Added Revision.timestamp attribute, which is a timestamp to the precision of msec. Intention is to get rid of the revision.number and use this one for sotrting etc. The problem with created_at / updated_at in this role is that trhey have precision of seconds, which is not good enough for some of the purposes.

app/models/revision.rb

@@ -112,11 +112,18 @@ class Revision < ActiveRecord::Base
   end
 
   protected
-  before_create :set_revision_number
+  before_create :set_revision_number, :set_timestamp
   after_create :force_rendering
   after_save :clear_display_cache
   
+  # TODO Refactor this away. Revisions collection should not rely on the revision number for 
+  # sorting etc - revisions must be easy to delete (this helps fighting wiki spam)
   def set_revision_number
     self.number = self.class.count(['page_id = ?', page_id]) + 1
   end
+  
+  def set_timestamp
+    self.timestamp = (Time.now.to_f * 1000).to_i.to_s
+  end
+
 end

db/revisions.erbsql

@@ -2,6 +2,8 @@ CREATE TABLE revisions (
     id <%= @pk %>,
     created_at <%= @datetime %> NOT NULL,
     updated_at <%= @datetime %> NOT NULL,
+
+    timestamp CHAR(13) NOT NULL,
     page_id INTEGER NOT NULL,
     content TEXT NOT NULL,
     author VARCHAR(60),

test/fixtures/revisions.yml

@@ -2,6 +2,7 @@ home_page_first_revision:
   id: 1
   created_at: <%= Time.local(2004, 4, 4, 15, 50).to_formatted_s(:db) %>
   updated_at: <%= Time.local(2004, 4, 4, 15, 50).to_formatted_s(:db) %>
+  timestamp: <%= (Time.local(2004, 4, 4, 15, 50).to_f * 1000).to_i %>
   page_id: 1
   number: 1
   content: First revision of the HomePage end
@@ -12,6 +13,7 @@ my_way_first_revision:
   id: 2
   created_at: <%= 9.days.ago.to_formatted_s(:db) %>
   updated_at: <%= 9.days.ago.to_formatted_s(:db) %>
+  timestamp: <%= (9.days.ago.to_f * 1000).to_i %>
   page_id: 2
   number: 1
   content: MyWay
@@ -21,6 +23,7 @@ smart_engine_first_revision:
   id: 3
   created_at: <%= 8.days.ago.to_formatted_s(:db) %>
   updated_at: <%= 8.days.ago.to_formatted_s(:db) %>
+  timestamp: <%= (8.days.ago.to_f * 1000).to_i %>
   page_id: 3
   number: 1
   content: SmartEngine
@@ -30,6 +33,7 @@ that_way_first_revision:
   id: 4
   created_at: <%= 7.days.ago.to_formatted_s(:db) %>
   updated_at: <%= 7.days.ago.to_formatted_s(:db) %>
+  timestamp: <%= (7.days.ago.to_f * 1000).to_i %>
   page_id: 4
   number: 1
   content: ThatWay
@@ -39,6 +43,7 @@ no_wiki_word_first_revision:
   id: 5
   created_at: <%= 6.days.ago.to_formatted_s(:db) %>
   updated_at: <%= 6.days.ago.to_formatted_s(:db) %>
+  timestamp: <%= (6.days.ago.to_f * 1000).to_i %>
   page_id: 5
   number: 1
   content: hey you
@@ -48,6 +53,7 @@ home_page_second_revision:
   id: 6
   created_at: <%= Time.local(2004, 4, 4, 16, 50).to_formatted_s(:db) %>
   updated_at: <%= Time.local(2004, 4, 4, 16, 50).to_formatted_s(:db) %>
+  timestamp: <%= (Time.local(2004, 4, 4, 16, 50).to_f * 1000).to_i %>
   page_id: 1
   number: 2
   content: HisWay would be MyWay in kinda ThatWay in HisWay though MyWay \OverThere -- see SmartEngine in that SmartEngineGUI
@@ -57,6 +63,7 @@ first_page_first_revision:
   id: 7
   created_at: <%= Time.local(2004, 4, 4, 16, 55).to_formatted_s(:db) %>
   updated_at: <%= Time.local(2004, 4, 4, 16, 55).to_formatted_s(:db) %>
+  timestamp: <%= (Time.local(2004, 4, 4, 16, 55).to_f * 1000).to_i %>
   page_id: 6
   number: 1
   content: HisWay would be MyWay in kinda ThatWay in HisWay though MyWay \\OverThere -- see SmartEngine in that SmartEngineGUI
@@ -66,6 +73,7 @@ oak_first_revision:
   id: 8
   created_at: <%= 5.days.ago.to_formatted_s(:db) %>
   updated_at: <%= 5.days.ago.to_formatted_s(:db) %>
+  timestamp: <%= (5.days.ago.to_f * 1000).to_i %>
   page_id: 7
   number: 1
   content: "All about oak.\ncategory: trees"
@@ -76,9 +84,9 @@ elephant_first_revision:
   id: 9
   created_at: <%= 10.minutes.ago.to_formatted_s(:db) %>
   updated_at: <%= 10.minutes.ago.to_formatted_s(:db) %>
+  timestamp: <%= (10.minutes.ago.to_f * 1000).to_i %>
   page_id: 8
   number: 1
   content: "All about elephants.\ncategory: animals"
   author: Guest
   ip: 127.0.0.2
-