Merge pull request #33299 from vespa-engine/toregge/extend-shared-str…

…ing-repo-handles-push-back-choices Extend vespalib::SharedStringRepo::Handles with a push_back member fu…
vespa-engine · Feb 11, 2025 · 6782a12 · 6782a12
2 parents 25a7e92 + 149eea2
commit 6782a12
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Showing 4 changed files with 26 additions and 6 deletions.
diff --git a/searchlib/src/vespa/searchlib/features/elementwise_output.cpp b/searchlib/src/vespa/searchlib/features/elementwise_output.cpp
@@ -46,7 +46,7 @@ ElementwiseOutput::build_helper(const vespalib::hash_map<uint32_t, double>& scor
     auto& cells = std::get<std::vector<CT>>(_cells);
     cells.clear();
     for (auto& elem : scores) {
-        _labels->push_back(SharedStringRepo::Handle::handle_from_number(elem.first).id());
+        _labels.push_back(SharedStringRepo::Handle::handle_from_number(elem.first));
         cells.emplace_back(static_cast<CT>(elem.second));
     }
     return TypedCells(cells);
@@ -58,10 +58,9 @@ ElementwiseOutput::build(const vespalib::hash_map<uint32_t, double>& scores)
     if (scores.empty()) {
         return _empty_output;
     }
-    _labels.reset();
-    _labels.emplace();
+    _labels.clear();
     auto cells = typify_invoke<1, TypifyCellType, CallBuilderHelper>(_empty_output.type().cell_type(), *this, scores);
-    _output = std::make_unique<FastValueView>(_empty_output.type(), _labels->view(), cells, 1, (size_t)cells.size);
+    _output = std::make_unique<FastValueView>(_empty_output.type(), _labels.view(), cells, 1, (size_t)cells.size);
     return *_output;
 }
 

diff --git a/searchlib/src/vespa/searchlib/features/elementwise_output.h b/searchlib/src/vespa/searchlib/features/elementwise_output.h
@@ -5,7 +5,6 @@
 #include <vespa/eval/eval/value.h>
 #include <vespa/vespalib/stllike/hash_map.h>
 #include <vespa/vespalib/util/shared_string_repo.h>
-#include <optional>
 #include <variant>
 
 namespace search::features {
@@ -18,7 +17,7 @@ namespace search::features {
 class ElementwiseOutput {
         struct CallBuilderHelper;
         friend struct CallBuilderHelper;
-        std::optional<vespalib::SharedStringRepo::Handles> _labels;
+        vespalib::SharedStringRepo::Handles _labels;
         std::variant<std::monostate, std::vector<double>, std::vector<float>, std::vector<vespalib::BFloat16>, std::vector<vespalib::eval::Int8Float>> _cells;
         const vespalib::eval::Value& _empty_output;
         std::unique_ptr<vespalib::eval::Value> _output;

diff --git a/vespalib/src/vespa/vespalib/util/shared_string_repo.cpp b/vespalib/src/vespa/vespalib/util/shared_string_repo.cpp
@@ -299,4 +299,15 @@ SharedStringRepo::Handles::~Handles()
     }
 }
 
+void
+SharedStringRepo::Handles::clear()
+{
+    if (should_reclaim) {
+        for (string_id handle : _handles) {
+            _repo.reclaim(handle);
+        }
+    }
+    _handles.clear();
+}
+
 }
diff --git a/vespalib/src/vespa/vespalib/util/shared_string_repo.h b/vespalib/src/vespa/vespalib/util/shared_string_repo.h
@@ -139,6 +139,8 @@ class SharedStringRepo {
     void reclaim(string_id id);
 
     static SharedStringRepo _repo;
+
+    struct access_token { };
 public:
     static bool will_reclaim() { return should_reclaim; }
     static Stats stats();
@@ -168,6 +170,11 @@ class SharedStringRepo {
             rhs._id = string_id();
             return *this;
         }
+        string_id release(access_token) noexcept {
+            auto res = _id;
+            _id = string_id();
+            return res;
+        }
         // NB: not lexical sorting order, but can be used in maps
         bool operator<(const Handle &rhs) const noexcept { return (_id < rhs._id); }
         bool operator==(const Handle &rhs) const noexcept { return (_id == rhs._id); }
@@ -197,6 +204,7 @@ class SharedStringRepo {
         Handles &operator=(const Handles &) = delete;
         Handles &operator=(Handles &&) = delete;
         ~Handles();
+        void clear();
         string_id add(std::string_view str) {
             string_id id = _repo.resolve(str);
             _handles.push_back(id);
@@ -207,6 +215,9 @@ class SharedStringRepo {
             string_id id = _repo.copy(handle);
             _handles.push_back(id);
         }
+        void push_back(Handle&& handle) {
+            _handles.push_back(handle.release(access_token()));
+        }
         [[nodiscard]] const StringIdVector &view() const { return _handles; }
     };