Initial implementation of backend config (#3110) (#3228)

* initial implementation of backend config

* check on backend that does not support config

src/ngraph/runtime/backend.cpp

@@ -90,3 +90,9 @@ std::shared_ptr<runtime::Executable> runtime::Backend::load(istream& input_strea
 {
     throw runtime_error("load opertion unimplemented.");
 }
+
+bool runtime::Backend::set_config(const map<string, string>& config, string& error)
+{
+    error = "set_config not supported";
+    return false;
+}

src/ngraph/runtime/backend.hpp

@@ -139,4 +139,13 @@ public:
     // \param op_name is the name of the backend specific op
     // \returns a shared pointer to the op if found, else nullptr
     virtual std::shared_ptr<ngraph::Node> get_backend_op(const std::string& op_name, ...);
+
+    /// \brief Allows sending backend specific configuration. The map contains key, value pairs
+    ///     specific to a particluar backend. The definition of these key, value pairs is
+    ///     defined by each backend.
+    /// \param config The configuration map sent to the backend
+    /// \param error An error string describing any error encountered
+    /// \returns true if the configuration is supported, false otherwise. On false the error
+    ///     parameter value is valid.
+    virtual bool set_config(const std::map<std::string, std::string>& config, std::string& error);
 };

src/ngraph/runtime/interpreter/int_backend.cpp

@@ -105,3 +105,16 @@ std::shared_ptr<runtime::Executable> runtime::interpreter::INTBackend::load(istr
     }
     return exec;
 }
+
+bool runtime::interpreter::INTBackend::set_config(const map<string, string>& config, string& error)
+{
+    bool rc = false;
+    auto it = config.find("test_echo");
+    error = "";
+    if (it != config.end())
+    {
+        error = it->second;
+        rc = true;
+    }
+    return rc;
+}

src/ngraph/runtime/interpreter/int_backend.hpp

@@ -58,6 +58,8 @@ public:
 
     bool is_supported(const Node& node) const override;
 
+    bool set_config(const std::map<std::string, std::string>& config, std::string& error) override;
+
 private:
     std::set<std::string> m_unsupported_op_name_list;
 };

test/backend_api.cpp

@@ -37,6 +37,28 @@ TEST(backend_api, invalid_name)
     ASSERT_ANY_THROW(ngraph::runtime::Backend::create("COMPLETELY-BOGUS-NAME"));
 }
 
+TEST(backend_api, config)
+{
+    auto backend = runtime::Backend::create("INTERPRETER");
+    string error;
+    string message = "hello";
+    map<string, string> config = {{"test_echo", message}};
+    EXPECT_TRUE(backend->set_config(config, error));
+    EXPECT_STREQ(error.c_str(), message.c_str());
+    EXPECT_FALSE(backend->set_config({}, error));
+    EXPECT_STREQ(error.c_str(), "");
+}
+
+TEST(backend_api, config_unsupported)
+{
+    auto backend = runtime::Backend::create("NOP");
+    string error;
+    string message = "hello";
+    map<string, string> config = {{"test_echo", message}};
+    EXPECT_FALSE(backend->set_config(config, error));
+    EXPECT_FALSE(error == "");
+}
+
 TEST(backend_api, save_load)
 {
     Shape shape{2, 2};