public static StaticRangeRequest[] GetRequestedRanges(
string rangeHeaderValue)
{
var matches = _pattern.Match(rangeHeaderValue);
var result = new StaticRangeRequest[matches.Groups[1].Captures.Count];
if (false == matches.Success)
{
throw new ArgumentException(nameof(rangeHeaderValue));
}
for (var i = 0; i < matches.Groups[1].Captures.Count; i++)
{
result[i] = GetRequestedRanges(matches, i);
}
return(result);
}
static void TreatAsLastXBytes(
StaticRangeRequest original,
long contentLength,
out long fromByte,
out long toByte)
{
var numLastBytes = original.To;
if (numLastBytes < 0)
{
throw new HttpBadRequestException();
}
if (numLastBytes == 0)
{
throw new StaticRangeNotSatisfiableException(
"Last number of bytes must be larger than 0"
);
}
fromByte = contentLength - numLastBytes;
toByte = contentLength - 1;
}
public static async Task WriteAsync(
this IStaticFileServer inst,
IHttpRequest request,
StaticRangeRequest rangeRequest,
IHttpResponse response,
string pathToContentFile,
int writeBufferSize)
{
Validation.RequireValidBufferSize(writeBufferSize);
// Set headers
response.Header[HttpKeys.ContentType] =
inst.GetContentTypeHeader(pathToContentFile);
// Open the file
using (var fs = inst.OpenRead(pathToContentFile))
{
// The requested range may contains relative values,
// Convert them to absolute values here, as we knew the
// content length
rangeRequest = rangeRequest.ToAbsolute(fs.Length);
// Set headers (cont)
var contentLength = rangeRequest.To - rangeRequest.From + 1L;
response.Header[HttpKeys.ContentLength]
= contentLength.Str();
response.Header[HttpKeys.ContentRange]
= rangeRequest.GenerateRangeHeaderValue(fs.Length);
// Write body (for GET method only)
if (request.Header.Method == HttpRequestMethod.GET)
{
fs.Position = rangeRequest.From;
await fs.CopyToAsync(
response.Body,
count : contentLength,
bufferSize : writeBufferSize);
}
}
}
public static StaticRangeRequest ToAbsolute(
this StaticRangeRequest original,
long contentLength)
{
long fromByte;
long toByte;
if (contentLength < 0)
{
throw new ArgumentException(nameof(contentLength));
}
if (original.From == long.MinValue && original.To == long.MinValue)
{
throw new HttpBadRequestException(
"Must specify either 'from' or 'to' value of the range"
);
}
else if (original.From == long.MinValue)
{
TreatAsLastXBytes(original, contentLength, out fromByte, out toByte);
}
else if (original.To == long.MinValue)
{
fromByte = original.From;
toByte = contentLength - 1;
}
else
{
fromByte = original.From;
toByte = original.To;
}
Validate(fromByte, toByte, contentLength);
return(new StaticRangeRequest(fromByte, toByte));
}
public static string GenerateRangeHeaderValue(
this StaticRangeRequest range,
long length)
=> $"bytes {range.From.Str()}-{range.To.Str()}/{length.Str()}";
public static string GenerateRangeHeaderKeyAndValue(
this StaticRangeRequest rangeRequest,
long length)
{
return($"{HttpKeys.ContentRange}: {GenerateRangeHeaderValue(rangeRequest, length)}");
}
