pkg/ioutils: remove OnEOFReader and move it internal

This type was originally in pkg/transport, but got moved to pkg/ioutils
in 276c640be4.

This type is only used in a single location, and has no external consumers,
so we can move it where it's used and un-export it.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

pkg/ioutils/readers.go

@@ -61,35 +61,6 @@ func NewReaderErrWrapper(r io.Reader, closer func()) io.Reader {
 	}
 }
 
-// OnEOFReader wraps an io.ReadCloser and a function
-// the function will run at the end of file or close the file.
-type OnEOFReader struct {
-	Rc io.ReadCloser
-	Fn func()
-}
-
-func (r *OnEOFReader) Read(p []byte) (n int, err error) {
-	n, err = r.Rc.Read(p)
-	if err == io.EOF {
-		r.runFunc()
-	}
-	return
-}
-
-// Close closes the file and run the function.
-func (r *OnEOFReader) Close() error {
-	err := r.Rc.Close()
-	r.runFunc()
-	return err
-}
-
-func (r *OnEOFReader) runFunc() {
-	if fn := r.Fn; fn != nil {
-		fn()
-		r.Fn = nil
-	}
-}
-
 // cancelReadCloser wraps an io.ReadCloser with a context for cancelling read
 // operations.
 type cancelReadCloser struct {

registry/search_session.go

@@ -6,6 +6,7 @@ import (
 	_ "crypto/sha512"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"net/http/cookiejar"
 	"net/url"
@@ -15,7 +16,6 @@ import (
 	"github.com/containerd/log"
 	"github.com/docker/docker/api/types/registry"
 	"github.com/docker/docker/errdefs"
-	"github.com/docker/docker/pkg/ioutils"
 	"github.com/pkg/errors"
 )
 
@@ -76,6 +76,35 @@ func cloneRequest(r *http.Request) *http.Request {
 	return r2
 }
 
+// onEOFReader wraps an io.ReadCloser and a function
+// the function will run at the end of file or close the file.
+type onEOFReader struct {
+	Rc io.ReadCloser
+	Fn func()
+}
+
+func (r *onEOFReader) Read(p []byte) (n int, err error) {
+	n, err = r.Rc.Read(p)
+	if err == io.EOF {
+		r.runFunc()
+	}
+	return
+}
+
+// Close closes the file and run the function.
+func (r *onEOFReader) Close() error {
+	err := r.Rc.Close()
+	r.runFunc()
+	return err
+}
+
+func (r *onEOFReader) runFunc() {
+	if fn := r.Fn; fn != nil {
+		fn()
+		r.Fn = nil
+	}
+}
+
 // RoundTrip changes an HTTP request's headers to add the necessary
 // authentication-related headers
 func (tr *authTransport) RoundTrip(orig *http.Request) (*http.Response, error) {
@@ -119,7 +148,7 @@ func (tr *authTransport) RoundTrip(orig *http.Request) (*http.Response, error) {
 	if len(resp.Header["X-Docker-Token"]) > 0 {
 		tr.token = resp.Header["X-Docker-Token"]
 	}
-	resp.Body = &ioutils.OnEOFReader{
+	resp.Body = &onEOFReader{
 		Rc: resp.Body,
 		Fn: func() {
 			tr.mu.Lock()