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

144 lines
3 KiB
Go

package continuity
import (
"fmt"
"io"
"log"
"os"
"sort"
pb "github.com/containerd/continuity/proto"
"github.com/golang/protobuf/proto"
)
// Manifest provides the contents of a manifest. Users of this struct should
// not typically modify any fields directly.
type Manifest struct {
// Resources specifies all the resources for a manifest in order by path.
Resources []Resource
}
func Unmarshal(p []byte) (*Manifest, error) {
var bm pb.Manifest
if err := proto.Unmarshal(p, &bm); err != nil {
return nil, err
}
var m Manifest
for _, b := range bm.Resource {
r, err := fromProto(b)
if err != nil {
return nil, err
}
m.Resources = append(m.Resources, r)
}
return &m, nil
}
func Marshal(m *Manifest) ([]byte, error) {
var bm pb.Manifest
for _, resource := range m.Resources {
bm.Resource = append(bm.Resource, toProto(resource))
}
return proto.Marshal(&bm)
}
func MarshalText(w io.Writer, m *Manifest) error {
var bm pb.Manifest
for _, resource := range m.Resources {
bm.Resource = append(bm.Resource, toProto(resource))
}
return proto.MarshalText(w, &bm)
}
// BuildManifest creates the manifest for the given context
func BuildManifest(ctx Context) (*Manifest, error) {
resourcesByPath := map[string]Resource{}
hardlinks := newHardlinkManager()
if err := ctx.Walk(func(p string, fi os.FileInfo, err error) error {
if err != nil {
return fmt.Errorf("error walking %s: %v", p, err)
}
if p == "/" {
// skip root
return nil
}
resource, err := ctx.Resource(p, fi)
if err != nil {
if err == ErrNotFound {
return nil
}
log.Printf("error getting resource %q: %v", p, err)
return err
}
// add to the hardlink manager
if err := hardlinks.Add(fi, resource); err == nil {
// Resource has been accepted by hardlink manager so we don't add
// it to the resourcesByPath until we merge at the end.
return nil
} else if err != errNotAHardLink {
// handle any other case where we have a proper error.
return fmt.Errorf("adding hardlink %s: %v", p, err)
}
resourcesByPath[p] = resource
return nil
}); err != nil {
return nil, err
}
// merge and post-process the hardlinks.
hardlinked, err := hardlinks.Merge()
if err != nil {
return nil, err
}
for _, resource := range hardlinked {
resourcesByPath[resource.Path()] = resource
}
var resources []Resource
for _, resource := range resourcesByPath {
resources = append(resources, resource)
}
sort.Stable(ByPath(resources))
return &Manifest{
Resources: resources,
}, nil
}
// VerifyManifest verifies all the resources in a manifest
// against files from the given context.
func VerifyManifest(ctx Context, manifest *Manifest) error {
for _, resource := range manifest.Resources {
if err := ctx.Verify(resource); err != nil {
return err
}
}
return nil
}
// ApplyManifest applies on the resources in a manifest to
// the given context.
func ApplyManifest(ctx Context, manifest *Manifest) error {
for _, resource := range manifest.Resources {
if err := ctx.Apply(resource); err != nil {
return err
}
}
return nil
}