public DownloadExceptionListenerContext(ComicDownloadRequest request, ComicChapter chapter,
ComicPage page, CancellationToken token,
Exception exception)
: base(request, chapter, page, token)
{
Exception = exception;
}
public DownloadListenerContext(ComicDownloadRequest request, ComicChapter chapter, ComicPage page, CancellationToken token)
{
Request = request;
Chapter = chapter;
Page = page;
Token = token;
}
public static async Task EmitAsync(this IComicDownloader downloader,
ComicDownloadRequest request,
CancellationToken token = default)
{
if (downloader is null)
{
throw new ArgumentNullException(nameof(downloader));
}
if (request is null)
{
throw new ArgumentNullException(nameof(request));
}
var tasks = downloader.EmitTasks(request, token);
foreach (var item in tasks)
{
await item();
}
}
public Func <Task>[] EmitTasks(ComicDownloadRequest request, CancellationToken token = default)
{
if (request is null)
{
throw new ArgumentNullException(nameof(request));
}
if (request.Provider is null || request.Saver is null || request.DownloadRequests is null)
{
throw new ArgumentNullException("Any null for " + nameof(request));
}
var tasks = new List <Func <Task> >();
foreach (var item in request.DownloadRequests)
{
if (token.IsCancellationRequested)
{
break;
}
tasks.Add(() => DownloadPageAsync(request, item.Chapter, item.Page, token));
}
return(tasks.ToArray());
}
public static Task BatchEmitAsync(this IComicDownloader downloader,
ComicDownloadRequest request,
int concurrent = 5,
CancellationToken token = default)
{
if (downloader is null)
{
throw new ArgumentNullException(nameof(downloader));
}
if (request is null)
{
throw new ArgumentNullException(nameof(request));
}
if (concurrent <= 0)
{
throw new ArgumentOutOfRangeException(nameof(concurrent));
}
var tasks = downloader.EmitTasks(request, token);
return(TaskQuene.RunVoidAsync(tasks, concurrent));
}
private async Task DownloadPageAsync(ComicDownloadRequest request, ComicChapter chapter, ComicPage page, CancellationToken token)
{
var listener = request.Listener;
DownloadListenerContext listenerContext = null;
if (listener != null)
{
listenerContext = new DownloadListenerContext(request, chapter, page, token);
await listener.ReadyFetchAsync(listenerContext);
}
if (listener != null && token.IsCancellationRequested)
{
await listener.CanceledAsync(listenerContext);
return;
}
var ctx = new ComicDownloadContext(request.Entity, chapter, page, null, token);
if (!request.Saver.NeedToSave(ctx))
{
if (listener != null)
{
await listener.NotNeedToSaveAsync(listenerContext);
}
return;
}
try
{
if (listener != null)
{
await listener.BeginFetchPageAsync(listenerContext);
}
using (var stream = await request.Provider.GetImageStreamAsync(page.TargetUrl))
using (var destStream = streamManager.GetStream())
{
DownloadSaveListenerContext saveCtx = null;
if (listener != null)
{
saveCtx = new DownloadSaveListenerContext(request, chapter, page, token, destStream);
await listener.ReadySaveAsync(saveCtx);
}
await stream.CopyToAsync(destStream);
destStream.Seek(0, SeekOrigin.Begin);
ctx = new ComicDownloadContext(request.Entity, chapter, page, destStream, token);
await request.Saver.SaveAsync(ctx);
if (listener != null)
{
await listener.EndFetchPageAsync(saveCtx);
}
}
}
catch (Exception ex)
{
if (listener != null)
{
var errCtx = new DownloadExceptionListenerContext(request, chapter, page, token, ex);
await listener.FetchPageExceptionAsync(errCtx);
}
}
if (listener != null)
{
await listener.ComplatedSaveAsync(listenerContext);
}
}
public DownloadSaveListenerContext(ComicDownloadRequest request, ComicChapter chapter, ComicPage page, CancellationToken token,
Stream targetStream)
: base(request, chapter, page, token)
{
baseStream = targetStream;
}