Optimize child include build performance

changelog.md

 Notice: All 1.7.x changes are present in 2.0.x aswell
 Notice: All 1.7.x changes are present in 2.0.x aswell
 
 
 # v2.0.0-dev10
 # v2.0.0-dev10
+- [PERFORMANCE] increased build performance when using include, which speeds up findAll etc.
+
 #### Backwards compatability changes
 #### Backwards compatability changes
 - selectedValues has been removed for performance reasons, if you depend on this, please open an issue and we will help you work around it.
 - selectedValues has been removed for performance reasons, if you depend on this, please open an issue and we will help you work around it.
 - foreign keys will now correctly be based on the alias of the model
 - foreign keys will now correctly be based on the alias of the model

lib/dao.js

@@ -220,9 +220,13 @@ module.exports = (function() {
     })
     })
     var association          = include.association
     var association          = include.association
       , self                 = this
       , self                 = this
+      , accessor             = Utils._.camelize(key)
+      , childOptions
+      , primaryKeyAttribute  = include.daoFactory.primaryKeyAttribute
+      , isEmpty              = value[0] && value[0][primaryKeyAttribute] === null
 
 
-    var accessor = Utils._.camelize(key)
-    var childOptions = {
+    if (!isEmpty) {
+      childOptions = {
         isNewRecord: false,
         isNewRecord: false,
         isDirty: false,
         isDirty: false,
         include: include.include,
         include: include.include,
@@ -231,29 +235,17 @@ module.exports = (function() {
         includeValidated: true,
         includeValidated: true,
         raw: options.raw
         raw: options.raw
       }
       }
+    }
 
 
     // downcase the first char
     // downcase the first char
     accessor = accessor.slice(0,1).toLowerCase() + accessor.slice(1)
     accessor = accessor.slice(0,1).toLowerCase() + accessor.slice(1)
 
 
-    value.forEach(function(data) {
-      var daoInstance = include.daoFactory.build(data, childOptions)
-        , isEmpty = !Utils.firstValueOfHash(daoInstance.identifiers)
-
     if (association.isSingleAssociation) {
     if (association.isSingleAssociation) {
-        accessor = Utils.singularize(accessor, self.sequelize.language)
-        self.dataValues[accessor] = isEmpty ? null : daoInstance
-        self[accessor] = self.dataValues[accessor]
+      accessor = Utils.singularize(accessor, self.Model.options.language)
+      self[accessor] = self.dataValues[accessor] = isEmpty ? null : include.daoFactory.build(value[0], childOptions)
     } else {
     } else {
-        if (!self.dataValues[accessor]) {
-          self.dataValues[accessor] = []
-          self[accessor] = self.dataValues[accessor]
-        }
-
-        if (!isEmpty) {
-          self.dataValues[accessor].push(daoInstance)
+      self[accessor] = self.dataValues[accessor] = isEmpty ? [] : include.daoFactory.bulkBuild(value, childOptions)
     }
     }
-      }
-    }.bind(this))
   };
   };
 
 
   // if an array with field names is passed to save()
   // if an array with field names is passed to save()