Merge pull request #1 from techbang/t7265

相同路徑產生相同 CDN 數字，並修正 .tw 圖片沒有上 CDN 的問題

lib/cdn_image_helper.rb

@@ -9,29 +9,40 @@ class <<self
 
   def render_with_cdn_images(text, size = :medium)
     return text unless text.respond_to?(:gsub)
-    text.gsub(/(href|src)="(#{CdnImageHelper.app_url})?\/system\/images\/(\d+)\/(\w+)\//) do |match|
-      link_type, host, id, scale = $1, $2, $3, $4
-      cdn_host = CdnImageHelper.cdn_host % rand(4) if Rails.env.production?
-      new_size = link_type == "href" ? :original : size
-      %|#{link_type}="#{cdn_host}/system/images/#{id}/#{new_size}/|
+
+    escaped_app_url = Regexp.escape(CdnImageHelper.app_url)
+    text.gsub(/(href|src)="(#{escaped_app_url}(\.tw)?)?\/system\/images\/(\d+)\/(\w+)\//) do |match|
+      link_type, host, tw, id, scale = $1, $2, $3, $4, $5
+      new_size = (link_type == "href") ? :original : size
+      path = "/system/images/#{id}/#{new_size}/"
+      %|#{link_type}="#{Rails.env.production? ? cdn_url_for(path) : path}|
     end
   end
 
   def render_with_cdn_excerpt_images(text, size = :medium)
     return text unless text.respond_to?(:gsub)
-    text.gsub(/(#{CdnImageHelper.app_url})?\/system\/excerpt_images\/(\d+)\/(\w+)\//) do |match|
-      host, id, scale = $1, $2, $3
-      cdn_host = CdnImageHelper.cdn_host % rand(4) if Rails.env.production?
-      %|#{cdn_host}/system/excerpt_images/#{id}/#{size}/|
+
+    escaped_app_url = Regexp.escape(CdnImageHelper.app_url)
+    text.gsub(/(#{escaped_app_url}(\.tw)?)?\/system\/excerpt_images\/(\d+)\/(\w+)\//) do |match|
+      host, tw, id, scale = $1, $2, $3, $4
+      path = "/system/excerpt_images/#{id}/#{size}/"
+      Rails.env.production? ? cdn_url_for(path) : path
     end
   end
 
   def replace_image_size(text, size = :medium)
     return text unless text.respond_to?(:gsub)
+
     text.gsub(/\/system\/images\/(\d+)\/(\w+)\//) do |match|
       id, scale = $1, $2
       %|/system/images/#{id}/#{size}/|
     end
   end
+
+  def cdn_url_for(path, cdn_host = CdnImageHelper.cdn_host)
+    cdn_number = Digest::MD5.hexdigest(path).to_i(16) % 4
+    cdn_host = cdn_host % cdn_number
+    "#{cdn_host}#{path}"
+  end
 
-end
+end

lib/cdn_image_helper/version.rb

@@ -1,3 +1,3 @@
 module CdnImageHelper
-  VERSION = "0.0.1"
+  VERSION = "0.0.2"
 end