1 /* Copyright 2020 The TensorFlow Authors. All Rights Reserved.
2
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6
7 http://www.apache.org/licenses/LICENSE-2.0
8
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15
16 #ifndef TENSORFLOW_LITE_SUPPORT_CC_TASK_CORE_TASK_UTILS_H_
17 #define TENSORFLOW_LITE_SUPPORT_CC_TASK_CORE_TASK_UTILS_H_
18
19 #include <algorithm>
20 #include <cstring>
21 #include <numeric>
22 #include <vector>
23
24 #include "absl/memory/memory.h"
25 #include "absl/strings/str_cat.h"
26 #include "flatbuffers/flatbuffers.h" // from @flatbuffers
27 #include "tensorflow/lite/kernels/internal/tensor_ctypes.h"
28 #include "tensorflow/lite/kernels/op_macros.h"
29 #include "tensorflow/lite/string_util.h"
30 #include "tensorflow/lite/type_to_tflitetype.h"
31 #include "tensorflow_lite_support/metadata/metadata_schema_generated.h"
32
33 namespace tflite {
34 namespace task {
35 namespace core {
36
37 // Checks if data type of tensor is T and returns the pointer casted to T if
38 // applicable, returns nullptr if tensor type is not T.
39 // See type_to_tflitetype.h for a mapping from plain C++ type to TfLiteType.
40 template <typename T>
TypedTensor(const TfLiteTensor * tensor_ptr)41 T* TypedTensor(const TfLiteTensor* tensor_ptr) {
42 if (tensor_ptr->type == typeToTfLiteType<T>()) {
43 return reinterpret_cast<T*>(tensor_ptr->data.raw);
44 }
45 return nullptr;
46 }
47
48 // Checks and returns type of a tensor, fails if tensor type is not T.
49 template <typename T>
AssertAndReturnTypedTensor(const TfLiteTensor * tensor)50 T* AssertAndReturnTypedTensor(const TfLiteTensor* tensor) {
51 if (T* v = TypedTensor<T>(tensor)) return v;
52 // TODO(b/150903834): throw exceptions instead
53 TF_LITE_ASSERT(tensor->data.raw);
54 TF_LITE_FATAL(absl::StrCat("Type mismatch for tensor ", tensor->name,
55 ". Requested ",
56 TfLiteTypeGetName(typeToTfLiteType<T>()), ", got ",
57 TfLiteTypeGetName(tensor->type), ".")
58 .c_str());
59 }
60
61 // Populates tensor with array of data, fails if data type doesn't match tensor
62 // type or has not the same number of elements.
63 template <typename T>
PopulateTensor(const T * data,int num_elements,TfLiteTensor * tensor)64 inline void PopulateTensor(const T* data, int num_elements,
65 TfLiteTensor* tensor) {
66 T* v = AssertAndReturnTypedTensor<T>(tensor);
67 size_t bytes = num_elements * sizeof(T);
68 // TODO(b/150903834): throw exceptions instead
69 TF_LITE_ASSERT(tensor->bytes == bytes);
70 memcpy(v, data, bytes);
71 }
72
73 // Populates tensor with vector of data, fails if data type doesn't match tensor
74 // type or has not the same number of elements.
75 template <typename T>
PopulateTensor(const std::vector<T> & data,TfLiteTensor * tensor)76 inline void PopulateTensor(const std::vector<T>& data, TfLiteTensor* tensor) {
77 return PopulateTensor<T>(data.data(), data.size(), tensor);
78 }
79
80 template <>
81 inline void PopulateTensor<std::string>(const std::vector<std::string>& data,
82 TfLiteTensor* tensor) {
83 if (tensor->type != kTfLiteString) {
84 TF_LITE_FATAL(absl::StrCat("Type mismatch for tensor ", tensor->name,
85 ". Requested STRING, got ",
86 TfLiteTypeGetName(tensor->type), ".")
87 .c_str());
88 }
89 tflite::DynamicBuffer input_buf;
90 for (const auto& value : data) {
91 input_buf.AddString(value.data(), value.length());
92 }
93 input_buf.WriteToTensorAsVector(tensor);
94 }
95
96 // Populates tensor one data item, fails if data type doesn't match tensor
97 // type.
98 template <typename T>
PopulateTensor(const T & data,TfLiteTensor * tensor)99 inline void PopulateTensor(const T& data, TfLiteTensor* tensor) {
100 T* v = AssertAndReturnTypedTensor<T>(tensor);
101 *v = data;
102 }
103
104 template <>
105 inline void PopulateTensor<std::string>(const std::string& data,
106 TfLiteTensor* tensor) {
107 tflite::DynamicBuffer input_buf;
108 input_buf.AddString(data.data(), data.length());
109 input_buf.WriteToTensorAsVector(tensor);
110 }
111
112 // Populates a vector from the tensor, fails if data type doesn't match tensor
113 // type.
114 template <typename T>
PopulateVector(const TfLiteTensor * tensor,std::vector<T> * data)115 inline void PopulateVector(const TfLiteTensor* tensor, std::vector<T>* data) {
116 AssertAndReturnTypedTensor<T>(tensor);
117 const T* results = GetTensorData<T>(tensor);
118 size_t num = tensor->bytes / sizeof(tensor->type);
119 data->reserve(num);
120 for (int i = 0; i < num; i++) {
121 data->emplace_back(results[i]);
122 }
123 }
124
125 template <>
126 inline void PopulateVector<std::string>(const TfLiteTensor* tensor,
127 std::vector<std::string>* data) {
128 AssertAndReturnTypedTensor<std::string>(tensor);
129 int num = GetStringCount(tensor);
130 data->reserve(num);
131 for (int i = 0; i < num; i++) {
132 const auto& strref = tflite::GetString(tensor, i);
133 data->emplace_back(strref.str, strref.len);
134 }
135 }
136
137 // Returns the reversely sorted indices of a vector.
138 template <typename T>
ReverseSortIndices(const std::vector<T> & v)139 std::vector<size_t> ReverseSortIndices(const std::vector<T>& v) {
140 std::vector<size_t> idx(v.size());
141 std::iota(idx.begin(), idx.end(), 0);
142
143 std::stable_sort(idx.begin(), idx.end(),
144 [&v](size_t i1, size_t i2) { return v[i2] < v[i1]; });
145
146 return idx;
147 }
148
149 // Returns the original (dequantized) value of the 'index'-th element of
150 // 'tensor.
151 double Dequantize(const TfLiteTensor& tensor, int index);
152
153 // Returns the index-th string from the tensor.
154 std::string GetStringAtIndex(const TfLiteTensor* labels, int index);
155
156 // Loads binary content of a file into a string.
157 std::string LoadBinaryContent(const char* filename);
158
159 // Gets the tensor from a vector of tensors with name specified inside metadata.
160 template <typename TensorType>
FindTensorByName(const std::vector<TensorType * > & tensors,const flatbuffers::Vector<flatbuffers::Offset<TensorMetadata>> * tensor_metadatas,const std::string & name)161 static TensorType* FindTensorByName(
162 const std::vector<TensorType*>& tensors,
163 const flatbuffers::Vector<flatbuffers::Offset<TensorMetadata>>*
164 tensor_metadatas,
165 const std::string& name) {
166 if (tensor_metadatas == nullptr ||
167 tensor_metadatas->size() != tensors.size()) {
168 return nullptr;
169 }
170 for (int i = 0; i < tensor_metadatas->size(); i++) {
171 if (strcmp(name.data(), tensor_metadatas->Get(i)->name()->c_str()) == 0) {
172 return tensors[i];
173 }
174 }
175 return nullptr;
176 }
177
178 } // namespace core
179 } // namespace task
180 } // namespace tflite
181
182 #endif // TENSORFLOW_LITE_SUPPORT_CC_TASK_CORE_TASK_UTILS_H_
183