VRFS-1665 rewrote daily email queries and adding pagination; other tweaks

ruby/lib/jam_ruby/app/views/jam_ruby/user_mailer/scheduled_session_daily.html.erb

@@ -25,7 +25,7 @@
 <tr>
 <td><%= sess.genre.description %></td>
 <td><%= sess.description %></td>
-<td style="text-align:center"><%= sess.latency_store %></td>
+<td style="text-align:center"><%= sess.latency %></td>
 </tr>
 <% end %>
 </table>

ruby/lib/jam_ruby/app/views/jam_ruby/user_mailer/scheduled_session_daily.text.erb

@@ -11,7 +11,7 @@ Take a look through these new sessions below, and just click the RSVP button on
 
 GENRE | DESCRIPTION | LATENCY
 <% @sessions_and_latency.each do |sess| %>
-<%= sess.genre.description %> | <%= sess.description %> | <%= sess.latency_store %>
+<%= sess.genre.description %> | <%= sess.description %> | <%= sess.latency %>
 <% end %>
 
 To see ALL the scheduled sessions that you might be interested in joining, view our Find Session page at: http://www.jamkazam.com/client#/findSession. 

ruby/lib/jam_ruby/models/email_batch_new_musician.rb

@@ -69,7 +69,9 @@ SQL
       self._fetch_eligible_receivers
 
       countsql = "SELECT DISTINCT COUNT(receiver_id) AS num FROM #{TMP_PAIRS} GROUP BY receiver_id"
-      num_pair = ActiveRecord::Base.connection.execute(countsql)[0]['num'].to_i
+      rr = ActiveRecord::Base.connection.execute(countsql)
+      num_pair = 0 < rr.count ? rr[0]['num'].to_i : 0
+        
       loops = (num_pair / per_page) + (num_pair % per_page) - 1
       0.upto(loops) do |nn|
         offset = nn * per_page

ruby/lib/jam_ruby/models/email_batch_scheduled_sessions.rb

@@ -5,8 +5,9 @@ module JamRuby
     SINCE_DAYS = 2
     MIN_HOURS_START = 2
 
-    TMP_SNAP = 'tmp_scheduled_session_snapshot'
-    TMP_USER = 'tmp_scheduled_session_user'
+    TMP_SESS = 'tmp_candidate_sessions'
+    TMP_RECIP = 'tmp_candidate_recipients'
+    TMP_MATCH = 'tmp_matches'
 
     def self.subject
       "New sessions have been scheduled that may be a good match for you!"
@@ -14,22 +15,23 @@ module JamRuby
 
     # inserts eligible sessions to temp table
     def _collect_eligible_sessions
-      ActiveRecord::Base.connection.execute("DROP TABLE IF EXISTS #{TMP_SNAP}")
+      ActiveRecord::Base.connection.execute("DROP TABLE IF EXISTS #{TMP_SESS}")
       sql =<<SQL
 SELECT 
-  rs.instrument_id AS instrument_id, 
-  msess.id AS session_id, 
-  msess.user_id AS creator_id,
-  users.last_jam_locidispid AS creator_score_idx
-INTO TEMP TABLE #{TMP_SNAP} 
+    msess.id AS session_id, 
+    msess.user_id AS creator_id,
+    users.last_jam_locidispid AS creator_score_idx,
+    rs.instrument_id
+INTO TEMP TABLE #{TMP_SESS} 
 FROM music_sessions msess
+INNER JOIN users ON users.id = msess.user_id
 INNER JOIN rsvp_slots AS rs ON rs.music_session_id = msess.id
 LEFT JOIN rsvp_requests_rsvp_slots AS rrrs ON rrrs.rsvp_slot_id = rs.id
-INNER JOIN users ON users.id = msess.user_id
 WHERE
     musician_access = 't' AND
     approval_required = 'f' AND
     msess.created_at > '#{time_since_last_batch(SINCE_DAYS)}' AND
+    msess.created_at < '#{self.created_at}' AND
     scheduled_start >= '#{Time.now() + MIN_HOURS_START.hours}' AND
     (rrrs.rsvp_slot_id IS NULL OR rrrs.chosen != 't')
 SQL
@@ -37,41 +39,65 @@ SQL
     end
 
     def _collect_eligible_recipients
-      ActiveRecord::Base.connection.execute("DROP TABLE IF EXISTS #{TMP_USER}")
+      ActiveRecord::Base.connection.execute("DROP TABLE IF EXISTS #{TMP_RECIP}")
       # load eligible recipients into tmp table
       sql =<<SQL
 SELECT 
-  users.id AS user_id, 
-  users.last_jam_locidispid AS user_score_idx,
-  tmp.session_id AS session_id, 
-  tmp.creator_id AS creator_id, 
-  tmp.creator_score_idx AS creator_score_idx
-INTO TEMP TABLE #{TMP_USER}
+    users.id AS receiver_id, 
+    users.last_jam_locidispid AS receiver_score_idx
+INTO TEMP TABLE #{TMP_RECIP}
 FROM users
 INNER JOIN musicians_instruments AS mi ON mi.user_id = users.id
-LEFT JOIN #{TMP_SNAP} AS tmp ON tmp.instrument_id = mi.instrument_id
+JOIN #{TMP_SESS} ON #{TMP_SESS}.instrument_id = mi.instrument_id
 WHERE
     users.musician = 't' AND
-    users.subscribe_email = 't' AND
-    tmp.session_id IS NOT NULL
-GROUP BY users.id, tmp.session_id, tmp.creator_id, tmp.creator_score_idx
+    users.subscribe_email = 't' 
+SQL
+      ActiveRecord::Base.connection.execute(sql)
+    end
+
+    def _collect_scored_recipients
+      ActiveRecord::Base.connection.execute("DROP TABLE IF EXISTS #{TMP_MATCH}")
+      sql =<<SQL
+SELECT 
+    DISTINCT #{TMP_RECIP}.receiver_id, 
+    #{TMP_SESS}.session_id,
+    scores.score AS latency
+INTO TEMP TABLE #{TMP_MATCH}
+FROM scores
+INNER JOIN #{TMP_SESS} ON #{TMP_SESS}.creator_score_idx = scores.alocidispid
+INNER JOIN #{TMP_RECIP} ON #{TMP_RECIP}.receiver_score_idx = scores.blocidispid
+WHERE
+    scores.score < #{Score::MAX_YELLOW_LATENCY}
+GROUP BY #{TMP_RECIP}.receiver_id, #{TMP_SESS}.session_id, latency
 SQL
       ActiveRecord::Base.connection.execute(sql)
     end
 
     # select recipients whose score is below minimum threshold
-    def _select_scored_recipients
-      sql =<<SQL
-SELECT DISTINCT user_id, scores.score AS latency
-FROM #{TMP_USER}
-INNER JOIN scores ON scores.alocidispid = #{TMP_USER}.creator_score_idx AND scores.blocidispid = #{TMP_USER}.user_score_idx 
-WHERE
-  scores.score < #{Score::MAX_YELLOW_LATENCY}
+    def _select_scored_recipients(offset=0)
+      if 0 > offset
+        sql =<<SQL
+SELECT DISTINCT COUNT(receiver_id) AS num
+FROM #{TMP_MATCH}
+GROUP BY receiver_id
 SQL
-      ActiveRecord::Base.connection.execute(sql) 
+        rr = ActiveRecord::Base.connection.execute(sql)
+        return 0 < rr.count ? rr[0]['num'].to_i : 0
+      else
+        sql =<<SQL
+SELECT DISTINCT receiver_id 
+FROM #{TMP_MATCH} 
+GROUP BY receiver_id
+ORDER BY receiver_id ASC
+LIMIT #{@per_page}
+OFFSET #{offset}
+SQL
+        return ActiveRecord::Base.connection.execute(sql)
+      end
     end
 
-    def fetch_recipients
+    def fetch_recipients(per_page=500)
       objs = []
 
       # load eligible sessions into tmp table
@@ -80,20 +106,24 @@ SQL
       # load eligible mail recipients into tmp table
       self._collect_eligible_recipients
 
-      # now just get the sessions/latency for each distinct mail recipient
-      _select_scored_recipients.each do |result|
-        user = User.find_by_id(result['user_id'])
+      # load mail recipients with minimum score into tmp table
+      self._collect_scored_recipients
 
-        sql = "SELECT session_id FROM #{TMP_USER} WHERE user_id = '#{user.id}'"
-        sessions = ActiveRecord::Base.connection.execute(sql).collect do |rr| 
-          msess = MusicSession.where(['id = ?',rr['session_id']])
-            .limit(1)
+      @per_page = per_page
+      num_recip = _select_scored_recipients(-1)
+      loops = (num_recip / @per_page) + (num_recip % @per_page) - 1
+
+      0.upto(loops) do |nn|
+        offset = nn * @per_page
+        # now just get the sessions/latency for each distinct mail recipient
+        _select_scored_recipients(offset).each do |result|
+          receiver = User.find_by_id(result['receiver_id'])
+          sessions = MusicSession.select("music_sessions.*, #{TMP_MATCH}.latency")
+            .joins("INNER JOIN #{TMP_MATCH} ON #{TMP_MATCH}.session_id = music_sessions.id")
+            .where(["#{TMP_MATCH}.receiver_id = ?", receiver.id])
             .includes([:genre, :creator])
-            .first
-          msess.latency_store = result['latency']
-          msess
+          block_given? ? yield(receiver, sessions) : objs << [receiver, sessions]
         end
-        block_given? ? yield(user, sessions) : objs << [user, sessions]
       end
       objs
     end

ruby/lib/jam_ruby/models/music_session.rb

@@ -10,9 +10,6 @@ module JamRuby
 
     attr_accessor :legal_terms, :recurring_mode, :language_description, :scheduled_start_time, :access_description
 
-    # used for temporary data store of latency between creator and some other user
-    attr_accessor :latency_store
-
     self.table_name = "music_sessions"
 
     self.primary_key = 'id'

ruby/lib/jam_ruby/models/user.rb

@@ -19,9 +19,6 @@ module JamRuby
     # updating_password corresponds to a lost_password
     attr_accessor :updating_password, :updating_email, :updated_email, :update_email_confirmation_url, :administratively_created, :current_password, :setting_password, :confirm_current_password, :updating_avatar, :updating_progression_field, :mods_json
 
-    # used for temporary data store of latency between self and some other user
-    attr_accessor :latency_store
-
     belongs_to :icecast_server_group, class_name: "JamRuby::IcecastServerGroup", inverse_of: :users, foreign_key: 'icecast_server_group_id'
 
     # authorizations (for facebook, etc -- omniauth)

ruby/spec/jam_ruby/models/email_batch_spec_scheduled_session.rb

@@ -41,14 +41,16 @@ describe EmailBatchScheduledSessions do
                          :creator => drummer, 
                          :scheduled_start => Time.now() + 2.days,
                          :musician_access => true,
-                         :approval_required => false)
+                         :approval_required => false,
+                         :created_at => Time.now - 1.hour)
     end
     let (:session2) do 
       FactoryGirl.create(:music_session, 
                          :creator => drummer,
                          :scheduled_start => Time.now() + 2.days,
                          :musician_access => true,
-                         :approval_required => false)
+                         :approval_required => false,
+                         :created_at => Time.now - 1.hour)
     end
 
     before(:each) do