containerd/services/content/ingester.go
Stephen J Day 5da4e1d0d2 services/content: move service client into package
Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-02-28 17:12:24 -08:00

163 lines
3.4 KiB
Go

package content
import (
"context"
"io"
contentapi "github.com/docker/containerd/api/services/content"
"github.com/docker/containerd/content"
digest "github.com/opencontainers/go-digest"
"github.com/pkg/errors"
)
func NewIngesterFromClient(client contentapi.ContentClient) content.Ingester {
return &remoteIngester{
client: client,
}
}
type remoteIngester struct {
client contentapi.ContentClient
}
func (ri *remoteIngester) Writer(ctx context.Context, ref string, size int64, expected digest.Digest) (content.Writer, error) {
wrclient, offset, err := ri.negotiate(ctx, ref, size, expected)
if err != nil {
return nil, rewriteGRPCError(err)
}
return &remoteWriter{
client: wrclient,
offset: offset,
}, nil
}
func (ri *remoteIngester) negotiate(ctx context.Context, ref string, size int64, expected digest.Digest) (contentapi.Content_WriteClient, int64, error) {
wrclient, err := ri.client.Write(ctx)
if err != nil {
return nil, 0, err
}
if err := wrclient.Send(&contentapi.WriteRequest{
Action: contentapi.WriteActionStat,
Ref: ref,
Total: size,
Expected: expected,
}); err != nil {
return nil, 0, err
}
resp, err := wrclient.Recv()
if err != nil {
return nil, 0, err
}
return wrclient, resp.Offset, nil
}
type remoteWriter struct {
ref string
client contentapi.Content_WriteClient
offset int64
digest digest.Digest
}
func newRemoteWriter(client contentapi.Content_WriteClient, ref string, offset int64) (*remoteWriter, error) {
return &remoteWriter{
ref: ref,
client: client,
offset: offset,
}, nil
}
// send performs a synchronous req-resp cycle on the client.
func (rw *remoteWriter) send(req *contentapi.WriteRequest) (*contentapi.WriteResponse, error) {
if err := rw.client.Send(req); err != nil {
return nil, err
}
resp, err := rw.client.Recv()
if err == nil {
// try to keep these in sync
if resp.Digest != "" {
rw.digest = resp.Digest
}
}
return resp, err
}
func (rw *remoteWriter) Status() (content.Status, error) {
resp, err := rw.send(&contentapi.WriteRequest{
Action: contentapi.WriteActionStat,
})
if err != nil {
return content.Status{}, err
}
return content.Status{
Ref: rw.ref,
Offset: resp.Offset,
StartedAt: resp.StartedAt,
UpdatedAt: resp.UpdatedAt,
}, nil
}
func (rw *remoteWriter) Digest() digest.Digest {
return rw.digest
}
func (rw *remoteWriter) Write(p []byte) (n int, err error) {
offset := rw.offset
resp, err := rw.send(&contentapi.WriteRequest{
Action: contentapi.WriteActionWrite,
Offset: offset,
Data: p,
})
if err != nil {
return 0, err
}
n = int(resp.Offset - offset)
if n < len(p) {
err = io.ErrShortWrite
}
rw.offset += int64(n)
return
}
func (rw *remoteWriter) Commit(size int64, expected digest.Digest) error {
resp, err := rw.send(&contentapi.WriteRequest{
Action: contentapi.WriteActionCommit,
Total: size,
Offset: rw.offset,
Expected: expected,
})
if err != nil {
return rewriteGRPCError(err)
}
if size != 0 && resp.Offset != size {
return errors.Errorf("unexpected size: %v != %v", resp.Offset, size)
}
if expected != "" && resp.Digest != expected {
return errors.Errorf("unexpected digest: %v != %v", resp.Digest, expected)
}
return nil
}
func (rw *remoteWriter) Truncate(size int64) error {
// This truncation won't actually be validated until a write is issued.
rw.offset = size
return nil
}
func (rw *remoteWriter) Close() error {
return rw.client.CloseSend()
}