public static HttpRange GetResponseRangeBy(HttpRange requestRange, long fileLength)
{
if (requestRange.Begin > fileLength)
{
throw new ArgumentOutOfRangeException("requestRange", requestRange.Begin, "The begin of range is too large");
}
var end = requestRange.End >= fileLength ? fileLength - 1 : requestRange.End;
return new HttpRange { Begin = requestRange.Begin, End = end };
}
public static bool TryParse(string header, out HttpRange range)
{
try
{
if (header.StartsWith(BytesEquals))
{
header = header.Remove(0, BytesEquals.Length);
}
else
{
throw new ArgumentException("The header should start with bytes=", "header");
}
var numbers = header.Split('-');
if (numbers.Length != 2)
{
throw new ArgumentException("There are more than 2 numbers in range header", "header");
}
var begin = long.Parse(numbers[0]);
var end = string.IsNullOrEmpty(numbers[1]) ? long.MaxValue : long.Parse(numbers[1]);
if (begin > end)
{
throw new ArgumentException("The range is invalid.", "header");
}
range = new HttpRange
{
Begin = begin,
End = end
};
}
catch
{
range = Empty;
return false;
}
return true;
}
public static bool IsEmpty(HttpRange range)
{
return range.Begin == 0L && range.End == 0L;
}