static void Main(string[] args)
{
Diagnostics.CassandraTraceSwitch.Level = TraceLevel.Verbose;
CassandraLogWriter LogWriter = new CassandraLogWriter();
TextWriterTraceListener twtl = new TextWriterTraceListener(LogWriter);
Trace.Listeners.Add(twtl);
Console.WriteLine("Connecting, setting keyspace and creating Tables..");
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture("en-US");
Cluster cluster = Cluster.Builder().AddContactPoint("cassi.cloudapp.net").Build();
using(var session = cluster.Connect())
{
var keyspaceName = "test" + Guid.NewGuid().ToString("N");
try
{
session.ChangeKeyspace(keyspaceName);
}
catch (InvalidQueryException)
{
session.CreateKeyspaceIfNotExists(keyspaceName);
session.ChangeKeyspace(keyspaceName);
}
LogWriter.GetContext(new CassandraLogContext(session));
TwitterContext twitterContext = new TwitterContext(session);
var TweetsTable = twitterContext.GetTable<Tweet>();
var AuthorsTable = twitterContext.GetTable<Author>();
var FollowedTweetsTable = twitterContext.GetTable<FollowedTweet>();
var StatisticsTable = twitterContext.GetTable<Statistics>();
Console.WriteLine("Done!");
//Adding authors and their followers to the Authors table:
Console.WriteLine("Adding authors and their followers to the Authors table..");
int AuthorsNo = 50;
List<Author> authorsLocal = new List<Author>();
List<Statistics> statisticsLocal = new List<Statistics>();
List<string> authorsID = new List<string>();
for (int i = 0; i < AuthorsNo; i++)
{
var author_ID = "Author" + i.ToString();
var authorEnt = new Author() { author_id = author_ID, followers = authorsID.Where(aut => aut != author_ID).ToList() };
AuthorsTable.AddNew(authorEnt);
AuthorsTable.EnableQueryTracing(authorEnt);
authorsLocal.Add(authorEnt);
authorsID.Add(authorEnt.author_id);
//We will also add current author to the Statistics table:
var statEnt = new Statistics() { author_id = author_ID };
StatisticsTable.Attach(statEnt, EntityUpdateMode.ModifiedOnly, EntityTrackingMode.KeepAttachedAfterSave);
//And increment number of followers for current author, also in Statistics table:
authorEnt.followers.ForEach(folo => statEnt.followers_count += 1);
statisticsLocal.Add(statEnt);
}
twitterContext.SaveChanges(SaveChangesMode.Batch);
var traces = AuthorsTable.RetriveAllQueryTraces();
foreach (var trace in traces)
{
Console.WriteLine("coordinator was {0}", trace.Coordinator);
}
Console.WriteLine("Done!");
//Now every author will add a single tweet:
Console.WriteLine("Now authors are writing their tweets..");
List<Tweet> tweetsLocal = new List<Tweet>();
List<FollowedTweet> followedTweetsLocal = new List<FollowedTweet>();
foreach (var auth in authorsID)
{
var tweetEnt = new Tweet() { tweet_id = Guid.NewGuid(), author_id = auth, body = "Hello world! My name is " + auth + (DateTime.Now.Second % 2 == 0 ? "." : ""), date = DateTimeOffset.Now };
TweetsTable.AddNew(tweetEnt);
tweetsLocal.Add(tweetEnt);
//We will update our statistics table
statisticsLocal.First(stat => stat.author_id == auth).tweets_count += 1;
//We also have to add this tweet to "FollowedTweet" table, so every user who follows that author, will get this tweet on his/her own wall!
FollowedTweet followedTweetEnt = null;
Author author = AuthorsTable.FirstOrDefault(a => a.author_id == auth).Execute();
if (author != default(Author) && author.followers != null)
foreach (var follower in author.followers)
{
followedTweetEnt = new FollowedTweet() { user_id = follower, author_id = tweetEnt.author_id, body = tweetEnt.body, date = tweetEnt.date, tweet_id = tweetEnt.tweet_id };
FollowedTweetsTable.AddNew(followedTweetEnt);
followedTweetsLocal.Add(followedTweetEnt);
}
}
twitterContext.SaveChanges(SaveChangesMode.Batch);
Console.WriteLine("Done!");
string separator = Environment.NewLine + "───────────────────────────────────────────────────────────────────────" + Environment.NewLine;
Console.WriteLine(separator);
//To display users that follows "Author8":
Console.WriteLine("\"Author8\" is followed by:" + Environment.NewLine);
try
{
Author Author8 = AuthorsTable.First(aut => aut.author_id == "Author8").Execute();
Author8.displayFollowers();
}
catch (InvalidOperationException)
{
Console.WriteLine("\"Author8\" does not exist in database!");
}
//To display all of user "Author15" tweets:
Console.WriteLine(separator + "All tweets posted by Author15:" + Environment.NewLine);
foreach (Tweet tweet in (from twt in TweetsTable where twt.author_id == "Author15" select twt).Execute())
tweet.display();
//To display all tweets from users that "Author45" follows:
string author_id = "Author45";
Console.WriteLine(separator + string.Format("All tweets posted by users that \"{0}\" follows:", author_id) + Environment.NewLine);
// At first we will check if specified above author_id is present in database:
Author specifiedAuthor = (from aut in AuthorsTable where aut.author_id == author_id select aut).FirstOrDefault().Execute(); // it's another possible way of using First/FirstOrDefault method
if (specifiedAuthor != default(Author))
{
var followedTweets = (from t in FollowedTweetsTable where t.user_id == author_id select t).Execute().ToList();
if (followedTweets.Count() > 0)
foreach (var foloTwt in followedTweets)
foloTwt.display();
else
Console.WriteLine(string.Format("There is no tweets from users that {0} follows.", author_id));
}
else
Console.WriteLine(string.Format("Nothing to display because specified author: \"{0}\" does not exist!", author_id));
//Let's check all of authors punctuation in their tweets, or at least, if they end their tweets with full stop, exclamation or question mark:
List<string> authorsWithPunctuationProblems = new List<string>();
//To check it, we can use anonymous class because we are interested only in author_id and body of the tweet
var slimmedTweets = (from twt in TweetsTable select new { twt.author_id, twt.body }).Execute();
foreach (var slimTwt in slimmedTweets)
if (!(slimTwt.body.EndsWith(".") || slimTwt.body.EndsWith("!") || slimTwt.body.EndsWith("?")))
if (!authorsWithPunctuationProblems.Contains(slimTwt.author_id))
authorsWithPunctuationProblems.Add(slimTwt.author_id);
// Now we can check how many of all authors have this problem..
float proportion = (float)authorsWithPunctuationProblems.Count() / AuthorsTable.Count().Execute() * 100;
Console.WriteLine(separator + string.Format("{0}% of all authors doesn't end tweet with punctuation mark!", proportion) + Environment.NewLine);
// This time I will help them, and update these tweets with a full stop..
foreach (var tweet in TweetsTable.Where(x => authorsWithPunctuationProblems.Contains(x.author_id)).Execute())
{
TweetsTable.Attach(tweet);
tweetsLocal.Where(twt => twt.tweet_id == tweet.tweet_id).First().body += ".";
tweet.body += ".";
}
twitterContext.SaveChanges(SaveChangesMode.Batch);
//Statistics before deletion of tweets:
Console.WriteLine(separator + "Before deletion of all tweets our \"Statistics\" table looks like:" + Environment.NewLine);
StatisticsTable.DisplayTable();
//Deleting all tweets from "Tweet" table
foreach (var ent in tweetsLocal)
{
TweetsTable.Delete(ent);
var statEnt = statisticsLocal.FirstOrDefault(auth => auth.author_id == ent.author_id);
if (statEnt != default(Statistics))
statEnt.tweets_count -= 1;
}
twitterContext.SaveChanges(SaveChangesMode.Batch);
//Statistics after deletion of tweets:
Console.WriteLine("After deletion of all tweets our \"Statistics\" table looks like:");
StatisticsTable.DisplayTable();
//Logs:
Console.WriteLine(separator + "Number of received logs: " + LogWriter.LogsTable.Count().Execute());
foreach (var log in LogWriter.LogsTable.Execute())
log.display();
LogWriter.StopWritingToDB();
Console.WriteLine(separator + "Deleting keyspace: \"" + keyspaceName + "\"");
session.DeleteKeyspaceIfExists(keyspaceName);
}
Console.WriteLine("Done! Press any key to exit..");
Console.ReadKey();
}
