| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | // | ||
| 2 | // Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com) | ||
| 3 | // Copyright (c) 2025 Mohammad Nejati | ||
| 4 | // | ||
| 5 | // Distributed under the Boost Software License, Version 1.0. (See accompanying | ||
| 6 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | ||
| 7 | // | ||
| 8 | // Official repository: https://github.com/cppalliance/capy | ||
| 9 | // | ||
| 10 | |||
| 11 | #ifndef SRC_CAPY_ZLIB_STREAM_CAST_HPP | ||
| 12 | #define SRC_CAPY_ZLIB_STREAM_CAST_HPP | ||
| 13 | |||
| 14 | #include <boost/capy/zlib/stream.hpp> | ||
| 15 | |||
| 16 | #include <cstddef> | ||
| 17 | |||
| 18 | #include <zlib.h> | ||
| 19 | |||
| 20 | namespace boost { | ||
| 21 | namespace capy { | ||
| 22 | namespace zlib { | ||
| 23 | |||
| 24 | //------------------------------------------------ | ||
| 25 | |||
| 26 | #define SAME_FIELD(T1,T2,M) \ | ||
| 27 | offsetof(T1,M)==offsetof(T2,M) && \ | ||
| 28 | sizeof(decltype(T1::M)) == sizeof(decltype(T2::M)) | ||
| 29 | |||
| 30 | template<class T1, class T2> | ||
| 31 | constexpr | ||
| 32 | bool | ||
| 33 | is_layout_identical() | ||
| 34 | { | ||
| 35 | return | ||
| 36 | sizeof(T1) == sizeof(T2) && | ||
| 37 | SAME_FIELD(T1, T2, next_in) && | ||
| 38 | SAME_FIELD(T1, T2, avail_in) && | ||
| 39 | SAME_FIELD(T1, T2, total_in) && | ||
| 40 | SAME_FIELD(T1, T2, next_out) && | ||
| 41 | SAME_FIELD(T1, T2, avail_out) && | ||
| 42 | SAME_FIELD(T1, T2, total_out) && | ||
| 43 | SAME_FIELD(T1, T2, msg) && | ||
| 44 | SAME_FIELD(T1, T2, state) && | ||
| 45 | SAME_FIELD(T1, T2, zalloc) && | ||
| 46 | SAME_FIELD(T1, T2, zfree) && | ||
| 47 | SAME_FIELD(T1, T2, opaque) && | ||
| 48 | SAME_FIELD(T1, T2, data_type) && | ||
| 49 | SAME_FIELD(T1, T2, adler) && | ||
| 50 | SAME_FIELD(T1, T2, reserved) | ||
| 51 | ; | ||
| 52 | } | ||
| 53 | |||
| 54 | //------------------------------------------------ | ||
| 55 | |||
| 56 | template<bool isLayoutIdentical = | ||
| 57 | is_layout_identical<stream, z_stream_s>()> | ||
| 58 | struct stream_cast_impl | ||
| 59 | { | ||
| 60 | explicit | ||
| 61 | stream_cast_impl( | ||
| 62 | stream& st) | ||
| 63 | : pzs_(reinterpret_cast<z_stream_s*>(&st)) | ||
| 64 | , st_(st) | ||
| 65 | { | ||
| 66 | zs_.next_in = st_.next_in; | ||
| 67 | zs_.avail_in = st_.avail_in; | ||
| 68 | zs_.total_in = st_.total_in; | ||
| 69 | zs_.next_out = st_.next_out; | ||
| 70 | zs_.avail_out = st_.avail_out; | ||
| 71 | zs_.total_out = st_.total_out; | ||
| 72 | zs_.msg = nullptr; | ||
| 73 | zs_.state = reinterpret_cast< | ||
| 74 | internal_state*>(st_.state); | ||
| 75 | zs_.zalloc = st_.zalloc; | ||
| 76 | zs_.zfree = st_.zfree; | ||
| 77 | zs_.opaque = st_.opaque; | ||
| 78 | zs_.data_type = st_.data_type; | ||
| 79 | zs_.adler = st_.adler; | ||
| 80 | zs_.reserved = st_.reserved; | ||
| 81 | } | ||
| 82 | |||
| 83 | ~stream_cast_impl() | ||
| 84 | { | ||
| 85 | st_.next_in = zs_.next_in; | ||
| 86 | st_.avail_in = zs_.avail_in; | ||
| 87 | st_.total_in = zs_.total_in; | ||
| 88 | st_.next_out = zs_.next_out; | ||
| 89 | st_.avail_out = zs_.avail_out; | ||
| 90 | st_.total_out = zs_.total_out; | ||
| 91 | st_.msg = zs_.msg; | ||
| 92 | st_.state = zs_.state; | ||
| 93 | st_.zalloc = zs_.zalloc; | ||
| 94 | st_.zfree = zs_.zfree; | ||
| 95 | st_.opaque = zs_.opaque; | ||
| 96 | st_.data_type = zs_.data_type; | ||
| 97 | st_.adler = zs_.adler; | ||
| 98 | st_.reserved = zs_.reserved; | ||
| 99 | } | ||
| 100 | |||
| 101 | z_stream_s* | ||
| 102 | get() noexcept | ||
| 103 | { | ||
| 104 | return pzs_; | ||
| 105 | } | ||
| 106 | |||
| 107 | private: | ||
| 108 | z_stream_s* pzs_ = nullptr; | ||
| 109 | stream& st_; | ||
| 110 | z_stream_s zs_; | ||
| 111 | }; | ||
| 112 | |||
| 113 | //------------------------------------------------ | ||
| 114 | |||
| 115 | template<> | ||
| 116 | struct stream_cast_impl<true> | ||
| 117 | { | ||
| 118 | explicit | ||
| 119 | ✗ | stream_cast_impl( | |
| 120 | stream& st) | ||
| 121 | // VFALCO A pinch of undefined behavior here | ||
| 122 | ✗ | : pzs_(reinterpret_cast<z_stream_s*>(&st)) | |
| 123 | { | ||
| 124 | |||
| 125 | ✗ | } | |
| 126 | |||
| 127 | z_stream_s* | ||
| 128 | ✗ | get() noexcept | |
| 129 | { | ||
| 130 | ✗ | return pzs_; | |
| 131 | } | ||
| 132 | |||
| 133 | private: | ||
| 134 | z_stream_s* pzs_; | ||
| 135 | }; | ||
| 136 | |||
| 137 | //------------------------------------------------ | ||
| 138 | |||
| 139 | using stream_cast = stream_cast_impl<>; | ||
| 140 | |||
| 141 | } // zlib | ||
| 142 | } // capy | ||
| 143 | } // boost | ||
| 144 | |||
| 145 | #endif | ||
| 146 |