private ContentInfo GetContentInfoFromRequest(HttpRequestMessage request, long entityLength)
{
var result = new ContentInfo
{
From = 0, To = entityLength - 1,
IsPartial = false, Length = entityLength
};
RangeHeaderValue rangeHeader = request.Headers.Range;
if (rangeHeader != null && rangeHeader.Ranges.Count != 0)
{
//we support only one range
if (rangeHeader.Ranges.Count > 1)
{
//we probably return other status code here
throw new HttpResponseException(HttpStatusCode.RequestedRangeNotSatisfiable);
}
RangeItemHeaderValue range = rangeHeader.Ranges.First();
if (range.From.HasValue && range.From < 0 || range.To.HasValue && range.To > entityLength - 1)
{
throw new HttpResponseException(HttpStatusCode.RequestedRangeNotSatisfiable);
}
result.From = range.From ?? 0;
result.To = range.To ?? entityLength - 1;
result.IsPartial = true;
result.Length = entityLength;
if (range.From.HasValue && range.To.HasValue)
{
result.Length = range.To.Value - range.From.Value + 1;
}
else if (range.From.HasValue)
{
result.Length = entityLength - range.From.Value + 1;
}
else if (range.To.HasValue)
{
result.Length = range.To.Value + 1;
}
}
return result;
}
private void SetResponseHeaders(HttpResponseMessage response, ContentInfo contentInfo,
long fileLength, string fileName)
{
response.Headers.AcceptRanges.Add("bytes");
response.StatusCode = contentInfo.IsPartial ? HttpStatusCode.PartialContent
: HttpStatusCode.OK;
response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
response.Content.Headers.ContentDisposition.FileName = fileName;
response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
response.Content.Headers.ContentLength = contentInfo.Length;
if (contentInfo.IsPartial)
{
response.Content.Headers.ContentRange
= new ContentRangeHeaderValue(contentInfo.From, contentInfo.To, fileLength);
}
}