created optimized_image model

app/models/optimized_image.rb

@@ -0,0 +1,7 @@
+class OptimizedImage < ActiveRecord::Base
+  belongs_to :upload
+
+  def filename
+    "#{sha[0..2]}/#{sha[3..5]}/#{sha[6..16]}_#{width}x#{height}#{ext}"
+  end
+end

app/models/upload.rb

@@ -9,6 +9,8 @@ class Upload < ActiveRecord::Base
   has_many :post_uploads
   has_many :posts, through: :post_uploads
 
+  has_many :optimized_images
+
   validates_presence_of :filesize
   validates_presence_of :original_filename
 

db/migrate/20130616082327_create_optimized_images.rb

@@ -0,0 +1,17 @@
+class CreateOptimizedImages < ActiveRecord::Migration
+  def up
+    create_table :optimized_images do |t|
+      t.string :sha, null: false
+      t.string :ext, null: false
+      t.integer :width, null: false
+      t.integer :height, null: false
+      t.integer :upload_id, null: false
+    end
+
+    add_index :optimized_images, :upload_id
+  end
+
+  def down
+    drop_table :optimized_images
+  end
+end

spec/models/optimized_image_spec.rb

@@ -0,0 +1,7 @@
+require 'spec_helper'
+
+describe OptimizedImage do
+
+  it { should belong_to :upload }
+
+end

spec/models/upload_spec.rb

@@ -8,6 +8,8 @@ describe Upload do
   it { should have_many :post_uploads }
   it { should have_many :posts }
 
+  it { should have_many :optimized_images }
+
   it { should validate_presence_of :original_filename }
   it { should validate_presence_of :filesize }