(0); }
+    public ExpressionNode getCondition() { return arguments.get(0); }
 
-    public ExpressionNode getTrueExpression() { return asList.get(1); }
+    public ExpressionNode getTrueExpression() { return arguments.get(1); }
 
-    public ExpressionNode getFalseExpression() { return asList.get(2); }
+    public ExpressionNode getFalseExpression() { return arguments.get(2); }
 
     /** The average probability that the condition of this node will evaluate to true, or null if not known */
     public Double getTrueProbability() { return trueProbability; }
@@ -95,4 +97,7 @@ public final class IfNode extends CompositeNode {
         return new IfNode(children.get(0), children.get(1), children.get(2));
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("if", arguments, trueProbability); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/LambdaFunctionNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/LambdaFunctionNode.java
index a2b86360923..9f07f146264 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/LambdaFunctionNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/LambdaFunctionNode.java
@@ -13,6 +13,7 @@ import java.util.Collections;
 import java.util.Deque;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.DoubleBinaryOperator;
@@ -162,6 +163,8 @@ public class LambdaFunctionNode extends CompositeNode {
         return Set.of();
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("lambdaFunction", arguments, functionExpression); }
 
     private class DoubleUnaryLambda implements DoubleUnaryOperator {
 
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NameNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NameNode.java
index 34c8664c0cf..fec643e81df 100755
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NameNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NameNode.java
@@ -8,6 +8,7 @@ import com.yahoo.tensor.TensorType;
 import com.yahoo.tensor.evaluation.TypeContext;
 
 import java.util.Deque;
+import java.util.Objects;
 
 /**
  * An opaque name in a ranking expression. This is used to represent names passed to the context
@@ -41,4 +42,7 @@ public final class NameNode extends ExpressionNode {
         throw new RuntimeException("Name nodes should never be evaluated");
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("name", name); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NegativeNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NegativeNode.java
index 9516f38a155..8d2cf7b6387 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NegativeNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NegativeNode.java
@@ -10,6 +10,7 @@ import com.yahoo.tensor.evaluation.TypeContext;
 import java.util.Collections;
 import java.util.Deque;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A node which flips the sign of the value produced from the nested expression
@@ -54,4 +55,7 @@ public class NegativeNode extends CompositeNode {
         return new NegativeNode(children.get(0));
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("negative", value); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NotNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NotNode.java
index 8b5ae256038..ac3566c26af 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NotNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/NotNode.java
@@ -10,6 +10,7 @@ import com.yahoo.tensor.evaluation.TypeContext;
 import java.util.Collections;
 import java.util.Deque;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A node which flips the logical value produced from the nested expression.
@@ -55,5 +56,8 @@ public class NotNode extends BooleanNode {
         return new NotNode(children.get(0));
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("not", value); }
+
 }
 
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/SetMembershipNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/SetMembershipNode.java
index 31f3013b756..5da2fbfe624 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/SetMembershipNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/SetMembershipNode.java
@@ -14,6 +14,7 @@ import com.yahoo.tensor.evaluation.TypeContext;
 import java.util.ArrayList;
 import java.util.Deque;
 import java.util.List;
+import java.util.Objects;
 import java.util.function.Predicate;
 
 /**
@@ -100,4 +101,7 @@ public class SetMembershipNode extends BooleanNode {
         return new SetMembershipNode(children.get(0), children.subList(1, children.size()));
     }
 
+    @Override
+    public int hashCode() { return Objects.hash("setMembership", testValue, setValues); }
+
 }
diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/TensorFunctionNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/TensorFunctionNode.java
index ce5832027b7..7b68ad7e2af 100644
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/TensorFunctionNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/TensorFunctionNode.java
@@ -144,6 +144,9 @@ public class TensorFunctionNode extends CompositeNode {
         return new ExpressionScalarFunction(node);
     }
 
+    @Override
+    public int hashCode() { return function.hashCode(); }
+
     private static class ExpressionScalarFunction implements ScalarFunction<Reference> {
 
         private final ExpressionNode expression;
@@ -251,6 +254,9 @@ public class TensorFunctionNode extends CompositeNode {
         }
 
         @Override
+        public int hashCode() { return expression.hashCode(); }
+
+        @Override
         public String toString(ToStringContext<Reference> c) {
             ToStringContext<Reference> outermost = c;
             while (outermost.parent() != null)