private async Task mergeParts(VideoFragment fragment)
{
var title = getTitle(fragment);
using (var writeStream = File.OpenWrite($"{title}.{fragment.Extension}"))
{
for (var part = 0; part < Config.Parts; part++)
{
using (var readStream = File.OpenRead($"{title}.part{part}"))
{
await readStream.CopyToAsync(writeStream);
}
}
}
}
private async Task <VideoDownloadResult> downloadFragment(VideoFragment fragment)
{
var partialLength = fragment.Size / Config.Parts + 1;
var title = getTitle(fragment);
var filename = title + fragment.Extension;
if (File.Exists(filename))
{
return(VideoDownloadResult.Skipped);
}
var startByte = 0;
var part = 0;
while (startByte < fragment.Size)
{
var partFilename = $"{title}.part{part}";
if (!File.Exists(partFilename))
{
var endByte = Math.Min(fragment.Size, startByte + partialLength) - 1;
var range = $"bytes={startByte}-{endByte}";
var client = new HttpClient();
client.DefaultRequestHeaders.Range = new RangeHeaderValue(startByte, endByte);
client.DefaultRequestHeaders.Referrer = new Uri("https://www.bilibili.com", UriKind.Absolute);
client.DefaultRequestHeaders.Add("Origin", "https://www.bilibili.com");
client.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36");
//client.Headers[HttpRequestHeader.Range] = range;
//client.Headers[HttpRequestHeader.Referer] = "https://www.bilibili.com";
//client.Headers[HttpRequestHeader.UserAgent] = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36";
//client.Headers["Origin"] = "https://www.bilibili.com";
Task task = null;
try
{
task = Task.Run(async() =>
{
using (var response = await client.GetStreamAsync(fragment.Url))
using (var file = File.OpenWrite(partFilename))
{
while (response.CanRead)
{
file.WriteByte((byte)response.ReadByte());
taskMap[task]++;
updateProgress();
}
}
});
//task = client.DownloadFileTaskAsync(fragment.Url, partFilename);
//client.DownloadProgressChanged += (s, e) =>
//{
// taskMap[task] = e.BytesReceived;
//};
taskMap.Add(task, 0L);
}
catch (Exception ex)
when(ex is WebException || ex is InvalidOperationException)
{
// TODO: handle web errors
return(VideoDownloadResult.Failed);
}
}
part++;
startByte = startByte + partialLength;
}
Downloading = true;
await Task.WhenAll(taskMap.Select(it => it.Key));
Downloading = false;
return(VideoDownloadResult.Success);
}
private string getTitle(VideoFragment fragment)
{
return(Video.Fragments.Length == 1 ? Video.Title : $"{Video.Title} - {Array.IndexOf(Video.Fragments, fragment) + 1}");
}