public IEnumerable <IExtractionResult <FormatObject> > Extract(FormatObject lastExtracted = default(FormatObject))
{
if (!(TempDownloadLocation.Exists))
{
TempDownloadLocation.Create();
}
Aggregator.Initialize();
IEnumerable <FormatObject> firstFormats;
if (lastExtracted.Equals(default(FormatObject)))
{
firstFormats = Source.GetPossibleFormatObjects(Source.FirstDateTimeOffset);
}
else
{
firstFormats = new [] { lastExtracted };
}
foreach (var format in firstFormats)
{
var aggregatorResult = Aggregator.DownloadFirst(format);
foreach (var result in ProcessResult(aggregatorResult))
{
yield return(result);
}
lastExtracted = aggregatorResult.CurrentPosition;
}
do
{
var aggregatorResult = Aggregator.DownloadNext(lastExtracted);
foreach (var result in ProcessResult(aggregatorResult))
{
yield return(result);
}
lastExtracted = aggregatorResult.CurrentPosition;
}while (Source.GetUpperBoundExclusive(lastExtracted) < DateTimeOffset.Now);
}
public IEnumerable <IExtractionResult <FormatObject> > Extract(FormatObject lastExtracted)
{
var lastAttemptedFormat = lastExtracted;
foreach (Pair pair in Source.GetDiscriminatingFilePairs())
{
if (!(TempDownloadLocation.Exists))
{
TempDownloadLocation.Create();
}
DateTimeOffset?dateUpperBoundExclusive = null;
bool isDownloadSuccess = true;
while ((dateUpperBoundExclusive ?? DateTimeOffset.MinValue) < DateTimeOffset.Now)
{
TryDownloadResult result = Downloader.TryDownload(lastAttemptedFormat);
var previous = dateUpperBoundExclusive;
if (previous == result.UpperBoundExclusive)
{
// downloader caught in a loop
break;
}
dateUpperBoundExclusive = result.UpperBoundExclusive;
isDownloadSuccess = result.IsSuccess;
lastAttemptedFormat = result.FormatObject;
if (result.IsSuccess)
{
yield return(new FileNameExtractionResult()
{
FileFullName = result.DestinationFile.FullName,
Pair = pair,
CurrentPosition = result.FormatObject,
IsSuccess = result.IsSuccess
});
}
}
}
}
