public void does_not_update_feed_that_was_not_modified()
{
var cached = new LocalFeedInfo()
{
Url = "http://cached.feed/rss",
Content = "cached-content",
Etag = "cached-etag",
LastFetch = new DateTime(2012, 2, 3)
};
_feedsProvider.Db().LocalFeedInfo.Insert(cached);
A.CallTo(
() => _remoteData.ReadRemoteSource(
A <LocalFeedInfo> .That.Matches(x => x.Url == cached.Url && x.Etag == cached.Etag && x.LastFetch == cached.LastFetch)
)
)
.Returns(RemoteContentResponse.NotModified(HttpStatusCode.OK));
execute(cached.Url);
List <LocalFeedInfo> fromDb = _feedsProvider.Db().LocalFeedInfo.All().ToList <LocalFeedInfo>();
Assert.Equal(1, fromDb.Count);
Assert.Equal(cached.Url, fromDb[0].Url);
Assert.Equal(cached.Content, fromDb[0].Content);
Assert.Equal(cached.Etag, fromDb[0].Etag);
Assert.Equal(cached.LastFetch, fromDb[0].LastFetch);
}
protected virtual void OnFeedUpdated(dynamic db, LocalFeedInfo feed, RemoteContentResponse remoteResponse)
{
}
protected virtual void OnNoNewContentInRemoteSource(dynamic db, LocalFeedInfo feed, RemoteContentResponse remoteResponse)
{
}
public void UpdateFeed(string url)
{
var db = _localFeedsProvider.Db();
dynamic read_view = GetLocalFeedInfoView(db);
LocalFeedInfo feed = read_view.FindByUrl(url)
?? new LocalFeedInfo
{
Url = url,
};
_log.Debug("Updating {0} feed '{1}'", feed.Id == 0 ? "new" : "existing", url);
RemoteContentResponse remoteResponse = null;
try
{
OnBeforeReadingRemoteSource(db, feed);
remoteResponse = _remoteData.ReadRemoteSource(feed);
}
catch (Exception exc)
{
OnReadingRemoteSourceError(db, feed, remoteResponse, exc);
throw;
}
if (remoteResponse.HasNewContent == false)
{
_log.Debug("Feed '{0}' does not have new content", url);
OnNoNewContentInRemoteSource(db, feed, remoteResponse);
return;
}
bool newFeed = feed.LastFetch == null;
string previousContent = feed.Content ?? string.Empty;
feed.Content = GetFeedStringContent(remoteResponse);
feed.LastFetch = ApplicationTime.Current;
feed.Etag = remoteResponse.Etag;
if (newFeed)
{
_log.Info("Inserting new feed '{0}' to local cache", url);
InsertNewFeed(db, feed, url);
}
else
{
_log.Info("Updating feed '{0}' in local cache", url);
UpdateExistingFeed(db, feed, url);
}
OnFeedUpdated(db, feed, remoteResponse);
if (previousContent.GetHashCode() == feed.Content.GetHashCode())
{
_log.Warn("Wasting resources: updating feed '{0}' with the same content it already had!", url);
}
}
/// <summary>
/// Gets whole feed content as string made of all it's items.
/// </summary>
protected virtual string GetFeedStringContent(RemoteContentResponse remoteResponse)
{
return(remoteResponse.Content.GetRssString());
}
protected virtual void OnReadingRemoteSourceError(dynamic db, LocalFeedInfo feed, RemoteContentResponse remoteResponse, Exception exc)
{
}
