refactor: extract code from the container package

pkg/container/sort.go

@@ -1,106 +0,0 @@
-package container
-
-import (
-	"fmt"
-	"time"
-)
-
-// ByCreated allows a list of Container structs to be sorted by the container's
-// created date.
-type ByCreated []Container
-
-func (c ByCreated) Len() int      { return len(c) }
-func (c ByCreated) Swap(i, j int) { c[i], c[j] = c[j], c[i] }
-
-// Less will compare two elements (identified by index) in the Container
-// list by created-date.
-func (c ByCreated) Less(i, j int) bool {
-	t1, err := time.Parse(time.RFC3339Nano, c[i].containerInfo.Created)
-	if err != nil {
-		t1 = time.Now()
-	}
-
-	t2, _ := time.Parse(time.RFC3339Nano, c[j].containerInfo.Created)
-	if err != nil {
-		t1 = time.Now()
-	}
-
-	return t1.Before(t2)
-}
-
-// SortByDependencies will sort the list of containers taking into account any
-// links between containers. Container with no outgoing links will be sorted to
-// the front of the list while containers with links will be sorted after all
-// of their dependencies. This sort order ensures that linked containers can
-// be started in the correct order.
-func SortByDependencies(containers []Container) ([]Container, error) {
-	sorter := dependencySorter{}
-	return sorter.Sort(containers)
-}
-
-type dependencySorter struct {
-	unvisited []Container
-	marked    map[string]bool
-	sorted    []Container
-}
-
-func (ds *dependencySorter) Sort(containers []Container) ([]Container, error) {
-	ds.unvisited = containers
-	ds.marked = map[string]bool{}
-
-	for len(ds.unvisited) > 0 {
-		if err := ds.visit(ds.unvisited[0]); err != nil {
-			return nil, err
-		}
-	}
-
-	return ds.sorted, nil
-}
-
-func (ds *dependencySorter) visit(c Container) error {
-
-	if _, ok := ds.marked[c.Name()]; ok {
-		return fmt.Errorf("Circular reference to %s", c.Name())
-	}
-
-	// Mark any visited node so that circular references can be detected
-	ds.marked[c.Name()] = true
-	defer delete(ds.marked, c.Name())
-
-	// Recursively visit links
-	for _, linkName := range c.Links() {
-		if linkedContainer := ds.findUnvisited(linkName); linkedContainer != nil {
-			if err := ds.visit(*linkedContainer); err != nil {
-				return err
-			}
-		}
-	}
-
-	// Move container from unvisited to sorted
-	ds.removeUnvisited(c)
-	ds.sorted = append(ds.sorted, c)
-
-	return nil
-}
-
-func (ds *dependencySorter) findUnvisited(name string) *Container {
-	for _, c := range ds.unvisited {
-		if c.Name() == name {
-			return &c
-		}
-	}
-
-	return nil
-}
-
-func (ds *dependencySorter) removeUnvisited(c Container) {
-	var idx int
-	for i := range ds.unvisited {
-		if ds.unvisited[i].Name() == c.Name() {
-			idx = i
-			break
-		}
-	}
-
-	ds.unvisited = append(ds.unvisited[0:idx], ds.unvisited[idx+1:]...)
-}