1 /** 2 * Copyright 2019 Huawei Technologies Co., Ltd 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef MINDDATA_PYBINDSUPPORT_H 18 #define MINDDATA_PYBINDSUPPORT_H 19 20 #include <string> 21 22 #include "pybind11/numpy.h" 23 #include "pybind11/pybind11.h" 24 #include "base/float16.h" 25 26 namespace py = pybind11; 27 28 namespace pybind11 { 29 namespace detail { 30 // Similar to enums in `pybind11/numpy.h`. Determined by doing: 31 // python3 -c 'import numpy as np; print(np.dtype(np.float16).num)' 32 constexpr int kNpyFloat16 = 23; 33 34 template <typename T> 35 struct npy_scalar_caster { 36 PYBIND11_TYPE_CASTER(T, _("PleaseOverride")); 37 using Array = array_t<T>; 38 loadnpy_scalar_caster39 bool load(handle src, bool convert) { 40 // Taken from Eigen casters. Permits either scalar dtype or scalar array. 41 handle type = dtype::of<T>().attr("type"); // Could make more efficient. 42 if (!convert && !isinstance<Array>(src) && !isinstance(src, type)) { 43 return false; 44 } 45 46 Array tmp = Array::ensure(src); 47 if (tmp && tmp.size() == 1 && tmp.ndim() == 0) { 48 this->value = *tmp.data(); 49 return true; 50 } 51 52 return false; 53 } 54 castnpy_scalar_caster55 static handle cast(T src, return_value_policy, handle) { 56 Array tmp({1}); 57 tmp.mutable_at(0) = src; 58 tmp.resize({}); 59 60 // You could also just return the array if you want a scalar array. 61 object scalar = tmp[tuple()]; 62 return scalar.release(); 63 } 64 }; 65 66 template <> 67 struct npy_format_descriptor<float16> { 68 static constexpr auto name = "float16"; 69 static pybind11::dtype dtype() { 70 handle ptr = npy_api::get().PyArray_DescrFromType_(kNpyFloat16); 71 return reinterpret_borrow<pybind11::dtype>(ptr); 72 } 73 virtual ~npy_format_descriptor<float16>() {} 74 75 static std::string format() { 76 // following: https://docs.python.org/3/library/struct.html#format-characters 77 return "e"; 78 } 79 }; 80 81 template <> 82 struct type_caster<float16> : public npy_scalar_caster<float16> { 83 static constexpr auto name = "float16"; 84 }; 85 } // namespace detail 86 } // namespace pybind11 87 88 #endif // MINDDATA_PYBINDSUPPORT_H 89