IVGCVSW-7555 Restructure Delegate

* New folders created:
  * common is for common code where TfLite API is not used
  * classic is for existing delegate implementations
  * opaque is for new opaque delegate implementation,
  * tests is for shared between existing Delegate and Opaque Delegate which have test utils to work which delegate to use.
* Existing delegate is built to libarmnnDelegate.so and opaque delegate is built as libarmnnOpaqueDelegate.so
* Opaque structure is introduced but no API is added yet.
* CmakeList.txt and delegate/CMakeList.txt have been modified and 2 new CmakeList.txt added
* Rename BUILD_ARMNN_TFLITE_DELEGATE as BUILD_CLASSIC_DELEGATE
* Rename BUILD_ARMNN_TFLITE_OPAQUE_DELEGATE as BUILD_OPAQUE_DELEGATE

Signed-off-by: Teresa Charlin <teresa.charlinreyes@arm.com>
Change-Id: Ib682b9ad0ac8d8acdc4ec6d9099bb0008a9fe8ed

1 files changed, 68 insertions, 0 deletions

diff --git a/delegate/classic/src/armnn_external_delegate.cpp b/delegate/classic/src/armnn_external_delegate.cpp
new file mode 100644
index 0000000000..444015d71c
--- /dev/null
+++ b/delegate/classic/src/armnn_external_delegate.cpp
@@ -0,0 +1,68 @@
+//
+// Copyright © 2020, 2023 Arm Ltd and Contributors. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+#include "armnn_delegate.hpp"
+#include <armnn/Logging.hpp>
+#include <armnn/utility/NumericCast.hpp>
+
+#include <iostream>
+#include <tensorflow/lite/minimal_logging.h>
+
+namespace tflite
+{
+
+/**
+ * This file defines two symbols that need to be exported to use the TFLite external delegate provider. This is a plugin
+ * that can be used for fast integration of delegates into benchmark tests and other tools. It allows loading of
+ * a dynamic delegate library at runtime.
+ *
+ * The external delegate also has Tensorflow Lite Python bindings. Therefore the dynamic external delegate
+ * can be directly used with Tensorflow Lite Python APIs.
+ *
+ * See tensorflow/lite/delegates/external for details or visit the tensorflow guide
+ * [here](https://www.tensorflow.org/lite/performance/implementing_delegate#option_2_leverage_external_delegate)
+ */
+
+extern "C"
+{
+
+/**
+  * Implementation of the TfLite external delegate plugin
+  *
+  * For details about what options_keys and option_values are supported please see:
+  * armnnDelegate::DelegateOptions::DelegateOptions(char const* const*, char const* const*,size_t,void (*)(const char*))
+  */
+TfLiteDelegate* tflite_plugin_create_delegate(char** options_keys,
+                                              char** options_values,
+                                              size_t num_options,
+                                              void (*report_error)(const char*))
+{
+    // Returning null indicates an error during delegate creation, we initialize with that
+    TfLiteDelegate* delegate = nullptr;
+    try
+    {
+        armnnDelegate::DelegateOptions options (options_keys, options_values, num_options, (*report_error));
+        delegate = TfLiteArmnnDelegateCreate(options);
+    }
+    catch (const std::exception& ex)
+    {
+        if(report_error)
+        {
+            report_error(ex.what());
+        }
+    }
+    return delegate;
+}
+
+/** Destroy a given delegate plugin
+ *
+ * @param[in] delegate Delegate to destruct
+ */
+void tflite_plugin_destroy_delegate(TfLiteDelegate* delegate)
+{
+    armnnDelegate::TfLiteArmnnDelegateDelete(delegate);
+}
+
+}  // extern "C"
+}  // namespace tflite
\ No newline at end of file