Method update

cli/command/service/progress/progress.go:416–472

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

}

func (u *globalProgressUpdater) update(_ swarm.Service, tasks []swarm.Task, activeNodes map[string]struct{}, rollback bool) (bool, error) {
	tasksByNode := u.tasksByNode(tasks)

	// We don't have perfect knowledge of how many nodes meet the
	// constraints for this service. But the orchestrator creates tasks
	// for all eligible nodes at the same time, so we should see all those
	// nodes represented among the up-to-date tasks.
	nodeCount := len(tasksByNode)

	if !u.initialized {
		if nodeCount == 0 {
			// Two possibilities: either the orchestrator hasn't created
			// the tasks yet, or the service doesn't meet constraints for
			// any node. Either way, we wait.
			u.progressOut.WriteProgress(progress.Progress{
				ID:     "overall progress",
				Action: "waiting for new tasks",
			})
			return false, nil
		}

		writeOverallProgress(u.progressOut, 0, nodeCount, rollback)
		u.initialized = true
	}

	// If we had reached a converged state, check if we are still converged.
	if u.done {
		for _, task := range tasksByNode {
			if task.Status.State != swarm.TaskStateRunning {
				u.done = false
				break
			}
		}
	}

	running := 0

	for _, task := range tasksByNode {
		if _, nodeActive := activeNodes[task.NodeID]; nodeActive {
			if !terminalState(task.DesiredState) && task.Status.State == swarm.TaskStateRunning {
				running++
			}

			u.writeTaskProgress(task, nodeCount)
		}
	}

	if !u.done {
		writeOverallProgress(u.progressOut, running, nodeCount, rollback)

		if running == nodeCount {
			u.done = true
		}
	}

	return running == nodeCount, nil
}