distribution/registry/storage/layerreader.go
Richard ae216e365a Make Storage Driver API calls context aware.
- Change driver interface to take a context as its first argument
     - Make newFileReader take a context as its first argument
     - Make newFileWriter take a context as its first argument
     - Make blobstore exists and delete take a context as a first argument
     - Pass the layerreader's context to the storage layer
     - Pass the app's context to purgeuploads
     - Store the app's context into the blobstore (was previously null)
     - Pass the trace'd context to the storage drivers

Signed-off-by: Richard Scothern <richard.scothern@gmail.com>
2015-04-27 15:58:58 -07:00

79 lines
2 KiB
Go

package storage
import (
"net/http"
"time"
"github.com/docker/distribution"
"github.com/docker/distribution/digest"
"github.com/docker/distribution/registry/storage/driver"
)
// layerReader implements Layer and provides facilities for reading and
// seeking.
type layerReader struct {
fileReader
digest digest.Digest
}
// newLayerReader returns a new layerReader with the digest, path and length,
// eliding round trips to the storage backend.
func newLayerReader(driver driver.StorageDriver, dgst digest.Digest, path string, length int64) (*layerReader, error) {
fr := &fileReader{
driver: driver,
path: path,
size: length,
}
return &layerReader{
fileReader: *fr,
digest: dgst,
}, nil
}
var _ distribution.Layer = &layerReader{}
func (lr *layerReader) Digest() digest.Digest {
return lr.digest
}
func (lr *layerReader) Length() int64 {
return lr.size
}
func (lr *layerReader) CreatedAt() time.Time {
return lr.modtime
}
// Close the layer. Should be called when the resource is no longer needed.
func (lr *layerReader) Close() error {
return lr.closeWithErr(distribution.ErrLayerClosed)
}
func (lr *layerReader) Handler(r *http.Request) (h http.Handler, err error) {
var handlerFunc http.HandlerFunc
redirectURL, err := lr.fileReader.driver.URLFor(lr.ctx, lr.path, map[string]interface{}{"method": r.Method})
switch err {
case nil:
handlerFunc = func(w http.ResponseWriter, r *http.Request) {
// Redirect to storage URL.
http.Redirect(w, r, redirectURL, http.StatusTemporaryRedirect)
}
case driver.ErrUnsupportedMethod:
handlerFunc = func(w http.ResponseWriter, r *http.Request) {
// Fallback to serving the content directly.
http.ServeContent(w, r, lr.digest.String(), lr.CreatedAt(), lr)
}
default:
// Some unexpected error.
return nil, err
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Docker-Content-Digest", lr.digest.String())
handlerFunc.ServeHTTP(w, r)
}), nil
}