/// <inheritdoc />
public Task <MediaStream> GetMediaStreamAsync(MediaStreamInfo info)
{
info.GuardNotNull(nameof(info));
// Determine if stream is rate-limited
var isRateLimited = !Regex.IsMatch(info.Url, "ratebypass[=/]yes");
// Determine segment size
var segmentSize = isRateLimited
? 9_898_989 // this number was carefully devised through research
: long.MaxValue; // don't use segmentation for non-rate-limited streams
// Get segmented stream
var stream = _httpClient.CreateSegmentedStream(info.Url, info.Size, segmentSize);
// This method must return a task for backwards-compatibility reasons
return(Task.FromResult(new MediaStream(info, stream)));
}
/// <summary>
/// Gets the actual media stream associated with given metadata
/// and downloads it to a file.
/// </summary>
public async Task DownloadMediaStreamAsync(MediaStreamInfo info, string filePath,
IProgress <double> progress, CancellationToken cancellationToken)
{
info.GuardNotNull(nameof(info));
filePath.GuardNotNull(nameof(filePath));
// Keep track of bytes copied for progress reporting
var totalBytesCopied = 0L;
// Determine if stream is rate-limited
var isRateLimited = !Regex.IsMatch(info.Url, @"ratebypass[=/]yes");
// Download rate-limited streams in segments
if (isRateLimited)
{
// Determine segment count
const long segmentSize = 9_898_989; // this number was carefully devised through research
var segmentCount = (int)Math.Ceiling(1.0 * info.Size / segmentSize);
using (var output = File.Create(filePath))
{
for (var i = 0; i < segmentCount; i++)
{
// Determine segment range
var from = i * segmentSize;
var to = (i + 1) * segmentSize - 1;
// Create request with range
var request = new HttpRequestMessage(HttpMethod.Get, info.Url);
request.Headers.Range = new RangeHeaderValue(from, to);
// Download segment
using (request)
using (var response = await _httpService.PerformRequestAsync(request).ConfigureAwait(false))
using (var input = await response.Content.ReadAsStreamAsync().ConfigureAwait(false))
{
int bytesCopied;
do
{
// Copy
bytesCopied = await input.CopyChunkToAsync(output, cancellationToken)
.ConfigureAwait(false);
// Report progress
totalBytesCopied += bytesCopied;
progress?.Report(1.0 * totalBytesCopied / info.Size);
} while (bytesCopied > 0);
}
}
}
}
// Download non-limited streams directly
else
{
using (var output = File.Create(filePath))
using (var input = await GetMediaStreamAsync(info).ConfigureAwait(false))
{
int bytesCopied;
do
{
// Copy
bytesCopied = await input.CopyChunkToAsync(output, cancellationToken)
.ConfigureAwait(false);
// Report progress
totalBytesCopied += bytesCopied;
progress?.Report(1.0 * totalBytesCopied / info.Size);
} while (bytesCopied > 0);
}
}
}
