sujithrs · March 24, 2012 03:22 · Nov 30, 2011 · Nov 21, 2011 · Nov 21, 2011
diff --git a/app.rb b/app.rb
@@ -4,6 +4,18 @@
 require 'date'
 
 class String
+
+  def &(str)
+    result = ''
+    result.force_encoding("BINARY")
+    min = [self.length, str.length].min
+    (0...min).each do |i|
+      result << (self[i].ord & str[i].ord)
+    end
+
+    result
+  end
+
   def |(str)
     result = ''
     result.force_encoding("BINARY")

diff --git a/app.rb b/app.rb
@@ -1,3 +1,67 @@
+require 'sinatra'
+require 'redis'
+require 'json'
+require 'date'
+
+class String
+  def |(str)
+    result = ''
+    result.force_encoding("BINARY")
+    min = [self.length, str.length].min
+    (0...min).each do |i|
+      result << (self[i].ord | str[i].ord)
+    end
+
+    if self.length > str.length
+      result << self[min ... self.length]
+    elsif self.length < str.length
+      result << str[min ... str.length]
+    end
+
+    result
+  end
+
+
+  def population_count
+    count = 0
+    (0 ... self.length).each do |i|
+      count += _population_count_byte(self[i].ord)
+    end
+    count
+  end
+
+  private
+  ONE_BITS = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
+
+  #It works with 8 bits
+  def _population_count_byte(x)
+    count = 0
+    count = ONE_BITS[x&0x0f]
+    count += ONE_BITS[x>>4]
+    count
+  end
+end
+
+helpers do
+  def redis
+    $redis ||= Redis.new
+  end
+
+  def unique_count(event, from, to)
+    uniques = ''
+    (from..to).each do |date|
+      key = "#{event}.#{date.strftime('%y%m%d')}"
+      bitmap = redis.get(key)
+      if bitmap
+        bitmap.force_encoding("BINARY")
+        uniques |= bitmap
+      end
+    end
+    uniques.population_count
+  end
+
+end
+
 get '/collect/:event/for/:user_id/on/:date' do |event,user_id,date|
   time = Date.parse(date)
   key = "#{event}.#{time.strftime('%y%m%d')}"
@@ -6,4 +70,11 @@
   else
     500
   end
-end
+end
+
+get '/unique/:event/in/last/:n/days?' do |event,n|
+  content_type :json
+  to = Date.today
+  from = to - n.to_i
+  {:from => from, :to => to, :unique_count => unique_count(event,from,to)}.to_json
+end
diff --git a/app.rb b/app.rb
@@ -0,0 +1,9 @@
+get '/collect/:event/for/:user_id/on/:date' do |event,user_id,date|
+  time = Date.parse(date)
+  key = "#{event}.#{time.strftime('%y%m%d')}"
+  if redis.setbit(key, user_id, 1)
+    204
+  else
+    500
+  end
+end