1/* Copyright 2021 The TensorFlow Authors. All Rights Reserved.
2
3Licensed under the Apache License, Version 2.0 (the "License");
4you may not use this file except in compliance with the License.
5You may obtain a copy of the License at
6
7 http://www.apache.org/licenses/LICENSE-2.0
8
9Unless required by applicable law or agreed to in writing, software
10distributed under the License is distributed on an "AS IS" BASIS,
11WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12See the License for the specific language governing permissions and
13limitations under the License.
14==============================================================================*/
15
16#include <stdint.h>
17#include <string.h>
18
19#include <string>
20#include <utility>
21
22#include "tensorflow/lite/c/builtin_op_data.h"
23#include "tensorflow/lite/c/common.h"
24#include "tensorflow/lite/core/subgraph.h"
25#include "tensorflow/lite/experimental/resource/resource_variable.h"
26#include "tensorflow/lite/kernels/internal/tensor.h"
27#include "tensorflow/lite/kernels/kernel_util.h"
28
29namespace tflite {
30namespace ops {
31namespace builtin {
32namespace var_handle {
33// Util struct with params that identifies the resource.
34struct VarParams {
35 int resource_id;
36};
37
38void* Init(TfLiteContext* context, const char* buffer, size_t length) {
39 const auto* var_params =
40 reinterpret_cast<const TfLiteVarHandleParams*>(buffer);
41 VarParams* params = new VarParams;
42 auto* subgraph = reinterpret_cast<Subgraph*>(context->impl_);
43 // Create a new entry if doesn't exist, return the existing one otherwise.
44 auto it = subgraph->resource_ids().insert(std::make_pair(
45 std::make_pair(
46 std::string(var_params->container ? var_params->container : ""),
47 std::string(var_params->shared_name ? var_params->shared_name : "")),
48 static_cast<int>(subgraph->resource_ids().size())));
49 params->resource_id = it.first->second;
50 return params;
51}
52
53void Free(TfLiteContext* context, void* buffer) {
54 delete reinterpret_cast<VarParams*>(buffer);
55}
56
57TfLiteStatus Prepare(TfLiteContext* context, TfLiteNode* node) {
58 TfLiteTensor* output;
59 TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output));
60
61 const int kBytesRequired = sizeof(int32_t);
62 TfLiteTensorRealloc(kBytesRequired, output);
63 output->bytes = kBytesRequired;
64
65 return kTfLiteOk;
66}
67
68TfLiteStatus Eval(TfLiteContext* context, TfLiteNode* node) {
69 auto* op_data = static_cast<VarParams*>(node->user_data);
70 TF_LITE_ENSURE(context, op_data != nullptr);
71
72 TfLiteTensor* output;
73 TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output));
74
75 memcpy(output->data.raw, reinterpret_cast<char*>(&op_data->resource_id),
76 sizeof(op_data->resource_id));
77 return kTfLiteOk;
78}
79
80} // namespace var_handle
81
82TfLiteRegistration* Register_VAR_HANDLE() {
83 static TfLiteRegistration r = {var_handle::Init, var_handle::Free,
84 var_handle::Prepare, var_handle::Eval};
85 return &r;
86}
87
88} // namespace builtin
89} // namespace ops
90} // namespace tflite
91