public bool DequeueRequest(ImageLoadContext request)
{
lock (pendingRequests)
{
return(this.pendingRequests.Remove(request));
}
}
/// <summary>
/// Requests loading the image of <paramref name="size"/> located on <paramref name="uri"/>.
/// </summary>
/// <param name="uri">
/// An uri of the image to load.
/// </param>
/// <param name="size">
/// The desired size of the image.
/// </param>
/// <returns>
/// Returns an observable sequence which contains an image(s) of <paramref name="size"/> loaded using <paramref name="uri"/>.
/// </returns>
/// <remarks>
/// Override this method to provide concrete logic of loading the image per each <see cref="BaseImageLoader"/>.
/// </remarks>
protected override IObservable<ImageInfo> WhenLoadedInternal(Uri uri, Size size)
{
var result = Observable.Create<ImageInfo>(observer =>
{
var imageLoadContext = new ImageLoadContext(uri, size, observer);
this.downloadManager.EnqeueReqeust(imageLoadContext);
return () => this.downloadManager.DequeueRequest(imageLoadContext);
});
return result;
}
/// <summary>
/// Requests loading the image of <paramref name="size"/> located on <paramref name="uri"/>.
/// </summary>
/// <param name="uri">
/// An uri of the image to load.
/// </param>
/// <param name="size">
/// The desired size of the image.
/// </param>
/// <returns>
/// Returns an observable sequence which contains an image(s) of <paramref name="size"/> loaded using <paramref name="uri"/>.
/// </returns>
/// <remarks>
/// Override this method to provide concrete logic of loading the image per each <see cref="BaseImageLoader"/>.
/// </remarks>
protected override IObservable <ImageInfo> WhenLoadedInternal(Uri uri, Size size)
{
var result = Observable.Create <ImageInfo>(observer =>
{
var imageLoadContext = new ImageLoadContext(uri, size, observer);
this.downloadManager.EnqeueReqeust(imageLoadContext);
return(() => this.downloadManager.DequeueRequest(imageLoadContext));
});
return(result);
}
public void EnqeueReqeust(ImageLoadContext request)
{
lock (pendingRequests)
{
if (requestsCounter < MaxConcurrentRequests)
{
requestsCounter++;
this.ProceedReqeustAsync(request);
}
else
{
this.pendingRequests.AddLast(request);
}
}
}
public void EnqeueReqeust(ImageLoadContext request)
{
lock (pendingRequests)
{
if (requestsCounter < MaxConcurrentRequests)
{
requestsCounter++;
this.ProceedReqeustAsync(request);
}
else
{
this.pendingRequests.AddLast(request);
}
}
}
private async void ProceedReqeustAsync(ImageLoadContext request)
{
try
{
var imageResponse = await WebRequest.Create(request.Uri).GetResponseAsync();
var imageData = await imageResponse.GetResponseStream().ToArrayAsync();
var resizedImageInfo = await imageData.ResizeAsync(request.Size, true);
var result = new ImageInfo
{
Data = resizedImageInfo.Data,
Size = resizedImageInfo.Size,
Uri = request.Uri
};
request.Observer.OnNext(result);
request.Observer.OnCompleted();
}
catch (WebException ex)
{
request.Observer.OnError(new ImageLoaderException(string.Format("An error occurred when loading the image on '{0}'", request.Uri), ex));
}
catch (Exception ex)
{
request.Observer.OnError(new ImageLoaderException(string.Format("An error occurred when parsing loaded image on '{0}'", request.Uri), ex));
}
finally
{
lock (this.pendingRequests)
{
if (this.pendingRequests.Any())
{
var newRequest = this.pendingRequests.First();
this.pendingRequests.RemoveFirst();
this.ProceedReqeustAsync(newRequest);
}
else
{
this.requestsCounter--;
}
}
}
}
private async void ProceedReqeustAsync(ImageLoadContext request)
{
try
{
var imageResponse = await WebRequest.Create(request.Uri).GetResponseAsync();
var imageData = await imageResponse.GetResponseStream().ToArrayAsync();
var resizedImageInfo = await imageData.ResizeAsync(request.Size, true);
var result = new ImageInfo
{
Data = resizedImageInfo.Data,
Size = resizedImageInfo.Size,
Uri = request.Uri
};
request.Observer.OnNext(result);
request.Observer.OnCompleted();
}
catch (WebException ex)
{
request.Observer.OnError(new ImageLoaderException(string.Format("An error occurred when loading the image on '{0}'", request.Uri), ex));
}
catch (Exception ex)
{
request.Observer.OnError(new ImageLoaderException(string.Format("An error occurred when parsing loaded image on '{0}'", request.Uri), ex));
}
finally
{
lock (this.pendingRequests)
{
if (this.pendingRequests.Any())
{
var newRequest = this.pendingRequests.First();
this.pendingRequests.RemoveFirst();
this.ProceedReqeustAsync(newRequest);
}
else
{
this.requestsCounter--;
}
}
}
}
public bool DequeueRequest(ImageLoadContext request)
{
lock (pendingRequests)
{
return this.pendingRequests.Remove(request);
}
}
