From c7fed71a3f9c6e4a05af23454984c51ec50ac0af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?I=CC=87lker=20Go=CC=88ktug=CC=86=20O=CC=88ztu=CC=88rk?=
 <ilkergoktugozturk@gmail.com>
Date: Mon, 24 Sep 2018 07:45:07 +0300
Subject: [PATCH] service: reduce cycling references, related with #475

---
 service/event.go   |  8 ++++----
 service/service.go | 10 ----------
 service/task.go    | 28 ++++++++++++++--------------
 3 files changed, 18 insertions(+), 28 deletions(-)

diff --git a/service/event.go b/service/event.go
index 9f6e99b93..e09589d8d 100644
--- a/service/event.go
+++ b/service/event.go
@@ -14,15 +14,15 @@ type Event struct {
 	// Data holds the input parameters of event.
 	Data []*Parameter `hash:"name:4"`
 
-	// service is the event's service.
-	service *Service `hash:"-"`
+	// serviceName is the event's service's name.
+	serviceName string `hash:"-"`
 }
 
 // GetEvent returns event eventKey of service.
 func (s *Service) GetEvent(eventKey string) (*Event, error) {
 	for _, event := range s.Events {
 		if event.Key == eventKey {
-			event.service = s
+			event.serviceName = s.Name
 			return event, nil
 		}
 	}
@@ -43,7 +43,7 @@ func (e *Event) RequireData(eventData map[string]interface{}) error {
 	if len(warnings) > 0 {
 		return &InvalidEventDataError{
 			EventKey:    e.Key,
-			ServiceName: e.service.Name,
+			ServiceName: e.serviceName,
 			Warnings:    warnings,
 		}
 	}
diff --git a/service/service.go b/service/service.go
index 258e708d0..1ec054228 100644
--- a/service/service.go
+++ b/service/service.go
@@ -130,16 +130,6 @@ func (s *Service) setOptions(options ...Option) error {
 
 // fromService upgrades service s by setting a calculated ID and cross-referencing its child fields.
 func (s *Service) fromService() *Service {
-	for _, event := range s.Events {
-		event.service = s
-	}
-	for _, task := range s.Tasks {
-		task.service = s
-		for _, output := range task.Outputs {
-			output.task = task
-			output.service = s
-		}
-	}
 	for _, dep := range s.Dependencies {
 		dep.service = s
 	}
diff --git a/service/task.go b/service/task.go
index 6042d8be4..9502bf7e2 100644
--- a/service/task.go
+++ b/service/task.go
@@ -17,8 +17,8 @@ type Task struct {
 	// Outputs are the definition of the execution results of task.
 	Outputs []*Output `hash:"name:5"`
 
-	// service is the task's service.
-	service *Service `hash:"-"`
+	// serviceName is the task's service's name.
+	serviceName string `hash:"-"`
 }
 
 // Output describes task output.
@@ -35,18 +35,18 @@ type Output struct {
 	// Data holds the output parameters of a task output.
 	Data []*Parameter `hash:"name:4"`
 
-	// task is the output's task.
-	task *Task `hash:"-"`
+	// taskKey is the output's task's key.
+	taskKey string `hash:"-"`
 
-	// service is the output's service.
-	service *Service `hash:"-"`
+	// serviceName is the output's service's name.
+	serviceName string `hash:"-"`
 }
 
 // GetTask returns task taskKey of service.
 func (s *Service) GetTask(taskKey string) (*Task, error) {
 	for _, task := range s.Tasks {
 		if task.Key == taskKey {
-			task.service = s
+			task.serviceName = s.Name
 			return task, nil
 		}
 	}
@@ -66,7 +66,7 @@ func (t *Task) GetInputParameter(inputKey string) (*Parameter, error) {
 	return nil, &TaskInputNotFoundError{
 		TaskKey:      t.Key,
 		TaskInputKey: inputKey,
-		ServiceName:  t.service.Name,
+		ServiceName:  t.serviceName,
 	}
 }
 
@@ -81,7 +81,7 @@ func (t *Task) RequireInputs(taskInputs map[string]interface{}) error {
 	if len(warnings) > 0 {
 		return &InvalidTaskInputError{
 			TaskKey:     t.Key,
-			ServiceName: t.service.Name,
+			ServiceName: t.serviceName,
 			Warnings:    warnings,
 		}
 	}
@@ -92,15 +92,15 @@ func (t *Task) RequireInputs(taskInputs map[string]interface{}) error {
 func (t *Task) GetOutput(outputKey string) (*Output, error) {
 	for _, output := range t.Outputs {
 		if output.Key == outputKey {
-			output.task = t
-			output.service = t.service
+			output.taskKey = t.Key
+			output.serviceName = t.serviceName
 			return output, nil
 		}
 	}
 	return nil, &TaskOutputNotFoundError{
 		TaskKey:       t.Key,
 		TaskOutputKey: outputKey,
-		ServiceName:   t.service.Name,
+		ServiceName:   t.serviceName,
 	}
 }
 
@@ -114,9 +114,9 @@ func (o *Output) RequireData(outputData map[string]interface{}) error {
 	warnings := o.ValidateData(outputData)
 	if len(warnings) > 0 {
 		return &InvalidTaskOutputError{
-			TaskKey:       o.task.Key,
+			TaskKey:       o.taskKey,
 			TaskOutputKey: o.Key,
-			ServiceName:   o.service.Name,
+			ServiceName:   o.serviceName,
 			Warnings:      warnings,
 		}
 	}