lib/ohm.rb in ohm-0.0.17 vs lib/ohm.rb in ohm-0.0.18

@@ -383,35 +383,49 @@
       end
     end
 
     def initialize(attrs = {})
       @_attributes = Hash.new {|hash,key| hash[key] = read_remote(key) }
-
-      attrs.each do |key, value|
-        send(:"#{key}=", value)
-      end
+      update_attributes(attrs)
     end
 
     def new?
       !id
     end
 
     def create
       return unless valid?
       initialize_id
-      create_model_membership
-      add_to_indices
-      save!
+
+      mutex do
+        create_model_membership
+        add_to_indices
+        save!
+      end
     end
 
     def save
       return create if new?
       return unless valid?
-      update_indices
-      save!
+
+      mutex do
+        update_indices
+        save!
+      end
     end
 
+    def update(attrs)
+      update_attributes(attrs)
+      save
+    end
+
+    def update_attributes(attrs)
+      attrs.each do |key, value|
+        send(:"#{key}=", value)
+      end
+    end
+
     def delete
       delete_from_indices
       delete_attributes(attributes)
       delete_attributes(counters)
       delete_attributes(collections)
@@ -455,10 +469,18 @@
       other.key == key
     rescue ModelIsNew
       false
     end
 
+    # Lock the object before ejecuting the block, and release it once the block is done.
+    def mutex
+      lock!
+      yield
+      unlock!
+      self
+    end
+
   protected
 
     def key(*args)
       raise ModelIsNew if new?
       self.class.key(id, *args)
@@ -550,8 +572,20 @@
       end
     end
 
     def index_key_for(attrs, values)
       self.class.key *(attrs + self.class.encode_each(values))
+    end
+
+    # Lock the object so no other instances can modify it.
+    # @see Model#mutex
+    def lock!
+      lock = db.setnx(key(:_lock), 1) until lock == 1
+    end
+
+    # Release the lock.
+    # @see Model#mutex
+    def unlock!
+      db.del(key(:_lock))
     end
   end
 end