/* pybind11/buffer_info.h: Python buffer object interface Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch> All rights reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. */ #pragma once #include "detail/common.h" NAMESPACE_BEGIN(PYBIND11_NAMESPACE) /// Information record describing a Python buffer object struct buffer_info { void *ptr = nullptr; // Pointer to the underlying storage ssize_t itemsize = 0; // Size of individual items in bytes ssize_t size = 0; // Total number of entries std::string format; // For homogeneous buffers, this should be set to format_descriptor<T>::format() ssize_t ndim = 0; // Number of dimensions std::vector<ssize_t> shape; // Shape of the tensor (1 entry per dimension) std::vector<ssize_t> strides; // Number of entries between adjacent entries (for each per dimension) buffer_info() { } buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim, detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in) : ptr(ptr), itemsize(itemsize), size(1), format(format), ndim(ndim), shape(std::move(shape_in)), strides(std::move(strides_in)) { if (ndim != (ssize_t) shape.size() || ndim != (ssize_t) strides.size()) pybind11_fail("buffer_info: ndim doesn't match shape and/or strides length"); for (size_t i = 0; i < (size_t) ndim; ++i) size *= shape[i]; } template <typename T> buffer_info(T *ptr, detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in) : buffer_info(private_ctr_tag(), ptr, sizeof(T), format_descriptor<T>::format(), static_cast<ssize_t>(shape_in->size()), std::move(shape_in), std::move(strides_in)) { } buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t size) : buffer_info(ptr, itemsize, format, 1, {size}, {itemsize}) { } template <typename T> buffer_info(T *ptr, ssize_t size) : buffer_info(ptr, sizeof(T), format_descriptor<T>::format(), size) { } explicit buffer_info(Py_buffer *view, bool ownview = true) : buffer_info(view->buf, view->itemsize, view->format, view->ndim, {view->shape, view->shape + view->ndim}, {view->strides, view->strides + view->ndim}) { this->view = view; this->ownview = ownview; } buffer_info(const buffer_info &) = delete; buffer_info& operator=(const buffer_info &) = delete; buffer_info(buffer_info &&other) { (*this) = std::move(other); } buffer_info& operator=(buffer_info &&rhs) { ptr = rhs.ptr; itemsize = rhs.itemsize; size = rhs.size; format = std::move(rhs.format); ndim = rhs.ndim; shape = std::move(rhs.shape); strides = std::move(rhs.strides); std::swap(view, rhs.view); std::swap(ownview, rhs.ownview); return *this; } ~buffer_info() { if (view && ownview) { PyBuffer_Release(view); delete view; } } private: struct private_ctr_tag { }; buffer_info(private_ctr_tag, void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim, detail::any_container<ssize_t> &&shape_in, detail::any_container<ssize_t> &&strides_in) : buffer_info(ptr, itemsize, format, ndim, std::move(shape_in), std::move(strides_in)) { } Py_buffer *view = nullptr; bool ownview = false; }; NAMESPACE_BEGIN(detail) template <typename T, typename SFINAE = void> struct compare_buffer_info { static bool compare(const buffer_info& b) { return b.format == format_descriptor<T>::format() && b.itemsize == (ssize_t) sizeof(T); } }; template <typename T> struct compare_buffer_info<T, detail::enable_if_t<std::is_integral<T>::value>> { static bool compare(const buffer_info& b) { return (size_t) b.itemsize == sizeof(T) && (b.format == format_descriptor<T>::value || ((sizeof(T) == sizeof(long)) && b.format == (std::is_unsigned<T>::value ? "L" : "l")) || ((sizeof(T) == sizeof(size_t)) && b.format == (std::is_unsigned<T>::value ? "N" : "n"))); } }; NAMESPACE_END(detail) NAMESPACE_END(PYBIND11_NAMESPACE)