Setting up redis based prompt_queue to speed up catchup algorithm

Dhruv Kapadia
1 parent 47320adc
Showing 4 changed files with 67 additions and 2 deletions Show diff stats
app/models/choice.rb
app/models/question.rb
config/initializers/redis.rb
spec/models/question_spec.rb
@@ -108,7 +108,7 @@ class Choice &lt; ActiveRecord::Base
  
   def generate_prompts
     #once a choice is added, we need to generate the new prompts (possible combinations of choices)
-    #do this in a new process (via delayed jobs)
+    #do this in a new process (via delayed jobs)? Maybe just for uploaded ideas
     previous_choices = (self.question.choices - [self])
     return if previous_choices.empty?
     inserts = []
@@ -127,7 +127,6 @@ class Choice &lt; ActiveRecord::Base
  
     Question.update_counters(self.question_id, :prompts_count => 2*previous_choices.size)
  
-    logger.info("The sql is:::: #{sql}")
  
     ActiveRecord::Base.connection.execute(sql)
  
@@ -298,6 +298,27 @@ class Question &lt; ActiveRecord::Base
 	  end
   end
  
+  def pq_key
+	  @pq_key ||= "#{self.id}_prompt_queue"
+  end
+
+  def clear_prompt_queue
+	  $redis.del(self.pq_key)
+  end
+
+  def add_prompt_to_queue
+	  prompt = self.catchup_choose_prompt
+	  $redis.rpush(self.pq_key, prompt.id)
+	  prompt
+  end
+
+  def pop_prompt_queue
+	  prompt_id = $redis.lpop(self.pq_key)
+	  prompt = prompt_id.nil? ? nil : Prompt.find(prompt_id.to_i)
+  end
+
+
+
  
  
 end
@@ -0,0 +1,2 @@
+require 'redis'
+$redis = Redis.new
@@ -84,6 +84,49 @@ describe Question do
 		  (sum - 1.0).abs.should < 0.000001
 	  end
  
+	  it "should allow the prompt queue to be cleared" do
+		  @catchup_q.add_prompt_to_queue
+		  @catchup_q.clear_prompt_queue
+
+		  @catchup_q.pop_prompt_queue.should == nil
+	  end
+	  it "should allow a prompt to be added to the prompt queue" do
+		  @catchup_q.clear_prompt_queue
+		  @catchup_q.pop_prompt_queue.should == nil
+
+		  @catchup_q.add_prompt_to_queue
+
+		  prompt = @catchup_q.pop_prompt_queue
+
+		  prompt.should_not == nil
+		  prompt.active?.should == true
+	  end
+	  it "should return prompts from the queue in FIFO order" do
+		  @catchup_q.clear_prompt_queue
+		  @catchup_q.pop_prompt_queue.should == nil
+		  
+		  prompt1 = @catchup_q.add_prompt_to_queue
+		  prompt2 = @catchup_q.add_prompt_to_queue
+		  prompt3 = @catchup_q.add_prompt_to_queue
+
+		  prompt_1 = @catchup_q.pop_prompt_queue
+		  prompt_2 = @catchup_q.pop_prompt_queue
+		  prompt_3 = @catchup_q.pop_prompt_queue
+
+
+		  prompt_1.should == prompt1
+		  prompt_2.should == prompt2
+		  prompt_3.should == prompt3
+
+		  # there is a small probability that the catchup algorithm
+		  # choose two prompts that are indeed equal
+		  prompt_1.should_not == prompt_2
+		  prompt_1.should_not == prompt_3
+		  prompt_2.should_not == prompt_3
+
+
+		  @catchup_q.pop_prompt_queue.should == nil
+	  end
  
  
   end
...	...	@@ -108,7 +108,7 @@ class Choice < ActiveRecord::Base
108	108
109	109	def generate_prompts
110	110	#once a choice is added, we need to generate the new prompts (possible combinations of choices)
111		- #do this in a new process (via delayed jobs)
	111	+ #do this in a new process (via delayed jobs)? Maybe just for uploaded ideas
112	112	previous_choices = (self.question.choices - [self])
113	113	return if previous_choices.empty?
114	114	inserts = []
...	...	@@ -127,7 +127,6 @@ class Choice < ActiveRecord::Base
127	127
128	128	Question.update_counters(self.question_id, :prompts_count => 2*previous_choices.size)
129	129
130		- logger.info("The sql is:::: #{sql}")
131	130
132	131	ActiveRecord::Base.connection.execute(sql)
133	132
...	...
...	...	@@ -298,6 +298,27 @@ class Question < ActiveRecord::Base
298	298	end
299	299	end
300	300
	301	+ def pq_key
	302	+ @pq_key \|\|= "#{self.id}_prompt_queue"
	303	+ end
	304	+
	305	+ def clear_prompt_queue
	306	+ $redis.del(self.pq_key)
	307	+ end
	308	+
	309	+ def add_prompt_to_queue
	310	+ prompt = self.catchup_choose_prompt
	311	+ $redis.rpush(self.pq_key, prompt.id)
	312	+ prompt
	313	+ end
	314	+
	315	+ def pop_prompt_queue
	316	+ prompt_id = $redis.lpop(self.pq_key)
	317	+ prompt = prompt_id.nil? ? nil : Prompt.find(prompt_id.to_i)
	318	+ end
	319	+
	320	+
	321	+
301	322
302	323
303	324	end
...	...
...	...	@@ -0,0 +1,2 @@
	1	+require 'redis'
	2	+$redis = Redis.new
...	...
...	...	@@ -84,6 +84,49 @@ describe Question do
84	84	(sum - 1.0).abs.should < 0.000001
85	85	end
86	86
	87	+ it "should allow the prompt queue to be cleared" do
	88	+ @catchup_q.add_prompt_to_queue
	89	+ @catchup_q.clear_prompt_queue
	90	+
	91	+ @catchup_q.pop_prompt_queue.should == nil
	92	+ end
	93	+ it "should allow a prompt to be added to the prompt queue" do
	94	+ @catchup_q.clear_prompt_queue
	95	+ @catchup_q.pop_prompt_queue.should == nil
	96	+
	97	+ @catchup_q.add_prompt_to_queue
	98	+
	99	+ prompt = @catchup_q.pop_prompt_queue
	100	+
	101	+ prompt.should_not == nil
	102	+ prompt.active?.should == true
	103	+ end
	104	+ it "should return prompts from the queue in FIFO order" do
	105	+ @catchup_q.clear_prompt_queue
	106	+ @catchup_q.pop_prompt_queue.should == nil
	107	+
	108	+ prompt1 = @catchup_q.add_prompt_to_queue
	109	+ prompt2 = @catchup_q.add_prompt_to_queue
	110	+ prompt3 = @catchup_q.add_prompt_to_queue
	111	+
	112	+ prompt_1 = @catchup_q.pop_prompt_queue
	113	+ prompt_2 = @catchup_q.pop_prompt_queue
	114	+ prompt_3 = @catchup_q.pop_prompt_queue
	115	+
	116	+
	117	+ prompt_1.should == prompt1
	118	+ prompt_2.should == prompt2
	119	+ prompt_3.should == prompt3
	120	+
	121	+ # there is a small probability that the catchup algorithm
	122	+ # choose two prompts that are indeed equal
	123	+ prompt_1.should_not == prompt_2
	124	+ prompt_1.should_not == prompt_3
	125	+ prompt_2.should_not == prompt_3
	126	+
	127	+
	128	+ @catchup_q.pop_prompt_queue.should == nil
	129	+ end
87	130
88	131
89	132	end
...	...