From 37fd8a38af2e2a2a9d532d72a00a99f41769f87b Mon Sep 17 00:00:00 2001
From: Davide Grohmann <davide.grohmann@arm.com>
Date: Thu, 7 Apr 2022 15:02:12 +0200
Subject: Add inference parsing to inference process library

Change-Id: If90ebe17cc33b8fef9e6a4ebae43a2e5749d8a37
---
 .../inference_process/include/inference_parser.hpp | 167 +++++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 applications/inference_process/include/inference_parser.hpp

diff --git a/applications/inference_process/include/inference_parser.hpp b/applications/inference_process/include/inference_parser.hpp
new file mode 100644
index 0000000..3d90818
--- /dev/null
+++ b/applications/inference_process/include/inference_parser.hpp
@@ -0,0 +1,167 @@
+/*
+ * Copyright (c) 2022 Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "tensorflow/lite/schema/schema_generated.h"
+
+#include <stdlib.h>
+#include <string>
+
+namespace InferenceProcess {
+
+template <typename T, typename U>
+class Array {
+public:
+    Array() = delete;
+    Array(T *const data, U &size, size_t capacity) : _data{data}, _size{size}, _capacity{capacity} {}
+
+    auto size() const {
+        return _size;
+    }
+
+    auto capacity() const {
+        return _capacity;
+    }
+
+    void push_back(const T &data) {
+        _data[_size++] = data;
+    }
+
+private:
+    T *const _data;
+    U &_size;
+    const size_t _capacity{};
+};
+
+template <typename T, typename U>
+Array<T, U> makeArray(T *const data, U &size, size_t capacity) {
+    return Array<T, U>{data, size, capacity};
+}
+
+class InferenceParser {
+public:
+    template <typename T, typename U, size_t S>
+    bool parseModel(const void *buffer, char (&description)[S], T &&ifmDims, U &&ofmDims) {
+        // Create model handle
+        const tflite::Model *model = tflite::GetModel(buffer);
+        if (model->subgraphs() == nullptr) {
+            printf("Warning: nullptr subgraph\n");
+            return true;
+        }
+
+        strncpy(description, model->description()->c_str(), sizeof(description));
+
+        // Get input dimensions for first subgraph
+        auto *subgraph = *model->subgraphs()->begin();
+        bool failed    = getSubGraphDims(subgraph, subgraph->inputs(), ifmDims);
+        if (failed) {
+            return true;
+        }
+
+        // Get output dimensions for last subgraph
+        subgraph = *model->subgraphs()->rbegin();
+        failed   = getSubGraphDims(subgraph, subgraph->outputs(), ofmDims);
+        if (failed) {
+            return true;
+        }
+
+        return false;
+    }
+
+private:
+    bool getShapeSize(const flatbuffers::Vector<int32_t> *shape, size_t &size) {
+        size = 1;
+
+        if (shape == nullptr) {
+            printf("Warning: nullptr shape size.\n");
+            return true;
+        }
+
+        if (shape->Length() == 0) {
+            printf("Warning: shape zero length.\n");
+            return true;
+        }
+
+        for (auto it = shape->begin(); it != shape->end(); ++it) {
+            size *= *it;
+        }
+
+        return false;
+    }
+
+    bool getTensorTypeSize(const enum tflite::TensorType type, size_t &size) {
+        switch (type) {
+        case tflite::TensorType::TensorType_UINT8:
+        case tflite::TensorType::TensorType_INT8:
+            size = 1;
+            break;
+        case tflite::TensorType::TensorType_INT16:
+            size = 2;
+            break;
+        case tflite::TensorType::TensorType_INT32:
+        case tflite::TensorType::TensorType_FLOAT32:
+            size = 4;
+            break;
+        default:
+            printf("Warning: Unsupported tensor type\n");
+            return true;
+        }
+
+        return false;
+    }
+
+    template <typename T>
+    bool getSubGraphDims(const tflite::SubGraph *subgraph, const flatbuffers::Vector<int32_t> *tensorMap, T &dims) {
+        if (subgraph == nullptr || tensorMap == nullptr) {
+            printf("Warning: nullptr subgraph or tensormap.\n");
+            return true;
+        }
+
+        if ((dims.capacity() - dims.size()) < tensorMap->size()) {
+            printf("Warning: tensormap size is larger than dimension capacity.\n");
+            return true;
+        }
+
+        for (auto index = tensorMap->begin(); index != tensorMap->end(); ++index) {
+            auto tensor = subgraph->tensors()->Get(*index);
+            size_t size;
+            size_t tensorSize;
+
+            bool failed = getShapeSize(tensor->shape(), size);
+            if (failed) {
+                return true;
+            }
+
+            failed = getTensorTypeSize(tensor->type(), tensorSize);
+            if (failed) {
+                return true;
+            }
+
+            size *= tensorSize;
+
+            if (size > 0) {
+                dims.push_back(size);
+            }
+        }
+
+        return false;
+    }
+};
+
+} // namespace InferenceProcess
-- 
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