Method update

cli/command/service/progress/progress.go:729–803

(service swarm.Service, tasks []swarm.Task, activeNodes map[string]struct{}, _ bool)

}

func (u *globalJobProgressUpdater) update(service swarm.Service, tasks []swarm.Task, activeNodes map[string]struct{}, _ bool) (bool, error) {
	if !u.initialized {
		// if there are not yet tasks, then return early.
		if len(tasks) == 0 && len(activeNodes) != 0 {
			_ = u.progressOut.WriteProgress(progress.Progress{
				ID:     "job progress",
				Action: "waiting for tasks",
			})
			return false, nil
		}

		// when a global job starts, all of its tasks are created at once, so
		// we can use len(tasks) to know how many we're expecting.
		u.taskNodes = map[string]struct{}{}

		for _, task := range tasks {
			// skip any tasks not belonging to this job iteration.
			if task.JobIteration == nil || task.JobIteration.Index != service.JobStatus.JobIteration.Index {
				continue
			}

			// collect the list of all node IDs for this service.
			//
			// basically, global jobs will execute on any new nodes that join
			// the cluster in the future. to avoid making things complicated,
			// we will only check the progress of the initial set of nodes. if
			// any new nodes come online during the operation, we will ignore
			// them.
			u.taskNodes[task.NodeID] = struct{}{}
		}

		u.total = len(u.taskNodes)
		u.progressDigits = len(strconv.Itoa(u.total))

		u.writeOverallProgress(0)
		u.initialized = true
	}

	// tasksByNodeID maps a NodeID to the latest task for that Node ID. this
	// lets us pick only the latest task for any given node.
	tasksByNodeID := map[string]swarm.Task{}

	for _, task := range tasks {
		// skip any tasks not belonging to this job iteration
		if task.JobIteration == nil || task.JobIteration.Index != service.JobStatus.JobIteration.Index {
			continue
		}

		// if the task is not on one of the initial set of nodes, ignore it.
		if _, ok := u.taskNodes[task.NodeID]; !ok {
			continue
		}

		// if there is already a task recorded for this node, choose the one
		// with the lower state
		if oldtask, ok := tasksByNodeID[task.NodeID]; ok {
			if numberedStates[oldtask.Status.State] > numberedStates[task.Status.State] {
				tasksByNodeID[task.NodeID] = task