1 files changed, 76 insertions, 0 deletions
diff --git a/config-model/src/main/java/com/yahoo/schema/document/HnswIndexParams.java b/config-model/src/main/java/com/yahoo/schema/document/HnswIndexParams.java
new file mode 100644
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+++ b/config-model/src/main/java/com/yahoo/schema/document/HnswIndexParams.java
@@ -0,0 +1,76 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.schema.document;
+
+import java.util.Optional;
+
+/**
+ * Configuration parameters for a hnsw index used together with a 1-dimensional indexed tensor for approximate nearest neighbor search.
+ *
+ * @author geirst
+ */
+public class HnswIndexParams {
+
+    public static final int DEFAULT_MAX_LINKS_PER_NODE = 16;
+    public static final int DEFAULT_NEIGHBORS_TO_EXPLORE_AT_INSERT = 200;
+
+    private final Optional<Integer> maxLinksPerNode;
+    private final Optional<Integer> neighborsToExploreAtInsert;
+    private final Optional<Boolean> multiThreadedIndexing;
+
+    public static class Builder {
+        private Optional<Integer> maxLinksPerNode = Optional.empty();
+        private Optional<Integer> neighborsToExploreAtInsert = Optional.empty();
+        private Optional<Boolean> multiThreadedIndexing = Optional.empty();
+
+        public void setMaxLinksPerNode(int value) {
+            maxLinksPerNode = Optional.of(value);
+        }
+        public void setNeighborsToExploreAtInsert(int value) {
+            neighborsToExploreAtInsert = Optional.of(value);
+        }
+        public void setMultiThreadedIndexing(boolean value) {
+            multiThreadedIndexing = Optional.of(value);
+        }
+        public HnswIndexParams build() {
+            return new HnswIndexParams(maxLinksPerNode, neighborsToExploreAtInsert, multiThreadedIndexing);
+        }
+    }
+
+    public HnswIndexParams() {
+        this.maxLinksPerNode = Optional.empty();
+        this.neighborsToExploreAtInsert = Optional.empty();
+        this.multiThreadedIndexing = Optional.empty();
+    }
+
+    public HnswIndexParams(Optional<Integer> maxLinksPerNode,
+                           Optional<Integer> neighborsToExploreAtInsert,
+                           Optional<Boolean> multiThreadedIndexing) {
+        this.maxLinksPerNode = maxLinksPerNode;
+        this.neighborsToExploreAtInsert = neighborsToExploreAtInsert;
+        this.multiThreadedIndexing = multiThreadedIndexing;
+    }
+
+    /**
+     * Creates a new instance where values from the given parameter instance are used where they are present,
+     * otherwise we use values from this.
+     */
+    public HnswIndexParams overrideFrom(Optional<HnswIndexParams> other) {
+        if (! other.isPresent()) return this;
+        HnswIndexParams rhs = other.get();
+        return new HnswIndexParams(rhs.maxLinksPerNode.or(() ->  maxLinksPerNode),
+                rhs.neighborsToExploreAtInsert.or(() ->  neighborsToExploreAtInsert),
+                rhs.multiThreadedIndexing.or(() -> multiThreadedIndexing));
+    }
+
+    public int maxLinksPerNode() {
+        return maxLinksPerNode.orElse(DEFAULT_MAX_LINKS_PER_NODE);
+    }
+
+    public int neighborsToExploreAtInsert() {
+        return neighborsToExploreAtInsert.orElse(DEFAULT_NEIGHBORS_TO_EXPLORE_AT_INSERT);
+    }
+
+    public boolean multiThreadedIndexing() {
+        return multiThreadedIndexing.orElse(true);
+    }
+}