traefik/vendor/github.com/containerd/continuity/hardlinks.go
2018-01-22 12:16:03 +01:00

57 lines
1.2 KiB
Go

package continuity
import (
"fmt"
"os"
)
var (
errNotAHardLink = fmt.Errorf("invalid hardlink")
)
type hardlinkManager struct {
hardlinks map[hardlinkKey][]Resource
}
func newHardlinkManager() *hardlinkManager {
return &hardlinkManager{
hardlinks: map[hardlinkKey][]Resource{},
}
}
// Add attempts to add the resource to the hardlink manager. If the resource
// cannot be considered as a hardlink candidate, errNotAHardLink is returned.
func (hlm *hardlinkManager) Add(fi os.FileInfo, resource Resource) error {
if _, ok := resource.(Hardlinkable); !ok {
return errNotAHardLink
}
key, err := newHardlinkKey(fi)
if err != nil {
return err
}
hlm.hardlinks[key] = append(hlm.hardlinks[key], resource)
return nil
}
// Merge processes the current state of the hardlink manager and merges any
// shared nodes into hardlinked resources.
func (hlm *hardlinkManager) Merge() ([]Resource, error) {
var resources []Resource
for key, linked := range hlm.hardlinks {
if len(linked) < 1 {
return nil, fmt.Errorf("no hardlink entrys for dev, inode pair: %#v", key)
}
merged, err := Merge(linked...)
if err != nil {
return nil, fmt.Errorf("error merging hardlink: %v", err)
}
resources = append(resources, merged)
}
return resources, nil
}