Add hnsw index params to config for attribute vector.

3 files changed, 53 insertions, 6 deletions

diff --git a/searchcommon/src/vespa/searchcommon/attribute/config.cpp b/searchcommon/src/vespa/searchcommon/attribute/config.cpp
index 53e57fd9c66..b4e05875820 100644
--- a/searchcommon/src/vespa/searchcommon/attribute/config.cpp
+++ b/searchcommon/src/vespa/searchcommon/attribute/config.cpp
@@ -17,7 +17,8 @@ Config::Config() :
     _growStrategy(),
     _compactionStrategy(),
     _predicateParams(),
-    _tensorType(vespalib::eval::ValueType::error_type())
+    _tensorType(vespalib::eval::ValueType::error_type()),
+    _hnsw_index_params()
 {
 }
 
@@ -34,7 +35,8 @@ Config::Config(BasicType bt, CollectionType ct, bool fastSearch_, bool huge_)
       _growStrategy(),
       _compactionStrategy(),
       _predicateParams(),
-      _tensorType(vespalib::eval::ValueType::error_type())
+      _tensorType(vespalib::eval::ValueType::error_type()),
+      _hnsw_index_params()
 {
 }
 
@@ -60,7 +62,8 @@ Config::operator==(const Config &b) const
            _compactionStrategy == b._compactionStrategy &&
            _predicateParams == b._predicateParams &&
            (_basicType.type() != BasicType::Type::TENSOR ||
-            _tensorType == b._tensorType);
+            _tensorType == b._tensorType) &&
+            _hnsw_index_params == b._hnsw_index_params;
 }
 
 }
diff --git a/searchcommon/src/vespa/searchcommon/attribute/config.h b/searchcommon/src/vespa/searchcommon/attribute/config.h
index 2f767061f7a..836fcfed84a 100644
--- a/searchcommon/src/vespa/searchcommon/attribute/config.h
+++ b/searchcommon/src/vespa/searchcommon/attribute/config.h
@@ -4,15 +4,21 @@
 
 #include "basictype.h"
 #include "collectiontype.h"
+#include "hnsw_index_params.h"
 #include "predicate_params.h"
-#include <vespa/searchcommon/common/growstrategy.h>
 #include <vespa/searchcommon/common/compaction_strategy.h>
+#include <vespa/searchcommon/common/growstrategy.h>
 #include <vespa/eval/eval/value_type.h>
+#include <optional>
 
 namespace search::attribute {
 
-class Config
-{
+/**
+ * Configuration for an attribute vector.
+ *
+ * Used to determine which implementation to instantiate.
+ */
+class Config {
 public:
     Config();
     Config(BasicType bt, CollectionType ct = CollectionType::SINGLE,
@@ -29,6 +35,7 @@ public:
     bool huge()                           const { return _huge; }
     const PredicateParams &predicateParams() const { return _predicateParams; }
     vespalib::eval::ValueType tensorType() const { return _tensorType; }
+    const std::optional<HnswIndexParams>& hnsw_index_params() const { return _hnsw_index_params; }
 
     /**
      * Check if attribute posting list can consist of a bitvector in
@@ -60,6 +67,10 @@ public:
         _tensorType = tensorType_in;
         return *this;
     }
+    Config& set_hnsw_index_params(const HnswIndexParams& params) {
+        _hnsw_index_params = params;
+        return *this;
+    }
 
     /**
      * Enable attribute posting list to consist of a bitvector in
@@ -107,6 +118,7 @@ private:
     CompactionStrategy _compactionStrategy;
     PredicateParams    _predicateParams;
     vespalib::eval::ValueType _tensorType;
+    std::optional<HnswIndexParams> _hnsw_index_params;
 };
 
 }
diff --git a/searchcommon/src/vespa/searchcommon/attribute/hnsw_index_params.h b/searchcommon/src/vespa/searchcommon/attribute/hnsw_index_params.h
new file mode 100644
index 00000000000..9e98a8c5fb7
--- /dev/null
+++ b/searchcommon/src/vespa/searchcommon/attribute/hnsw_index_params.h
@@ -0,0 +1,32 @@
+// Copyright 2020 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#pragma once
+
+namespace search::attribute {
+
+/**
+ * Configuration parameters for a hnsw index used together with a 1-dimensional indexed tensor
+ * for approximate nearest neighbor search.
+ */
+class HnswIndexParams {
+private:
+    uint32_t _max_links_per_node;
+    uint32_t _neighbors_to_explore_at_insert;
+
+public:
+    HnswIndexParams(uint32_t max_links_per_node_in,
+                    uint32_t neighbors_to_explore_at_insert_in)
+            : _max_links_per_node(max_links_per_node_in),
+              _neighbors_to_explore_at_insert(neighbors_to_explore_at_insert_in)
+    {}
+
+    uint32_t max_links_per_node() const { return _max_links_per_node; }
+    uint32_t neighbors_to_explore_at_insert() const { return _neighbors_to_explore_at_insert; }
+
+    bool operator==(const HnswIndexParams& rhs) const {
+        return _max_links_per_node == rhs._max_links_per_node &&
+                _neighbors_to_explore_at_insert == rhs._neighbors_to_explore_at_insert;
+    }
+};
+
+}