File size: 7,074 Bytes
be11144
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/*
    tests/test_buffers.cpp -- supporting Pythons' buffer protocol

    Copyright (c) 2016 Wenzel Jakob <[email protected]>

    All rights reserved. Use of this source code is governed by a
    BSD-style license that can be found in the LICENSE file.
*/

#include "pybind11_tests.h"
#include "constructor_stats.h"

TEST_SUBMODULE(buffers, m) {
    // test_from_python / test_to_python:
    class Matrix {
    public:
        Matrix(ssize_t rows, ssize_t cols) : m_rows(rows), m_cols(cols) {
            print_created(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
            m_data = new float[(size_t) (rows*cols)];
            memset(m_data, 0, sizeof(float) * (size_t) (rows * cols));
        }

        Matrix(const Matrix &s) : m_rows(s.m_rows), m_cols(s.m_cols) {
            print_copy_created(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
            m_data = new float[(size_t) (m_rows * m_cols)];
            memcpy(m_data, s.m_data, sizeof(float) * (size_t) (m_rows * m_cols));
        }

        Matrix(Matrix &&s) : m_rows(s.m_rows), m_cols(s.m_cols), m_data(s.m_data) {
            print_move_created(this);
            s.m_rows = 0;
            s.m_cols = 0;
            s.m_data = nullptr;
        }

        ~Matrix() {
            print_destroyed(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
            delete[] m_data;
        }

        Matrix &operator=(const Matrix &s) {
            print_copy_assigned(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
            delete[] m_data;
            m_rows = s.m_rows;
            m_cols = s.m_cols;
            m_data = new float[(size_t) (m_rows * m_cols)];
            memcpy(m_data, s.m_data, sizeof(float) * (size_t) (m_rows * m_cols));
            return *this;
        }

        Matrix &operator=(Matrix &&s) {
            print_move_assigned(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
            if (&s != this) {
                delete[] m_data;
                m_rows = s.m_rows; m_cols = s.m_cols; m_data = s.m_data;
                s.m_rows = 0; s.m_cols = 0; s.m_data = nullptr;
            }
            return *this;
        }

        float operator()(ssize_t i, ssize_t j) const {
            return m_data[(size_t) (i*m_cols + j)];
        }

        float &operator()(ssize_t i, ssize_t j) {
            return m_data[(size_t) (i*m_cols + j)];
        }

        float *data() { return m_data; }

        ssize_t rows() const { return m_rows; }
        ssize_t cols() const { return m_cols; }
    private:
        ssize_t m_rows;
        ssize_t m_cols;
        float *m_data;
    };
    py::class_<Matrix>(m, "Matrix", py::buffer_protocol())
        .def(py::init<ssize_t, ssize_t>())
        /// Construct from a buffer
        .def(py::init([](py::buffer const b) {
            py::buffer_info info = b.request();
            if (info.format != py::format_descriptor<float>::format() || info.ndim != 2)
                throw std::runtime_error("Incompatible buffer format!");

            auto v = new Matrix(info.shape[0], info.shape[1]);
            memcpy(v->data(), info.ptr, sizeof(float) * (size_t) (v->rows() * v->cols()));
            return v;
        }))

       .def("rows", &Matrix::rows)
       .def("cols", &Matrix::cols)

        /// Bare bones interface
       .def("__getitem__", [](const Matrix &m, std::pair<ssize_t, ssize_t> i) {
            if (i.first >= m.rows() || i.second >= m.cols())
                throw py::index_error();
            return m(i.first, i.second);
        })
       .def("__setitem__", [](Matrix &m, std::pair<ssize_t, ssize_t> i, float v) {
            if (i.first >= m.rows() || i.second >= m.cols())
                throw py::index_error();
            m(i.first, i.second) = v;
        })
       /// Provide buffer access
       .def_buffer([](Matrix &m) -> py::buffer_info {
            return py::buffer_info(
                m.data(),                               /* Pointer to buffer */
                { m.rows(), m.cols() },                 /* Buffer dimensions */
                { sizeof(float) * size_t(m.cols()),     /* Strides (in bytes) for each index */
                  sizeof(float) }
            );
        })
        ;


    // test_inherited_protocol
    class SquareMatrix : public Matrix {
    public:
        SquareMatrix(ssize_t n) : Matrix(n, n) { }
    };
    // Derived classes inherit the buffer protocol and the buffer access function
    py::class_<SquareMatrix, Matrix>(m, "SquareMatrix")
        .def(py::init<ssize_t>());


    // test_pointer_to_member_fn
    // Tests that passing a pointer to member to the base class works in
    // the derived class.
    struct Buffer {
        int32_t value = 0;

        py::buffer_info get_buffer_info() {
            return py::buffer_info(&value, sizeof(value),
                                   py::format_descriptor<int32_t>::format(), 1);
        }
    };
    py::class_<Buffer>(m, "Buffer", py::buffer_protocol())
        .def(py::init<>())
        .def_readwrite("value", &Buffer::value)
        .def_buffer(&Buffer::get_buffer_info);


    class ConstBuffer {
        std::unique_ptr<int32_t> value;

    public:
        int32_t get_value() const { return *value; }
        void set_value(int32_t v) { *value = v; }

        py::buffer_info get_buffer_info() const {
            return py::buffer_info(value.get(), sizeof(*value),
                                   py::format_descriptor<int32_t>::format(), 1);
        }

        ConstBuffer() : value(new int32_t{0}) { };
    };
    py::class_<ConstBuffer>(m, "ConstBuffer", py::buffer_protocol())
        .def(py::init<>())
        .def_property("value", &ConstBuffer::get_value, &ConstBuffer::set_value)
        .def_buffer(&ConstBuffer::get_buffer_info);

    struct DerivedBuffer : public Buffer { };
    py::class_<DerivedBuffer>(m, "DerivedBuffer", py::buffer_protocol())
        .def(py::init<>())
        .def_readwrite("value", (int32_t DerivedBuffer::*) &DerivedBuffer::value)
        .def_buffer(&DerivedBuffer::get_buffer_info);

    struct BufferReadOnly {
        const uint8_t value = 0;
        BufferReadOnly(uint8_t value): value(value) {}

        py::buffer_info get_buffer_info() {
            return py::buffer_info(&value, 1);
        }
    };
    py::class_<BufferReadOnly>(m, "BufferReadOnly", py::buffer_protocol())
        .def(py::init<uint8_t>())
        .def_buffer(&BufferReadOnly::get_buffer_info);

    struct BufferReadOnlySelect {
        uint8_t value = 0;
        bool readonly = false;

        py::buffer_info get_buffer_info() {
            return py::buffer_info(&value, 1, readonly);
        }
    };
    py::class_<BufferReadOnlySelect>(m, "BufferReadOnlySelect", py::buffer_protocol())
        .def(py::init<>())
        .def_readwrite("value", &BufferReadOnlySelect::value)
        .def_readwrite("readonly", &BufferReadOnlySelect::readonly)
        .def_buffer(&BufferReadOnlySelect::get_buffer_info);

}