Move client package under registry package

Signed-off-by: Stephen J Day <stephen.day@docker.com>

docs/client/push.go

@@ -0,0 +1,137 @@
+package client
+
+import (
+	"fmt"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/docker/distribution/manifest"
+)
+
+// simultaneousLayerPushWindow is the size of the parallel layer push window.
+// A layer may not be pushed until the layer preceeding it by the length of the
+// push window has been successfully pushed.
+const simultaneousLayerPushWindow = 4
+
+type pushFunction func(fsLayer manifest.FSLayer) error
+
+// Push implements a client push workflow for the image defined by the given
+// name and tag pair, using the given ObjectStore for local manifest and layer
+// storage
+func Push(c Client, objectStore ObjectStore, name, tag string) error {
+	manifest, err := objectStore.Manifest(name, tag)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"error": err,
+			"name":  name,
+			"tag":   tag,
+		}).Info("No image found")
+		return err
+	}
+
+	errChans := make([]chan error, len(manifest.FSLayers))
+	for i := range manifest.FSLayers {
+		errChans[i] = make(chan error)
+	}
+
+	cancelCh := make(chan struct{})
+
+	// Iterate over each layer in the manifest, simultaneously pushing no more
+	// than simultaneousLayerPushWindow layers at a time. If an error is
+	// received from a layer push, we abort the push.
+	for i := 0; i < len(manifest.FSLayers)+simultaneousLayerPushWindow; i++ {
+		dependentLayer := i - simultaneousLayerPushWindow
+		if dependentLayer >= 0 {
+			err := <-errChans[dependentLayer]
+			if err != nil {
+				log.WithField("error", err).Warn("Push aborted")
+				close(cancelCh)
+				return err
+			}
+		}
+
+		if i < len(manifest.FSLayers) {
+			go func(i int) {
+				select {
+				case errChans[i] <- pushLayer(c, objectStore, name, manifest.FSLayers[i]):
+				case <-cancelCh: // recv broadcast notification about cancelation
+				}
+			}(i)
+		}
+	}
+
+	err = c.PutImageManifest(name, tag, manifest)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"error":    err,
+			"manifest": manifest,
+		}).Warn("Unable to upload manifest")
+		return err
+	}
+
+	return nil
+}
+
+func pushLayer(c Client, objectStore ObjectStore, name string, fsLayer manifest.FSLayer) error {
+	log.WithField("layer", fsLayer).Info("Pushing layer")
+
+	layer, err := objectStore.Layer(fsLayer.BlobSum)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"error": err,
+			"layer": fsLayer,
+		}).Warn("Unable to read local layer")
+		return err
+	}
+
+	layerReader, err := layer.Reader()
+	if err != nil {
+		log.WithFields(log.Fields{
+			"error": err,
+			"layer": fsLayer,
+		}).Warn("Unable to read local layer")
+		return err
+	}
+	defer layerReader.Close()
+
+	if layerReader.CurrentSize() != layerReader.Size() {
+		log.WithFields(log.Fields{
+			"layer":       fsLayer,
+			"currentSize": layerReader.CurrentSize(),
+			"size":        layerReader.Size(),
+		}).Warn("Local layer incomplete")
+		return fmt.Errorf("Local layer incomplete")
+	}
+
+	length, err := c.BlobLength(name, fsLayer.BlobSum)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"error": err,
+			"layer": fsLayer,
+		}).Warn("Unable to check existence of remote layer")
+		return err
+	}
+	if length >= 0 {
+		log.WithField("layer", fsLayer).Info("Layer already exists")
+		return nil
+	}
+
+	location, err := c.InitiateBlobUpload(name)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"error": err,
+			"layer": fsLayer,
+		}).Warn("Unable to upload layer")
+		return err
+	}
+
+	err = c.UploadBlob(location, layerReader, int(layerReader.CurrentSize()), fsLayer.BlobSum)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"error": err,
+			"layer": fsLayer,
+		}).Warn("Unable to upload layer")
+		return err
+	}
+
+	return nil
+}