1 /* Copyright 2022 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 #ifndef TENSORFLOW_CORE_KERNELS_DATA_OPTIONAL_OPS_UTIL_H_ 16 #define TENSORFLOW_CORE_KERNELS_DATA_OPTIONAL_OPS_UTIL_H_ 17 18 #include <functional> 19 #include <memory> 20 #include <utility> 21 #include <vector> 22 23 #include "tensorflow/core/framework/tensor.h" 24 #include "tensorflow/core/framework/variant_tensor_data.h" 25 #include "tensorflow/core/util/tensor_ops_util.h" 26 27 namespace tensorflow { 28 namespace data { 29 30 const char kOptionalVariantTypeName[] = "tensorflow::data::Optional"; 31 32 // An `OptionalVariant` can represent either an "actual value" (a tuple of 33 // tensors) or "none", and may be stored in a DT_VARIANT tensor. 34 class OptionalVariant { 35 public: 36 // Create an `OptionalVariant` with no actual value. OptionalVariant()37 OptionalVariant() : values_(nullptr) {} 38 39 // Create an `OptionalVariant` with the actual value given by the tuple of 40 // tensors in `values`. OptionalVariant(std::vector<Tensor> values)41 explicit OptionalVariant(std::vector<Tensor> values) { 42 values_ = std::make_shared<std::vector<Tensor>>(std::move(values)); 43 } 44 OptionalVariant(const OptionalVariant & other)45 OptionalVariant(const OptionalVariant& other) : values_(other.values_) {} 46 47 // Returns true if `this` represents an actual value. has_value()48 bool has_value() const { return values_ != nullptr; } 49 50 // REQUIRES: `this->has_value()` must be true. get_values()51 const std::vector<Tensor>& get_values() const { 52 DCHECK(values_) << "Tried to get values from an empty OptionalVariant"; 53 return *values_; 54 } 55 56 // Implementations of the necessary methods for using `OptionalVariant` 57 // objects in DT_VARIANT tensors. TypeName()58 string TypeName() const { return kOptionalVariantTypeName; } Encode(VariantTensorData * data)59 void Encode(VariantTensorData* data) const { 60 data->set_metadata(values_ != nullptr); 61 if (values_ != nullptr) { 62 for (const auto& t : *values_) { 63 *(data->add_tensors()) = t; 64 } 65 } 66 } 67 Decode(const VariantTensorData & data)68 bool Decode(const VariantTensorData& data) { 69 if (data.type_name() != TypeName()) { 70 return false; 71 } 72 bool has_value = false; 73 if (!data.get_metadata(&has_value)) { 74 return false; 75 } 76 if (has_value) { 77 values_ = std::make_shared<std::vector<Tensor>>(data.tensors()); 78 } else { 79 values_.reset(); 80 } 81 return true; 82 } 83 DebugString()84 string DebugString() const { 85 if (values_) { 86 return strings::StrCat("OptionalVariant<", "values: (", 87 absl::StrJoin(*values_, ", ", 88 [](string* s, const Tensor& elem) { 89 *s = elem.DebugString(); 90 }), 91 ")>"); 92 } else { 93 return strings::StrCat("OptionalVariant<None>"); 94 } 95 } 96 97 private: 98 std::shared_ptr<const std::vector<Tensor>> values_; 99 }; 100 101 Status OptionalZerosLike(OpKernelContext* ctx, const OptionalVariant& x, 102 OptionalVariant* y, 103 std::function<Status(OpKernelContext* ctx, 104 const Tensor& input, Tensor* out)> 105 zeros_like_func); 106 107 Status OptionalBinaryAdd( 108 OpKernelContext* ctx, const OptionalVariant& a, const OptionalVariant& b, 109 OptionalVariant* out, 110 std::function<Status(OpKernelContext* ctx, const Tensor& a, const Tensor& b, 111 Tensor* out)> 112 binary_add_func); 113 114 } // namespace data 115 } // namespace tensorflow 116 117 #endif // TENSORFLOW_CORE_KERNELS_DATA_OPTIONAL_OPS_UTIL_H_ 118