Add a time budget of 100ms. If counting not complete by then, abort, and let the count be incomplete.

2 files changed, 17 insertions, 7 deletions

diff --git a/searchlib/src/vespa/searchlib/tensor/hnsw_index.cpp b/searchlib/src/vespa/searchlib/tensor/hnsw_index.cpp
index a1515534cbc..f11381070e1 100644
--- a/searchlib/src/vespa/searchlib/tensor/hnsw_index.cpp
+++ b/searchlib/src/vespa/searchlib/tensor/hnsw_index.cpp
@@ -12,6 +12,7 @@
 #include <vespa/vespalib/util/memory_allocator.h>
 #include <vespa/vespalib/util/rcuvector.hpp>
 #include <vespa/vespalib/util/size_literals.h>
+#include <vespa/vespalib/util/time.h>
 #include <vespa/log/log.h>
 
 LOG_SETUP(".searchlib.tensor.hnsw_index");
@@ -30,6 +31,7 @@ constexpr float alloc_grow_factor = 0.3;
 // TODO: Adjust these numbers to what we accept as max in config.
 constexpr size_t max_level_array_size = 16;
 constexpr size_t max_link_array_size = 64;
+constexpr vespalib::duration MAX_COUNT_DURATION(100ms);
 
 bool has_link_to(vespalib::ConstArrayRef<uint32_t> links, uint32_t id) {
     for (uint32_t link : links) {
@@ -500,9 +502,13 @@ HnswIndex::get_state(const vespalib::slime::Inserter& inserter) const
     for (uint32_t hist_val : histograms.links_histogram) {
         links_hst_array.addLong(hist_val);
     }
-    uint32_t reachable = count_reachable_nodes();
-    uint32_t unreachable = valid_nodes - reachable;
-    object.setLong("unreachable_nodes", unreachable);
+    auto count_result = count_reachable_nodes();
+    uint32_t unreachable = valid_nodes - count_result.first;
+    if (count_result.second) {
+        object.setLong("unreachable_nodes", unreachable);
+    } else {
+        object.setLong("unreachable_nodes_incomplete_count", unreachable);
+    }
     auto entry_node = _graph.get_entry_node();
     object.setLong("entry_docid", entry_node.docid);
     object.setLong("entry_level", entry_node.level);
@@ -650,20 +656,24 @@ HnswIndex::check_link_symmetry() const
     return all_sym;
 }
 
-uint32_t
+std::pair<uint32_t, bool>
 HnswIndex::count_reachable_nodes() const
 {
     auto entry = _graph.get_entry_node();
     int search_level = entry.level;
     if (search_level < 0) {
-        return 0;
+        return {0, true};
     }
     std::vector<bool> visited(_graph.size());
     LinkArray found_links;
     found_links.push_back(entry.docid);
     visited[entry.docid] = true;
+    vespalib::steady_time doom = vespalib::steady_clock::now() + MAX_COUNT_DURATION;
     while (search_level >= 0) {
         for (uint32_t idx = 0; idx < found_links.size(); ++idx) {
+            if (vespalib::steady_clock::now() > doom) {
+                return {found_links.size(), false};
+            }
             uint32_t docid = found_links[idx];
             auto neighbors = _graph.get_link_array(docid, search_level);
             for (uint32_t neighbor : neighbors) {
@@ -674,7 +684,7 @@ HnswIndex::count_reachable_nodes() const
         }
         --search_level;
     }
-    return found_links.size();
+    return {found_links.size(), true};
 }
 
 } // namespace
diff --git a/searchlib/src/vespa/searchlib/tensor/hnsw_index.h b/searchlib/src/vespa/searchlib/tensor/hnsw_index.h
index 5bd9d17adc3..ef0f38c2263 100644
--- a/searchlib/src/vespa/searchlib/tensor/hnsw_index.h
+++ b/searchlib/src/vespa/searchlib/tensor/hnsw_index.h
@@ -183,7 +183,7 @@ public:
     HnswNode get_node(uint32_t docid) const;
     void set_node(uint32_t docid, const HnswNode &node);
     bool check_link_symmetry() const;
-    uint32_t count_reachable_nodes() const;
+    std::pair<uint32_t, bool> count_reachable_nodes() const;
 
     static vespalib::datastore::ArrayStoreConfig make_default_node_store_config();
     static vespalib::datastore::ArrayStoreConfig make_default_link_store_config();