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Allows layers to be partially pulled and resumed

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Adds a sort of contrived test for resumable pulls
This commit is contained in:
Brian Bland 2014-11-18 15:44:39 -08:00
parent 73d6e8af84
commit 50d64ac63a
4 changed files with 271 additions and 59 deletions
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30
client/pull.go
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@ -89,7 +89,7 @@ func pullLayer(c Client, objectStore ObjectStore, name string, fsLayer registry.
return err
}
writer, err := layer.Writer()
layerWriter, err := layer.Writer()
if err == ErrLayerAlreadyExists {
log.WithField("layer", fsLayer).Info("Layer already exists")
return nil
@ -106,9 +106,17 @@ func pullLayer(c Client, objectStore ObjectStore, name string, fsLayer registry.
}).Warn("Unable to write local layer")
return err
}
defer writer.Close()
defer layerWriter.Close()
layerReader, length, err := c.GetBlob(name, fsLayer.BlobSum, 0)
if layerWriter.CurrentSize() > 0 {
log.WithFields(log.Fields{
"layer": fsLayer,
"currentSize": layerWriter.CurrentSize(),
"size": layerWriter.Size(),
}).Info("Layer partially downloaded, resuming")
}
layerReader, length, err := c.GetBlob(name, fsLayer.BlobSum, layerWriter.CurrentSize())
if err != nil {
log.WithFields(log.Fields{
"error": err,
@ -118,7 +126,9 @@ func pullLayer(c Client, objectStore ObjectStore, name string, fsLayer registry.
}
defer layerReader.Close()
copied, err := io.Copy(writer, layerReader)
layerWriter.SetSize(layerWriter.CurrentSize() + length)
_, err = io.Copy(layerWriter, layerReader)
if err != nil {
log.WithFields(log.Fields{
"error": err,
@ -126,15 +136,15 @@ func pullLayer(c Client, objectStore ObjectStore, name string, fsLayer registry.
}).Warn("Unable to download layer")
return err
}
if copied != int64(length) {
if layerWriter.CurrentSize() != layerWriter.Size() {
log.WithFields(log.Fields{
"expected": length,
"written": copied,
"layer": fsLayer,
}).Warn("Wrote incorrect number of bytes for layer")
"size": layerWriter.Size(),
"currentSize": layerWriter.CurrentSize(),
"layer": fsLayer,
}).Warn("Layer invalid size")
return fmt.Errorf(
"Wrote incorrect number of bytes for layer %v. Expected %d, Wrote %d",
fsLayer, length, copied,
fsLayer, layerWriter.Size(), layerWriter.CurrentSize(),
)
}
return nil