private static async Task RequestImagePathForCalendarStartRequestAsync(BingImageInfo info, RangeRequestInfo rangeInfo)
{
DateTime date;
string path = null;
Debug.WriteLine("Task for " + info.StartDate + " started");
if (!BingDataHelper.TryConvertStartdate(info.StartDate, out date))
{
rangeInfo.Callback(date, false, null);
return;
}
if (RequestImagePathCheckCache(info.StartDate, out path))
{
rangeInfo.Callback(date, true, path);
return;
}
await calendarRequestSemaphore.WaitAsync();
try
{
if (rangeInfo.IsCancelled) return;
var fileName = info.StartDate + ".jpg";
var filePath = Path.Combine(Setting.GetCurrentSetting().TempPath.LocalPath, fileName);
if (File.Exists(filePath)) File.Delete(filePath);
// see if we can grab the 1080 source. if failed, try to get the 1366 source
if (await RequestImagePathTryBingApiAsync(new Uri(BingBaseUri, info.Url), date, rangeInfo, filePath))
{
if (rangeInfo.IsCancelled) return;
if (RequestImagePathCheckCache(info.StartDate, out path))
{
rangeInfo.Callback(date, true, path);
return;
}
}
else if (await RequestImagePathTryBingApiAsync(new Uri(BingBaseUri, info.UrlBase + "_1366x768.jpg"), date, rangeInfo, filePath))
{
if (rangeInfo.IsCancelled) return;
if (RequestImagePathCheckCache(info.StartDate, out path))
{
rangeInfo.Callback(date, true, path);
return;
}
}
}
catch (Exception e)
{
// any exception cause the thread to fail
Debug.WriteLine(e.Message);
}
finally
{
rangeInfo.RemoveRequest(date);
calendarRequestSemaphore.Release();
}
if (!rangeInfo.IsCancelled) rangeInfo.Callback(date, false, null);
}
private static async Task<bool> RequestImagePathTryBingApiAsync(Uri uri, DateTime date, RangeRequestInfo rangeInfo, string path)
{
var request = WebRequest.CreateHttp(uri);
rangeInfo.SaveRequest(date, request);
try
{
using (var response = await request.GetResponseAsync())
using (var stream = response.GetResponseStream())
{
try
{
using (var image = Image.FromStream(stream, true, true))
{
image.Save(path, ImageFormat.Jpeg);
}
return true;
}
catch (Exception) { }
}
}
catch (WebException e)
{
// only consume case where response isn't canceled
if (e.Status == WebExceptionStatus.RequestCanceled) throw e;
}
return false;
}
public static async void StartRequestImagePathForCalendar(IEnumerable<DateTime> list, RangedQueryIndivisualResultCallback handler)
{
if (list == null) throw new ArgumentNullException("list");
if (handler == null) throw new ArgumentNullException("handler");
var currentRangeInfo = _currentRangeRequestInfo;
if (currentRangeInfo != null) currentRangeInfo.StopTasks();
_currentRangeRequestInfo = currentRangeInfo = new RangeRequestInfo(handler);
DateTime maxTime = DateTime.MinValue, minTime = DateTime.MaxValue;
foreach (var item in list)
{
if (maxTime < item.Date) maxTime = item.Date;
if (minTime > item.Date) minTime = item.Date;
}
var infos = await _readonlyStore.ReadImageInfosAsync(minTime, maxTime);
if (infos != null)
{
var llist = new LinkedList<Task>();
for (int i = 0; i < infos.Length; i++)
{
var info = infos[i];
llist.AddLast(Task.Run(async () => await RequestImagePathForCalendarStartRequestAsync(info, currentRangeInfo)));
if (llist.Count == 9)
{
// limit to 9 running at the same time
await Task.WhenAny(llist);
var walker = llist.First;
while (walker != null)
{
if (walker.Value.IsCompleted)
{
var marked = walker;
walker = walker.Next;
llist.Remove(marked);
}
else walker = walker.Next;
}
}
}
llist.Clear(); // don't care about thread endstats;
}
}
