UriHeaderParser.cs

Go to the documentation of this file.

using System.Diagnostics.CodeAnalysis;
using System.Text;
 
namespace System.Net.Http.Headers;
 
internal sealed class UriHeaderParser : HttpHeaderParser
{
    private readonly UriKind _uriKind;
 
    internal static readonly UriHeaderParser RelativeOrAbsoluteUriParser = new UriHeaderParser(UriKind.RelativeOrAbsolute);
 
    private UriHeaderParser(UriKind uriKind)
        : base(supportsMultipleValues: false)
    {
        _uriKind = uriKind;
    }
 
    public override bool TryParseValue([NotNullWhen(true)] string value, object storeValue, ref int index, [NotNullWhen(true)] out object parsedValue)
    {
        parsedValue = null;
        if (string.IsNullOrEmpty(value) || index == value.Length)
        {
            return false;
        }
        string text = value;
        if (index > 0)
        {
            text = value.Substring(index);
        }
        if (!Uri.TryCreate(text, _uriKind, out Uri result))
        {
            text = DecodeUtf8FromString(text);
            if (!Uri.TryCreate(text, _uriKind, out result))
            {
                return false;
            }
        }
        index = value.Length;
        parsedValue = result;
        return true;
    }
 
    internal static string DecodeUtf8FromString(string input)
    {
        if (string.IsNullOrWhiteSpace(input))
        {
            return input;
        }
        bool flag = false;
        for (int i = 0; i < input.Length; i++)
        {
            if (input[i] > 'ÿ')
            {
                return input;
            }
            if (input[i] > '\u007f')
            {
                flag = true;
                break;
            }
        }
        if (flag)
        {
            byte[] array = new byte[input.Length];
            for (int j = 0; j < input.Length; j++)
            {
                if (input[j] > 'ÿ')
                {
                    return input;
                }
                array[j] = (byte)input[j];
            }
            try
            {
                Encoding encoding = Encoding.GetEncoding("utf-8", EncoderFallback.ExceptionFallback, DecoderFallback.ExceptionFallback);
                return encoding.GetString(array, 0, array.Length);
            }
            catch (ArgumentException)
            {
            }
        }
        return input;
    }
 
    public override string ToString(object value)
    {
        Uri uri = (Uri)value;
        if (uri.IsAbsoluteUri)
        {
            return uri.AbsoluteUri;
        }
        return uri.GetComponents(UriComponents.SerializationInfoString, UriFormat.UriEscaped);
    }
}