static void BackgroundDownloader()
{
while (!DownloadQueue.IsCompleted)
{
if (!DownloadQueue.TryTake(out var def, System.Threading.Timeout.InfiniteTimeSpan))
{
continue;
}
var bytes = downloadBytes(def);
lock (cacheLocker)
cache[def] = bytes;
PictureCached?.Invoke(nameof(PictureStorage), new PictureCachedEventArgs {
Definition = def, Picture = bytes
});
}
}
private static void timerDownload()
{
// must live outside try-catch, else 'finally' can reset another thread's lock
if (isProcessing)
{
return;
}
try
{
isProcessing = true;
var def = cache
.Where(kvp => kvp.Value is null)
.Select(kvp => kvp.Key)
// 80x80 should be 1st since it's enum value == 0
.OrderBy(d => d.PictureId)
.FirstOrDefault();
// no more null entries. all requsted images are cached
if (string.IsNullOrWhiteSpace(def.PictureId))
{
return;
}
var bytes = downloadBytes(def);
saveFile(def, bytes);
cache[def] = bytes;
PictureCached?.Invoke(nameof(PictureStorage), def.PictureId);
}
finally
{
isProcessing = false;
}
}
