containerd/content/content.go
Michael Crosby 2e048ec589 Merge pull request #965 from dmcgowan/content-read-at
Update push to use copy
2017-06-12 16:19:53 -07:00

121 lines
3.2 KiB
Go

package content
import (
"context"
"io"
"sync"
"time"
"github.com/opencontainers/go-digest"
"github.com/pkg/errors"
)
var (
// ErrNotFound is returned when an item is not found.
//
// Use IsNotFound(err) to detect this condition.
ErrNotFound = errors.New("content: not found")
// ErrExists is returned when something exists when it may not be expected.
//
// Use IsExists(err) to detect this condition.
ErrExists = errors.New("content: exists")
// ErrLocked is returned when content is actively being uploaded, this
// indicates that another process is attempting to upload the same content.
//
// Use IsLocked(err) to detect this condition.
ErrLocked = errors.New("content: locked")
bufPool = sync.Pool{
New: func() interface{} {
return make([]byte, 1<<20)
},
}
)
type Provider interface {
Reader(ctx context.Context, dgst digest.Digest) (io.ReadCloser, error)
ReaderAt(ctx context.Context, dgst digest.Digest) (io.ReaderAt, error)
}
type Ingester interface {
Writer(ctx context.Context, ref string, size int64, expected digest.Digest) (Writer, error)
}
// TODO(stevvooe): Consider a very different name for this struct. Info is way
// to general. It also reads very weird in certain context, like pluralization.
type Info struct {
Digest digest.Digest
Size int64
CommittedAt time.Time
}
type Status struct {
Ref string
Offset int64
Total int64
Expected digest.Digest
StartedAt time.Time
UpdatedAt time.Time
}
// WalkFunc defines the callback for a blob walk.
type WalkFunc func(Info) error
// Manager provides methods for inspecting, listing and removing content.
type Manager interface {
// Info will return metadata about content available in the content store.
//
// If the content is not present, ErrNotFound will be returned.
Info(ctx context.Context, dgst digest.Digest) (Info, error)
// Walk will call fn for each item in the content store.
Walk(ctx context.Context, fn WalkFunc) error
// Delete removes the content from the store.
Delete(ctx context.Context, dgst digest.Digest) error
// Status returns the status of any active ingestions whose ref match the
// provided regular expression. If empty, all active ingestions will be
// returned.
//
// TODO(stevvooe): Status may be slighly out of place here. If this remains
// here, we should remove Manager and just define these on store.
Status(ctx context.Context, re string) ([]Status, error)
// Abort completely cancels the ingest operation targeted by ref.
//
// TODO(stevvooe): Same consideration as above. This should really be
// restricted to an ingest management interface.
Abort(ctx context.Context, ref string) error
}
type Writer interface {
io.WriteCloser
Status() (Status, error)
Digest() digest.Digest
Commit(size int64, expected digest.Digest) error
Truncate(size int64) error
}
// Store combines the methods of content-oriented interfaces into a set that
// are commonly provided by complete implementations.
type Store interface {
Manager
Ingester
Provider
}
func IsNotFound(err error) bool {
return errors.Cause(err) == ErrNotFound
}
func IsExists(err error) bool {
return errors.Cause(err) == ErrExists
}
func IsLocked(err error) bool {
return errors.Cause(err) == ErrLocked
}