| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | // | ||
| 2 | // Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com) | ||
| 3 | // Copyright (c) 2020 Peter Dimov (pdimov at gmail dot com), | ||
| 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/boostorg/json | ||
| 9 | // | ||
| 10 | |||
| 11 | #ifndef BOOST_JSON_DETAIL_IMPL_FORMAT_IPP | ||
| 12 | #define BOOST_JSON_DETAIL_IMPL_FORMAT_IPP | ||
| 13 | |||
| 14 | #include <boost/json/detail/ryu/ryu.hpp> | ||
| 15 | #include <cstring> | ||
| 16 | |||
| 17 | namespace boost { | ||
| 18 | namespace json { | ||
| 19 | namespace detail { | ||
| 20 | |||
| 21 | /* Reference work: | ||
| 22 | |||
| 23 | https://www.ampl.com/netlib/fp/dtoa.c | ||
| 24 | https://www.exploringbinary.com/fast-path-decimal-to-floating-point-conversion/ | ||
| 25 | https://kkimdev.github.io/posts/2018/06/15/IEEE-754-Floating-Point-Type-in-C++.html | ||
| 26 | */ | ||
| 27 | |||
| 28 | 4839 | inline char const* digits_lut() noexcept | |
| 29 | { | ||
| 30 | return | ||
| 31 | "00010203040506070809" | ||
| 32 | "10111213141516171819" | ||
| 33 | "20212223242526272829" | ||
| 34 | "30313233343536373839" | ||
| 35 | "40414243444546474849" | ||
| 36 | "50515253545556575859" | ||
| 37 | "60616263646566676869" | ||
| 38 | "70717273747576777879" | ||
| 39 | "80818283848586878889" | ||
| 40 | 4839 | "90919293949596979899"; | |
| 41 | } | ||
| 42 | |||
| 43 | 1988 | inline void format_four_digits( char * dest, unsigned v ) | |
| 44 | { | ||
| 45 | 1988 | std::memcpy( dest + 2, digits_lut() + (v % 100) * 2, 2 ); | |
| 46 | 1988 | std::memcpy( dest , digits_lut() + (v / 100) * 2, 2 ); | |
| 47 | 1988 | } | |
| 48 | |||
| 49 | 863 | inline void format_two_digits( char * dest, unsigned v ) | |
| 50 | { | ||
| 51 | 863 | std::memcpy( dest, digits_lut() + v * 2, 2 ); | |
| 52 | 863 | } | |
| 53 | |||
| 54 | 405 | inline void format_digit( char * dest, unsigned v ) | |
| 55 | { | ||
| 56 | 405 | *dest = static_cast<char>( v + '0' ); | |
| 57 | 405 | } | |
| 58 | |||
| 59 | unsigned | ||
| 60 | 3614 | format_uint64( | |
| 61 | char* dest, | ||
| 62 | std::uint64_t v) noexcept | ||
| 63 | { | ||
| 64 |
2/2✓ Branch 0 taken 2475 times.
✓ Branch 1 taken 1139 times.
|
3614 | if(v < 10) |
| 65 | { | ||
| 66 | 2475 | *dest = static_cast<char>( '0' + v ); | |
| 67 | 2475 | return 1; | |
| 68 | } | ||
| 69 | |||
| 70 | char buffer[ 24 ]; | ||
| 71 | |||
| 72 | 1139 | char * p = buffer + 24; | |
| 73 | |||
| 74 |
2/2✓ Branch 0 taken 1988 times.
✓ Branch 1 taken 1139 times.
|
3127 | while( v >= 1000 ) |
| 75 | { | ||
| 76 | 1988 | p -= 4; | |
| 77 | 1988 | format_four_digits( p, v % 10000 ); | |
| 78 | 1988 | v /= 10000; | |
| 79 | } | ||
| 80 | |||
| 81 |
2/2✓ Branch 0 taken 863 times.
✓ Branch 1 taken 276 times.
|
1139 | if( v >= 10 ) |
| 82 | { | ||
| 83 | 863 | p -= 2; | |
| 84 | 863 | format_two_digits( p, v % 100 ); | |
| 85 | 863 | v /= 100; | |
| 86 | } | ||
| 87 | |||
| 88 |
2/2✓ Branch 0 taken 405 times.
✓ Branch 1 taken 734 times.
|
1139 | if( v ) |
| 89 | { | ||
| 90 | 405 | p -= 1; | |
| 91 | 405 | format_digit( p, static_cast<unsigned>(v) ); | |
| 92 | } | ||
| 93 | |||
| 94 | 1139 | unsigned const n = static_cast<unsigned>( buffer + 24 - p ); | |
| 95 | 1139 | std::memcpy( dest, p, n ); | |
| 96 | |||
| 97 | 1139 | return n; | |
| 98 | } | ||
| 99 | |||
| 100 | unsigned | ||
| 101 | 3189 | format_int64( | |
| 102 | char* dest, int64_t i) noexcept | ||
| 103 | { | ||
| 104 | 3189 | std::uint64_t ui = static_cast< | |
| 105 | std::uint64_t>(i); | ||
| 106 |
2/2✓ Branch 0 taken 2747 times.
✓ Branch 1 taken 442 times.
|
3189 | if(i >= 0) |
| 107 | 2747 | return format_uint64(dest, ui); | |
| 108 | 442 | *dest++ = '-'; | |
| 109 | 442 | ui = ~ui + 1; | |
| 110 | 442 | return 1 + format_uint64(dest, ui); | |
| 111 | } | ||
| 112 | |||
| 113 | unsigned | ||
| 114 | 477 | format_double( | |
| 115 | char* dest, double d, bool allow_infinity_and_nan) noexcept | ||
| 116 | { | ||
| 117 | return static_cast<int>( | ||
| 118 | 477 | ryu::d2s_buffered_n(d, dest, allow_infinity_and_nan)); | |
| 119 | } | ||
| 120 | |||
| 121 | } // detail | ||
| 122 | } // namespace json | ||
| 123 | } // namespace boost | ||
| 124 | |||
| 125 | #endif | ||
| 126 |