Only update changed attributes. Don't store values that are nil or ma…

…tch the default.

benchmark/create.rb → benchmark/persistence.rb

@@ -4,7 +4,7 @@
 class User
   include Modis::Model
 
-  attribute :name, :string
+  attribute :name, :string, default: 'Test'
   attribute :age, :integer
   attribute :percentage, :float
   attribute :created_at, :timestamp
@@ -16,13 +16,17 @@ class User
   index :name
 end
 
+def create_user
+  User.create!(name: 'Test', age: 30, percentage: 50.0, created_at: Time.now,
+               flag: true, array: [1, 2, 3], hash: { k: :v }, string_or_hash: "an string")
+end
+
 n = 10_000
 
 Bench.run do |b|
   b.report(:create) do
     n.times do
-      User.create!(name: 'Test', age: 30, percentage: 50.0, created_at: Time.now,
-                   flag: true, array: [1, 2, 3], hash: { k: :v }, string_or_hash: "an string")
+      create_user
     end
   end
 
@@ -47,4 +51,25 @@ class User
                flag: true, array: [1, 2, 3], hash: { k: :v }, string_or_hash: "an string")
     end
   end
+
+  b.report(:update_without_changes) do
+    user = create_user
+    n.times do
+      user.update_attributes!(name: user.name, age: user.age)
+    end
+  end
+
+  b.report(:update_with_changes) do
+    user = create_user
+    n.times do |i|
+      user.update_attribute(:name, i.to_s)
+    end
+  end
+
+  b.report(:reload) do
+    user = create_user
+    n.times do
+      user.reload
+    end
+  end
 end

lib/modis/persistence.rb

@@ -145,7 +145,7 @@ def create_or_update(args = {})
       validate(args)
       future = persist
 
-      if future && future.value == 'OK'
+      if future && (future == :unchanged || future.value == 'OK')
         reset_changes
         @new_record = false
         new_record? ? add_to_index : update_index
@@ -170,9 +170,8 @@ def persist
         run_callbacks :save do
           run_callbacks callback do
             run_callbacks "_internal_#{callback}" do
-              attrs = []
-              attributes.each { |k, v| attrs << k << coerce_for_persistence(v) }
-              future = redis.hmset(self.class.key_for(id), attrs)
+              attrs = coerced_attributes
+              future = attrs.any? ? redis.hmset(self.class.key_for(id), attrs) : :unchanged
             end
           end
         end
@@ -181,6 +180,24 @@ def persist
       future
     end
 
+    def coerced_attributes # rubocop:disable Metrics/AbcSize
+      attrs = []
+
+      if new_record?
+        attributes.each do |k, v|
+          if (self.class.attributes[k][:default] || nil) != v
+            attrs << k << coerce_for_persistence(v)
+          end
+        end
+      else
+        changed_attributes.each do |k, _|
+          attrs << k << coerce_for_persistence(attributes[k])
+        end
+      end
+
+      attrs
+    end
+
     def set_id
       Modis.with_connection do |redis|
         self.id = redis.incr("#{self.class.absolute_namespace}_id_seq")

spec/persistence_spec.rb

@@ -279,9 +279,10 @@ def test_before_save
         model.reload
         expect(model.name).to eq('Ian')
 
+        model.name = 'Kyle'
         model.save!
         record = redis.hgetall(key)
-        expect(record["name"]).to eq("\xA3Ian")
+        expect(record["name"]).to eq("\xA4Kyle")
       end
     end
   end