1 /* Copyright 2019 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 #include <string>
16
17 #include "tensorflow/lite/c/builtin_op_data.h"
18 #include "tensorflow/lite/c/common.h"
19 #include "tensorflow/lite/core/subgraph.h"
20 #include "tensorflow/lite/experimental/resource/lookup_interfaces.h"
21 #include "tensorflow/lite/kernels/kernel_util.h"
22
23 namespace tflite {
24 namespace ops {
25 namespace builtin {
26 namespace hashtable {
27
28 // The current hash table op returns a key of the hash table resource objects,
29 // shared by the context. Later, this implementation might be updated by sharing
30 // the actual reference of hash table objects in the tensor buffer.
31
32 static constexpr int kResourceHandleTensor = 0;
33
PrepareHashtable(TfLiteContext * context,TfLiteNode * node)34 TfLiteStatus PrepareHashtable(TfLiteContext* context, TfLiteNode* node) {
35 TF_LITE_ENSURE_EQ(context, NumInputs(node), 0);
36 TF_LITE_ENSURE_EQ(context, NumOutputs(node), 1);
37
38 TF_LITE_ENSURE(context, node->builtin_data != nullptr);
39 const auto* params =
40 reinterpret_cast<const TfLiteHashtableParams*>(node->builtin_data);
41
42 TF_LITE_ENSURE(context, (params->key_dtype == kTfLiteInt64 &&
43 params->value_dtype == kTfLiteString) ||
44 (params->key_dtype == kTfLiteString &&
45 params->value_dtype == kTfLiteInt64));
46
47 TfLiteTensor* resource_handle_tensor;
48 TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, kResourceHandleTensor,
49 &resource_handle_tensor));
50 TF_LITE_ENSURE_EQ(context, resource_handle_tensor->type, kTfLiteResource);
51 size_t bytesRequired = sizeof(int32_t);
52
53 // Realloc space for an integer handle value.
54 TfLiteTensorRealloc(bytesRequired, resource_handle_tensor);
55 resource_handle_tensor->bytes = bytesRequired;
56
57 TfLiteIntArray* outputSize = TfLiteIntArrayCreate(1);
58 outputSize->data[0] = 1;
59 if (resource_handle_tensor->dims)
60 TfLiteIntArrayFree(resource_handle_tensor->dims);
61 resource_handle_tensor->dims = outputSize;
62
63 return kTfLiteOk;
64 }
65
EvalHashtable(TfLiteContext * context,TfLiteNode * node)66 TfLiteStatus EvalHashtable(TfLiteContext* context, TfLiteNode* node) {
67 TF_LITE_ENSURE(context, node->builtin_data != nullptr);
68 const auto* params =
69 reinterpret_cast<const TfLiteHashtableParams*>(node->builtin_data);
70
71 const int32_t resource_id = params->table_id;
72
73 TfLiteTensor* resource_handle_tensor;
74 TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, kResourceHandleTensor,
75 &resource_handle_tensor));
76 *resource_handle_tensor->data.i32 = resource_id;
77
78 Subgraph* subgraph = reinterpret_cast<Subgraph*>(context->impl_);
79 auto& resources = subgraph->resources();
80 resource::CreateHashtableResourceIfNotAvailable(
81 &resources, resource_id, params->key_dtype, params->value_dtype);
82 return kTfLiteOk;
83 }
84
85 } // namespace hashtable
86
Register_HASHTABLE()87 TfLiteRegistration* Register_HASHTABLE() {
88 static TfLiteRegistration r = {nullptr, nullptr, hashtable::PrepareHashtable,
89 hashtable::EvalHashtable};
90 return &r;
91 }
92
93 } // namespace builtin
94 } // namespace ops
95 } // namespace tflite
96