public async void Run(IBackgroundTaskInstance taskInstance)
{
AddQuestionsResult result = null;
BackgroundTaskDeferral deferral = taskInstance.GetDeferral();
#if DEBUG
InvokeSimpleToast("Hello from " + taskInstance.Task.Name);
#endif
try
{
result = await FeedManager.QueryWebsitesAsync();
#if DEBUG
InvokeSimpleToast(String.Format(
"There are {0} new questions and {1} updated questions.",
result.AddedQuestions,
result.UpdatedQuestions));
#endif
}
catch (Exception ex)
{
Debug.WriteLine(ex);
#if DEBUG
InvokeSimpleToast(ex.Message);
#endif
}
deferral.Complete();
}
// This method can be call simultaneously. Make sure only one thread is touching it.
public static AddQuestionsResult AddQuestions(string websiteUrl, SyndicationFeed feed, bool skipLatestPubDate)
{
AddQuestionsResult globalResult = new AddQuestionsResult();
DateTimeOffset latestPubDate = SettingsManager.GetLastestPubDate(websiteUrl);
DateTimeOffset newLatestPubDate = DateTimeOffset.MinValue;
Debug.WriteLine("{0} Current LastestPubDate is {1}.", websiteUrl, latestPubDate);
// Wait until the event is set by another thread.
addEvent.WaitOne();
try
{
CheckSettingsAreLoaded();
foreach (SyndicationItem item in feed.Items)
{
AddQuestionResult result = AddQuestionResult.None;
if (skipLatestPubDate || DateTimeOffset.Compare(item.PublishedDate.DateTime, latestPubDate) > 0)
{
result = AddQuestion(websiteUrl, item);
// Chances are we need to update the LatestPubDate.
if (result == AddQuestionResult.Added && item.PublishedDate > newLatestPubDate)
{
newLatestPubDate = item.PublishedDate;
Debug.WriteLine("{0} New LastestPubDate is {1}.", websiteUrl, newLatestPubDate);
}
}
else
{
result = UpdateQuestion(websiteUrl, item);
}
switch (result)
{
case AddQuestionResult.Added:
globalResult.AddedQuestions++;
break;
case AddQuestionResult.Updated:
globalResult.UpdatedQuestions++;
break;
}
}
// If the quesiton list did not change, there should not be a new LatestPubDate.
if (globalResult.AddedQuestions > 0)
{
SettingsManager.SetLastestPubDate(websiteUrl, newLatestPubDate);
}
return globalResult;
}
finally
{
// Set the event, so other threads waiting on it can do their job.
addEvent.Set();
}
}
public static IAsyncOperation <AddQuestionsResult> QueryTagAsync(string websiteUrl, string tagEncoded)
{
return(AsyncInfo.Run(async(cancellationToken) =>
{
// Retrieve questions, skip the LatestPubDate validation and add all questions.
AddQuestionsResult result = await FeedManager.QuerySingleWebsiteAsync(websiteUrl, tagEncoded, true);
// Only limit and save questions if list changed.
if (result.AddedQuestions > 0 || result.UpdatedQuestions > 0)
{
uint removedQuestions = await QuestionsManager.RemoveQuestionsInReadList();
await QuestionsManager.LimitTo150AndSaveAsync();
FeedManager.UpdateTileAndBadge();
}
return result;
}));
}
// 1. Load settings.
// 2. query -> Retrieve feeds.
// 3. skipLatestPubDate -> Add questions.
// 4. Sort questions (needed to show tile and badge).
// 5. Update tile.
// 6. Update badge.
// TODO: Maybe check for buzz words here.
public static IAsyncOperation <AddQuestionsResult> QueryWebsitesAsync()
{
return(AsyncInfo.Run(async(cancellationToken) =>
{
SettingsManager.Load();
await QuestionsManager.LoadAsync();
// Query websites in parallel.
List <Task <AddQuestionsResult> > tasks = new List <Task <AddQuestionsResult> >();
IEnumerable <string> keys = SettingsManager.GetWebsiteKeys();
foreach (string website in keys)
{
string query = SettingsManager.ConcatenateAllTags(website);
tasks.Add(QuerySingleWebsiteAsync(website, query, false).AsTask());
}
if (tasks.Count == 0)
{
// There is nothing to wait.
return new AddQuestionsResult();
}
await Task.Factory.ContinueWhenAll(tasks.ToArray(), (tasks2) => {});
// Add up the results.
AddQuestionsResult result = new AddQuestionsResult();
foreach (Task <AddQuestionsResult> task in tasks)
{
AddQuestionsResult taskResult = task.Result;
result.AddedQuestions += taskResult.AddedQuestions;
result.UpdatedQuestions += taskResult.UpdatedQuestions;
if (!taskResult.FileFound)
{
result.FileFound = false;
}
}
Debug.WriteLine(
"{0} questions added, {0} questions modified.",
result.AddedQuestions,
result.UpdatedQuestions);
// Only limit and save questions if list changed.
if (result.AddedQuestions > 0 || result.UpdatedQuestions > 0)
{
uint removedQuestions = await QuestionsManager.RemoveQuestionsInReadList();
await QuestionsManager.LimitTo150AndSaveAsync();
UpdateTileAndBadge();
SettingsManager.SaveLocal(); // Save updated latestPubDate.
}
// Update last query date-time, only if all queries were successful.
if (result.FileFound)
{
SettingsManager.LatestQueryDate = DateTimeOffset.Now;
}
return result;
}));
}
public static IAsyncOperation <AddQuestionsResult> QuerySingleWebsiteAsync(
string websiteUrl,
string query,
bool skipLatestPubDate)
{
return(AsyncInfo.Run(async(cancellationToken) =>
{
AddQuestionsResult result = new AddQuestionsResult();
Uri uri;
if (!SettingsManager.TryCreateUri(websiteUrl, query, out uri))
{
Debugger.Break();
}
SyndicationFeed feed = null;
try
{
client.BypassCacheOnRetrieve = true;
feed = await client.RetrieveFeedAsync(uri);
}
catch (Exception ex)
{
Debug.WriteLine("{0} {1}", websiteUrl, ex.Message);
int hr = ex.HResult;
int facility = (hr & 0x7FFF0000) / 0xFFFF;
int error = hr & 0xFFFF;
const int WEB_E_INVALID_XML = unchecked ((int)0x83750002);
const int FACILITY_WIN32 = 7;
const int FACILITY_HTTP = 25;
const int NOT_FOUND = 404;
if (hr == WEB_E_INVALID_XML)
{
// An invalid XML is equivalent to file not found.
result.FileFound = false;
return result;
}
else if (facility == FACILITY_HTTP && error == NOT_FOUND)
{
result.FileFound = false;
return result;
}
else if (facility == FACILITY_HTTP)
{
// Swallow HTTP errors. Treat them as file not found.
result.FileFound = false;
return result;
}
else if (facility == FACILITY_WIN32 && error > 12001 && error < 12156)
{
// Swallow WININET errors. Treat as file not found.
result.FileFound = false;
return result;
}
else
{
throw;
}
}
result = QuestionsManager.AddQuestions(websiteUrl, feed, skipLatestPubDate);
result.FileFound = true;
return result;
}));
}
// This method can be call simultaneously. Make sure only one thread is touching it.
public static AddQuestionsResult AddQuestions(string websiteUrl, SyndicationFeed feed, bool skipLatestPubDate)
{
AddQuestionsResult globalResult = new AddQuestionsResult();
DateTimeOffset latestPubDate = SettingsManager.GetLastestPubDate(websiteUrl);
DateTimeOffset newLatestPubDate = DateTimeOffset.MinValue;
Debug.WriteLine("{0} Current LastestPubDate is {1}.", websiteUrl, latestPubDate);
// Wait until the event is set by another thread.
addEvent.WaitOne();
try
{
CheckSettingsAreLoaded();
foreach (SyndicationItem item in feed.Items)
{
AddQuestionResult result = AddQuestionResult.None;
if (skipLatestPubDate || DateTimeOffset.Compare(item.PublishedDate.DateTime, latestPubDate) > 0)
{
result = AddQuestion(websiteUrl, item);
// Chances are we need to update the LatestPubDate.
if (result == AddQuestionResult.Added && item.PublishedDate > newLatestPubDate)
{
newLatestPubDate = item.PublishedDate;
Debug.WriteLine("{0} New LastestPubDate is {1}.", websiteUrl, newLatestPubDate);
}
}
else
{
result = UpdateQuestion(websiteUrl, item);
}
switch (result)
{
case AddQuestionResult.Added:
globalResult.AddedQuestions++;
break;
case AddQuestionResult.Updated:
globalResult.UpdatedQuestions++;
break;
}
}
// If the quesiton list did not change, there should not be a new LatestPubDate.
if (globalResult.AddedQuestions > 0)
{
SettingsManager.SetLastestPubDate(websiteUrl, newLatestPubDate);
}
return(globalResult);
}
finally
{
// Set the event, so other threads waiting on it can do their job.
addEvent.Set();
}
}
public static IAsyncOperation<AddQuestionsResult> QuerySingleWebsiteAsync(
string websiteUrl,
string query,
bool skipLatestPubDate)
{
return AsyncInfo.Run(async (cancellationToken) =>
{
AddQuestionsResult result = new AddQuestionsResult();
Uri uri;
if (!SettingsManager.TryCreateUri(websiteUrl, query, out uri))
{
Debugger.Break();
}
SyndicationFeed feed = null;
try
{
client.BypassCacheOnRetrieve = true;
feed = await client.RetrieveFeedAsync(uri);
}
catch (Exception ex)
{
Debug.WriteLine("{0} {1}", websiteUrl, ex.Message);
int hr = ex.HResult;
int facility = (hr & 0x7FFF0000) / 0xFFFF;
int error = hr & 0xFFFF;
const int WEB_E_INVALID_XML = unchecked((int)0x83750002);
const int FACILITY_WIN32 = 7;
const int FACILITY_HTTP = 25;
const int NOT_FOUND = 404;
if (hr == WEB_E_INVALID_XML)
{
// An invalid XML is equivalent to file not found.
result.FileFound = false;
return result;
}
else if (facility == FACILITY_HTTP && error == NOT_FOUND)
{
result.FileFound = false;
return result;
}
else if (facility == FACILITY_HTTP)
{
// Swallow HTTP errors. Treat them as file not found.
result.FileFound = false;
return result;
}
else if (facility == FACILITY_WIN32 && error > 12001 && error < 12156)
{
// Swallow WININET errors. Treat as file not found.
result.FileFound = false;
return result;
}
else
{
throw;
}
}
result = QuestionsManager.AddQuestions(websiteUrl, feed, skipLatestPubDate);
result.FileFound = true;
return result;
});
}
// 1. Load settings.
// 2. query -> Retrieve feeds.
// 3. skipLatestPubDate -> Add questions.
// 4. Sort questions (needed to show tile and badge).
// 5. Update tile.
// 6. Update badge.
// TODO: Maybe check for buzz words here.
public static IAsyncOperation<AddQuestionsResult> QueryWebsitesAsync()
{
return AsyncInfo.Run(async (cancellationToken) =>
{
SettingsManager.Load();
await QuestionsManager.LoadAsync();
// Query websites in parallel.
List<Task<AddQuestionsResult>> tasks = new List<Task<AddQuestionsResult>>();
IEnumerable<string> keys = SettingsManager.GetWebsiteKeys();
foreach (string website in keys)
{
string query = SettingsManager.ConcatenateAllTags(website);
tasks.Add(QuerySingleWebsiteAsync(website, query, false).AsTask());
}
if (tasks.Count == 0)
{
// There is nothing to wait.
return new AddQuestionsResult();
}
await Task.Factory.ContinueWhenAll(tasks.ToArray(), (tasks2) => {});
// Add up the results.
AddQuestionsResult result = new AddQuestionsResult();
foreach (Task<AddQuestionsResult> task in tasks)
{
AddQuestionsResult taskResult = task.Result;
result.AddedQuestions += taskResult.AddedQuestions;
result.UpdatedQuestions += taskResult.UpdatedQuestions;
if (!taskResult.FileFound)
{
result.FileFound = false;
}
}
Debug.WriteLine(
"{0} questions added, {0} questions modified.",
result.AddedQuestions,
result.UpdatedQuestions);
// Only limit and save questions if list changed.
if (result.AddedQuestions > 0 || result.UpdatedQuestions > 0)
{
uint removedQuestions = await QuestionsManager.RemoveQuestionsInReadList();
await QuestionsManager.LimitTo150AndSaveAsync();
UpdateTileAndBadge();
SettingsManager.SaveLocal(); // Save updated latestPubDate.
}
// Update last query date-time, only if all queries were successful.
if (result.FileFound)
{
SettingsManager.LatestQueryDate = DateTimeOffset.Now;
}
return result;
});
}
