From e03eea710bba422046fb993d0f17ccba6d74629f Mon Sep 17 00:00:00 2001
From: Mauricio Giacomini Girardello <mauriciogiacomini4@gmail.com>
Date: Mon, 31 Aug 2015 16:23:14 -0300
Subject: [PATCH] refactoring ranking module decouple rater class from sort
alg, create concrete classes for item, rated item and basic rater strategy
---
lib/ranking/README.md | 29 +++++++--------
lib/ranking/item.rb | 18 +++++++++
lib/ranking/rank.rb | 53 ---------------------------
lib/ranking/rated_item.rb | 10 +++++
lib/ranking/rater.rb | 11 ++++++
lib/ranking/strategies/basic_rater.rb | 26 +++++++++++++
lib/ranking/strategy.rb | 15 ++++++++
7 files changed, 94 insertions(+), 68 deletions(-)
create mode 100644 lib/ranking/item.rb
delete mode 100644 lib/ranking/rank.rb
create mode 100644 lib/ranking/rated_item.rb
create mode 100644 lib/ranking/rater.rb
create mode 100644 lib/ranking/strategies/basic_rater.rb
create mode 100644 lib/ranking/strategy.rb
diff --git a/lib/ranking/README.md b/lib/ranking/README.md
index a05757ba7..0f01c85eb 100644
--- a/lib/ranking/README.md
+++ b/lib/ranking/README.md
@@ -1,19 +1,18 @@
-# Use Example
-### Input :
- items = [Item.new("ax",1,1,1,["otherStuffA","lala",'a']),Item.new("bx",2,2,2,[1,2,3,"teste","lblb",'b']),Item.new("cx",1,1,99,[3,2,1,"teste","lclc",'c'])]
+# Ranking docs
+
+# Refactored
-### Rank call :
+```ruby
+items = []
+items << Ranking::Item.new("ax",1,1,1,["otherStuffA","lala",'a'])
+items << Ranking::Item.new("bx",2,2,2,[1,2,3,"teste","lblb",'b'])
+items << Ranking::Item.new("cx",1,1,99,[3,2,1,"teste","lclc",'c'])
- Rater.new.sortByRate(items).each { |i| puts i }
-
-###### OR
+rater = Ranking::Rater.new(Ranking::Strategies::BasicRater.new(1000, 1, 100))
+rater.sortByRate(items).each do |i|
+ p i.name
+end
+```
- Rater.new( # Order of the arguments is important!
- positionWeight = 1000,
- useWeight = 1,
- likeWeight = 100
- ).sortByRate(items).each { |i| puts i }
-
-
-#### Return (output) :
+## Output
- ordered array of Items, starting from the most ranked to the least
\ No newline at end of file
diff --git a/lib/ranking/item.rb b/lib/ranking/item.rb
new file mode 100644
index 000000000..33fc5009b
--- /dev/null
+++ b/lib/ranking/item.rb
@@ -0,0 +1,18 @@
+# This class represents an item of ranking
+class Ranking::Item
+ # name = name of object
+ # views = view count
+ # downloads = download count
+ # likes = like count
+ # info = just for convinience of sorting it together, won't be touched
+ attr_accessor :name, :views, :downloads, :likes, :info
+
+ def initialize(name, views = 0, downloads = 0, likes = 0, info = nil)
+ @name = name
+ @views = views
+ @downloads = downloads
+ @likes = likes
+ @info = info
+ end
+
+end
\ No newline at end of file
diff --git a/lib/ranking/rank.rb b/lib/ranking/rank.rb
deleted file mode 100644
index 73698a258..000000000
--- a/lib/ranking/rank.rb
+++ /dev/null
@@ -1,53 +0,0 @@
-# Input: Array of struct Item (sorted by DB name matching)
-# Output: Array of struct Item sorted by ranking
-
-Item = Struct.new :name,:views,:downloads,:likes,:otherInfo # For interfacing
-# name = name of object
-# views = view count
-# downloads = download count
-# likes = like count
-# otherInfo = Anything, just for convinience of sorting it together, won't be touched
-
-class Rater #INTERFACE
- def initialize positionWeight = nil, useWeight = nil, likeWeight = nil
- @rater = BasicRater.new positionWeight, useWeight, likeWeight
- end
- def sortByRate items
- @rater.sortByRate items
- end
-end
-
-class BasicRater # Don't instanciate this directly, use Rater
-
- RatedItem = Struct.new(:item,:rate)
-
- def initialize positionWeight = nil, useWeight = nil, likeWeight = nil
- @positionWeight = (positionWeight == nil ? 1000 : positionWeight)
- @useWeight = (useWeight == nil ? 3 : useWeight)
- @likeWeight = (likeWeight == nil ? 100 : likeWeight)
- end
-
- def rateItem item, inversePosition # Returns: RatedItem instance
-
- positionRating = inversePosition * @positionWeight
- useRating = (item.downloads < item.views ? item.downloads : item.views)*@useWeight
- likeRating = item.likes * @likeWeight
-
- rate = positionRating + useRating + likeRating
- RatedItem.new( item, rate )
-
- end
-
- def sortByRate items
- first = items.first
- rest = items.drop(1)
-
- rest.zip( rest.size.downto(1) )
- .collect { |item,reverseIndex| self.rateItem( item, reverseIndex ) } # Returns RatedItem instance
- .sort { |itemA,itemB| itemA.rate <=> itemB.rate }
- .collect { |ri| ri.item }
- .push( first )
- .reverse # Best ranked comes first
- end
-
-end
diff --git a/lib/ranking/rated_item.rb b/lib/ranking/rated_item.rb
new file mode 100644
index 000000000..baa5aa8ec
--- /dev/null
+++ b/lib/ranking/rated_item.rb
@@ -0,0 +1,10 @@
+# This class represents an item rated in ranking
+# Have an association with a rank item
+class Ranking::RatedItem
+ attr_accessor :item, :rate
+
+ def initialize(item, rate)
+ @item = item
+ @rate = rate
+ end
+end
\ No newline at end of file
diff --git a/lib/ranking/rater.rb b/lib/ranking/rater.rb
new file mode 100644
index 000000000..75b3d4018
--- /dev/null
+++ b/lib/ranking/rater.rb
@@ -0,0 +1,11 @@
+class Ranking::Rater
+
+ def initialize(rater_strategy)
+ @rater = rater_strategy
+ end
+
+ def sortByRate(items)
+ @rater.sortByRate items
+ end
+
+end
\ No newline at end of file
diff --git a/lib/ranking/strategies/basic_rater.rb b/lib/ranking/strategies/basic_rater.rb
new file mode 100644
index 000000000..8c03c3d29
--- /dev/null
+++ b/lib/ranking/strategies/basic_rater.rb
@@ -0,0 +1,26 @@
+class Ranking::Strategies::BasicRater < Ranking::Strategy
+
+ def sortByRate(items)
+ first = items.first
+ rest = items.drop(1)
+
+ rest.zip(rest.size.downto(1))
+ .collect { |item, reverseIndex| rateItem(item, reverseIndex) } # Returns RatedItem instance
+ .sort { |itemA, itemB| itemA.rate <=> itemB.rate }
+ .collect { |ri| ri.item }
+ .push(first)
+ .reverse # Best ranked comes first
+ end
+
+ private
+
+ def rateItem(item, inversePosition)
+ positionRating = inversePosition * @positionWeight
+ useRating = (item.downloads < item.views ? item.downloads : item.views) * @useWeight
+ likeRating = item.likes * @likeWeight
+
+ rate = positionRating + useRating + likeRating
+ build_rated_item item, rate
+ end
+
+end
\ No newline at end of file
diff --git a/lib/ranking/strategy.rb b/lib/ranking/strategy.rb
new file mode 100644
index 000000000..ffce28174
--- /dev/null
+++ b/lib/ranking/strategy.rb
@@ -0,0 +1,15 @@
+class Ranking::Strategy
+
+ def initialize(positionWeight = nil, useWeight = nil, likeWeight = nil)
+ @positionWeight = (positionWeight == nil ? 1000 : positionWeight)
+ @useWeight = (useWeight == nil ? 3 : useWeight)
+ @likeWeight = (likeWeight == nil ? 100 : likeWeight)
+ end
+
+ protected
+
+ def build_rated_item(item, rate)
+ Ranking::RatedItem.new(item, rate)
+ end
+
+end
\ No newline at end of file
--
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