Revert "Balder/cached xxh3 hash"

4 files changed, 7 insertions, 81 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/compress/Hasher.java b/vespajlib/src/main/java/com/yahoo/compress/Hasher.java
index 7a3d34eca7b..92a9ed26085 100644
--- a/vespajlib/src/main/java/com/yahoo/compress/Hasher.java
+++ b/vespajlib/src/main/java/com/yahoo/compress/Hasher.java
@@ -8,25 +8,8 @@ import net.openhft.hashing.LongHashFunction;
  * @author baldersheim
  */
 public class Hasher {
-    private final LongHashFunction hasher;
     /** Uses net.openhft.hashing.LongHashFunction.xx3() */
     public static long xxh3(byte [] data) {
         return LongHashFunction.xx3().hashBytes(data);
     }
-    public static long xxh3(byte [] data, long seed) {
-        return LongHashFunction.xx3(seed).hashBytes(data);
-    }
-
-    private Hasher(LongHashFunction hasher) {
-        this.hasher = hasher;
-    }
-    public static Hasher withSeed(long seed) {
-        return new Hasher(LongHashFunction.xx3(seed));
-    }
-    public long hash(long v) {
-        return hasher.hashLong(v);
-    }
-    public long hash(String s) {
-        return hasher.hashChars(s);
-    }
 }
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/MixedTensor.java b/vespajlib/src/main/java/com/yahoo/tensor/MixedTensor.java
index 55fb4af551e..62b0dd88b7d 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/MixedTensor.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/MixedTensor.java
@@ -10,7 +10,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -309,7 +308,7 @@ public class MixedTensor implements Tensor {
     public static class BoundBuilder extends Builder {
 
         /** For each sparse partial address, hold a dense subspace */
-        private final Map<TensorAddress, double[]> denseSubspaceMap = new LinkedHashMap<>();
+        private final Map<TensorAddress, double[]> denseSubspaceMap = new HashMap<>();
         private final Index.Builder indexBuilder;
         private final Index index;
         private final TensorType denseSubtype;
diff --git a/vespajlib/src/main/java/com/yahoo/tensor/TensorAddress.java b/vespajlib/src/main/java/com/yahoo/tensor/TensorAddress.java
index e011717cdd8..f841b7757fb 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/TensorAddress.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/TensorAddress.java
@@ -1,7 +1,6 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.tensor;
 
-import com.yahoo.compress.Hasher;
 import com.yahoo.tensor.impl.NumericTensorAddress;
 import com.yahoo.tensor.impl.StringTensorAddress;
 
@@ -29,9 +28,6 @@ public abstract class TensorAddress implements Comparable<TensorAddress> {
         return NumericTensorAddress.of(labels);
     }
 
-    // If the hash ends up as 0 it will be recalculated everytime, but that is not a practical issue.
-    private int cached_hash = 0;
-
     /** Returns the number of labels in this */
     public abstract int size();
 
@@ -66,18 +62,12 @@ public abstract class TensorAddress implements Comparable<TensorAddress> {
 
     @Override
     public int hashCode() {
-        if (cached_hash != 0) return cached_hash;
-        Hasher hasher = Hasher.withSeed(0);
-        long hash = 0;
+        int result = 1;
         for (int i = 0; i < size(); i++) {
-            String label = label(i);
-            if (label != null) {
-                hash = hash ^ hasher.hash(label);
-            }
+            if (label(i) != null)
+                result = 31 * result + label(i).hashCode();
         }
-        int low = (int) hash;
-        int high = (int) (hash >> 32);
-        return cached_hash = low ^ high;
+        return result;
     }
 
     @Override
@@ -115,7 +105,7 @@ public abstract class TensorAddress implements Comparable<TensorAddress> {
     public static class Builder {
 
         final TensorType type;
-        String[] labels;
+        final String[] labels;
 
         public Builder(TensorType type) {
             this(type, new String[type.dimensions().size()]);
@@ -172,9 +162,7 @@ public abstract class TensorAddress implements Comparable<TensorAddress> {
 
         public TensorAddress build() {
             validate();
-            var address = StringTensorAddress.unsafeOf(labels);
-            labels = null;
-            return address;
+            return TensorAddress.of(labels);
         }
 
     }
diff --git a/vespajlib/src/test/java/com/yahoo/tensor/TensorAddressTestCase.java b/vespajlib/src/test/java/com/yahoo/tensor/TensorAddressTestCase.java
deleted file mode 100644
index 79202e3f07e..00000000000
--- a/vespajlib/src/test/java/com/yahoo/tensor/TensorAddressTestCase.java
+++ /dev/null
@@ -1,44 +0,0 @@
-// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.tensor;
-
-import org.junit.jupiter.api.Test;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertNotEquals;
-
-/**
- * Test for tensor address.
- *
- * @author baldersheim
- */
-public class TensorAddressTestCase {
-    private void equal(Object a, Object b) {
-        assertEquals(a.hashCode(), b.hashCode());
-        assertEquals(a, b);
-    }
-    private void notEqual(Object a, Object b) {
-        assertNotEquals(a.hashCode(), b.hashCode()); // This might not hold, but is bad if not very rare
-        assertNotEquals(a, b);
-    }
-    @Test
-    void testStringVersusNumericAddressEquality() {
-        equal(TensorAddress.ofLabels("1"), TensorAddress.of(1));
-    }
-    @Test
-    void testInEquality() {
-        notEqual(TensorAddress.ofLabels("1"), TensorAddress.ofLabels("2"));
-        notEqual(TensorAddress.of(1), TensorAddress.of(2));
-    }
-    @Test
-    void testDimensionsEffectsEqualityAndHash() {
-        notEqual(TensorAddress.ofLabels("1"), TensorAddress.ofLabels("1", "1"));
-        notEqual(TensorAddress.of(1), TensorAddress.of(1, 1));
-    }
-    @Test
-    void testAllowNullDimension() {
-        TensorAddress s1 = TensorAddress.ofLabels("1", null, "2");
-        TensorAddress s2 = TensorAddress.ofLabels("1", "2");
-        assertNotEquals(s1, s2);
-        assertEquals(s1.hashCode(), s2.hashCode());
-    }
-}