// NewGroup creates Group instance
func NewGroup(tasks ...*signatures.TaskSignature) *Group {
// Generate a group UUID
groupUUID := uuid.New()
// Auto generate task UUIDs
// Group tasks by common UUID
for _, task := range tasks {
task.UUID = fmt.Sprintf("task_%v", uuid.New())
task.GroupUUID = fmt.Sprintf("group_%v", groupUUID)
task.GroupTaskCount = len(tasks)
}
return &Group{Tasks: tasks}
}
// NewChord creates Chord instance
func NewChord(group *Group, callback *signatures.TaskSignature) *Chord {
// Generate a UUID for the chord callback
callback.UUID = fmt.Sprintf("chord_%v", uuid.New())
// Add a chord callback to all tasks
for _, task := range group.Tasks {
task.ChordCallback = callback
}
return &Chord{Group: group, Callback: callback}
}
// NewChain creates Chain instance
func NewChain(tasks ...*signatures.TaskSignature) *Chain {
for i := len(tasks) - 1; i > 0; i-- {
if i > 0 {
tasks[i-1].OnSuccess = []*signatures.TaskSignature{tasks[i]}
}
}
chain := &Chain{Tasks: tasks}
// Auto generate task UUIDs
for _, task := range chain.Tasks {
task.UUID = fmt.Sprintf("task_%v", uuid.New())
}
return chain
}
// SendTask publishes a task to the default queue
func (server *Server) SendTask(signature *signatures.TaskSignature) (*backends.AsyncResult, error) {
// Auto generate a UUID if not set already
if signature.UUID == "" {
signature.UUID = fmt.Sprintf("task_%v", uuid.New())
}
// Set initial task state to PENDING
if err := server.backend.SetStatePending(signature); err != nil {
return nil, fmt.Errorf("Set State Pending: %v", err)
}
if err := server.broker.Publish(signature); err != nil {
return nil, fmt.Errorf("Publish Message: %v", err)
}
return backends.NewAsyncResult(signature, server.backend), nil
}
