aboutsummaryrefslogtreecommitdiff
path: root/src/Ryujinx.Horizon/Sdk/Ngc/Detail/Utf8Text.cs
blob: 47f780494633b407424013de6d3c419ca7cd1b24 (plain) (blame)
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
using System;
using System.Text;

namespace Ryujinx.Horizon.Sdk.Ngc.Detail
{
    readonly struct Utf8Text
    {
        private readonly byte[] _text;
        private readonly int[] _charOffsets;

        public int CharacterCount => _charOffsets.Length - 1;

        public Utf8Text()
        {
            _text = Array.Empty<byte>();
            _charOffsets = Array.Empty<int>();
        }

        public Utf8Text(byte[] text)
        {
            _text = text;

            UTF8Encoding encoding = new(encoderShouldEmitUTF8Identifier: false, throwOnInvalidBytes: true);

            string str = encoding.GetString(text);

            _charOffsets = new int[str.Length + 1];

            int offset = 0;

            for (int index = 0; index < str.Length; index++)
            {
                _charOffsets[index] = offset;
                offset += encoding.GetByteCount(str.AsSpan().Slice(index, 1));
            }

            _charOffsets[str.Length] = offset;
        }

        public Utf8Text(ReadOnlySpan<byte> text) : this(text.ToArray())
        {
        }

        public static Utf8ParseResult Create(out Utf8Text utf8Text, ReadOnlySpan<byte> text)
        {
            try
            {
                utf8Text = new(text);
            }
            catch (ArgumentException)
            {
                utf8Text = default;

                return Utf8ParseResult.InvalidCharacter;
            }

            return Utf8ParseResult.Success;
        }

        public ReadOnlySpan<byte> AsSubstring(int startCharIndex, int endCharIndex)
        {
            int startOffset = _charOffsets[startCharIndex];
            int endOffset = _charOffsets[endCharIndex];

            return _text.AsSpan()[startOffset..endOffset];
        }

        public Utf8Text AppendNullTerminated(ReadOnlySpan<byte> toAppend)
        {
            int length = toAppend.IndexOf((byte)0);
            if (length >= 0)
            {
                toAppend = toAppend[..length];
            }

            return Append(toAppend);
        }

        public Utf8Text Append(ReadOnlySpan<byte> toAppend)
        {
            byte[] combined = new byte[_text.Length + toAppend.Length];

            _text.AsSpan().CopyTo(combined.AsSpan()[.._text.Length]);
            toAppend.CopyTo(combined.AsSpan()[_text.Length..]);

            return new(combined);
        }

        public void CopyTo(Span<byte> destination)
        {
            _text.CopyTo(destination[.._text.Length]);

            if (destination.Length > _text.Length)
            {
                destination[_text.Length] = 0;
            }
        }

        public ReadOnlySpan<byte> AsSpan()
        {
            return _text;
        }
    }
}