distribution/registry/storage/signaturestore.go
Stephen J Day 1eab4b79bc Parallelize signature fetch in signature store
To avoid compounded round trips leading to slow retrieval of manifests with a
large number of signatures, the fetch of signatures has been parallelized. This
simply spawns a goroutine for each path, coordinated with a sync.WaitGroup.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-04-06 19:13:15 -07:00

101 lines
2.2 KiB
Go

package storage
import (
"path"
"sync"
"github.com/docker/distribution"
"github.com/docker/distribution/context"
"github.com/docker/distribution/digest"
)
type signatureStore struct {
*repository
}
var _ distribution.SignatureService = &signatureStore{}
func (s *signatureStore) Get(dgst digest.Digest) ([][]byte, error) {
signaturesPath, err := s.pm.path(manifestSignaturesPathSpec{
name: s.Name(),
revision: dgst,
})
if err != nil {
return nil, err
}
// Need to append signature digest algorithm to path to get all items.
// Perhaps, this should be in the pathMapper but it feels awkward. This
// can be eliminated by implementing listAll on drivers.
signaturesPath = path.Join(signaturesPath, "sha256")
signaturePaths, err := s.driver.List(signaturesPath)
if err != nil {
return nil, err
}
var wg sync.WaitGroup
signatures := make([][]byte, len(signaturePaths)) // make space for everything
errCh := make(chan error, 1) // buffered chan so one proceeds
for i, sigPath := range signaturePaths {
// Append the link portion
sigPath = path.Join(sigPath, "link")
wg.Add(1)
go func(idx int, sigPath string) {
defer wg.Done()
context.GetLogger(s.ctx).
Debugf("fetching signature from %q", sigPath)
p, err := s.blobStore.linked(sigPath)
if err != nil {
context.GetLogger(s.ctx).
Errorf("error fetching signature from %q: %v", sigPath, err)
// try to send an error, if it hasn't already been sent.
select {
case errCh <- err:
default:
}
return
}
signatures[idx] = p
}(i, sigPath)
}
wg.Wait()
select {
case err := <-errCh:
// just return the first error, similar to single threaded code.
return nil, err
default:
// pass
}
return signatures, nil
}
func (s *signatureStore) Put(dgst digest.Digest, signatures ...[]byte) error {
for _, signature := range signatures {
signatureDigest, err := s.blobStore.put(signature)
if err != nil {
return err
}
signaturePath, err := s.pm.path(manifestSignatureLinkPathSpec{
name: s.Name(),
revision: dgst,
signature: signatureDigest,
})
if err != nil {
return err
}
if err := s.blobStore.link(signaturePath, signatureDigest); err != nil {
return err
}
}
return nil
}