コード例 #1
0
ファイル: ToDo.cs プロジェクト: vteori/CS421-DB
        //----------------------------------------------------------------------
        // ToDo.LoadFollowerTableFromBlob
        //
        // Input   : blobContainer - blob container which has data file we uploaded
        //           followerTable - empty follower table
        // Return  : Number of inserted entries (records) into follower table
        // Purpose : Load followerTable with follower entries which are composed from blob object
        // Note    :
        //
        // * To read a blob file line by line:
        //
        // StreamReader sr = new StreamReader(blobContainer.GetBlobReference(BlobAddressUri).OpenRead());
        // String line;
        // while ((line = sr.ReadLine()) != null)
        // {  ...
        //
        // * Format of the line of input data:
        //
        // user_id  \t  follower_id
        //
        // * To insert an entry to follower table:
        //
        // followerTable.AddFollowerEntry(new FollowerEntry(userID, followerID, partitionKey));
        // followerTable.SaveChanges();
        //----------------------------------------------------------------------
        public static int LoadFollowerTableFromBlob(CloudBlobContainer blobContainer, FollowerEntryDataSource followerTable)
        {
            int numFollowerEntries = 0;

            StreamReader sr = new StreamReader(blobContainer.GetBlockBlobReference(ToDo.blobAddressUri).OpenRead());
            String line;
            while ((line = sr.ReadLine()) != null)
            {
                numFollowerEntries++;
                String [] split = line.Split(new Char [] {'\t'});
                int User = Convert.ToInt32(split[0]);
                int Follower = Convert.ToInt32(split[1]);
                // Partition Key = (User + Follower) % #(Worker Role Instances)
                // Users who are mutually friends to each other are contained in the same partition
                string PartitionKey = ((User + Follower) % ToDo.NumWorkerRoleInstances).ToString();
                followerTable.AddFollowerEntry(new FollowerEntry(User, Follower, PartitionKey));
                followerTable.SaveChages();
            }

            return numFollowerEntries;
        }
コード例 #2
0
ファイル: Default.aspx.cs プロジェクト: vteori/CS421-DB
        protected void LoadFollowerTableFromBlobButton_Click(object sender, EventArgs e)
        {
            FollowerEntryDataSource followerTable = new FollowerEntryDataSource();
            followerTable.DeleteTable();
            followerTable.CreateTable();

            loadStopwatch.Restart();

            int numFollowerEntries = ToDo.LoadFollowerTableFromBlob(blobContainer, followerTable);

            loadStopwatch.Stop();
            System.Diagnostics.Trace.TraceInformation("Loading completed. (" + loadStopwatch.Elapsed.TotalSeconds + " sec)");
            LoadFollowerTableFromBlobLabel.Text = "Loading completed. (" + loadStopwatch.Elapsed.TotalSeconds + " sec)";
            LoadFollowerTableFromBlobTTD.InnerText = "" + loadStopwatch.Elapsed.TotalSeconds;
            LoadFollowerTableFromBlobRTD.InnerText = "" + numFollowerEntries;
        }
コード例 #3
0
ファイル: ToDo.cs プロジェクト: vteori/CS421-DB
        //----------------------------------------------------------------------
        // ToDo.FindMutualFriendsInEachWorkerRole
        //
        // Input   : instanceIdx - worker role instance index number in string type,
        //                         which begins with 0, i.g., "0", "1", "2", ...
        //           responseQueue - queue data structure to send a complete message to web role
        // Return  : mutual friend pairs found within a worker role
        // Purpose : Retrieve some of entries from follwer table
        //           and find mutual friends among them,
        //           In other words, do a self-join on a part of follower table.
        // Note    : This method may be called several times in concurrent by web role(ToDo.FindMutualFriends)
        //           When we put together all of results of this method calls,
        //           we should obtain exact and complete mutual friend pairs.
        //
        // * To bring some of entries in follower table:
        //
        // FollowerEntryDataSource followerTable = new FollowerEntryDataSource();
        // List<FollowerEntry> partition = followerTable.getEntryList(PartitionKey);
        //----------------------------------------------------------------------
        public static List<MutualFriend> FindMutualFriendsInEachWorkerRole(string instanceIdx, CloudQueue responseQueue)
        {
            List<MutualFriend> mutualFriends = new List<MutualFriend>();

            FollowerEntryDataSource followerTable = new FollowerEntryDataSource();

            if (isNestedLoopsJoin)
            {
                //  Nested Loops Join
                List<FollowerEntry> S = followerTable.getEntryList(instanceIdx);
                List<FollowerEntry> R = S;

                foreach (FollowerEntry r in R)
                {
                    foreach (FollowerEntry s in S)
                    {
                        if (r.User == s.Follower && r.Follower == s.User)
                        {
                            mutualFriends.Add(new MutualFriend(s.User, s.Follower));
                        }
                    }
                }
            }
            else
            {
                // Sort Merge Join
                FollowerEntry[] S = followerTable.getEntryList(instanceIdx).ToArray();
                FollowerEntry[] R = S;

                Array.Sort(S,
                    delegate(FollowerEntry fe1, FollowerEntry fe2)
                    {
                        return (fe1.User + fe1.Follower).CompareTo(fe2.User + fe2.Follower);
                    });

                Array.Sort(R,
                    delegate(FollowerEntry fe1, FollowerEntry fe2)
                    {
                        return (fe1.User + fe1.Follower).CompareTo(fe2.User + fe2.Follower);
                    });

                int Tr = 0;    // ranges over R
                int Ts = 0;    // ranges over S
                int Gs = 0;    // start of current S-partition

                while (Tr < R.Length && Gs < S.Length)
                {
                    // continue scan of R
                    while ((R[Tr].User + R[Tr].Follower) < (S[Gs].User + S[Gs].Follower))
                        Tr++;
                    // continue scan of S
                    while ((R[Tr].User + R[Tr].Follower) > (S[Gs].User + S[Gs].Follower))
                        Gs++;

                    if (Tr >= R.Length || Gs >= S.Length)
                        break;

                    Ts = Gs;        // Needed in case Tri != Gsj
                    // process current R partition
                    while ((R[Tr].User + R[Tr].Follower) == (S[Gs].User + S[Gs].Follower))
                    {
                        // reset S partition scan
                        Ts = Gs;
                        // process current R tuple
                        while ((S[Ts].User + S[Ts].Follower) == (R[Tr].User + R[Tr].Follower))
                        {
                            // output joined tuples
                            if (S[Ts].Follower == R[Tr].User && S[Ts].User == R[Tr].Follower)
                                mutualFriends.Add(new MutualFriend(S[Ts].User, S[Ts].Follower));
                            Ts++;   // advance S partition scan

                            // check if Ts == eof
                            if (Ts >= S.Length)
                                break;  // then escape this loop (no more tuples to read in S!)
                        }

                        Tr++;   // advance scan of R

                        // check if Tr == eof
                        if (Tr >= R.Length)
                            break;  // then escape this loop (no more tuples to read in R!)
                    }   // done with current R partition

                    // initialize search for next R partition
                    Gs = Ts;
                }
            }

            return mutualFriends;
        }