Merge pull request #14842 from vespa-engine/havardpe/engine-or-factory-global-switch-with-default

global implementation switch with default

6 files changed, 138 insertions, 1 deletions

diff --git a/eval/CMakeLists.txt b/eval/CMakeLists.txt
index db178342359..eb94a9498cb 100644
--- a/eval/CMakeLists.txt
+++ b/eval/CMakeLists.txt
@@ -14,6 +14,7 @@ vespa_define_module(
     src/tests/eval/aggr
     src/tests/eval/compile_cache
     src/tests/eval/compiled_function
+    src/tests/eval/engine_or_factory
     src/tests/eval/fast_sparse_map
     src/tests/eval/function
     src/tests/eval/function_speed
diff --git a/eval/src/tests/eval/engine_or_factory/CMakeLists.txt b/eval/src/tests/eval/engine_or_factory/CMakeLists.txt
new file mode 100644
index 00000000000..f0bd0f63251
--- /dev/null
+++ b/eval/src/tests/eval/engine_or_factory/CMakeLists.txt
@@ -0,0 +1,17 @@
+# Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+vespa_add_executable(eval_engine_or_factory_test_app TEST
+    SOURCES
+    engine_or_factory_test.cpp
+    DEPENDS
+    vespaeval
+    GTest::GTest
+)
+vespa_add_test(NAME eval_engine_or_factory_test_app COMMAND eval_engine_or_factory_test_app)
+vespa_add_executable(eval_engine_or_factory_override_test_app TEST
+    SOURCES
+    engine_or_factory_override_test.cpp
+    DEPENDS
+    vespaeval
+    GTest::GTest
+)
+vespa_add_test(NAME eval_engine_or_factory_override_test_app COMMAND eval_engine_or_factory_override_test_app)
diff --git a/eval/src/tests/eval/engine_or_factory/engine_or_factory_override_test.cpp b/eval/src/tests/eval/engine_or_factory/engine_or_factory_override_test.cpp
new file mode 100644
index 00000000000..8480bb7d39e
--- /dev/null
+++ b/eval/src/tests/eval/engine_or_factory/engine_or_factory_override_test.cpp
@@ -0,0 +1,25 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include <vespa/eval/eval/engine_or_factory.h>
+#include <vespa/eval/tensor/default_tensor_engine.h>
+#include <vespa/eval/eval/fast_value.h>
+#include <vespa/vespalib/util/exceptions.h>
+#include <vespa/vespalib/gtest/gtest.h>
+
+using namespace vespalib::eval;
+using namespace vespalib::tensor;
+
+TEST(EngineOrFactoryOverrideTest, set_can_override_get_result) {
+    EngineOrFactory::set(FastValueBuilderFactory::get());
+    EXPECT_EQ(EngineOrFactory::get().to_string(), "FastValueBuilderFactory");
+}
+
+TEST(EngineOrFactoryOverrideTest, set_with_same_value_is_allowed) {
+    EngineOrFactory::set(FastValueBuilderFactory::get());
+}
+
+TEST(EngineOrFactoryOverrideTest, set_with_another_value_is_not_allowed) {
+    EXPECT_THROW(EngineOrFactory::set(DefaultTensorEngine::ref()), vespalib::IllegalStateException);
+}
+
+GTEST_MAIN_RUN_ALL_TESTS()
diff --git a/eval/src/tests/eval/engine_or_factory/engine_or_factory_test.cpp b/eval/src/tests/eval/engine_or_factory/engine_or_factory_test.cpp
new file mode 100644
index 00000000000..6cb9cc0c89c
--- /dev/null
+++ b/eval/src/tests/eval/engine_or_factory/engine_or_factory_test.cpp
@@ -0,0 +1,24 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include <vespa/eval/eval/engine_or_factory.h>
+#include <vespa/eval/tensor/default_tensor_engine.h>
+#include <vespa/eval/eval/fast_value.h>
+#include <vespa/vespalib/util/exceptions.h>
+#include <vespa/vespalib/gtest/gtest.h>
+
+using namespace vespalib::eval;
+using namespace vespalib::tensor;
+
+TEST(EngineOrFactoryTest, default_is_default_tensor_engine) {
+    EXPECT_EQ(EngineOrFactory::get().to_string(), "DefaultTensorEngine");
+}
+
+TEST(EngineOrFactoryTest, set_with_same_value_is_allowed) {
+    EngineOrFactory::set(DefaultTensorEngine::ref());
+}
+
+TEST(EngineOrFactoryTest, set_with_another_value_is_not_allowed) {
+    EXPECT_THROW(EngineOrFactory::set(FastValueBuilderFactory::get()), vespalib::IllegalStateException);
+}
+
+GTEST_MAIN_RUN_ALL_TESTS()
diff --git a/eval/src/vespa/eval/eval/engine_or_factory.cpp b/eval/src/vespa/eval/eval/engine_or_factory.cpp
index d297cc91f6f..67885ede48e 100644
--- a/eval/src/vespa/eval/eval/engine_or_factory.cpp
+++ b/eval/src/vespa/eval/eval/engine_or_factory.cpp
@@ -2,11 +2,29 @@
 
 #include "engine_or_factory.h"
 #include "fast_value.h"
-#include <vespa/eval/tensor/default_tensor_engine.h>
+#include "simple_value.h"
 #include "value_codec.h"
+#include "simple_tensor_engine.h"
+#include <vespa/eval/tensor/default_tensor_engine.h>
+#include <vespa/eval/tensor/default_value_builder_factory.h>
+#include <vespa/eval/tensor/mixed/packed_mixed_tensor_builder_factory.h>
+#include <vespa/vespalib/util/exceptions.h>
+#include <vespa/vespalib/util/stringfmt.h>
+
+using vespalib::make_string_short::fmt;
 
 namespace vespalib::eval {
 
+EngineOrFactory EngineOrFactory::_default{tensor::DefaultTensorEngine::ref()};
+
+
+EngineOrFactory
+EngineOrFactory::get_shared(EngineOrFactory hint)
+{
+    static EngineOrFactory shared{hint};
+    return shared;
+}
+
 const TensorFunction &
 EngineOrFactory::optimize(const TensorFunction &expr, Stash &stash) const {
     if (is_engine()) {
@@ -88,4 +106,49 @@ EngineOrFactory::rename(const Value &a, const std::vector<vespalib::string> &fro
     return engine().rename(a, from, to, stash);
 }
 
+void
+EngineOrFactory::set(EngineOrFactory wanted)
+{
+    auto engine = get_shared(wanted);
+    if (engine._value != wanted._value) {
+        auto msg = fmt("EngineOrFactory: trying to set implementation to [%s] when [%s] is already in use",
+                       wanted.to_string().c_str(), engine.to_string().c_str());
+        throw IllegalStateException(msg);
+    }
+}
+
+EngineOrFactory
+EngineOrFactory::get()
+{
+    return get_shared(_default);
+}
+
+vespalib::string
+EngineOrFactory::to_string() const
+{
+    if (is_engine()) {
+        if (&engine() == &tensor::DefaultTensorEngine::ref()) {
+            return "DefaultTensorEngine";
+        }
+        if (&engine() == &SimpleTensorEngine::ref()) {
+            return "SimpleTensorEngine";
+        }
+    }
+    if (is_factory()) {
+        if (&factory() == &FastValueBuilderFactory::get()) {
+            return "FastValueBuilderFactory";
+        }
+        if (&factory() == &SimpleValueBuilderFactory::get()) {
+            return "SimpleValueBuilderFactory";
+        }
+        if (&factory() == &tensor::DefaultValueBuilderFactory::get()) {
+            return "DefaultValueBuilderFactory";
+        }
+        if (&factory() == &PackedMixedTensorBuilderFactory::get()) {
+            return "PackedMixedTensorBuilderFactory";
+        }
+    }
+    return "???";
+}
+
 }
diff --git a/eval/src/vespa/eval/eval/engine_or_factory.h b/eval/src/vespa/eval/eval/engine_or_factory.h
index a95bfda6bd5..e94febd54ea 100644
--- a/eval/src/vespa/eval/eval/engine_or_factory.h
+++ b/eval/src/vespa/eval/eval/engine_or_factory.h
@@ -32,6 +32,8 @@ private:
     using engine_t = const TensorEngine *;
     using factory_t = const ValueBuilderFactory *;
     std::variant<engine_t,factory_t> _value;
+    static EngineOrFactory _default;
+    static EngineOrFactory get_shared(EngineOrFactory hint);
 public:
     EngineOrFactory(const TensorEngine &engine_in) : _value(&engine_in) {}
     EngineOrFactory(const ValueBuilderFactory &factory_in) : _value(&factory_in) {}
@@ -52,6 +54,11 @@ public:
     const Value &reduce(const Value &a, Aggr aggr, const std::vector<vespalib::string> &dimensions, Stash &stash) const;
     const Value &concat(const Value &a, const Value &b, const vespalib::string &dimension, Stash &stash) const;
     const Value &rename(const Value &a, const std::vector<vespalib::string> &from, const std::vector<vespalib::string> &to, Stash &stash) const;
+    // global switch with default; call set before get to override the default
+    static void set(EngineOrFactory wanted);
+    static EngineOrFactory get();
+    // try to describe the value held by this object as a human-readable string
+    vespalib::string to_string() const;
 };
 
 }