Working on adding checksum support to design documents to handle updates

Gemfile.lock

@@ -12,21 +12,22 @@ GEM
   remote: http://rubygems.org/
   specs:
     abstract (1.0.0)
-    actionpack (3.0.5)
-      activemodel (= 3.0.5)
-      activesupport (= 3.0.5)
+    actionpack (3.0.6)
+      activemodel (= 3.0.6)
+      activesupport (= 3.0.6)
       builder (~> 2.1.2)
       erubis (~> 2.6.6)
-      i18n (~> 0.4)
+      i18n (~> 0.5.0)
       rack (~> 1.2.1)
-      rack-mount (~> 0.6.13)
+      rack-mount (~> 0.6.14)
       rack-test (~> 0.5.7)
       tzinfo (~> 0.3.23)
-    activemodel (3.0.5)
-      activesupport (= 3.0.5)
+    activemodel (3.0.6)
+      activesupport (= 3.0.6)
       builder (~> 2.1.2)
-      i18n (~> 0.4)
-    activesupport (3.0.5)
+      i18n (~> 0.5.0)
+    activesupport (3.0.6)
+    bouncy-castle-java (1.5.0145.2)
     builder (2.1.2)
     couchrest (1.1.0.pre2)
       json (~> 1.5.1)
@@ -36,16 +37,19 @@ GEM
     erubis (2.6.6)
       abstract (>= 1.0.0)
     i18n (0.5.0)
+    jruby-openssl (0.7.3)
+      bouncy-castle-java
     json (1.5.1)
+    json (1.5.1-java)
     mime-types (1.16)
     rack (1.2.1)
     rack-mount (0.6.14)
       rack (>= 1.0.0)
     rack-test (0.5.7)
       rack (>= 1.0)
-    railties (3.0.5)
-      actionpack (= 3.0.5)
-      activesupport (= 3.0.5)
+    railties (3.0.6)
+      actionpack (= 3.0.6)
+      activesupport (= 3.0.6)
       rake (>= 0.8.7)
       thor (~> 0.14.4)
     rake (0.8.7)
@@ -63,12 +67,14 @@ GEM
     tzinfo (0.3.26)
 
 PLATFORMS
+  java
   ruby
 
 DEPENDENCIES
   activemodel (~> 3.0.0)
   couchrest (= 1.1.0.pre2)
   couchrest_model!
+  jruby-openssl (>= 0.7.3)
   mime-types (~> 1.15)
   rack-test (>= 0.5.7)
   railties (~> 3.0.0)

couchrest_model.gemspec

@@ -30,5 +30,6 @@ Gem::Specification.new do |s|
   s.add_dependency(%q<railties>, "~> 3.0.0")
   s.add_development_dependency(%q<rspec>, ">= 2.0.0")
   s.add_development_dependency(%q<rack-test>, ">= 0.5.7")
+  s.add_development_dependency("jruby-openssl", ">= 0.7.3")
 end
 

lib/couchrest/model/design_doc.rb

@@ -7,7 +7,7 @@ module CouchRest
       module ClassMethods
         
         def design_doc
-          @design_doc ||= Design.new(default_design_doc)
+          @design_doc ||= ::CouchRest::Design.new(default_design_doc)
         end
     
         # Use when something has been changed, like a view, so that on the next request
@@ -90,24 +90,17 @@ module CouchRest
         # Writes out a design_doc to a given database, returning the
         # updated design doc
         def update_design_doc(design_doc, db, force = false)
+          design_doc['couchrest-hash'] = design_doc.checksum
           saved = stored_design_doc(db)
           if saved
-            changes = force
-            design_doc['views'].each do |name, view|
-              if !compare_views(saved['views'][name], view)
-                changes = true
-                saved['views'][name] = view
-              end
-            end
-            if changes
+            if force || saved['couchrest-hash'] != design_doc['couchrest-hash']
+              saved.merge!(design_doc)
               db.save_doc(saved)
             end
-            design_doc
           else
-            design_doc.database = db
-            design_doc.save
-            design_doc
+            db.save_doc(design_doc)
           end
+          design_doc
         end
 
         # Return true if the two views match

lib/couchrest/model/designs/view.rb

@@ -90,6 +90,13 @@ module CouchRest
           result ? all.last : limit(1).descending.all.last
         end
 
+        # Return the number of documents in the currently defined result set.
+        # Use <tt>#count</tt> for the total number of documents regardless
+        # of the current limit defined.
+        def length
+          docs.length
+        end
+
         # Perform a count operation based on the current view. If the view
         # can be reduced, the reduce will be performed and return the first
         # value. This is okay for most simple queries, but may provide
@@ -383,30 +390,24 @@ module CouchRest
         def execute
           return self.result if result
           raise "Database must be defined in model or view!" if use_database.nil?
-          retryable = true
+
           # Remove the reduce value if its not needed
           query.delete(:reduce) unless can_reduce?
-          begin
-            self.result = model.design_doc.view_on(use_database, name, query.reject{|k,v| v.nil?})
-          rescue RestClient::ResourceNotFound => e
-            if retryable
+
+          # Save the design doc for the current database. This should be efficient
+          # and check for changes
           model.save_design_doc(use_database)
-              retryable = false
-              retry
-            else
-              raise e
-            end
-          end
+
+          self.result = model.design_doc.view_on(use_database, name, query.reject{|k,v| v.nil?})
         end
 
         # Class Methods
         class << self
-          
           # Simplified view creation. A new view will be added to the 
           # provided model's design document using the name and options.
           #
           # If the view name starts with "by_" and +:by+ is not provided in 
-          # the options, the new view's map method will be interpretted and
+          # the options, the new view's map method will be interpreted and
           # generated automatically. For example:
           #
           #   View.create(Meeting, "by_date_and_name")

lib/couchrest/model/support/couchrest_database.rb

@@ -0,0 +1,15 @@
+
+CouchRest::Database.class_eval do
+
+  alias :delete_orig! :delete!
+  def delete!
+    clear_model_fresh_cache
+    delete_orig!
+  end
+
+  # If the database is deleted, ensure that the design docs will be refreshed.
+  def clear_model_fresh_cache
+    ::CouchRest::Model::Base.subclasses.each{|klass| klass.req_design_doc_refresh if klass.respond_to?(:req_design_doc_refresh)}
+  end
+
+end

lib/couchrest/model/support/couchrest_design.rb

@@ -0,0 +1,24 @@
+
+CouchRest::Design.class_eval do
+
+  # Calculate a checksum of the Design document. Used for ensuring the latest
+  # version has been sent to the database.
+  #
+  # This will generate an flatterned, ordered array of all the elements of the
+  # design document, convert to string then generate an MD5 Hash. This should
+  # result in a consisitent Hash accross all platforms.
+  #
+  def checksum
+    # create a copy of basic elements
+    base = self.dup
+    base.delete('_id')
+    base.delete('_rev')
+    result = nil
+    flatten =
+      lambda{|v|
+        v.is_a?(Hash) ? v.flatten.map{|v| flatten.call(v)}.flatten : v
+      }
+    Digest::MD5.hexdigest(flatten.call(base).sort.join(''))
+  end
+
+end

lib/couchrest_model.rb

@@ -45,7 +45,8 @@ require "couchrest/model/designs"
 require "couchrest/model/designs/view"
 
 # Monkey patches applied to couchrest
-require "couchrest/model/support/couchrest"
+require "couchrest/model/support/couchrest_database"
+require "couchrest/model/support/couchrest_design"
 # Core Extensions
 require "couchrest/model/core_extensions/hash"
 require "couchrest/model/core_extensions/time_parsing"

spec/couchrest/designs/view_spec.rb

@@ -163,6 +163,13 @@ describe "Design View" do
         end
       end
 
+      describe "#length" do
+        it "should provide a length from the docs array" do
+          @obj.should_receive(:docs).and_return([1, 2, 3])
+          @obj.length.should eql(3)
+        end
+      end
+
       describe "#count" do
         it "should raise an error if view prepared for group" do
           @obj.should_receive(:query).and_return({:group => true})