Merge pull request #2907 from yahoo/havardpe/ranking-expressions-are-pure

make sure ranking expression executors are pure

2 files changed, 24 insertions, 0 deletions

diff --git a/searchlib/src/tests/fef/rank_program/rank_program_test.cpp b/searchlib/src/tests/fef/rank_program/rank_program_test.cpp
index 90447b79fc8..8e23731e961 100644
--- a/searchlib/src/tests/fef/rank_program/rank_program_test.cpp
+++ b/searchlib/src/tests/fef/rank_program/rank_program_test.cpp
@@ -336,4 +336,25 @@ TEST_F("require that interpreted ranking expressions are always lazy", Fixture()
     EXPECT_EQUAL(f1.track_cnt, 2u);
 }
 
+TEST_F("require that compiled ranking expressions are pure", Fixture()) {
+    f1.lazy_expressions(false).add_expr("rank", "value(7)").compile();
+    EXPECT_EQUAL(2u, count_features(f1.program));
+    EXPECT_EQUAL(2u, count_const_features(f1.program));
+    EXPECT_EQUAL(f1.get(), 7.0);
+}
+
+TEST_F("require that lazy compiled ranking expressions are pure", Fixture()) {
+    f1.lazy_expressions(true).add_expr("rank", "value(7)").compile();
+    EXPECT_EQUAL(2u, count_features(f1.program));
+    EXPECT_EQUAL(2u, count_const_features(f1.program));
+    EXPECT_EQUAL(f1.get(), 7.0);
+}
+
+TEST_F("require that interpreted ranking expressions are pure", Fixture()) {
+    f1.add_expr("rank", "box(value(7))").compile();
+    EXPECT_EQUAL(4u, count_features(f1.program));
+    EXPECT_EQUAL(4u, count_const_features(f1.program));
+    EXPECT_EQUAL(f1.get(), 7.0);
+}
+
 TEST_MAIN() { TEST_RUN_ALL(); }
diff --git a/searchlib/src/vespa/searchlib/features/rankingexpressionfeature.cpp b/searchlib/src/vespa/searchlib/features/rankingexpressionfeature.cpp
index f5339dec0e6..c173ee97536 100644
--- a/searchlib/src/vespa/searchlib/features/rankingexpressionfeature.cpp
+++ b/searchlib/src/vespa/searchlib/features/rankingexpressionfeature.cpp
@@ -54,6 +54,7 @@ private:
 
 public:
     CompiledRankingExpressionExecutor(const CompiledFunction &compiled_function);
+    bool isPure() override { return true; }
     void execute(uint32_t docId) override;
 };
 
@@ -70,6 +71,7 @@ private:
 
 public:
     LazyCompiledRankingExpressionExecutor(const CompiledFunction &compiled_function);
+    bool isPure() override { return true; }
     void execute(uint32_t docId) override;
 };
 
@@ -102,6 +104,7 @@ private:
 public:
     InterpretedRankingExpressionExecutor(const InterpretedFunction &function,
                                          ConstArrayRef<char> input_is_object);
+    bool isPure() override { return true; }
     void execute(uint32_t docId) override;
 };